Impact of control measures including decolonization and hand hygiene for orthopaedic surgical site infection caused by MRSA at a Japanese tertiary-care hospital

BACKGROUND

Meticillin-resistant Staphylococcus aureus (MRSA) is the most common pathogen in orthopaedic surgical site infections (SSIs). However, few studies have investigated the transmission process of orthopaedic MRSA SSI.

AIM

To investigate the transmission process of orthopaedic MRSA SSI using epidemiological and molecular analyses and to determine a method to prevent MRSA SSI in nosocomial orthopaedic surgery.

METHODS

Active MRSA surveillance, preoperative decolonization and contact precautions for MRSA-positive cases was performed at our institution. Changes in epidemic strains were evaluated and the possibility of transmission from patients in an orthopaedic ward of a Japanese tertiary-care hospital was assessed by genotyping stored MRSA strains. In addition, data on the prevalence of MRSA SSI, MRSA colonization, and use of an alcohol antiseptic agent (mL/patient-days) during 2005-2022 were retrospectively assessed.

FINDINGS

SCCmec type II strain in the SSI group decreased over time, associated with fewer outbreaks. Even during a period of high infection rates, no cases of transmission-induced SSI from nasal MRSA carriers were identified. The infection rate correlated negatively with the use of an alcohol antiseptic agent (r = -0.82; P < 0.0001). Two cases among five nasal carriers developed MRSA SSI caused by strains different from those related to nasal colonization.

CONCLUSION

The infection control measures for transmission from the hospital reservoirs including strict adherence to hand hygiene and decolonization of carriers is likely to be important for the prevention of orthopaedic MRSA SSI. However, the need for contact precautions for decolonized nasal carriers might be low.

Development of a novel animal model of rotator cuff tear arthropathy replicating clinical features of progressive osteoarthritis with subchondral bone collapse

OBJECTIVE

To establish an animal model of modified cuff tear arthropathy (mCTA) in order to better replicate the pathophysiology associated with rotator cuff tear-induced humeral head collapse.

DESIGN

mCTA was induced by transection of the rotator cuff, the long head of the biceps brachii (LHB), and superior half of the joint capsule in the right shoulder of 12-week-old rats; the left shoulder underwent sham surgery. The severity of CTA was quantitated using the Murine Shoulder Arthritis Score (MSAS). The trabecular bone of the humeral head and metaphysis was analyzed using bone histomorphometry. The expression of proinflammatory cytokines and catabolic enzymes was evaluated immunohistochemically.

RESULTS

In the mCTA model, the MSAS increased starting from 2 weeks after induction, and there was notable subchondral bone collapse with fibrous cells at 4 weeks. The mCTA cartilage exhibited positive staining for TNF-α, IL-1β/6, MMP-3/13, and ADAMTS5. The trabecular bone volume was reduced not only in the subchondral bone but also in the metaphysis of the humeri, and bone resorption was enhanced in these areas. In the collapsed subchondral bone, both bone formation and resorption were increased. The fibrous cells showed expression of TNF-α, IL-6, and MMP-13, along with specific markers of mesenchymal stem cells. Furthermore, the fibrous cells showed osteoblastic characteristics (RUNX2-positive) and expressed RANKL.

CONCLUSIONS

The LHB and the capsuloligamentous complex are critical stabilizers of the glenohumeral joint, serving to prevent the advancement of CTA following massive rotator cuff tears. Fibrous cells appear to play a role in the humeral head bone resorption.

Test of Light-Lepton Universality in the Rates of Inclusive Semileptonic B-Meson Decays at Belle II

We present the first measurement of the ratio of branching fractions of inclusive semileptonic B-meson decays, R(X_{e/μ})=B(B→Xeν)/B(B→Xμν), a precision test of electron-muon universality, using data corresponding to 189  fb^{-1} from electron-positron collisions collected with the Belle II detector. In events where the partner B meson is fully reconstructed, we use fits to the lepton momentum spectra above 1.3  GeV/c to obtain R(X_{e/μ})=1.007±0.009(stat)±0.019(syst), which is the most precise lepton-universality test of its kind and agrees with the standard-model expectation.

Search for an Invisible Z^{'} in a Final State with Two Muons and Missing Energy at Belle II

The L_{μ}-L_{τ} extension of the standard model predicts the existence of a lepton-flavor-universality-violating Z^{'} boson that couples only to the heavier lepton families. We search for such a Z^{'} through its invisible decay in the process e^{+}e^{-}→μ^{+}μ^{-}Z^{'}. We use a sample of electron-positron collisions at a center-of-mass energy of 10.58 GeV collected by the Belle II experiment in 2019-2020, corresponding to an integrated luminosity of 79.7  fb^{-1}. We find no excess over the expected standard-model background. We set 90%-confidence-level upper limits on the cross section for this process as well as on the coupling of the model, which ranges from 3×10^{-3} at low Z^{'} masses to 1 at Z^{'} masses of 8  GeV/c^{2}.

