Effects of smoking cessation on the risk of cardiovascular disease: a nationwide population-based study

Introduction

Cardiovascular disease (CVD) is the global leading cause of death, and the economic and social burden of CVD is still increasing, Smoking is one of the top three leading risk factors for the disease and one of the well-established and important modifiable risk factors for CVD. However, the time course of CVD risk after smoking cessation is unclear.

Purpose

We assess the association between smoking and CVD and the incidence of CVD with years quitting smoking.

Methods

This study used the Korean National Health Insurance Service (NHIS) database. Self-reported smoking habit data were used to classify participants as current, former or never smokers and to investigate the duration and intensity of smoking. Smoking records of participants were updated every 2 years, and all participants whose smoking records were changed or unclear were excluded. The primary outcome was the development of CVD, including myocardial infarction, stroke, heart failure, and cardiovascular death.

Results

Total 5,391,231 participants (953,756 subjects were current smokers, 104,604 subjects were former smokers, 4,432,871 subjects never smoker) were followed-up for an average of 4.2 years. The mean age was 45.8 years, 39.9% were male. Cumulative pack-year (PY) were 14 in current smoker, 10.5 in former smokers at baseline. The median years of quitting smoking for former smoker was 4.

Regardless of whether smoking continues or not, a dose-dependent relationship exists between smoking and CVD (Fig. 1). For those smoked less than 8PY, smoking cessation significantly lowered the CVD risk within 10 years compared to current smokers, and the CVD risk was not significantly different from never smokers (Fig. 2A). However, in the case of smokers over 8PY, although smoking cessation affects the reduction of CVD, the CVD risk decreases slowly over decades, and it takes more than 20 years for the effect of smoking on the CVD risk to disappear (Fig. 2B).

Conclusion

Smoking and CVD have a dose-dependent relationship, and mild smokers with less than 8PY had a similar CVD risk to never smokers when quitting smoking. However, for heavy smokers over 8PY, it takes a long time for the CVD risk from smoking to disappear

Funding Acknowledgement

Type of funding sources: None.

Intracardiac echocardiographically guided permanent pacemaker implantation is a feasible imaging tool with comparable procedural efficacy and safety

Background

Amongst cardiovascular interventions, pacemaker implantation procedure is one of the most hazardous in terms of radiation exposure due to its proximity and unprotected radiation exposure. In order to reduce radiation hazards, alternative imaging tool to guide pacemaker implantation should be sought. The aim of this study is to investigate the feasibility, efficacy, and safety of intracardiac echocardiographically (ICE) guided pacemaker implantation.

Methods

We retrospectively investigated pacemaker implantation with ICE guidance. ICE catheter was placed in right atrium (RA). Right ventricular (RV) lead was placed in RV apex within home view (low RA, 2-4 O'clock). Then RA lead was placed in RA appendage within mid RA 1-2 O'clock view. Fluoroscopy was used only for verifying lead redundancy (2 or 3 second duration before pocket closure). Other procedure steps were similarly performed as in conventional fluoroscopic method. Radiation dosage, patient safety, total procedure time, and lead parameters were assessed and compared.

Results

From June 2013 to March 2021, a total of 270 patients underwent pacemaker implantation either with ICE or with fluoroscopy. Amongst them, ICE guided implantation was attempted in 35 patients. In order to exclude potential bias caused by the operator's learning curve, we excluded early 5 cases out of ICE group. Radiation exposure was markedly decreased within ICE group (2.3±4.4 Gy cm2 in ICE group vs. 27.2±50.5 Gy cm2 in fluoroscopy group, P<0.001). The total procedure time and complication rate showed no significant difference between groups. In ICE group, atrial lead parameters were better than those of fluoroscopy group (impedance 454±57 Ω vs. 533±125 Ω, P<0.001).

Conclusion

In 30 patients with ICE guided pacemaker implantation, radiation exposure was markedly decreased without any trade-offs in terms of patients' safety and procedural success. Furthermore, operation team members' physical stress reduction also might be potentially guaranteed.

Funding Acknowledgement

Type of funding sources: None.

Net clinical benefit of NOAC in Korean atrial fibrillation patients with low to intermediate stroke risk

Background

The balance of stroke risk reduction and potential hemorrhagic risk associated with anti-thrombotic treatment (ATT) remain unclear in Korean atrial fibrillation (AF) patients with low to intermediate stroke risk, defined as non-gender CHA2DS2-VASc score 0–1.

Purpose

The net clinical benefit (NCB) analysis of ATT may be helpful to guide stroke prevention strategy in AF patients with non-gender CHA2DS2-VASc score 0–1.

Methods

This Korean multi-center cohort study retrospectively evaluated the clinical outcomes with single antiplatelet (SAPT), vitamin K antagonist (VKA), and non-vitamin K antagonist oral anticoagulant (NOAC) in non-gender CHA2DS2-VASc score 0–1 and further stratified by biomarker-based ABCD score (Age [≥60 years], B-type natriuretic peptide [BNP] or N-terminal pro-BNP [≥300 pg/ml], Creatinine clearance [<50 ml/min/1.73 m2], and Dimension of the left atrium [≥45 mm]). The primary outcome was the NCB of ATT including thromboembolic and major bleeding events.

Results

We included 2465 patients (56.2±9.5 years; female, 665 [27.0%]) followed-up for 4.0±2.8 years, of whom 661 (26.8%) were treated with SAPT; 423 (17.2%) with VKA; and 1040 (42.2%) with NOAC. In comparison with no treatment, only NOAC demonstrated a positive tendency for stroke prevention (NOAC, NCB 0.47, 95% confidence interval [CI] −0.40 to 2.10; SAPT, NCB −0.31, 95% CI −1.48 to 1.40; and VKA, NCB −1.26, 95% CI −2.97 to 0.67). With detailed risk stratification with ABCD score, NOAC showed a significant NCB for stroke prevention compared with SAPT and VKA (SAPT vs. NOAC, NCB 1.6, 95% CI 0.26–3.50; VKA vs. NOAC, NCB 1.96, 95% CI 0.47–4.16) in patients with ABCD score ≥1. ATT failed to show NCB in patients with truly low stroke risk defined as ABCD score=0.

Conclusion

Korean AF cohort with low to intermediate stroke risk indicates that, in comparison with no ATT, only ATT with NOAC showed marginal NCB. With further risk stratification by ABCD score, NOAC showed significant advantages over other ATTs (VKA or SAPT) in patients with ABCD ≥1.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Korean Disease Control and Prevention Agency

External validation of the biomarker based ABCD score in atrial fibrillation patients with a non gender CHA2DS2 VASc score 0 to 1, A Korean multicenter retrospective cohort

Background

Patients with low to intermediate risk atrial fibrillation (AF), defined as non-gender CHA2DS2-VASc score of 0–1, are still at risk of stroke. This study verified the usefulness of ABCD score (Age [≥60 years], B-type natriuretic peptide [BNP] or N-terminal pro-BNP [≥300 pg/ml], Creatinine clearance [<50 ml/min/1.73 m2], and Dimension of the left atrium [≥45 mm]) for stroke risk stratification in non-gender CHA2DS2-VASc score 0–1.

Methods

This multi-center cohort study retrospectively analyzed AF patients with non-gender CHA2DS2-VASc score 0–1. The primary endpoint was the incidence of stroke with or without anti-thrombotic treatment (ATT). An ABCD score was also validated.

Results

Overall, 2694 patients (56.3±9.5 years; female, 726 [26.9%]) were followed-up for 4.0±2.8 years. The overall stroke rate was 0.84/100 person-years (P-Y), stratified as follows: 0.46/100P-Y for an ABCD score 0; 1.02/100P-Y for an ABCD score≥1. The ABCD score was superior to the non-gender CHA2DS2-VASc score in stroke risk stratification (C-index=0.618, P=0.015; net reclassification improvement=0.576, P=0.040; integrated differential improvement=0.033, P=0.066). ATT was prescribed in 2353 patients (86.5%), and the stroke rate was significantly lower in patients receiving non-vitamin K antagonist oral anticoagulant (NOAC) therapy and an ABCD score≥1 than in those without ATT (0.44/100P-Y versus 1.55/100 P-Y; hazard ratio=0.26, 95% confidence interval 0.11–0.63, P=0.003).

