A Rapid Method for Generating Infectious SARS-CoV-2 and Variants Using Mutagenesis and Circular Polymerase Extension Cloning

The appearance of SARS-CoV-2 variants in late 2020 raised alarming global public health concerns. Despite continued scientific progress, the genetic profiles of these variants bring changes in viral properties that threaten vaccine efficacy. Thus, it is critically important to investigate the biologic profiles and significance of these evolving variants. In this study, we demonstrate the application of circular polymerase extension cloning (CPEC) to the generation of full-length clones of SARS-CoV-2. We report that, combined with a specific primer design scheme, this yields a simpler, uncomplicated, and versatile approach for engineering SARS-CoV-2 variants with high viral recovery efficiency. This new strategy for genomic engineering of SARS-CoV-2 variants was implemented and evaluated for its efficiency in generating point mutations (K417N, L452R, E484K, N501Y, D614G, P681H, P681R, Δ69-70, Δ157-158, E484K+N501Y, and Ins-38F) and multiple mutations (N501Y/D614G and E484K/N501Y/D614G), as well as a large truncation (ΔORF7A) and insertion (GFP). The application of CPEC to mutagenesis also allows the inclusion of a confirmatory step prior to assembly and transfection. This method could be of value in the molecular characterization of emerging SARS-CoV-2 variants as well as the development and testing of vaccines, therapeutic antibodies, and antivirals. IMPORTANCE Since the first emergence of the SARS-CoV-2 variant in late 2020, novel variants have been continuously introduced to the human population, causing severe public health threats. In general, because these variants acquire new genetic mutation/s, it is critical to analyze the biological function of viruses that such mutations can confer. Therefore, we devised a method that can construct SARS-CoV-2 infectious clones and their variants rapidly and efficiently. The method was developed based on a PCR-based circular polymerase extension cloning (CPEC) combined with a specific primer design scheme. The efficiency of the newly designed method was evaluated by generating SARS-CoV-2 variants with single point mutations, multiple point mutations, and a large truncation and insertion. This method could be of value for the molecular characterization of emerging SARS-CoV-2 variants and the development and testing of vaccines and antiviral agents.

Development of a Universal Cloning System for Reverse Genetics of Human Enteroviruses

Enteroviruses (EVs) have been associated with several human diseases. Due to their continuous emergence and divergence, EV species have generated more than 100 types and recombinant strains, increasing the public health threat caused by them. Hence, an efficient and universal cloning system for reverse genetics (RG) of highly divergent viruses is needed to understand the molecular mechanisms of viral pathology and evolution. In this study, we generated a versatile human EV whole-genome cDNA template by enhancing the template-switching method and designing universal primers capable of simultaneous cloning and rapid amplification of cDNA ends (RACE)-PCR of EVs. Moreover, by devising strategies to overcome limitations of previous cloning methods, we simplified significant cloning steps to be completed within a day. Of note, we successfully verified our efficient universal cloning system enabling RG of a broad range of human EVs, including EV-A (EV-A71), EV-B (CV-B5, ECHO6, and ECHO30), EV-C (CV-A24), and EV-D (EV-D68), with viral titers and phenotypes comparable to those of their wild types. This rapid and straightforward universal EV cloning strategy will help us elucidate molecular characteristics, pathogenesis, and applications of a broad range of EV serotypes for further development of genetic vaccines and delivery tools using various replication systems. IMPORTANCE Due to the broad spread, incidence, and genetic divergence of enteroviruses (EVs), it has been challenging to deal with this virus that causes severe human diseases, including aseptic meningitis, myocarditis, encephalitis, and poliomyelitis. Therefore, an efficient and universal cloning system for the reverse genetics of highly divergent EVs contributes to an understanding of the viral pathology and molecular mechanisms of evolution. We have simplified the important cloning steps, hereby enhancing the template-switching method and designing universal primers, which enable the important cloning steps to be completed in a day. We have also successfully demonstrated recovery of a broad range of human EVs, including EV-A to -D types, using this advanced universal cloning system. This rapid and robust universal EV cloning strategy will aid in elucidating the molecular characteristics, pathogenesis, and applications of a wide range of EVs for further development of genetic vaccines and antiviral screening using various replication systems.

Combination therapy with nirmatrelvir and molnupiravir improves the survival of SARS-CoV-2 infected mice

As the SARS-CoV-2 pandemic remains uncontrolled owing to the continuous emergence of variants of concern, there is an immediate need to implement the most effective antiviral treatment strategies, especially for risk groups. Here, we evaluated the therapeutic potency of nirmatrelvir, remdesivir and molnupiravir, and their combinations in SARS-CoV-2 infected K18-hACE2 transgenic mice. Systemic treatment of mice with each drug (20 mg/kg) resulted in slightly enhanced antiviral efficacy and yielded an increased life expectancy of only about 20-40% survival. However, combination therapy with nirmatrelvir (20 mg/kg) and molnupiravir (20 mg/kg) in lethally infected mice showed profound inhibition of SARS-CoV-2 replication in both the lung and brain and synergistically improved survival rates up to 80% compared to those with nirmatrelvir (36%, P < 0.001) and molnupiravir (43%, P < 0.001) administered alone. This combination therapy effectively reduced clinical severity score, virus-induced tissue damage, and viral distribution compared to those in animals treated with these monotherapies. Furthermore, all these assessments associated with this combination were also significantly higher than that of mice receiving remdesivir monotherapy (P < 0.001) and the nirmatrelvir (20 mg/kg) and remdesivir (20 mg/kg) combination (P < 0.001), underscored the clinical significance of this combination. By contrast, the nirmatrelvir and remdesivir combination showed less antiviral efficacy, with lower survival compared to nirmatrelvir monotherapy due to the insufficient plasma exposure of the remdesivir, demonstrating the inefficient therapeutic effect of this combination in the mouse model. The combination therapy with nirmatrelvir and molnupiravir contributes to alleviated morbidity and mortality, which can serve as a basis for the design of clinical studies of this combination in the treatment of COVID-19 patients.

P5989Effect of neprilysin inhibitor for ischemic mitral regurgitation after myocardial injury

Background

After myocardial infarction (MI), mitral valve (MV) tethering and fibrosis stimulate functional mitral regurgitation (MR), resulting in high morbidity of heart failure and cardiac mortality. However, pharmacological treatment has not been proven effective in reducing ischemic MR. MV change post-MI is associated with an excessive endothelial-to-mesenchymal transition (EMT) by transforming growth factor (TGF)-β overexpression and also with left ventricular (LV) remodeling. In a recent clinical study using echocardiography, angiotensin receptor neprilysin inhibitor (ARNI) reduced functional MR to a greater extent than did valsartan, but the mechanism was not revealed.

Purpose

This study tested the hypothesis that treatment of neprilysin inhibitor attenuates functional MR after MI by facilitating LV reverse remodeling and suppressing EMT which mitigates inadequate leaflet adaptation.

Methods

In male Sprague-Dawley rats (n=31), functional MR was induced by occluding the left circumflex coronary artery. Two weeks after MI, MR and LV dilatation were confirmed by echocardiography and magnetic resonance imaging (MRI). Rats were randomly assigned to LCZ696 treatment (ARNI, 60 mg/kg/d, n=10), valsartan treatment (30mg/kg/d, n=10), or corn oil only (MR control group; n=11). After 6 weeks, LV volumes, functions and MR extent were quantified by using echocardiography, cardiac MRI and pressure-volume loop analysis. Also, excised mitral leaflets and LV were analyzed by histopathology and primary cultured valvular endothelial cells (VECs) were evaluated focusing on molecular changes.