Measurement of the Λ_{c}^{+} Lifetime

An absolute measurement of the Λ_{c}^{+} lifetime is reported using Λ_{c}^{+}→pK^{-}π^{+} decays in events reconstructed from data collected by the Belle II experiment at the SuperKEKB asymmetric-energy electron-positron collider. The total integrated luminosity of the data sample, which was collected at center-of-mass energies at or near the ϒ(4S) resonance, is 207.2  fb^{-1}. The result, τ(Λ_{c}^{+})=203.20±0.89±0.77  fs, where the first uncertainty is statistical and the second systematic, is the most precise measurement to date and is consistent with previous determinations.

Precise Measurement of the D^{0} and D^{+} Lifetimes at Belle II

We report a measurement of the D^{0} and D^{+} lifetimes using D^{0}→K^{-}π^{+} and D^{+}→K^{-}π^{+}π^{+} decays reconstructed in e^{+}e^{-}→cc[over ¯] data recorded by the Belle II experiment at the SuperKEKB asymmetric-energy e^{+}e^{-} collider. The data, collected at center-of-mass energies at or near the ϒ(4S) resonance, correspond to an integrated luminosity of 72  fb^{-1}. The results, τ(D^{0})=410.5±1.1(stat)±0.8(syst)  fs and τ(D^{+})=1030.4±4.7(stat)±3.1(syst)  fs, are the most precise to date and are consistent with previous determinations.

Search for B^{+}→K^{+}νν[over ¯] Decays Using an Inclusive Tagging Method at Belle II

A search for the flavor-changing neutral-current decay B^{+}→K^{+}νν[over ¯] is performed at the Belle II experiment at the SuperKEKB asymmetric energy electron-positron collider. The data sample corresponds to an integrated luminosity of 63  fb^{-1} collected at the ϒ(4S) resonance and a sample of 9  fb^{-1} collected at an energy 60 MeV below the resonance. Because the measurable decay signature involves only a single charged kaon, a novel measurement approach is used that exploits not only the properties of the B^{+}→K^{+}νν[over ¯] decay, but also the inclusive properties of the other B meson in the ϒ(4S)→BB[over ¯] event, to suppress the background from other B meson decays and light-quark pair production. This inclusive tagging approach offers a higher signal efficiency compared to previous searches. No significant signal is observed. An upper limit on the branching fraction of B^{+}→K^{+}νν[over ¯] of 4.1×10^{-5} is set at the 90% confidence level.

External validation of H2ARDD score for the prediction of heart failure events in patients with atrial fibrillation

Background

Heart failure is an important consequence in patients with atrial fibrillation (AF) which is associated with worse prognosis. The H2ARDD score, calculated from 5 clinical risk factors, was reported as a predictor of heart failure events in patients with AF. However, this score has not been externally validated.

Purpose

The purpose of this study was to evaluate and validate the usefulness of the H2ARDD score for the prediction of heart failure events in AF patients.

Methods

We used prospective data of patients with AF followed up from 2007 to 2017 in our institute. Patients with active cancer were excluded according to the previous report. H2ARDD score was calculated as follows; history of heart disease=2 points, anemia=1 point, renal dysfunction=1 point, diabetes =1 point, diuretic use=1 point (range from 0 to 6 points). Outcome of interest was defined as heart failure events including new-onset heart failure and death with heart failure. Heart failure was ascertained based on the Framingham criteria. Univariable and multivariable Cox-proportional hazards model were used to assess the risk of heart failure events. Heart failure events-free survival was estimated with Kaplan-Meier methods, and the predictive accuracy of the H2ARDD score for the prediction of heart failure events was measured by the area under the receiver operating characteristic (ROC) curve.

Results

Of 562 AF patients, 522 (age 69±10 year–old, 64.9%men) met study criteria. Patients who had a history of heart disease was 185 (35%), diabetes mellitus was 135 (26%), anemia was 54 (10%), renal dysfunction was 221 (43%), and diuretic use was 193 (37%). The mean H2ARDD score was 1.88±1.57. Of all study patients, 84 (16.2%) developed heart failure events during a mean follow–up of 54±42 months. Patients who developed heart failure events in 1 year was 24 (4.6%). In multivariable Cox–proportional hazards model, H2ARDD score was shown as an significant predictor for heart failure events (hazard ratio: 1.56, 95% confidence interval: 1.36 - 1.79, P&lt;0.0001), independently of age (per 10 years, hazard ratio: 1.35, 95% confidence interval: 1.03 – 1.78, P&lt;0.05). In the Kaplan–Meier analyses stratified by H2ARDD score (0–1, 2–3, 4–6), patients who had a higher H2ARDD sore had significantly worse heart failure event-free survival (log-rank P&lt;0.0001) (Figure 1). The area under the ROC curve for the prediction of heart failure events in 1-year was 0.812 (95% confidence interval: 0.737 – 0.887, P&lt;0.0001), and the best cut-off value was ≥4 points (sensitivity: 67%, specificity: 83%) (Figure 2).