Conclusion

The biomarker-based ABCD score demonstrated improved stroke risk stratification in AF patients with non-gender CHA2DS2-VASc score 0–1. Furthermore, NOAC with an ABCD score≥1 was associated with significantly lower stroke rate in AF patients with a non-gender CHA2DS2-VASc score 0–1.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Korean Disease Control and Prevention Agency

Wearable Sensors Improve Prediction of Post-Stroke Walking Function Following Inpatient Rehabilitation

OBJECTIVE

A primary goal of acute stroke rehabilitation is to maximize functional recovery and help patients reintegrate safely in the home and community. However, not all patients have the same potential for recovery, making it difficult to set realistic therapy goals and to anticipate future needs for short- or long-term care. The objective of this study was to test the value of high-resolution data from wireless, wearable motion sensors to predict post-stroke ambulation function following inpatient stroke rehabilitation.

METHOD

Supervised machine learning algorithms were trained to classify patients as either household or community ambulators at discharge based on information collected upon admission to the inpatient facility (N=33-35). Inertial measurement unit (IMU) sensor data recorded from the ankles and the pelvis during a brief walking bout at admission (10 meters, or 60 seconds walking) improved the prediction of discharge ambulation ability over a traditional prediction model based on patient demographics, clinical information, and performance on standardized clinical assessments.

RESULTS

Models incorporating IMU data were more sensitive to patients who changed ambulation category, improving the recall of community ambulators at discharge from 85% to 89-93%.

CONCLUSIONS

This approach demonstrates significant potential for the early prediction of post-rehabilitation walking outcomes in patients with stroke using small amounts of data from three wearable motion sensors.

CLINICAL IMPACT

Accurately predicting a patient's functional recovery early in the rehabilitation process would transform our ability to design personalized care strategies in the clinic and beyond. This work contributes to the development of low-cost, clinically-implementable prognostic tools for data-driven stroke treatment.

Graphene Oxide Functionalized Biosensor for Detection of Stress-Related Biomarkers

A graphene oxide (GO)-based cortisol biosensor was developed to accurately detect cortisol concentrations from sweat samples at point-of-care (POC) sites. A reference electrode, counter electrode, and working electrode make up the biosensor, and the working electrode was functionalized using multiple layers consisting of GO and antibodies, including Protein A, IgG, and anti-Cab. Sweat samples contact the anti-Cab antibodies to transport electrons to the electrode, resulting in an electrochemical current response. The sensor was tested at each additional functionalization layer and at cortisol concentrations between 0.1 and 150 ng/mL to determine how the current response differed. A potentiostat galvanostat device was used to measure and quantify the electrochemical response in the GO-based biosensor. In both tests, the electrochemical responses were reduced in magnitude with the addition of antibody layers and with increased cortisol concentrations. The proposed cortisol biosensor has increased accuracy with each additional functionalization layer, and the proposed device has the capability to accurately measure cortisol concentrations for diagnostic purposes.

P997Improving left atrial appendage occluder size determination by using 3-dimensional printing model of the left atrial appendage

Introduction

Given the complexity of left atrial appendage (LAA) structure, current 2D based LAA occluder (LAAO) size prediction system using transesophageal echocardiography (TEE) has limitations.

Objective

To assess the accuracy of LAAO size determination method by implantation simulation using a 3D printed model compared with a conventional method based on TEE.

Methods

We retrospectively reviewed 57 cases with percutaneous LAAO using Amplatzer Cardiac Plug and Amulet from 2014 to 2018. We excluded cases without cardiac CT (21 cases) or with peri-device leakage or inappropriate position of the device on six months follow up TEE (6 cases), or with paroxysmal atrial fibrillation (2 cases). We finally included 28 cases with anatomically and physiologically properly implanted LAAO, using the final size of the implanted devices as a standard for the size prediction accuracy. We generated 3D printing model from cardiac CT images. LAAO size was determined with device implantation simulation using 3D printing model and occluder devices (Figure C), and conventional 2D TEE measurements by two experienced cardiologists who were blinded to the size of the finally implanted device.

Results

The accuracy in size of 3D printed left atrium (LA) models, compared with CT image sources, were validated by measuring the distance between artifacts which were intentionally implanted to LA model during image processing. There was minimal bias (−0.11 mm) between 3D images and printed LA models (Figure A). As plotted in Figure B, LAAO sizing by implantation simulation with 3D printing model showed excellent agreement with actually implanted LAAO size (r=0.927; bias=0.7±2.5), while LAAO sizing by 2D TEE measurements remained poor (r=0.544; bias 2.3±6.7).

Conclusions

LAAO size determination by using 3D printing model of LAA showed excellent accuracy. A prospective study to evaluate the clinical utility of this method should be done in future.

P1026Risk factors for the occurrence of stroke after atrial fibrillation ablation

Background

Risk factors for the occurrence of embolic stroke (ES) after atrial fibrillation (AF) ablation have not been fully elucidated. Our aim was to assess incidence of ES during long-term follow-up following AF ablation and to identify predicting factors associated with post-ablation ES.

Methods

We enrolled patients who experienced ES after AF ablation and body mass index-matched controls from AF ablation registries. Epicardial adipose tissue (EAT) was assessed using multislice computed tomography prior to ablation.

Results

A total of 3,464 patients who underwent AF ablation were recruited. During a mean follow-up of 47.2 months, ES occurred in 47 patients (1.36%) with a mean CHA2DS2-VAS score of 2.15 and overall incidence of ES was 0.34 per 100 patients/year. Compared with control group (n=190), ES group had more higher prior thromboembolic event and AF recurrence rates, larger LA size, lower creatinine clearance rate (CCr), and greater total and periatrial EAT volumes although no differences in AF type, CHA2DS2-VASc score, ablation extent, and anti-thrombotics use were found. On multivariate regression analysis, a prior history of thromboembolism, CCr, and periatrial EAT volume were independently associated with ES occurrence after AF ablation.

Cox regression analysis Risk factor Univariate Multivariate HR (95% CI) p value HR (95% CI) p value Age 1.017 (0.984–1.051) 0.31 Prior thromboembolism 2.488 (1.134–5.460) 0.023 2.916 (1.178–7.219) 0.021 CHA2DS2-VASc score 1.139 (0.899–1.445) 0.282 CCr 0.984 (0.970–0.999) 0.038 0.982 (0.996–0.998) 0.029 LA diameter (mm) 1.070 (1.012–1.130) 0.017 1.072 (0.999–1.150) 0.054 EAT_total (ml) 1.020 (1.010–1.029) <0.001 1.008 (0.993–1.023) 0.297 EAT_periatrial (ml) 1.085 (1.045–1.126) <0.001 1.065 (1.005–1.128) 0.032 PVI + additional ablation 0.846 (0.460–1.557) 0.592 No anticoagulant use 0.651 (0.346–1.226) 0.184 Recurrence 2.011 (1.007–4.013) 0.048 1.240 (0.551–2.793) 0.603 CCr, creatinine clearance rate; EAT, epicardial adipose tissue; LA, left atrium; PVI, pulmonary vein isolation.

K-M curve for stroke-free survival

Conclusions

Incidence of ES after AF ablation was lower than expected rate based on CHA2DS2-VASc score even though anticoagulants use was limited. Periatrial EAT volume, a prior thromboembolism event, and CCr were independent factors in predicting ES irrespective of AF recurrence and CHA2DS2-VASc score in patients who underwent AF ablation.

Efficacy and Safety of Ethanol Ablation for Branchial Cleft Cysts

BACKGROUND AND PURPOSE

Branchial cleft cyst is a common congenital lesion of the neck. This study evaluated the efficacy and safety of ethanol ablation as an alternative treatment to surgery for branchial cleft cyst.