Results

LCZ696 significantly attenuated post-MI LV dilatation after 6 weeks when compared with the control group (LV end-diastolic volume (EDV), 461.3±41.3 uL versus 525.1±78.2 uL; p<0.05), while valsartan did not (LV EDV, 471.2±26.8 uL; p>0.05 to control). There were no significant differences in the change of arterial pressure and ejection fraction between the treatment groups, however, dP/dt was greater in the LCZ696 group than in the MR control group (8203±286 mmHg/s for LCZ696 versus 6936±555 mmHg/s for MR control; p=0.01). MR extent and LA volume were significantly decreased in the LCZ696 group compared with the valsartan group. Pathological analysis showed that fibrosis was more prominent in the MR control than in the LCZ696 group. LCZ696 strongly reduced leaflet thickness, TGF-β, and downstream phosphorylated extracellular-signal-regulated kinase and EMT (25.4±11.8% vs. 53.4±12.6% α-smooth muscle actin-positive VECs; p<0.05). Leaflet area increased comparably (5%) in the LCZ696 group compared with the valsartan group.

Conclusions

Neprilysin inhibitor has positive effects on LV reverse remodeling and also directly modulates profibrotic changes of MV leaflets post-MI without eliminating adaptive growth. Understanding the mechanisms could provide new opportunities to ARNI reducing ischemic MR.

Acknowledgement/Funding

This work was supported by the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2014R1A6A3A04056205). It was also

Effect of relative humidity on inactivation of foodborne pathogens using chlorine dioxide gas and its residues on tomatoes

The effect of relative humidity (RH) on the antimicrobial efficacy of chlorine dioxide (ClO₂ ) gas against foodborne pathogens on tomatoes was evaluated. Also, levels of ClO₂ residues on tomatoes after exposure to ClO₂ gas under different RH conditions were measured to determine the quantity of solubilized ClO₂ gas on tomato surfaces. Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes were inoculated on tomatoes and exposed to ClO₂ gas (5, 10, 20 and 30 ppmv) under different RH conditions (50, 70 and 90%). As ClO₂ gas concentration and treatment time increased, significant differences (P < 0·05) were observed between inactivation levels under different RH conditions. Exposure to 30 ppmv of ClO₂ gas (50% RH) for 20 min resulted in 1·22-1·52 log reductions of the three foodborne pathogens. Levels of the three foodborne pathogens were reduced to below the detection limit (0·48 log CFU per cm² ) within 15 min when exposed to 30 ppmv of ClO₂ gas at 70% RH and within 10 min at 90% RH. At a given ClO₂ gas concentration, ClO₂ residues on tomatoes significantly (P < 0·05) increased with increasing RH, and there were close correlations between log reductions of pathogens and ClO₂ residues on tomatoes.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study reported on the correlation between the amount of ClO₂ residues on produce surfaces and the level of inactivation of pathogens after ClO₂ gas treatment. Variations in RH have great effect on the solubilization of ClO₂ gas on tomato surfaces considering that ClO₂ residues on tomatoes increased with increasing RH. Also, the amount of ClO₂ residues on tomatoes is positively correlated with the level of inactivation of pathogens. The results of this study provide insights for predicting inactivation patterns of foodborne pathogens by ClO₂ gas for practical application by the fresh produce industry.

Association of body composition with bone mineral density in northern Chinese men by different criteria for obesity

With impressive economic development, obesity has emerged as a critical public health issue in China. Recently it was reported that obesity has taken an adverse effect on osteoporosis. Because there is different body mass index (BMI) for obesity globally, studies based on BMI levels on association of obesity with osteoporosis were quite few. Therefore, we discussed the relationship of body composition with skeletal BMD according to WHO BMI and BMI on Working Group on Obesity in China (WGOC).

METHODS

A total of 502 adult men aged 20-89 were enrolled as healthy subjects for osteoporosis study at Qianfoshan Hospital, Shandong University between September 2008 and August 2010. According to WHO BMI, all subjects were divided into three groups: normal weight (18.5 ≤ BMI < 25 kg/m(2), n = 202), overweight (25 ≤ BMI < 30 kg/m(2), n = 242), and obesity (BMI ≥ 30 kg/m(2), n = 58). According to WGOC BMI, normal weight (18.5 ≤ BMI < 24 kg/m(2), n = 137), overweight (24 ≤ BMI < 28 kg/m(2), n = 225), and obesity (BMI ≥ 28 kg/m(2), n = 140). Total body and regional BMD, lean mass (LM), lean body mass index (LBMI), fat mass (FM), percent body fat (%BF) and fat mass index (FMI) were measured by dual-energy X-ray absorptiometry. Age-partial Pearson correlation analyses between body composition-related parameters and BMD. Multiple regression analyses were performed to explore the associations of BMD with LM, LBMI, FM, %BF and FMI.

RESULTS

Fat mass (FM), %BF, FMI, LM and LBMI were positively correlated with BMD at almost sites (P < 0.001) in all subjects. However, the relationship was not different among groups. LM, LBMI, FM and FMI were positively correlated with BMD (P < 0.01) in normal weight. LM and LBMI appeared significantly positive with BMD in overweight and obesity according to WHO and WGOC criteria. %BF and FMI were negative significance with BMD at total body and some regional BMD according to WHO criteria in overweight (P < 0.05). In two obese groups, %BF appeared negatively significant with BMD (P < 0.05) according to WGOC criteria, and %BF and FMI appeared negatively significant with BMD (P < 0.05) according to WHO criteria. In regression of independent variables as FM and LM, LM showed statistically positively significant relations with BMD at almost sites (P < 0.05) in all groups. FM appeared positively significant with BMD in normal groups and overweight group according to WGOC criteria. In regression of independent variables as %BF and FMI, %BF and FMI appeared statistically negatively significant relations with BMD in overweight and obesity, but %BF and FMI were inconsistent in same site.

CONCLUSIONS

Lean mass (LM) and LBMI could help to determinant of BMD, and %BF and FMI were adverse to BMD in overweight and obesity. Comparing with two criteria, we found the differences in fat-related parameters and BMD according to WHO criteria were more obvious than that according to WGOC criteria. We also found that %BF and FMI were useful to research the relationship between osteoporosis and obesity at the same time.

Investigation of thermal and electrical stabilities of a GdBCO coil using grease as an insulation material for practical superconducting applications

This paper presents the effects of thermal grease on the electrical and thermal characteristics of GdBCO pancake coils, observed through charge-discharge, sudden discharge, over-current, and thermal quench testing. In charge-discharge and sudden discharge tests, a coil using thermal grease as an insulation material demonstrated faster charging/discharging rates compared to a coil without turn-to-turn insulation. In the case of over-current tests, the coil using thermal grease exhibited the highest electrical stability. Furthermore, thermal quench testing showed the coil employing thermal grease to possess superior thermal characteristics, with rapid cooling and low temperature rise. Overall, the use of thermal grease as an insulation material may be a potential solution to the problems observed with the existing insulation materials, possessing fast charging/discharging rates with superior thermal and electrical stabilities.

Evaluation of patient outcome after discontinuation of alfuzosin treatment for benign prostatic hyperplasia: a multicentre, prospective study

AIMS

The aim of this study was to assess patient outcome after discontinuation of alfuzosin treatment in patients with benign prostatic hyperplasia (BPH).

METHODS

This study included 200 BPH patients. Alpha-blockers were discontinued after 12 weeks of treatment when the International Prostatic Symptom Score (IPSS) was reduced to < 8 points, peak urine flow rate (Q(max)) was increased to ≥ 15 ml/s, the postvoiding residual (PVR) urine volume was ≤ 100 ml and the patient agreed to discontinue treatment. Urinary symptoms of the patients were assessed at 4, 8, 12 and 24 weeks after discontinuation of medication, and surveys were performed asking whether patients wanted to restart administration of medication.

RESULTS

Of 200 enrolled patients, 142 (71.00%) received 12 weeks of treatment with 10 mg of alfuzosin. The medication was discontinued in 58 of 142 patients (40.85%) because urinary symptoms had improved. Among these patients, follow-up observations were performed for 49 patients up to 24 weeks after treatment discontinued. Of these 49 patients, 28 (57.14%) showed correct urination without a need to restart treatment up to 24 weeks after the medication was discontinued. The discontinuation group demonstrated improved voiding symptoms, including Q(max) and PVR, relative to the re-administration group at baseline. Furthermore, the discontinuation group showed a smaller prostate volume than the re-administration group (p = 0.045).

CONCLUSION

When patients with BPH displayed symptomatic improvement upon treatment with alpha-blockers, the improvements were maintained in a select subpopulation of patients without the need to re-administer the alpha-blockers.

Comparison of efficacy for erectile function and lower urinary tract symptoms of tadalafil 20 mg on-demand and 5 mg once daily in patients with erectile dysfunction

Aim:  To compare the improvement in erectile dysfunction (ED) and lower urinary tract symptoms (LUTS) as well as safety of tadalafil dosed at 20 mg on-demand and 5 mg once daily among ED patients. Materials and methods:  A total of 194 ED patients visited between March 2010 and June 2011 were recruited. Out of 194 individuals, 168 (86.6%) met inclusion criteria after completing the two-week screening period (V0). The Patients were randomly allocated into two groups: (i) 20 mg of tadalafil as needed (Group 1: n = 84, 50.0%) and (ii) 5 mg of tadalafil once daily (Group 2: n = 84, 50.0%). Blood pressure (BP), heart rate (HR) and the five-item version of the International Index of Erectile Function (IIEF-5) were assessed immediately before initiation of treatment (V1) and after four (V2) and twelve weeks of treatment (V3). In men with an IPSS of ≥ 8 at V1, IPSS, maximal flow rate (Qmax) and post-void residual volume (PVR) were also assessed. Results:  Of the 168 patients, 134 (79.8%; Group 1: n = 68, 81.0%; Group 2: n = 66, 78.6%) patients completed the trial. IIEF-5 improved in both groups, and the mean change was larger in Group 2 at V3 (4.9 ± 4.2 vs. 6.5 ± 4.5; p = 0.032) Similarly, though IPSS (with ≥ 8, n = 88, 65.7%; Group 1: n = 44, 64.7%; Group 2: n = 44, 66.7%) improved in both groups, the mean change was larger in Group 2 at V3 (-2.8 ± 4.3 vs. -4.8 ± 4.1; p = 0.026). Qmax and PVR did not differ significantly in either group. Conclusions:  Once daily tadalafil was more efficacious in treating both ED and LUTS than on-demand dosing. However, no differences were observed between the two dosing schedules with regard to the improvement in LUTS when stratified by improvement in ED. The side effects were insignificant for both dosing schedules.

Development and evaluation of a new device to effectively detach micro-organisms from food samples

AIMS

 To develop a new instrument of great versatility for recovering micro-organisms from all types of food samples and to compare the effects with existing sample preparation methods.

METHODS AND RESULTS

 To detach micro-organisms from large-size unbroken food samples such as apples, carrots, potatoes and tomatoes without preprocessing, the Spindle apparatus was newly developed. The Spindle was used to effectively detach micro-organisms from large-size samples. In a comparative study involving 51 food samples, treatment with the Spindle and Stomacher showed that recovery of total aerobic micro-organisms (naturally occurring mesophilic microflora) and foodborne pathogens (from samples inoculated with Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes) for both methods was highly correlated (R² = 0·98). Furthermore, diluents treated by the Spindle contained much less food debris than those treated by stomaching.

CONCLUSIONS

 These results indicate that Spindle is a novel, effective alternative method for detaching micro-organisms from food samples including four kinds of large-size samples without the need for preprocessing.

SIGNIFICANCE AND IMPACT OF STUDY

 The Spindle might be used to widely detaching micro-organisms from all types of food samples for microbiological assay.

Isolation and characterization of a lytic Myoviridae bacteriophage PAS-1 with broad infectivity in Aeromonas salmonicida

To search for candidate control agents against Aeromonas salmonicida subsp. salmonicida infections in aquaculture, one bacteriophage (phage), designated as PAS-1, was isolated from the sediment samples of the rainbow trout (Oncorhynchus mykiss) culture farm in Korea. The PAS-1 was morphologically classified as Myoviridae and possessed approximately 48 kb of double-strand genomic DNA. The phage showed broad host ranges to other subspecies of A. salmonicida as well as A. salmonicida subsp. salmonicida including antibiotic-resistant strains. Its latent period and burst size were estimated to be approximately 40 min and 116.7 PFU/cell, respectively. Furthermore, genomic and structural proteomic analysis of PAS-1 revealed that the phage was closely related to other Myoviridae phages infecting enterobacteria or Aeromonas species. The bacteriolytic activity of phage PAS-1 was evaluated using three subspecies of A. salmonicida strain at different doses of multiplicity of infection, and the results proved to be efficient for the reduction of bacterial growth. Based on these results, PAS-1 could be considered as a novel Aeromonas phage and might have potentiality to reduce the impacts of A. salmonicida infections in aquaculture.

Nano-scaled Pt/Ag/Ni/Au contacts on p-type GaN for low contact resistance and high reflectivity

We synthesized the vertical-structured LED (VLED) using nano-scaled Pt between p-type GaN and Ag-based reflector. The metallization scheme on p-type GaN for high reflectance and low was the nano-scaled Pt/Ag/Ni/Au. Nano-scaled Pt (5 A) on Ag/Ni/Au exhibited reasonably high reflectance of 86.2% at the wavelength of 460 nm due to high transmittance of light through nano-scaled Pt (5 A) onto Ag layer. Ohmic behavior of contact metal, Pt/Ag/Ni/Au, to p-type GaN was achieved using surface treatments of p-type GaN prior to the deposition of contact metals and the specific contact resistance was observed with decreasing Pt thickness of 5 A, resulting in 1.5 x 10(-4) ohms cm2. Forward voltages of Pt (5 A)/Ag/Ni contact to p-type GaN showed 4.19 V with the current injection of 350 mA. Output voltages with various thickness of Pt showed the highest value at the smallest thickness of Pt due to its high transmittance of light onto Ag, leading to high reflectance. Our results propose that nano-scaled Pt/Ag/Ni could act as a promising contact metal to p-type GaN for improving the performance of VLEDs.

CT differentiation of pyogenic liver abscesses caused by Klebsiella pneumoniae vs non-Klebsiella pneumoniae

OBJECTIVE

Klebsiella pneumoniae is one of the organisms most commonly isolated from pyogenic liver abscesses in Asian populations. We compared CT findings in liver abscesses caused by K. pneumoniae with those caused by other bacterial pathogens.

METHODS

Of 214 patients with liver abscesses examined over a 5 year period, 129 patients with positive blood or aspirate cultures were enrolled. The patients were divided into two groups: the K. pneumoniae monomicrobial liver abscess (KLA) group (n = 59) and the non-K. pneumoniae monomicrobial or polymicrobial liver abscess (non-KLA) group (n = 70). Two radiologists blinded to the culture results evaluated the CT images, recording the number, size, location and configuration of abscesses, the thickness of the abscess wall, the pattern of rim enhancement, septal enhancement, the double target sign, internal necrotic debris, internal gas bubbles and underlying biliary disease. The presence of diabetes and metastatic infection was also compared between groups. Statistical analyses were performed using univariate (Student's t-test and χ(2) test) and multivariate analyses.