MATERIALS AND METHODS

Between September 2006 and October 2016, ethanol ablation was performed in 22 patients who refused an operation for a second branchial cleft cyst. After the exclusion of 2 patients who were lost to follow-up, the data of 20 patients were retrospectively evaluated. All index masses were confirmed as benign before treatment. Sonography-guided aspiration of the cystic fluid was followed by injection of absolute ethanol (99%) into the lesion. The injected volume of ethanol was 50%-80% of the volume of fluid aspirated. Therapeutic outcome, including the volume reduction ratio, therapeutic success rate (volume reduction ratio of >50% and/or no palpable mass), and complications, was evaluated.

RESULTS

The mean index volume of the cysts was 26.4 ± 15.7 mL (range, 3.8-49.9 mL). After ablation, the mean volume of the cysts decreased to 1.2 ± 1.1 mL (range, 0.0-3.5 mL). The mean volume reduction ratio at last follow-up was 93.9% ± 7.9% (range, 75.5%-100.0%; P < .001). Therapeutic success was achieved in all nodules (20/20, 100%), and the symptomatic (P < .001) and cosmetic (P < .001) scores had improved significantly by the last follow-up. In 1 patient, intracystic hemorrhage developed during the aspiration; however, no major complications occurred in any patient.

CONCLUSIONS

Ethanol ablation is an effective and safe treatment for patients with branchial cleft cysts who refuse, or are ineligible for, an operation.

Integrin α1β1 protects against signs of post-traumatic osteoarthritis in the female murine knee partially via regulation of epidermal growth factor receptor signalling

OBJECTIVE

To investigate the role of integrin α1β1 in the progression of post-traumatic osteoarthritis (PTOA), and elucidate the contribution of epidermal growth factor receptor (EGFR) signalling to the mechanism by which integrin α1β1 might control PTOA. We hypothesised that integrin α1β1 plays a protective role in the course of PTOA and that the effect of PTOA (e.g., synovitis, loss of cartilage and growth of osteophytes) would be exacerbated in mice lacking integrin α1β1 at every time point post destabilisation of medial meniscus (DMM).

METHODS

DMM or sham surgery was performed on integrin α1-null and wild type (WT) mice and the progression of PTOA analysed at 2, 4, 8 and 12 weeks post-surgery (PS) using micro-computed tomography (microCT), histology, and immunohistochemistry. In addition, the effects of EGFR blockade were examined by treating the mice with the EGFR inhibitor erlotinib.

RESULTS

Integrin α1-null female, but not male, mice showed earlier cartilage degradation post DMM surgery compared to WT controls. Furthermore, erlotinib treatment resulted in significantly less cartilage damage in integrin α1-null but not WT mice. Independent of genotype, erlotinib treatment significantly mitigated the effects of PTOA on many tissues of female mice including meniscal and fabella bone volume, subchondral bone thickness and density and cartilage degradation. In contrast, reduced EGFR signalling had little effect on signs of PTOA in male mice.

CONCLUSION

Integrin α1β1 protects against PTOA-induced cartilage degradation in female mice partially via the reduction of EGFR signalling. Furthermore, reduction of EGFR signalling protects against the development of PTOA in female, but not male mice.

Serum Metabolite Profiles Are Altered by Erlotinib Treatment and the Integrin α1-Null Genotype but Not by Post-Traumatic Osteoarthritis

The risk of developing post-traumatic osteoarthritis (PTOA) following joint injury is high. Furthering our understanding of the molecular mechanisms underlying PTOA and/or identifying novel biomarkers for early detection may help to improve treatment outcomes. Increased expression of integrin α1β1 and inhibition of epidermal growth factor receptor (EGFR) signaling protect the knee from spontaneous OA; however, the impact of the integrin α1β1/EGFR axis on PTOA is currently unknown. We sought to determine metabolic changes in serum samples collected from wild-type and integrin α1-null mice that underwent surgery to destabilize the medial meniscus and were treated with the EGFR inhibitor erlotinib. Following (1)H nuclear magnetic resonance spectroscopy, we generated multivariate statistical models that distinguished between the metabolic profiles of erlotinib- versus vehicle-treated mice and the integrin α1-null versus wild-type mouse genotype. Our results show the sex-dependent effects of erlotinib treatment and highlight glutamine as a metabolite that counteracts this treatment. Furthermore, we identified a set of metabolites associated with increased reactive oxygen species production, susceptibility to OA, and regulation of TRP channels in α1-null mice. Our study indicates that systemic pharmacological and genetic factors have a greater effect on serum metabolic profiles than site-specific factors such as surgery.

Effects of Feeding Barley Naturally Contaminated with Fusarium Mycotoxins on Growth Performance, Nutrient Digestibility, and Blood Chemistry of Gilts and Growth Recoveries by Feeding a Non-contaminated Diet

The objectives of this study were to investigate the effects of feeding barley naturally contaminated with Fusarium mycotoxins on growth performance, vulva swelling, and digestibility of dry matter, organic matter, and crude protein of gilts and the recovery of gilts fed normal diets immediately after the exposure to contaminated diets by measuring growth performance and vulva swelling. In Exp. 1, four diets were prepared to contain 0%, 15%, 30%, or 45% contaminated barley containing 25.7 mg/kg deoxynivalenol and 26.0 μg/kg zearalenone. Sixteen gilts with an initial body weight (BW) of 33.3 kg (standard deviation = 3.0) were individually housed in a metabolism crate and assigned to 4 diets with 4 replicates in a randomized complete block design based on BW. During the 14-d feeding trial, individual BW and feed consumption were measured weekly and the vertical and horizontal lengths of vulva were measured every 3 d. From d 10, feces were collected by the maker-to-marker method for 4 d. Blood samples were collected on d 14. During the overall period, the average daily gain, average daily feed intake, and gain:feed of pigs linearly decreased (p<0.01) as the dietary concentration of contaminated barley increased. However, the digestibility of crude protein was linearly increased (p = 0.011) with the increasing amounts of contaminated barley. Increasing dietary Fusarium mycotoxin concentrations did not influence vulva size, blood characteristic as well as immunoglobulin level of pigs. In the Exp. 2, a corn-soybean meal-based diet was formulated as a recovery diet. Pigs were fed the recovery diet immediately after completion of the Exp. 1. During the 14-d of recovery period, the individual BW and feed consumption were measured weekly and the vertical and horizontal length of vulva were measured every 3 d from d 0. On d 7, the feed intake of pigs previously fed contaminated diets already reached that of pigs fed a diet with 0% contaminated barley and no significant difference in growth performance among treatments was observed during d 7 to 14 of the recovery period. In conclusion, increasing levels of mycotoxins in diets linearly decreased the growth performance of pigs, and these damages can be recovered in 7 d after the diet was replaced with a normal diet. The vulva size, blood characteristic, immune responses were not affected by increasing level of contaminated barley in the diets fed to pigs.

Total Solution Synthesis of Human Epidermal Growth Factor (h-EGF) by the Assembly of Nine Building Blocks

Human epidermal growth factor (h-EGF) composed of 53 amino acids bearing three intramolecular disulfide bridges was synthesized by the maximum protecting solution method. The synthetic h-EGF coincided with recombinant h-EGF by reverse-phase HPLC, and the sites of three intramolecular disulfide bridges were ascertained by a thermolytic digestion. The synthetic h-EGF possessed m/z 6215.7 in its FAB-MS as expected, and exhibited compatible mitogenic activity.

Integrin α1β1 differentially regulates cytokine-mediated responses in chondrocytes

OBJECTIVE

To elucidate the role of integrin α1β1 in chondrocyte responses to inflammatory interleukin-1α (IL-1) and anabolic transforming growth factor-β1 (TGF-β1) in the knee.

METHODS

Intracellular calcium transient responses to IL-1 and TGF-β1 were measured in wild type and integrin α1-null chondrocytes using real time ex vivo confocal microscopy, and immunohistochemistry was performed to analyze TGF-β1-mediated activation of Smad2/3 in tibial and femoral chondrocytes.

RESULTS

Loss of integrin α1β1 reduces intracellular calcium transient response to IL-1, while it enhances chondrocyte responses to TGF-β1 as measured by intracellular calcium transients and activation of downstream Smad2/3.

CONCLUSIONS

Integrin α1β1 plays a vital role in mediating chondrocyte responses to two contrasting factors that are critical players in the onset and progression of osteoarthritis - inflammatory IL-1 and anabolic TGF-β. Further investigation into the molecular mechanisms by which integrin α1β1 mediates these responses will be an important next step in understanding the influence of increased expression of integrin α1β1 during the early stages of osteoarthritis on disease progression.