RESULTS

Multivariate analysis showed that a thin wall, necrotic debris, metastatic infection and the absence of underlying biliary disease were the most significant predictors of KLA. When three of the four criteria were used in combination, a specificity of 98.6% was achieved for the diagnosis of KLA.

CONCLUSION

A thin-walled abscess, internal necrotic debris, the presence of metastatic infection and the absence of underlying biliary disease may be useful CT findings in the early diagnosis of K. pneumoniae liver abscesses.

Eight enrichment broths for the isolation of Campylobacter jejuni from inoculated suspensions and ground pork

AIMS

The efficiency of eight enrichment broths for the selective isolation of Campylobacter jejuni was compared to identify an optimal enrichment broth.

METHODS AND RESULTS

Brucella-FBP, Preston, Doyle and Roman, modified CCD (mCCD), Park and Sanders, Bolton, Hunt and Radle and Hunt broths were compared for their recovery of (i) Camp. jejuni in suspension, (ii) Camp. jejuni from inoculated ground pork, (iii) heat-injured Camp. jejuni (55 degrees C for 20 min) in suspension and (iv) heat-injured Camp. jejuni from inoculated ground pork. Hunt broth and Bolton broth showed the highest and most rapid enrichment efficacy for the cell suspensions and ground pork, respectively. Preston, Park and Sanders and mCCD broths had relatively high enrichment efficiencies, while Brucella-FBP broth was significantly inferior to the other broths (P < 0.05).

CONCLUSIONS

Cell recovery from the eight enrichment broths was dependent on the sample type and the state of the cells. The use of the appropriate broth is important for the rapid and efficacious enrichment of Camp. jejuni. In particular, heat-injured Camp. jejuni require a longer cultivation time and a suitable enrichment broth.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results from the present study provide information for selecting the most appropriate enrichment broth for Camp. jejuni and may contribute to improved detection methods for the organism.

Bragg reflection of terahertz waves in plasmonic crystals

We present experimental and theoretical studies on terahertz surface plasmon (TSP) propagation on slit and rectangular aperture arrays in an aluminum sheet. Terahertz waves are coupled onto the plasmonic structures via a parallel plate waveguide. Long-lasting oscillations are observed in the temporal pulse shape after propagating through the periodic structure, whose Fourier transformation into the frequency domain results in Bragg-resonance spectral features. We show that the interference between the incident wave and the radiation reflected from both the aperture array and the waveguide block is responsible for this Bragg-resonance behavior. The reflection coefficient for a single slit is deduced to be 0.017 +/- 0.002.

Immediate and late clinical and angiographic outcomes after GFX coronary stenting: is high-pressure balloon dilatation necessary?

BACKGROUND

The GFX stent is a balloon-expandable stent made of sinusoidal element of stainless steel. The adjunct high-pressure balloon dilatations were usually recommended in routine stenting procedure.

HYPOTHESIS

The aim of this study was to evaluate the immediate and long-term clinical and angiographic outcomes and to investigate the necessity of high-pressure balloon dilatation during GFX stenting.

METHODS

In all, 172 consecutive patients underwent single 12 or 18 mm GFX stent implantation in 188 native coronary lesions. Two types of stenting technique were used: (1) stent size of a final stent-to-artery ratio of 1:1 (inflation pressure > 10 atm, high-pressure group), and (2) stent size of 0.5 mm bigger than reference vessel (inflation pressure < or = 10 atm, low-pressure group). The adjunct high-pressure balloon dilatations were performed only in cases of suboptimal results.

RESULTS

The adjunct high-pressure balloon dilatation was required in 11 of 83 lesions (13%) in the high-pressure group and in 7 of 105 lesions (7%) in the low-pressure group (p = 0.203). Procedural success rate was 100%. There were no significant differences of in-hospital and long-term clinical events between the two groups. The overall angiographic restenosis rate was 17.7%; 18.4% in the high-pressure group and 17.1% in the low-pressure group (p = 0.991).

CONCLUSIONS

The GFX stent is a safe and effective device with a high procedural success rate and favorable late clinical outcome for treatment of native coronary artery disease. Further randomized trials may be needed to compare stenting techniques in GFX stent implantation.

Rescue use of abciximab improves regional left ventricular function after early incomplete reperfusion in acute myocardial infarction

BACKGROUND

Abciximab was shown to have important beneficial effects beyond the maintenance of epicardial coronary artery patency. However, it remains uncertain whether abciximab may lead to a better functional outcome in patients with acute myocardial infarction (AMI) and with incomplete reperfusion after primary angioplasty (PA).

HYPOTHESIS

The study aimed to evaluate whether rescue use of abciximab may lead to a better functional outcome in such patients.

METHODS

The study included 25 patients with first AMI who met the following criteria: (1) total occlusion of the infarct-related artery, (2) PA within 12 h of symptom onset, (3) postprocedural diameter stenosis < 30%, and final Thrombolysis in Myocardial Infarction (TIMI) flow grade 2. Echocardiographic examination was performed before and on Days 7 and 30 after PA. The study population was divided into two groups: Group 1 (usual care, n = 13) and Group 2 (rescue use of abciximab, n = 12). Baseline characteristics were similar between the two groups.

RESULTS

Peak level of creatine kinase was higher in Group 1 than in Group 2 (5,800+/-2,700 vs. 3,800+/-2,000 U/I, p < 0.05). At 1 month follow-up, infarct zone wall motion score index (2.71+/-0.26 vs. 2.05+/-0.63, p < 0.01) and left ventricular (LV) volume indices were smaller in Group 2 than in Group 1, whereas LV ejection fraction was higher in Group 2 than in Group 1 (52.1+/-7.8 vs. 42.1+/-6.4, p < 0.01). At 1-month, abciximab was the only independent predictor of wall motion recovery index by multiple regression analysis.

CONCLUSIONS

Rescue use of abciximab may reduce the infarct size in patients with AMI and TIMI grade 2 flow after PA, which may improve the recovery of regional LV function.

Effect of electrolyzed water for reduction of foodborne pathogens on lettuce and spinach

The ability of electrolyzed water (EW) to inactivate foodborne pathogens on the surfaces of lettuce and spinach was investigated. Lettuce and spinach leaves were inoculated with a cocktail of 3 strains each of Escherichia col O157:H7, Salmnonella Typhimurium, and Listeria monocytogenes and treated with acidic electrolyzed water (AC-EW), alkaline electrolyzed water (AK-EW), alkaline electrolyzed water followed by acidic electrolyzed water (sequential treatment, AK-EW + AC-EW), deionized water followed by acidic electrolyzed water (sequential treatment, DW + AC-EW), and deionized water (control, DW) for 15, 30 s, and 1, 3, and 5 min at room temperature (22 +/- 2 degrees C). For all 3 pathogens, the same pattern of microbial reduction on lettuce and spinach were apparent. The relative efficacy of reduction was AC-EW > DW + AC-EW approximately = AK-EW + AC-EW > AK-EW > control. After a 3-min treatment of AC-EW, the 3 tested pathogens were reduced below the detection limit (0.7 log). DW + AC-EW and AK-EW + AC-EW produced the same levels of reduction after 5 min when compared to the control. AK-EW did not reduce levels of pathogens even after a 5-min treatment on lettuce and spinach. Results suggest that AC-EW treatment was able to significantly reduce populations of the 3 tested pathogens from the surfaces of lettuce and spinach with increasing time of exposure.