Interleukin 22 polymorphisms and papillary thyroid cancer

BACKGROUND

IL22RA1 (Interleukin 22 receptor-alpha 1), a member of the class II cytokine receptor family, mediates diverse biologic activities and appears to be important in pathogen defense, wound healing, and tissue reorganization. Polymorphisms in genes encoding inflammatory cytokines are associated with increased cancer risk.

AIM

The aim of this study was to evaluate the association between the single nucleotide polymorphisms (SNP) in the IL22 and IL22RA1 and papillary thyroid cancer (PTC), and to assess the relationship between the SNP in the IL22 and IL22RA1 and the clinical parameters of PTC.

MATERIAL AND METHODS

Study enrolled experimental group of 94 PTC patients and 213 controls. PTC patients were grouped and compared for clinical PTC parameters. One promoter SNP of IL22, -429C/T (rs2227485), and one SNP of IL22RA1, Arg518Gly (rs3795299) were analyzed using direct sequencing. Genetic data were analyzed using Helixtree, SNPAnalyzer Pro, SNPStats, and Haploview.

RESULTS

A SNP in IL22 (rs2227485) was significantly associated with PTC (codominant2 model [C/C vs T/T], odds ratio (OR) 2.39, 95% confidence interval (CI) 1.21-4.71, p=0.012; dominant model, OR 1.89, 95% CI 1.08-3.31, p=0.022). The allele T frequency of rs2227485 in IL22 was also associated with PTC (OR 1.59, 95% CI 1.13-2.25, p=0.009). According to clinical parameters, rs2227485 of IL22 was associated with number of cancers (dominant model, OR 3.03, 95% CI 1.02-9.01, p=0.035). By haplotype analysis, TG was associated with PTC (codominant model, OR 1.52, 95% CI 1.07-2.16, p=0.019; dominant model, OR 1.91, 95% CI 1.13- 3.24, p=0.015). Genotype and allele analysis of rs3795299 in IL22RA1 showed no significant differences between PTC patients and controls.

CONCLUSION

The rs2227485 SNP in IL22 might be associated with the risk and the multifocality of PTC.

Four cases of possible human infections with Delftia lacustris

We report four cases of possible human infections with Delftia lacustris. D. lacustris isolates, which were isolated from blood cultures and bile fluid of patients with underlying diseases such as empyema, renal injury, hepatocellular carcinoma, and renal infarction, were identified using 16S rRNA gene sequencing and biochemical tests. Four D. lacustris isolates did not show the same antimicrobial susceptibility profiles and enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) patterns, indicating their non-clonality.

Application of an immune-magnetic cell sorting method for CD138-positive plasma cells in FISH analysis of multiple myeloma

INTRODUCTION

Interphase fluorescence in situ hybridization (FISH) analysis of multiple myeloma (MM) may indiscriminately count signals of nonplasma cells, thus decreasing specificity and sensitivity. We aimed to evaluate the usefulness of an immune-magnetic sorting method for plasma cells in FISH analysis of MM and define optimal sample preparation conditions.

METHODS

Plasma cells were purified using EasySep(®) CD138 Positive Selection Cocktail and Magnetic Nanoparticles (Invitrogen). We compared FISH results with and without plasma cell purification for three sample preparation methods: direct harvest, 24-h culture, and 96-h culture with interleukin-4 in five newly diagnosed MM patients. Archived fixed bone marrow cells of 17 MM patients were also studied.

RESULTS

The percentage of abnormal cells identified was significantly higher with plasma cell purification than without purification (median, 88.0%; range, 84.0-100.0%vs. 15.0%, 12.5-29.5%, respectively). The three sample preparation methods showed comparable results. Immune-magnetic sorting also significantly increased the percentage of abnormal cells identified in FISH analysis of archived fixed bone marrow cells (P < 0.001).

CONCLUSIONS

Immune-magnetic CD138-positive cell sorting significantly increased the percentage of abnormal cells identified in FISH analysis of MM samples for all sample preparation methods. This method could also be applied for retrospective FISH analysis of archived fixed bone marrow cells.

Single cell analysis of voltage-gated potassium channels that determines neuronal types of rat hypothalamic paraventricular nucleus neurons

The hypothalamic paraventricular nucleus (PVN), a site for the integration of both the neuroendocrine and autonomic systems, has heterogeneous cell composition. These neurons are classified into type I and type II neurons based on their electrophysiological properties. In the present study, we investigated the molecular identification of voltage-gated K+ (Kv) channels, which determines a distinctive characteristic of type I PVN neurons, by means of single-cell reverse transcription-polymerase chain reaction (RT-PCR) along with slice patch clamp recordings. In order to determine the mRNA expression profiles, firstly, the PVN neurons of male rats were classified into type I and type II neurons, and then, single-cell RT-PCR and single-cell real-time RT-PCR analysis were performed using the identical cell. The single-cell RT-PCR analysis revealed that Kv1.2, Kv1.3, Kv1.4, Kv4.1, Kv4.2, and Kv4.3 were expressed both in type I and in type II neurons, and several Kv channels were co-expressed in a single PVN neuron. However, we found that the expression densities of Kv4.2 and Kv4.3 were significantly higher in type I neurons than in type II neurons. Taken together, several Kv channels encoding A-type K+ currents are present both in type I and in type II neurons, and among those, Kv4.2 and Kv4.3 are the major Kv subunits responsible for determining the distinct electrophysiological properties. Thus these 2 Kv subunits may play important roles in determining PVN cell types and regulating PVN neuronal excitability. This study further provides key molecular mechanisms for differentiating type I and type II PVN neurons.

Blood donors on teratogenic drugs and donor deferral periods in a clinical situation

Deferral of blood donors taking teratogenic drugs is critical. From March 2008 to January 2009, we analysed stored blood specimens from donors who had taken teratogenic drugs and whose blood was transfused to women of childbearing age to determine the plasma concentration at the time of donation using high-performance liquid chromatography. In total, 167 specimens were examined. The numbers of specimens exceeding the quantification limit were 7, 39, 4, 2 and 1 for finasteride, isotretinoin, acitretin, etretinate and dutasteride, respectively. Finasteride was beyond the recommended drug deferral period in one specimen. These results may help create practical deferral policies.

A rare case of Lennert's type peripheral T-cell lymphoma with t(14;19)(q11.2;q13.3)

Although most patients with peripheral T-cell lymphoma (PTCL) show clonal rearrangement of T-cell receptor genes, few PTCLs show recurrent chromosomal abnormalities. We describe here a rare chromosomal rearrangement, t(14;19)(q11.2;q13.3), in a Lennert's lymphoma, a variant of PTCL, not otherwise specified. Sequential fluorescence in situ hybridization assays showed that the breakpoint in 19q13.3 was located distal to the BCL3 and PVRL2 genes, both of which may be candidate proto-oncogenes. These findings suggest that another gene is involved in the pathogenic characteristics observed in this patient with Lennert's lymphoma.

CT characteristics of a uterus-like mass in the sigmoid mesocolon

A uterus-like mass is a rare, benign extra-uterine tumour composed of smooth muscle and endometrium. The majority of uterus-like masses occur in the ovary. Rarely, uterus-like masses occur in the broad ligament, small bowel, small bowel mesentery or uterine cervix. Here, we report a case of a uterus-like mass in the sigmoid mesocolon. A well-defined, markedly enhanced soft-tissue mass with central cystic change and haemorrhage was observed on CT. The current report describes the CT characteristics of this sigmoid mesocolon uterus-like mass together with the differential diagnoses.

Design of a LiNbO(3) ribbon waveguide for efficient difference-frequency generation of terahertz wave in the collinear configuration

We propose and investigate a ribbon waveguide for difference-frequency generation of terahertz (THz) wave from infrared light sources. The proposed ribbon waveguide is composed of a nonlinear optic crystal and has a thickness less than the wavelength of the THz wave to support the surface-wave mode in the THz region. By utilizing the waveguide dispersion of the surface-wave mode, the phase matching condition between infrared pump, idler and THz waves can be realized in the collinear configuration. Owing to the weak mode confinement of the THz wave, the absorption coefficient can also be reduced. We design the ribbon waveguide which uses LiNbO(3) crystal and discuss the phase-matching condition for DFG of THz wave. Highly efficient THz-wave generation is confirmed by numerical simulations.