Microwave dielectric properties of (A2+(1/3)B5+(2/3))0.5Ti0(0.5)O2 (A2+ = Zn, Mg, B5+ = Nb, Ta) ceramics

Dielectric properties of (A(2+)(1/3)B(5+)(2/3))(0.5)Ti0(0.5)O(2) (A(2+) = Zn, Mg, B(5+) = Nb, Ta) ceramics were investigated at microwave frequencies. A single phase with tetragonal rutile structure was obtained through the entire compositions. Dielectric properties were strongly dependent on the structural characteristics. The specimens with B(5+) = Nb showed a larger dielectric constant than those with B(5+) = Ta due to the decrease of bond valence. Quality factors (Qf) of the specimens with B(5+) = Ta were larger than those with B(5+) = Nb. Temperature coefficient of the resonant frequencies (TCF) of (Zn(1/3)Nb(2/3) )0(0.5)Ti0(0.5)O(2) was larger than that of (Mg(1/3)Ta(2/3))0(0.5)Ti0(0.5)O(2). These results could be attributed to the changes of the temperature coefficient of dielectric constant and the degree of oxygen octahedral distortion.

Correlation between the in vitro ATP-based chemosensitivity assay and HER2/neu expression in women with breast cancer

Several in vitro chemosensitivity tests have been developed to predict the chemotherapeutic response of tumours prior to initiation of individualized treatment for breast cancer. This study investigated whether the in vitro chemosensitivity response of cell lines derived from breast cancer patients was affected by HER2/neu expression. We cultured breast cancer cell lines from 50 patients and the adenosine triphosphatebased chemotherapy response assay (ATPCRA) was performed with 5-fluorouracil, gemcitabine, docetaxel, doxorubicin, methotrexate, vinorelbine and paclitaxel. 5-fluorouracil combined a high median cell death rate (32.4%) with the narrowest range of cytotoxic effects (7.3-65.7%). In addition, gemcitabine showed significantly greater activity in HER2/neupositive patients. In contrast, docetaxel was significantly less effective in HER2/neu-positive patients. No significant correlation was found between the other agents and HER2/neu expression. The use of the ATP-CRA test for metastatic tissue from patients with recurrent disease might be a useful approach to determine the most effective chemotherapy regimen.

Terahertz electromagnetic wave transmission through random arrays of single rectangular holes and slits in thin metallic sheets

We report on the observation of terahertz transparency in random arrays of the single rectangular holes and slits with the areal coverage of only 12%. The terahertz transparency occurs at the fundamental shape resonance of the rectangular holes and confirms the theoretical predictions of earlier works of García-Vidal et al. [Phys. Rev. Lett. 95, 103901 (2005)] on single rectangular holes and of Ruan and Qiu [Phys. Rev. Lett. 96, 233901 (2006)] on random arrays of holes.

Hypolipidemic effect of lactobacillus ferment as a functional food supplement

The Lactobacillus ferment used in this study was composed of Lactobacillus fermented wheat, barley and kefir grains. Fermentation increased the CFU of lactic acid bacteria with a reduction in pH value and in the contents of dietary fi ber and glucan. Male SD rats were fed a high fat diet with or without 10% Lactobacillus ferment for 4 weeks. In the Lactic-F group (group fed high-fat diet with Lactobacillus ferment) there was a significantly reduced increase of body weight compared with the HF-control (group fed high-fat diet without Lactobacillus ferment). The food efficiency ratio (FER) tended to be decreased in the Lactic-F group, but there was no significant difference between the Lactic-F and HF-control groups. The perirenal and the epididymal fat weights in the normal dietary group (control) and in the Lactic-F group were significantly lower than those of the HF-control. The serum HDL-cholesterol and the total cholesterol in the Lactic-F group were similar to the control group, and were significantly different from those of the HF-control. These results indicated that the Lactobacillus ferment is a functional material having antiobesity effects, with use as a supplement in functional, health-favoring food.

Promotion of Formaldehyde Production from Adsorbed Methoxy by Oxidation of Mo(110) with NO2

The reaction of methoxy (OCH3) in the presence of NO2 is studied on a thin-film oxide of Mo(110) for its relevance to the alkane-assisted reduction of NO(x). Temperature-programmed reaction indicates that oxygen deposited by NO2 dissociation promotes formaldehyde evolution. This pathway is not observed in any appreciable amount for methoxy on the thin-film oxide of Mo(110), nor for the reaction of methoxy in the presence of NO or O2. No new intermediates, in particular those containing C-N bonds, are detected after NO2 is exposed to the surface containing methoxy. Furthermore, infrared spectra provide evidence that the presence of NO2 does not significantly perturb the methoxy intermediate. These results indicate that surface oxidation rather than intermolecular complexation is the most likely mechanism by which NO2 promotes the evolution of oxygenates. In addition, the presence of methoxy decreases the capacity of the Mo surface to reduce NO2. No N2 is produced, and molecular desorption predominates. There are also no NO(x) species present after heating to 500 K when NO2 reacts in the presence of methoxy, whereas monomeric NO and dinitrosyl are present when NO2 reacts alone. These results are discussed in the context of CH4-assisted NO(x) reduction.

Sensitivity of methyl thiolate desulfurization selectivity to reaction temperature and hydroxyl coverage

The adsorption and reaction of methanethiol (CH3SH) and dimethyl disulfide (CH3SSCH3) on Mo(110)-(1 x 6)-O have been studied using temperature-programmed reaction spectroscopy and reflection-absorption infrared spectroscopy over the temperature range of 110-550 K. The S-H bond is broken upon adsorption to form adsorbed OH, water, and methyl thiolate (CH3S-) at low temperature. Water is evolved at 210 and 310 K via molecular desorption and disproportionation of OH, respectively. Some hydroxyl remains on the surface up to 350 K. Methyl thiolate is also formed from CH3SSCH3 on Mo(110)-(1 x 6)-O. Methyl thiolate undergoes C-S cleavage above 300 K, yielding methane and methyl radicals. There is also a minor amount of nonselective decomposition leading to the formation of carbon and hydrogen. Methane production is promoted by adsorbed hydroxyl. As the hydroxyl coverage increases, the yield of methyl radicals relative to methane diminishes. Accordingly, there is more methane produced from methanethiol reaction than from dimethyl disulfide, since S-H dissociation in CH3SH produces OH. The maximum coverage of the thiolate is approximately 0.5 monolayers, based on the amount of sulfur remaining after reaction measured by Auger electron spectroscopy. In contrast to cyclopropylmethanethiol (c-C3H5CH2SH), for which alkyl transfer from sulfur to oxygen is observed, there is no evidence for transfer of the methyl group of methyl thiolate to oxygen on the surface. Specifically, there is no evidence for methoxy (CH3O-) in infrared spectroscopy or temperature-programmed reaction experiments.

Which types of stent, uncovered or covered, should be used in gastric outlet obstructions?

BACKGROUND

Self-expandable metallic stents (SEMS) have been widely used in inoperable malignant gastric outlet obstructions, but stent obstructions caused by tumor ingrowth and migration are a major problem of SEMS. The aims of this study were to assess the rate of stent restenosis, to identify lesion characteristics related to early restenosis by tumor ingrowth, and, in particular, to find suitable patient groups for uncovered or covered stents at first implantation.

METHODS

Forty-nine patients were reviewed: stomach cancer in 34 patients, primary duodenal cancer in 3 patients, pancreatic cancer in 5 patients, and common bile duct cancer in 7 patients. In principle, uncovered stents were initially placed at the time when obstruction symptoms occurred and the endoscope would not pass through. Stent obstruction due to tumor ingrowth within 4 weeks after the first stent implantation was regarded as early stent restenosis.