Intracellular K(+) inhibits apoptosis by suppressing the Apaf-1 apoptosome formation and subsequent downstream pathways but not cytochrome c release

Cellular ionic homeostasis, fundamentally K(+) homeostasis, has been implicated as a critical regulator of apoptosis. The intracellular K(+) efflux on apoptotic insult and suppression of apoptosis by high concentration of extracellular K(+) or after inhibition of this efflux by K(+) channel blockers have established the crucial role of K(+) in turning on the apoptotic machinery. Several contrasting observations have reported the antiapoptotic effect of intracellular K(+) concentration to be the result of inhibition of cytochrome c release from mitochondria, but the exact inhibitory mechanism remains obscure. However, here we show the blockage of K(+) efflux during apoptosis did not affect cytochrome c release from the mitochondria, still completely inhibited the formation of the apoptosome comprising Apaf-1, cytochrome c, caspase-9 and other accessories. As a consequence of this event, procaspase-9, -3, -8 and other death-related proteins were not processed. Furthermore, physiological concentrations of K(+) also inhibited the processing of procaspase-3 by purified caspase-8 or -9, the nucleosomal DNA fragmentation by purified DFF40/CAD and the nuclear fragmentation to varying extents. Altogether, these findings suggest that the efflux of K(+) is prerequisite not only for the formation of the apoptosome but also for the downstream apoptotic signal-transduction pathways.

Mortality risk factors of Acinetobacter baumannii bacteraemia

BACKGROUND

Acinetobacter baumannii is one of the most important nosocomial pathogens, and its multiple antibiotic resistance has emerged as an obstacle in the treatment of these infections worldwide.

AIMS

To identify risk factors of mortality for A. baumannii bacteraemia.

METHODS

A retrospective cohort study of 72 patients with significant A. baumannii bacteraemia was conducted to evaluate risk factors for mortality.

RESULTS

The median age of the 72 enrolled patients was 48 years, 96% of the cases were hospital-acquired, and the bacteraemia-related mortality rate was 29% (21 of 72 patients). Univariate analysis revealed that the risk factors for mortality included: an elevated acute physiology and chronic health evaluation (APACHE II) score, receipt of in vitro ineffective definitive antimicrobial therapy, in vitro A. baumannii resistance to cefoperazone/ sulbactam, neutropenia, and presentation with septic shock. Multivariate analysis reveals that the independent risk factors for mortality are neutropenia and elevated APACHE II scores.

CONCLUSION

Risk factors such as neutropenia and elevated APACHE II scores are found to be associated with higher mortality rates of A. baumannii bacteraemia. Further study is necessary for the determination of optimal strategies for both the prevention and treatment of these infections.

Management of Meloidogyne incognita on tomato by root-dip treatment in culture filtrate of the blue-green alga, Microcoleus vaginatus

The nematicidal potential of culture filtrates of the blue-green alga, Microcoleus vaginatus (Cyanobacterium) was tested against Meloidogyne incognita on tomato in pots under greenhouse conditions. Prior to the transplantation of tomato seedling, roots were dipped in different concentrations (0.2%, 0.5%, 1%, 2%, 10%, 50% and 100%) of culture filtrate of M. vaginatus for 30 min. Root-dip treatment reduced the root galling and final population of M. incognita and increased vegetative growth of plants and root-mass production compared with the control. The beneficial effect of root-dip treatment increased with the increase in the concentration of culture filtrate. Root galling and final nematode populations were reduced by 65.9% and 97.5%, respectively when treated at the highest concentration.

Synergic in-vitro activity of imipenem and sulbactam against Acinetobacter baumannii

The interaction between sulbactam and imipenem was evaluated with four clinical isolates of Acinetobacter baumannii, including two isolates resistant to imipenem, one of which produced IMP-1 metallo-beta-lactamase. Two isolates (one of which was imipenem-resistant) were sulbactam-resistant by undefined mechanisms. MICs were determined by standard broth microdilution methods. Time-kill assays with imipenem and sulbactam, alone or in combination at 0.5 x MIC and 1 x MIC, showed a synergic effect in all four isolates of A. baumannii after incubation for 0, 4, 8 and > 24 h at 35 degrees C.

Ion-channel currents of smooth muscle cells isolated from the prostate of guinea-pig

OBJECTIVE

To characterize the voltage-activated ion-channel currents in guinea-pig prostate smooth muscle cells (GPSMCs).

MATERIALS AND METHODS

GPSMCs were isolated using collagenase, and used in a whole-cell patch clamp study.

RESULTS

When GPSMCs were dialysed with a CsCl solution all the outward K+ currents were blocked and the step-like depolarization (holding voltage -70 mV) of the cell membrane evoked inward currents that were completely blocked by nifedipine (1 micromol/L). With KCl solution, step depolarizations showed outward K+ currents composed of fast, transient outward current (Ito) and outward currents that did not inactivate. Ito was resistant to a high concentration of tetraethylammonium (TEA, 5 mmol/L) but was blocked by 4-aminopyridine (5 mmol/L). The half-activation and half-inactivation voltages of Ito were 6 mV and -58 mV, respectively. With low Ca2+ buffer (0.1 mmol/L EGTA) in the solution, there were spontaneous transient outward currents (STOCs) at depolarized membrane voltages (0 mV). STOCs were blocked by TEA (1 mmol/L) or iberiotoxin (10 nmol/L) but were insensitive to apamin (100 nmol/L).

CONCLUSION

This voltage-clamp study showed that GPSMCs have l-type Ca2+ channels and more than two types of K+ channels. The voltage- and time-dependent changes of these ion channels and their interactions might be important in forming action potentials and regulating contractility.

Solution structure of a cathelicidin-derived antimicrobial peptide, CRAMP as determined by NMR spectroscopy

CRAMP was identified from a cDNA clone derived from mouse femoral marrow cells as a member of cathelicidin-derived antimicrobial peptides. This peptide shows potent antimicrobial activity against gram-positive and gram-negative bacteria but no hemolytic activity against human erythrocytes. CRAMP was known to cause rapid permeabilization of the inner membrane of Escherichia coli. In this study, the structure of CRAMP in TFE/H2O (1 : 1, v/v) solution was determined by CD and NMR spectroscopy. CD spectra showed that CRAMP adopts a mainly alpha-helical conformation in TFE/H2O solution, DPC micelles, SDS micelles and liposomes, whereas it has a random structure in aqueous solution. The tertiary structure of CRAMP in TFE/H2O (1 : 1, v/v), as determined by NMR spectroscopy, consists of two amphipathic alpha-helices from Leu4 to Lys10 and from Gly16 to Leu33. These two helices are connected by a flexible region from Gly11 to Gly16. Previous analysis of series of fragments composed of various portion of CRAMP revealed that an 18-residue fragment with the sequence from Gly16 to Leu33 was found to retain antibacterial activity. Therefore, the amphipathic alpha-helical region from Gly16 to Leu33 of CRAMP plays important roles in spanning the lipid bilayers as well as its antibiotic activity. Based on this structure, novel antibiotic peptides having strong antibiotic activity, with no hemolytic effect will be developed.

Isolation of Bacillus subtilis (chungkookjang), a poly-gamma-glutamate producer with high genetic competence

A bacterium with high poly-gamma-glutamate (PGA) productivity was isolated from the traditional Korean seasoning, Chung-Kook-Jang. This bacterium could be classified as a Bacillus subtilis, but sporulation in culture was infrequent in the absence of Mn2+. It was judged to be a variety of B. subtilis and designated B. subtilis (chungkookjang). L-Glutamate significantly induced PGA production, and highly elongated PGAs were synthesized. The volumetric yield reached 13.5 mg ml(-1) in the presence of 2% L-glutamate. The D-glutamate content was over 50% in every PGA produced under the conditions used. During PGA production, glutamate racemase activity was found in the cells, suggesting that the enzyme is involved in the D-glutamate supply. Molecular sizes of PGAs were changed by the salt concentration in the medium; PGAs with comparatively low molecular masses were produced in culture media containing high concentrations of NaCl. B. subtilis (chungkookjang) harbors no plasmid and is the first B. subtilis strain reported with both naturally high PGA productivity and high genetic competence.

Antibacterial, antitumor and hemolytic activities of alpha-helical antibiotic peptide, P18 and its analogs

The alpha-helical antibiotic peptide (P18: KWKLFKKIPKFLHLAKKF-NH2) designed from the cecropin A(1-8)-magainin 2 (1-12) hybrid displayed strong bactericidal and tumoricidal activity without inducing hemolysis. The effect of the Pro9 residue at central position of P18 on cell selectivity was investigated by Pro9 --> Leu or Pro9 --> Ser substitution. Either substitution markedly reduced the antibacterial activity of P18 and increased hemolysis, although it did not significantly affect cytotoxicity against human transformed tumor and normal fibroblast cells. These results suggest that a proline kink in alpha-helical antibiotic peptide P18 serves as a hinge region to facilitate ion channel formation on bacterial cell membranes and thus plays an important role in providing high selectivity against bacterial cells. Furthermore, to investigate the structure-antibiotic activity relationships of P18, a series of N- or C-terminal deletion and substitution analogs of P18 were synthesized. The C-terminal region of P18 was related to its antibiotic activity and alpha-helical conformation on lipid membranes rather than N-terminal one. Higher alpha-helicity of the peptides was involved in the hemolytic and antitumor activity rather than antibacterial activity. Except for [L9]-P18 and [S9]-P18, all the designed peptides containing a Pro residue showed potent antibacterial activity, although they did not induce a cytolytic effect against human erythrocyte and normal fibroblast cells at the concentration required to kill bacteria. In particular, P18 and some analogs (N-1, N-2, N-3, N-3L and N-4L) with potent bactericidal and tumoricidal activity and little or no normal cell toxicity may serve as an attractive candidate for the development of novel anti-infective or antitumor agents.

Effect of Phospholipase C-gamma1 Overexpression on the Protein Level of Waf1, PCNA, and Cyclin B1 Following Ultraviolet C Irradiation

PURPOSE

It has been demonstrated that PLC-gamma1 is overexpressed in many tumor cells, and that overexpression of Phospholipase C (PLC)-gamma1 is associated with tumor progression. In order to understand the effect of the PLC-gamma1 overexpression on the regulation of cell cycle regulators following DNA damage, we analyzed the expression level of PCNA, cyclin B1, and p21 Waf1 after ultraviolet C (UVC) irradiation in PLC-gamma1-transfected PC12 cells.

MATERIALS AND METHODS

PC12 and 3Y1 cells, transfected with empty vector or rat PLC-gamma1 cDNA, were used for this study. Following UVC irradiation, cell cycle progression was analyzed by flow cytometry and protein expression was detected by Western blotting.

RESULTS

Waf1 protein was markedly down-regulated, whereas PCNA and cyclin B1 was up-regulated in PLC-gamma1 overexpressed-cells as compared to the vector transfected-cells. When the cells were irradiated with UVC, PCNA was slightly increased within 3-hours of the UV irradiation and then was markedly decreased in Vector/ PC12 cells, while it remained high until 37 hour after UVC in PLC-gamma1/PC12 cells. In contrast, cyclin B1 was gradually decreased following UVC irradiation in both cells.

CONCLUSION

The overexpression of PLC-gamma1 affects the expression level of PCNA after UVC irradiation. We proposed that the overexpression of PLC-gamma1 may contribute to the UV-induced genomic instability by up-regulating the expression of PCNA.

Structure-activity analysis of SMAP-29, a sheep leukocytes-derived antimicrobial peptide

SAMP-29 is a cathelecidin-derived antimicrobial peptide deduced from sheep myeloid mRNA. To elucidate the structural-activity relationship of SMAP-29, several analogues were synthesized and their antibiotic activity was investigated. Compared to parental SMAP-29, SMAP-29(1-17) and [K(22,25,27)]-SMAP-29 retained relatively effective antimicrobial activity (MIC: 1.0-8.0 microM), but resulted in a complete loss of hemolytic activity. Pro-19 --> Ala substitution ([A19]-SMAP-29) in SMAP-29 induced a significant reduction in antibacterial activity. These results suggested that the N-terminal amphipathic alpha-helical region and the C-terminal hydrophobic region of SMAP-29 are responsible for antimicrobial activity and hemolytic activity, respectively, and the central Pro-19 in SMAP-29 plays a critical role in showing improved antibacterial activity. In particular, [K(2,7,13)]-SMAP-29(1-17) showed potent antimicrobial activity under high salt conditions without hemolytic activity. Thus, this short peptide could serve as an attractive candidate for the development of therapeutic antimicrobial drugs. Structural analysis by circular dichroism suggested that SMAP-29 seems to adopt a helix-bend/turn-extended random conformation.

Induction of early growth response-1 gene expression by calmodulin antagonist trifluoperazine through the activation of Elk-1 in human fibrosarcoma HT1080 cells

The early growth response gene-1 (Egr-1) is a transcription factor that plays an important role in cell growth and differentiation. It has been known that Egr-1 expression is down-regulated in many types of tumor tissues, including human fibrosarcoma HT1080 cells, and introduction of the Egr-1 gene into HT1080 cells inhibits cell growth and tumorigenic potential. Trifluoperazine (TFP), a phenothiazine class calmodulin antagonist, is known to inhibit DNA synthesis and cell proliferation and potentially important in antitumor activities. To understand the regulatory mechanism of Egr-1, we investigated the effect of TFP on expression of Egr-1 in HT1080 cells. Herein, we report that Egr-1 expression was increased by TFP in synergy with serum at the transcriptional level. Both the Ca(2+)/calmodulin-dependent protein kinase II inhibitor KN62 and the calcineurin inhibitor cyclosporin A enhanced TFP-dependent increase of Egr-1, suggesting that the Ca(2+)/calmodulindependent pathway plays a role in regulation of Egr-1 expression in HT1080 cells. The TFP-stimulated increase of the Egr-1 protein was preferentially inhibited by the MEK-specific inhibitor PD98059. In addition, activation of human Egr-1 promoter and the transcriptional activation of the ternary complex factor Elk-1 induced by TFP were inhibited both by pretreatment of PD98059 and by expression of the dominant-negative RasN17. These results indicate that the Ras/MEK/Erk/Elk-1 pathway is necessary for TFP-induced Egr-1 expression. We propose that the calmodulin antagonist TFP stimulates Egr-1 gene expression by modulating Ras/MEK/Erk and activation of the Elk-1 pathway in human fibrosarcoma HT1080 cells.

Determination of the protective effects of neutralizing anti-hepatitis B virus (HBV) immunoglobulins by epitope mapping with recombinant HBV surface-antigen proteins

Anti-hepatitis B virus (HBV) surface-antigen immunoglobulins prepared from human sera are clinical reagents which have been approved for prophylactic treatment in HBV-exposed persons. The passive immunoprophylaxis with immunoglobulins is meant to cross-link viral particles, which are then further cleared by the host's own immune system. While antibodies specific for both anti-S- and anti-preS proteins have been proved to serve as effective anti-viral agents, so far the fine antigen specificity of clinical immunoglobulin preparations has not been determined. Using recombinant proteins covering the hepatitis B surface antigen, in the present study, the specificity of a commercially available immunoglobulin preparation was determined and immunodominant epitopes were mapped. Here, it is shown that the major reactivity of anti-HBV immunoglobulins is directed against the S-protein, and that no reactivity to the preS2 but a weak binding activity to the preS1 region was detectable. The antigen reactivity within the preS1 region was biased to the C-terminal region, which indicates the presence of a putative B-cell epitope. The evaluation of the antigen specificity and determination of novel protective epitopes will provide valuable information for the further development and improvement of prophylactic HBV immunoglobulins.