RESULTS

Technical success was seen in 49/49 patients (100%). Migration did not occur. Stent obstructions caused by tumor overgrowth were found in 2/49 patients (4.1%) after 1 month. Stent obstructions caused by tumor ingrowth occurred in 14/49 patients (28.5%), and 7 of them (14.3%) were found to have early restenosis. The only statistically significant factor for early restenosis was stenosis site, and early restenosis was more frequent in the postoperative anastomosis site in the current study; a) 2/18 antropyloric obstructions (11.1%), b) 1/15 pyloric and duodenal bulb obstructions (6.7%), c) 0/10 duodenal second portion obstructions (0%), and d) 4/6 postoperative anastomosis site obstructions (66.7) (P < 0.05, 95% CI 0.003-0.005).

CONCLUSIONS

Uncovered stents are technically feasible and effective for most malignant gastric outlet obstructions. However, because of frequent early restenosis among patients with postoperative anastomosis site obstructions, the placement of covered or simultaneous dual stents to prevent early restenosis should be considered when stenting postoperative anastomosis site obstructions.

Inactivation of Listeria innocua in nisin-treated salmon (Oncorhynchus keta) and sturgeon (Acipenser transmontanus) caviar heated by radio frequency

Recent regulatory concerns about the presence of the pathogen Listeria monocytogenes in ready-to-eat aquatic foods such as caviar has prompted the development of postpackaging pasteurization processes. However, caviar is heat labile, and conventional pasteurization processes affect the texture, color, and flavor of these foods negatively. In this study, chum salmon (Oncorhynchus keta, 2.5% total salt) caviar or ikura and sturgeon (Acipenser transmontanus, 3.5% total salt) caviar were inoculated with three strains of Listeria innocua in stationary phase at a level of more than 10(7) CFU/g. L innocua strains were used because they exhibit an equivalent response to L monocytogenes for many physicochemical processing treatments, including heat treatment. The products were treated by immersion in 500 IU/ml nisin solution and heat processed (an 8-D process without nisin or a 4-D process with 500 IU/ml nisin) in a newly developed radio frequency (RF; 27 MHz) heating method at 60, 63, and 65 degrees C. RF heating along with nisin acted synergistically to inactivate L. innocua cells and total mesophilic microorganisms. In the RF-nisin treatment at 65 degrees C, no surviving L. innocua microbes were recovered in sturgeon caviar or ikura. The come-up times in the RF-heated product were significantly lower compared with the water bath-heated caviar at all treatment temperatures. The visual quality of the caviar products treated by RF with or without nisin was comparable to the untreated control.

Yeast hydrolysate reduces body fat of dietary obese rats

The purpose of this study was to assess the antiobesity effect of the yeast hydrolysate (DNF) on the body weight, body fat and plasma lipids levels of high-fat fed rats. The weight gain of the HF (high fat diet) (162.58 +/- 6.68 g) was significantly (p < 0.05) greater than that of DNF-1, DNF-2, (high fat diet with DNF of 0.5 and 1.0 g/kg body weight, respectively) and control groups (143.19 +/- 7.33 g, 139.20 +/- 8.36 g, 130.23 +/- 8.02 g, respectively). The wet weight of the epididymal fat and the perirenal fat pads of the DNF-1, DNF-2 and control groups were reduced significantly (p < 0.05). A significant (p < 0.05) increase of HDL-cholesterol level of the DNF-2 and control groups was observed. However, there was no significant difference between DNF-1 and DNF-2. It was also found that the triacylglycerol (TG) levels decreased significantly (p < 0.05) in the DNF-2 group from that of the HF, but there was no significant (p < 0.05) difference between DNF-1 and DNF-2.

Development of a miniaturized four-culture method for the rapid enumeration of four bacterial groups in ground beef

AIMS

A simplified and rapid method was developed to identify and enumerate total mesophilic microbial load, gram-negative bacteria, coliforms, and Escherichia coli in ground beef, using a single module.

METHODS AND RESULTS

A 96-well microtiter plate was divided into four sections of two lanes (24 wells), with each section dedicated to each of the four critical bacterial groups. Double strength of four different selective broths (100 microl) was added to each well and an aliquot of sample (100 microl) from the first well was transferred to the next to achieve a twofold serial dilution in each series (24 wells). Initial bacterial load was calculated using the final consecutive positive reaction exhibiting color change or fluorescence. To validate the method, ground beef (n = 32), inoculated with a three-strain mixture of E. coli, together with 30 samples of commercial ground beef, were assayed by the four-culture method and conventional plating. For all media tested, the coefficients of determinations (r2) between the results derived from the four-culture method and those of conventional plating method ranged from 0.83 to 0.92.

CONCLUSIONS

The high degree of association between the two methods indicates that the four-culture method could be easily applied to the enumeration of four critical bacterial groups in ground beef.

SIGNIFICANCE AND IMPACT OF THE STUDY

This method will facilitate sanitation monitoring at meat processing plants by shortening time required for results, reducing consumable material costs, simplifying procedures, reducing the space required, and cutting the cost of start up equipment.

Patterns of changes in temperament and character inventory scales in subjects with obsessive-compulsive disorder following a 4-month treatment

OBJECTIVE

The purpose of this study was to assess changes in the temperament and character patterns in subjects with obsessive-compulsive disorder (OCD) following the treatment for obsessive/compulsive and accompanying depressive symptoms.

METHOD

Study subjects were 35 patients who met the DSM-IV criteria for OCD. All subjects were assessed with the Temperament and Character Inventory (TCI), the Yale-Brown Obsessive-Compulsive Scale, the Beck Depression Inventory, and the Beck Anxiety Inventory before and after a 4-month treatment.

RESULTS

Harm Avoidance (HA) scores in OCD subjects before treatment significantly decreased after treatment. However, the Self-Directedness scores, which were significantly lower than healthy comparison subjects before treatment, did not change. In addition, Reward Dependence scores in OCD subjects, which were not significantly different from healthy comparison subjects before treatment, significantly increased after treatment.

CONCLUSION

The TCI pattern of untreated OCD subjects (high HA and low Self-Directedness, relative to healthy comparison subjects) and the decrease of HA scores and no change in Self-Directedness scores following a successful treatment suggest that temperaments are more amenable to treatment than characters.

Anti-stress and anti-fatigue effect of fermented rice bran

The anti-stress and anti-fatigue effects of a hot water extract of fermented rice bran (FRB) were investigated with Saccharomyces cerevisae IFO 2346 on rats or mice. Oral administration (1 g/kg/day) of a hot water extract of FRB inhibited major changes in weight of the adrenal, thymus, spleen and thyroid, showing the anti-stress effect. A hot water extract of FRB also inhibited the increase of GPT and LDH activity, cholesterol and serum glucose levels. Administration (1 g/kg/day) for 2 weeks significantly prolonged the swimming time, resulting in an increase of the anti-fatigue effect. From these results, it can be considered that FRB has an anti-stress and anti-fatigue effect.

The correlation method for rapid monitoring of Escherichia coli in foods

AIMS

A new rapid method was developed to rapidly monitor Escherichia coli counts in foods.

MATERIALS AND RESULTS

One ml of modified selective broth with 4-methylumbelliferyl beta-D-glucuronide and 1 ml of food sample were mixed in a sterile test tube and incubated at 37 degrees C. The positive reaction (fluorescence under u.v. light) was monitored at regular 30 min intervals. The positive reaction times in test tubes were compared with actual E. coli numbers from tested samples. The growth of E. coli in test tubes (broth) was much faster than growth on agar. The first experiment was performed to evaluate the rapid correlation method using pure E. coli cultures. The correlation between E. coli counts by the conventional plating method and positive reaction (fluorescence production) times in test tubes was highly agreeable (r(2) = 0 x 95). In the case of low E. coli numbers, such as 2 x 0 log10 cfu ml(-1), the rapid correlation method detected their presence after 10 h incubation. When highly contaminated samples were assayed (8 log10 cfu ml(-1)), the rapid correlation method detected the presence of E. coli after 4 h incubation. In the ground beef experiment, the correlation between fluorescence production time and actual E. coli numbers was also strongly agreeable (r(2) = 0 x 92).

CONCLUSIONS

From these results, it is obvious that the new rapid method can rapidly monitor E. coli counts in foods.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results indicated that the new method saved about 10-14 h incubation time compared to conventional plating methods. The rapid correlation method required much shorter incubation times compared to conventional plating methods for monitoring E. coli.

Development of membrane filter holder (MFH) method for recovery of heat-injured Escherichia coli O157:H7 and Salmonella typhimurium

AIMS

A method of recovering sublethally heat-injured bacteria was developed with specific apparatus (membrane filter holder; MFH) which was originally used for Iso-Grid Hydrophobic membrane. filter holder.

METHODS AND RESULTS

The procedure used a non-selective agar underlayed with a selective medium with a MFH. A non-selective agar was poured on upper part (compartment A) of MFH, and then injured foodborne pathogens were inoculated on the non-selective medium. After 3-h repair incubation period, selective agar was added to the bottom of the chamber (compartment B) of the MFH and further incubated. By diffusing through the non-selective top agar, selective agents from the underlay medium impart selectivity to the system.

CONCLUSIONS

Using the MFH method, recovery of heat-injured foodborne pathogens (Escherichia coli O157:H7 and Salmonella typhimurium) were not different (P > 0.05) from recoveries with non-selective media (TSA). However, the recoveries of foodborne pathogens on MFH were significantly higher (P < 0.05) than those of direct plating on selective medium such as SMAC (MacConkey Sorbitol Agar) or XLD (Xylose Lysine Desoxycholate).

SIGNIFICANCE AND IMPACT OF THE STUDY

In conclusion, the MFH method is a simple and convenient method for recovery of heat-injured foodborne pathogens.

Atrial fibrillation surgery simplified with cryoablation to improve left atrial function

BACKGROUND

The Maze procedure restores atrial fibrillation to normal sinus rhythm. However, concurrent left atrial functional recovery is not always achieved. To address this limitation, a modification using linear cryoablation is described.

METHODS

Between July 1997 and December 1999, 83 patients received atrial fibrillation surgery in association with mitral valve surgery with or without additional concurrent procedures by either the conventional technique, group I (n = 30) or the modified technique, group II (n = 53). Onset of sinus conversion and echocardiographic assessment of postoperative left ventricular function, left atrial size, and mitral A-wave velocity were compared in the early postoperative period and 6 months after surgery.

RESULTS

Sinus conversion occurred significantly earlier in group II, 2.4 +/- 5 days versus group I, 7.0 +/- 10 days. The mean transmitral A-wave velocity and the incidence of A-wave appearance in the early postoperative period and 6 months postoperatively were greater in group II than group I.

CONCLUSIONS

With the current modification, restoration of sinus rhythm and superior left atrial contractile function occurred earlier than with the standard Maze III technique.

Elevated uric acid increases blood pressure in the rat by a novel crystal-independent mechanism

An elevation in circulating serum uric acid is strongly associated with the development of hypertension and renal disease, but whether uric acid has a causal role or whether it simply indicates patients at risk for these complications remains controversial. We tested the hypothesis that uric acid may have a causal role in the development of hypertension and renal disease by examining the effects of mild hyperuricemia in rats. Mild hyperuricemia was induced in rats by providing a uricase inhibitor (oxonic acid) in the diet. Hyperuricemic rats developed elevated blood pressure after 3 weeks, whereas control rats remained normotensive. The development of hypertension was prevented by concurrent treatment with either a xanthine oxidase inhibitor (allopurinol) or a uricosuric agent (benziodarone), both of which lowered uric acid levels. Blood pressure could also be lowered by reducing uric acid levels with either allopurinol or oxonic acid withdrawal. A direct relationship was found between blood pressure and uric acid (r=0.75, n=69), with a 10-mm Hg blood pressure increase for each 0.03-mmol/L (0.5-mg/dL) incremental rise in serum uric acid. The kidneys were devoid of urate crystals and were normal by light microscopy. However, immunohistochemical stains documented an ischemic type of injury with collagen deposition, macrophage infiltration, and an increase in tubular expression of osteopontin. Hyperuricemic rats also exhibited an increase in juxtaglomerular renin and a decrease in macula densa neuronal NO synthase. Both the renal injury and hypertension were reduced by treatment with enalapril or L-arginine. In conclusion, mild hyperuricemia causes hypertension and renal injury in the rat via a crystal-independent mechanism, with stimulation of the renin-angiotensin system and inhibition of neuronal NO synthase.

Successful treatment of Boerhaave's syndrome with endoscopic insertion of a self-expandable metallic stent: report of three cases and a review of the literature

Boerhaave's syndrome is a rare but life-threatening condition which presents a diagnostic as well as therapeutic challenge. Early diagnosis and prompt surgical repair are critical for survival; however late recognition of esophageal rupture is not unusual. A variety of nonsurgical approaches have been proposed, particularly in the case of delayed diagnosis. In recent years, the insertion of a metallic stent has been described as a promising modality in the treatment of spontaneous esophageal rupture. We report three cases of Boerhaave's syndrome treated with self-expandable metallic stents and review previously published cases.

Screening bovine carcass sponge samples for Escherichia coli O157 using a short enrichment coupled with immunomagnetic separation and a polymerase chain reaction-based (BAX) detection stept

A bovine carcass sponge sample screening protocol for detecting Escherichia coli O157:H7 was composed of a short selective enrichment followed by an immunomagnetic separation (IMS) and target detection using the BAX E. coli O157 polymerase chain reaction assay. This screening protocol was compared to a culture-based method for detection of the organism in carcass sponge samples. Enriched samples were subjected to IMS; the bead suspension was divided and plated on selected media or stored at -20 degrees C, then subjected to BAX analysis. The results showed a high degree of agreement between the plating method and the BAX system. Fifty-two of the 59 culture-positive samples were also positive using the BAX system (88.1% sensitivity). Of the 76 samples that appeared negative for the presence of E. coli O157:H7 by the culture method, 66 were determined as negative using the BAX system (86.8% specificity). Four of the 10 samples found negative by the initial culture method and positive by the BAX method were subsequently found to be culture positive upon reanalysis. Based on these data, the BAX system combined with a short, selective enrichment and IMS may be a rapid, reliable, and simple method to screen for E. coli O157:H7 in carcass sponge samples. Our data indicate that optimization and subsequent testing of this protocol for use as a carcass screening tool are warranted.

Intravascular ultrasound analysis of beta radiation therapy for diffuse in-stent restenosis to inhibit intimal hyperplasia

We evaluated the efficacy of beta-radiation therapy ((188)Re-MAG(3)) to inhibit intimal hyperplasia (IH) in diffuse in-stent restenosis by intravascular ultrasound (IVUS) analysis in 50 patients. Nine patients who did not agree with radiation therapy, and therefore underwent rotational atherectomy and balloon angioplasty for diffuse in-stent restenosis in the same study period, were selected for control groups. Serial IVUS comparisons were available in 44 of 50 patients with radiation therapy and 7 of 9 control patients. At 6-month follow-up, there was less significant increase of IH area in patients with radiation therapy than in control patients (Delta IH area = 0.1 +/- 0.8 mm(2) vs. 2.6 +/- 1.8 mm(2), P > 0.001 in mean values, and 0.6 +/- 1.4 mm(2) vs. 2.9 +/- 2.1 mm(2), P = 0.026 in values of follow-up lesion site, respectively). In conclusion, beta-radiation therapy might be an effective treatment modality to inhibit intimal hyperplasia in patients with diffuse in-stent restenosis.