Role of the hinge region and the tryptophan residue in the synthetic antimicrobial peptides, cecropin A(1-8)-magainin 2(1-12) and its analogues, on their antibiotic activities and structures

A 20-residue hybrid peptide CA(1-8)-MA(1-12) (CA-MA), incorporating residues 1-8 of cecropin A (CA) and residues 1-12 of magainin 2 (MA), has potent antimicrobial activity without toxicity against human erythrocytes. To investigate the effects of the Gly-Ile-Gly hinge sequence of CA-MA on the antibacterial and antitumor activities, two analogues in which the Gly-Ile-Gly sequence of CA-MA is either deleted (P1) or substituted with Pro (P2) were synthesized. The role of the tryptophan residue at position 2 of CA-MA on its antibiotic activity was also investigated using two analogues, in which the Trp2 residue of CA-MA is replaced with either Ala (P3) or Leu (P4). The tertiary structures of CA-MA, P2, and P4 in DPC micelles, as determined by NMR spectroscopy, have a short amphiphilic helix in the N-terminus and about three turns of alpha-helix in the C-terminus, with the flexible hinge region between them. The P1 analogue has an alpha-helix from Leu4 to Ala14 without any hinge structure. P1 has significantly decreased lytic activities against bacterial and tumor cells and PC/PS vesicles (3:1, w/w), and reduced pore-forming activity on lipid bilayers, while P2 retained effective lytic activities and pore-forming activity. The N-terminal region of P3 has a flexible structure without any specific secondary structure. The P3 modification caused a drastic decrease in the antibiotic activities, whereas P4, with the hydrophobic Leu side chain at position 2, retained its activities. On the basis of the tertiary structures, antibiotic activities, vesicle-disrupting activities, and pore-forming activities, the structure-function relationships can be summarized as follows. The partial insertion of the Trp2 of CA-MA into the membrane, as well as the electrostatic interactions between the positively charged Lys residues at the N-terminus of the CA-MA and the anionic phospholipid headgroups, leads to the primary binding to the cell membrane. Then, the flexibility or bending potential induced by the Gly-Ile-Gly hinge sequence or the Pro residue in the central part of the peptides may allow the alpha-helix in the C-terminus to span the lipid bilayer. These structural features are crucial for the potent antibiotic activities of CA-MA.

CRAMP analogues having potent antibiotic activity against bacterial, fungal, and tumor cells without hemolytic activity

CRAMP-18 (GEKLKKIGQKIKNFFQKL) is the antibacterial sequence derived from CRMAP, a member of cathelicidin-derived antimicrobial peptides. To develop the novel antibiotic peptides useful as therapeutic drugs requires strong antibiotic activity against bacterial and fungal cells without hemolytic effect. To this goal, the analogues were designed to increase only net positively charge by Lys-substitution of positions 2, 9, 13, or 16 at the hydrophilic helix face of CRAMP-18 without any change at the hydrophobic helix face. In particular, Lys-substitution (K(2)-CRAMP-18) of position 2 in CRAMP-18 induced the enhanced antibiotic activity without any increase in hemolysis. Thus, this peptide may provide a useful template for the design novel antibiotic peptides for the treatment of infectious diseases. Additional CD spectra studies suggested that the alpha-helical structure of the peptides plays an important role in killing bacterial and fungal cells, but the increase of alpha-helical content is less connected with the enhanced antibiotic activity.

Surgical management of recurrent iris stromal cyst

PURPOSE

To report the clinical history and surgical management of recurrent congenital iris stromal cyst.

METHOD

Case report. Argon laser endophotocoagulation and cryotherapy were used to treat a recurrent iris stromal cyst in an 18-month-old boy.

RESULTS

At 43 months of follow-up, there was no recurrence or evidence of epithelial ingrowth.

CONCLUSION

Treatment with argon laser endophotocoagulation and cryotherapy resulted in complete resolution of a recurrent congenital iris cyst.

Genetic alterations of gastric cancer: comparative genomic hybridization and fluorescence In situ hybridization studies

Genetic changes leading to the development of gastric cancers are still in dispute. In the following study, we used comparative genomic hybridization (CGH) to screen for DNA copy number changes along all chromosomes in 37 gastric carcinomas, and fluorescence in situ hybridization (FISH) with the C-MYC and TP53 probes in 14 cases for comparison. The aim of this study was to identify those chromosome regions that contain genes important for the development of gastric carcinomas and to identify genetic markers associated with tumor progression. The most often involved gains were 2q, 7pq, 8pq, 13q, 17q, 18q, and 20pq. The most commonly deleted regions were 17p. The pattern of genetic changes was different depending on the existence of nodal metastasis and histologic types. Gains in 8q and losses in 17p were the most common features of the CGH changes. However, only 3 among the available 10 cases (30%) showed an amplification of the C-MYC gene by FISH. Allelic loss of TP53 was found in 2 of 4 cases (50%). This difference might be due to another rearrangement of these 2 genes which cannot be detected by FISH, or other possible genes in that area may be involved in the tumorigenesis and nodal metastasis of gastric carcinomas.

Effects of the hinge region of cecropin A(1-8)-magainin 2(1-12), a synthetic antimicrobial peptide, on liposomes, bacterial and tumor cells

A 20-residue hybrid peptide (CA(1-8)-MA(1-12): KWKLFKKIGIGKFLHSAKKF-NH(2)) incorporating 1-8 residues of cecropin A (CA) and 1-12 residues of magainin 2 (MA) has potent antibiotic activity without hemolytic activity. In order to investigate the effects of the flexible hinge sequence, Gly-Ile-Gly of CA(1-8)-MA(1-12) (CA-MA) on antibiotic activity, CA-MA and its three analogues, CA-MA1, CA-MA2 and CA-MA3 were synthesized. The Gly-Ile-Gly sequence of CA-MA was deleted in CA-MA1 and replaced with Pro and Gly-Pro-Gly in CA-MA2 and CA-MA3, respectively. CA-MA1 and CA-MA3 caused a significant decrease in the bactericidal rate against Escherichia coli and Bacillus subtilis and the tumoricidal activity against four different tumor cells, and the PC/PS (4:1, w/w) vesicle-aggregating and disrupting activities. However, CA-MA2 showed a similar bactericidal rate and antitumor, vesicle-aggregating and disrupting activities, as compared with CA-MA. These results suggested that the flexibility or beta-turn induced by Gly-Ile-Gly or Pro in the central part of CA-MA may be important in the electrostatic interaction of the cationic short alpha-helical region in the N-terminus with the cell membrane surface and the hydrophobic interaction of amphipathic alpha-helical region in the C-terminus with the hydrophobic acyl chains in the cell membrane. CA-MA3 exhibited lower activity in antibacterial, antitumor, and vesicle-aggregating and disrupting activities than CA-MA and CA-MA2. This result suggested that the excessive beta-turn structure by Gly-Pro-Gly in CA-MA3 seems to interrupt the ion channel/pore formation on the lipid bilayer. It was concluded that the appropriate flexibility or beta-turn structure provided by the central hinge is responsible for the effective antibiotic activity of the antimicrobial peptides with the helix-hinge-helix structure.

Fluorescein angiographic features of choroidal insufficiency in anterior ischemic optic neuropathy

Anterior ischemic optic neuropathy(AION) is known to be caused by circulatory disturbance in the anterior optic nerve(AON). Because the AON shares blood supply from the paraoptic short posterior ciliary artery with peripapillary choroid, the authors investigated the angiographic evidences of combined choroidal insufficiency in patients with acute AION. Fundus fluorescein angiograms from 30 eyes from 28 patients with acute AION were enrolled in this study. The diagnosis of acute AION was based primarily on angiographic evidences of filling delay of optic nerve head and the various clinical features, such as decreased visual acuity, visual field defects, afferent pupillary defect, and optic disc swelling. Angiographic evidences of combined choroidal filling delay were as follows: 1) circular or localized filling delay of peripapillary choroid in 15 eyes (50%), 2) generalized filling delay of posterior pole in 11 eyes (36.7%), 3) filling delay of unilateral choroid divided by watershed zone in 5 eyes (16.7%), and 4) choriocapillary filling delay in 10 eyes (33.3%). In this study, various types of choroidal insufficiency in patients with AION were observed, which helped us to differentiate AION from the other various diseases of the anterior optic nerve.

Effects of tryptophan residues of porcine myeloid antibacterial peptide PMAP-23 on antibiotic activity

PMAP-23 is a 23-residue antimicrobial peptide from porcine myeloid cells. In order to determine the effects of two Trp residues in positions 7 and 21 of PMAP-23 on antibacterial activity and phospholipid vesicle interacting property, two analogues in which Ala is substituted for Trp residue in position 7 or 21 were synthesized. A(21)-PMAP-23 exhibited reduced antibacterial activity and phospholipid vesicle disrupting activity when compared to those of PMAP-23 and A(7)-PMAP-23. PMAP-23 readily interacted with model lipid membrane and induced membrane destabilization. Therefore antibacterial activity induced by PMAP-23 is due to the interaction of cell membrane with peptide followed by membrane perturbation. A significant structural change on the SDS micelle was not found by Ala substitution of the Trp residue of PMAP-23. Also, there is a good correlation between hydrophobic interaction on RP-HPLC, expressed as retention time on RP-HPLC, and antibacterial activity. The vesicle titration experiment indicated that Trp residues located at near C-terminus are accessible to hydrophobic tail of phospholipid vesicle. This result suggests that the C-terminal end of PMAP-23 penetrates into the lipid bilayer in the course of the interaction with phospholipid membranes and is important for its antibacterial activity.

Isolation and characterization of a novel antifungal peptide from Aspergillus niger

A novel antifungal peptide (termed as Anafp) was isolated from the culture supernatant of the filamentous fungi, Aspergillus niger. The whole amino acid sequence of Anafp was determined and the peptide was found to be composed of a single polypeptide chain with 58 amino acids including six cysteine residues. The peptide shows some degree of sequence homology to a cysteine-rich antifungal peptides reported from the seeds of Sinapis alba and Arabidopsis thaliana or the extracellular media of Aspergillus giganteus and Penicillium chrysogenumsome. Cysteine-spacing pattern of Anafp was similar to that of the antifungal peptide from Penicillium chrysogenum. The Anafp exhibited potent growth inhibitory activities against yeast strains as well as filamentous fungi at a range from 4 to 15 microM. In contrast, Anafp did not show antibacterial activity against Escherichia coli and Bacillus subtilis even at 50 microM.

NMR structural characterization of cecropin A(1-8) - magainin 2(1-12) and cecropin A (1-8) - melittin (1-12) hybrid peptides

In order to elucidate the structure-antibiotic activity relationships of the peptides, the three-dimensional structures of two hybrid peptides, CA(1-8) - MA(1-12) and CA(1-8) - ME(1-12) in trifluoroethanol-containing aqueous solution were investigated by NMR spectroscopy. Both CA(1-8) - MA(1-12) and CA(1-8) - ME(1-12) have strong antibacterial activity but only CA(1-8) - ME(1-12) has hemolytic activity against human erythrocytes. CA(1-8) - MA(1-12) has a hydrophobic 310-helix of only two turns combined with one short helix in the N-terminus with a flexible hinge section in between. CA(1-8) - MA(1-12) has a severely bent structure in the middle of the peptide. These structural features as well as the low hydrophobicity of CA(1-8) - MA(1-12) seem to be crucial for the selective lysis against the membrane of prokaryotic cells. CA(1-8) - ME(1-12) has an alpha-helical structure of about three turns in the melittin domain and a flexible structure with one turn in the cecropin domain connected with a flexible hinge section in between, and these might be the structural features required for membrane disruption against prokaryotic and eukaryotic cells. The central hinge region (Gly9-Ile10-Gly11) in an amphipathic antibacterial peptide is considered to play an important role in providing the conformational flexibility required for ion channel formation of the C-terminal hydrophobic alpha-helix on cell membrane.

Biological actions of the epidermal growth factors-like domain peptides of mouse schwannoma-derived growth factor and human amphiregulin

Several members of the epidermal growth factor (EGF) family of growth factors that contain EGF-like units at their carboxy portion have been isolated and characterized. Schwannoma-derived growth factor (SDGF) and amphiregulin (AR) are members of this family. SDGF has high sequence homology to AR, and is known to be not only a potent mitogen for astrocytes and fibroblasts but also a neurotrophic factor. We previously confirmed that the synthetic EGF-like peptides SDGF(38-80) and AR(44-84), corresponding to the EGF-like domain of mouse SDGF and human AR, respectively, formed similar disulfide bond patterns to that of EGF. In the present study, we further investigated the biological actions of these two EGF-like peptides on several cultured cell lines. We found that SDGF(38-80) and AR(44-84) have weak mitogenic activity in NIH/3T3 cells and weak binding affinity to the EGF receptor on the surface of A431 cells compared with EGF. However, SDGF(38-80) and EGF induced short neurite outgrowth in PC12 h cells, a subclone of PC12 cells, at 100 nM. In addition, a significant increase in acetylcholinesterase (AChE) activity induced by SDGF(38-80) was observed at a concentration similar range to that of EGF, which is known as a differentiation marker of these cells. The effect of AR(44-84) in PC12 h cells was weaker than those of SDGF(38-80) and EGF, but the AChE activity was significantly increased by the addition of 100 nM AR(44-84), which did not stimulate NIH/3T3 cell growth. These results also suggest that SDGF(38-80) and AR(44-84) may be effective for neuronal differentiation rather than proliferation.

Integrated optical polarization splitter based on photobleaching-induced birefringence in azo dye polymers

An integrated optical polarization splitter has been fabricated by utilizing the photobleaching-induced birefringence in an azo dye polymer. It consists of a Y-branch waveguide formed by the reactive ion etching with one of the two arms photobleached. The refractive index of the photobleached arm is decreased for the TE mode and increased for the TM mode. The performance of the splitter was measured as a function of the energy of the photobleaching beam and compared to a wave propagation simulation of the device. The measured cross talks are less than -28 dB for the TM mode and -24 dB for the TE mode at a wavelength of 1310 nm. The measured excess losses for the TE and TM modes, which measure the effect of the Y branch and the photobleaching, are 0.3 and 0.4 dB, respectively. The insertion loss was 5 dB, which includes the input fiber to waveguide coupling loss.

Structure-antibacterial, antitumor and hemolytic activity relationships of cecropin A-magainin 2 and cecropin A-melittin hybrid peptides

In order to elucidate the structure-antibiotic activity relationship of cecropin A-magainin 2 and cecropin A-melittin hybrid peptides, several truncated peptides and the analogues with amino acid substitutions were synthesized and their antibacterial, antitumor and hemolytic activities of were examined. Cecropin A-magainin 2 hybrid analog, L16-CA(1-8)-MA(1-12) (termed as L-CA-MA in this study: KWKLFKKIGIGKFLHLAKKF-NH2), is known to have potent antibacterial and antitumor activity with less hemolytic activity. We found that the C-terminal region of L-CA-MA is more involved in the alpha-helical structure on cell membrane-like environment than N-terminal one by circular dichroism analysis. Deletion of the Gly-Ile-Gly sequence, the central hinge region of L-CA-MA, produced a considerable reduction in antitumor and hemolytic activity rather than an antibacterial one. The insertion of Pro, Gly-Ile or Gly-Pro in this hinge region of L-CA-MA caused retention of both antibacterial and antitumor activity while causing a significant decrease in hemolytic activity. However, the substitution with Gly-Pro-Gly instead of the Gly-Ile-Gly in CA(1-8)-MA(1-12), CA(1-8)-ME(1-12), CA(1-13)-MA(1-13) and CA(1-13)-ME(1-13) hybrids resulted in a drastic decrease in antibacterial, antitumor and hemolytic activity. The increase of hydrophobicity at position 16 in CA(1-8)-MA(1-12) by substituting Trp or Phe induced a significant increase in hemolytic activity without a considerable change in either antibacterial or antitumor activity. Therefore, these results suggested that the appropriate flexibility in the hinge region of CA-MA and CA-ME hybrid peptides and the appropriate hydrophobicity at position 16 in the hydrophobic region of CA (1-8)-MA(1-12) are important in potent antibacterial and antitumor activity with no hemolytic effect.