Elective stenting of unprotected left main coronary artery stenosis: effect of debulking before stenting and intravascular ultrasound guidance

OBJECTIVES

We sought to evaluate: 1) the long-term outcomes of 127 selected patients receiving unprotected left main coronary artery (LMCA) stenting; and 2) the impact of the debulking procedure before stenting and intravascular ultrasound (IVUS) guidance on their clinical outcomes.

BACKGROUND

The long-term safety of stenting of unprotected LMCA stenoses has not been established yet.

METHODS

A total of 127 consecutive patients with unprotected LMCA stenosis and normal left ventricular function were treated by elective stenting. The long-term outcomes were evaluated between two groups: IVUS guidance (n = 77) vs. angiographic guidance (n = 50); and debulking plus stenting (debulking/stenting; n = 40) vs. stenting only (n = 87).

RESULTS

Angiographic restenosis was documented in 19 (19%) of 100 patients. The lumen diameter after stenting was significantly larger in IVUS-guided group (p = 0.003). The angiographic restenosis rate was significantly lower in the debulking/stenting group (8.3% vs. 25%, p = 0.034). The reference artery size was the only independent predictor of angiographic restenosis. During follow-up (25.5 +/- 16.7 months), there were four deaths, but no nonfatal myocardial infarctions occurred. The survival rate was 97.0 +/- 1.7% at two years.

CONCLUSIONS

These data suggest that stenting of unprotected LMCA stenosis might be associated with a favorable long-term outcome in selected patients. Guidance with IVUS may optimize the immediate results, and debulking before stenting seems to be effective in reducing the restenosis rate. However, we need a large-scale, randomized study.

Vascular endothelial growth factor (VEGF121) protects rats from renal infarction in thrombotic microangiopathy

BACKGROUND

Renal thrombotic microangiopathy, typified by the hemolytic uremic syndrome, is associated with endothelial cell injury in which the presence of cortical necrosis, extensive glomerular involvement, and arterial occlusive lesions correlates with a poor clinical outcome. We hypothesized that the endothelial survival factor vascular endothelial growth factor (VEGF) may provide protection.

METHOD

Severe, necrotizing, thrombotic microangiopathy was induced in rats by the renal artery perfusion of antiglomerular endothelial antibody, followed by the administration of VEGF or vehicle, and renal injury was evaluated.

RESULTS

Control rats developed severe glomerular and tubulointerstitial injury with extensive renal necrosis. The administration of VEGF significantly reduced the necrosis, preserved the glomerular endothelium and arterioles, and reduced the number of apoptotic cells in glomeruli (at 4 hours) and in the tubulointerstitium (at 4 days). The prosurvival effect of VEGF for endothelium may relate in part to the ability of VEGF to protect endothelial cells from factor-induced apoptosis, as demonstrated for tumor necrosis factor-alpha (TNF-alpha), which was shown to be up-regulated through the course of this model of renal microangiopathy. Endothelial nitric oxide synthase expression was preserved in VEGF-treated rats compared with its marked decrease in the surviving glomeruli and interstitium of the antibody-treated rats that did not receive VEGF.

CONCLUSIONS

VEGF protects against renal necrosis in this model of thrombotic microangiopathy. This protection may be mediated by maintaining endothelial nitric oxide production and/or preventing endothelial cell death.

Clinical characteristics of constrictive pericarditis diagnosed by echo-Doppler technique in Korea

A retrospective analysis of clinical data of 71 patients with constrictive pericarditis (CP) diagnosed by echo-Doppler technique (mean age, 49+/-17) was done. In 27 patients (38%), the etiology was unknown, and the three most frequent identifiable causes were tuberculosis (23/71, 32%), cardiac surgery (8/71, 11%), and mediastinal irradiation (6/71, 9%). Pericardiectomy was performed in 35 patients (49%) with a surgical mortality of 6% (2/35), and 11 patients (15%, 11/ 71) showed complete resolution of constrictive physiology with medical treatment. Patients with transient CP were characterized by absence of pericardial calcification, shorter symptom duration, and higher incidence of fever, weight loss, and tuberculosis. The 5-yr survival rates of patients with transient CP and those undergoing pericardiectomy were 100% and 85+/-6%, respectively, which were significantly higher than that of patients without undergoing pericardiectomy (33+/-17%, p=0.0083). Mediastinal irradiation, higher functional class, low voltage in ECG, low serum albumin, and old age were the independent variables associated with a higher mortality. Tuberculosis is still the most important etiology of CP in Korea, and not infrequently, it may cause transient CP. Early diagnosis and decision-making using follow-up echocardiography are crucial to improve the prognosis of patients with CP.

Anti-stress and anti-fatigue effects of fermented rice bran

The anti-stress and anti-fatigue effects on rats and mice of a hot water extract of rice bran fermented with Saccharomyces cerevisae IFO 2346 were investigated. Oral administration (1 g/kg/day) of the hot water extract of fermented rice bran (FRB) inhibited major changes in the weight of the adrenal, thymus, spleen and thyroid, showing an anti-stress effect. The hot water extract of FRB also inhibited increases in the GPT and LDH activity, cholesterol and glucose in the serum. The administration (1 g/kg/day) for 2 weeks significantly prolonged the swimming time, resulting in an increase in the anti-fatigue effect. It is considered from these results that FRB had anti-stress and anti-fatigue effects.

A rapid twofold dilution method for microbial enumeration and resuscitation of uninjured and sublethally injured bacteria

AIMS

A rapid and simple method for enumerating uninjured and sublethally injured bacterial cells, the twofold dilution method (2FD), was developed and evaluated.

METHODS AND RESULTS

Following twofold serial dilution of samples in a 96 well microtiter plate, double strength selective broth or nonselective broth was added to each well. For resuscitation of heat-injured (55 degrees C for 10 min) coliforms, the selective broth was added to the wells after 3 h preresuscitation time in buffered peptone water. The results of the 2FD were compared to plating methods for total and coliform plate counts from mixed cultures and beef carcass surface tissue samples.

CONCLUSION

The 2FD method results were not significantly different for uninjured cells (P > 0.05) from those obtained using Petrifilm and standard plating. Correlation of the scatterplot of spread plating and 2FD indicated a high level of agreement between these two methods (R(2)=0.98 for total counts and R(2)=0.96 for coliforms from mixed cultures; R(2)=0.98 for total cell counts and R(2)=0.94 for coliforms from faeces inoculated beef carcasses).

SIGNIFICANCE AND IMPACT OF THE STUDY

The twofold dilution method recovered significantly higher numbers of heat-injured coliforms compared to conventional plating methods (P < 0.05).

Th1 and Th2 cytokine responses to academic stress

Predominant Th2 profiles are associated with the worsening of asthma, and stress is speculated to induce a Th2 profile. The goals of this study were to examine the responses of the cytokines Th1 (IFN-gamma and IL-2) and Th2 (IL-4, IL-5, and IL-6) to a stressor and to look at the relationships between cytokine and psychological responses. Twenty-four students with and without a history of asthma completed questionnaires and gave blood samples during nonexam and exam periods. Cytokines were measured by ELISA from supernatants of stimulated mononuclear cells (MNC) and whole blood. During examinations, there were a significant decrease in IL-2 and a significant increase in IL-6 production (both cultures) and a significant decrease in IFN-gamma production (MNC cultures). Baseline IL-2 levels showed significant negative correlations with several stress and mood scores. Findings of this study indicate a down-regulation of Th1 and a selective up-regulation of Th2 cytokines during a stressful exposure.