Conclusion

H2ARDD score was demonstrated as a significant independent predictor for the prediction of heart failure events, with high predictive accuracy. H2ARDD score may be useful for heart failure risk stratification of AF patients.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Usefulness of H2FPEF score as an independent predictor of heart failure development in patients with atrial fibrillation

Background

The H2 FPEF score, which based on simple clinical characteristics and echocardiography, enables discrimination of HFpEF from noncardiac causes of dyspnea.

Purpose

We sought to evaluate whether H2 FPEF score predicts congestive heart failure (CHF) development in patients with atrial fibrillation (AF).

Methods

Among adult AF patients who underwent transthoracic echocardiography between July 2007 and December 2008, those with preserved left ventricular ejection fraction (LVEF) (≥50%) were included and followed up to new-onset CHF events. Patients with a history of CHF, cardiac surgery, or significant left-sided valvular heart disease were excluded. The H2 FPEF score was calculated from 6 variables (obesity = 2 points, treatment with ≥2 antihypertensive drugs = 1 point, AF = 3 points, echocardiographic pulmonary artery systolic pressure &gt;35 mmHg = 1 point, age &gt;60 years = 1 point, and echocardiographic E/e'ratio &gt;9 = 1 point). CHF was ascertained using Framingham criteria. Cox-proportional hazards modeling was used to assess risk of CHF development.

Results

Of 562 AF patients, 367 (69±10 year old, 66% men) met all study criteria. Of whom, 37 (10%) developed CHF events during a mean follow–up of 56±43 months. The mean H2 FPEF score was 5.50±1.14, and the number of patients with H2 FPEF score ≥7 was 64 (17%). After adjusting for comorbidities in a multivariate model, H2 FPEF score was significant predictor of new-onset CHF events both as continuous (HR=1.43, 95% CI: 1.05–1.96, P&lt;0.05) or categorical (H2 FPEF score ≥7) (HR=2.32, 95% CI: 1.17–4.63, P&lt;0.05) variables. The Kaplan-Meier estimates of CHF-free survival stratified by H2 FPEF status (≥7 or &lt;7) were shown in Figure.

Conclusion

H2 FPEF score provides prognostic information for new-onset CHF development in patients with AF.

Figure 1

Funding Acknowledgement

Type of funding source: None

Search for an Invisibly Decaying Z^{'} Boson at Belle II in e^{+}e^{-}→μ^{+}μ^{-}(e^{±}μ^{∓}) Plus Missing Energy Final States

Theories beyond the standard model often predict the existence of an additional neutral boson, the Z^{'}. Using data collected by the Belle II experiment during 2018 at the SuperKEKB collider, we perform the first searches for the invisible decay of a Z^{'} in the process e^{+}e^{-}→μ^{+}μ^{-}Z^{'} and of a lepton-flavor-violating Z^{'} in e^{+}e^{-}→e^{±}μ^{∓}Z^{'}. We do not find any excess of events and set 90% credibility level upper limits on the cross sections of these processes. We translate the former, in the framework of an L_{μ}-L_{τ} theory, into upper limits on the Z^{'} coupling constant at the level of 5×10^{-2}-1 for M_{Z^{'}}≤6  GeV/c^{2}.

P1761Distal transradial approach for primary percutaneous coronary intervention for patients with acute myocardial infarction: a multicentre study

Background

The distal transradial approach (dTRA) for coronary catheterisation is a newly introduced alternative to the conventional transradial approach. This technique is expected to decrease the incidence of haemorrhagic complications and improve patient comfort. However, limited data are available regarding the application of this technique in patients with acute myocardial infarction (AMI). This study investigated the feasibility and safety of the dTRA for primary percutaneous coronary intervention (PCI) in patients with AMI.

Methods

This study included patients with AMI who underwent primary PCI via the distal radial artery across 3 Japanese hospitals between January 2018 and January 2019. Patients' background, procedural characteristics, and clinical outcomes including the incidence of haemorrhagic complications were analysed.

Results

This study enrolled 95 consecutive patients with AMI, including 68 patients (71.6%) with ST-segment elevation myocardial infarction (STEMI), in whom distal radial artery puncture was attempted for primary PCI. The patients included 70 men (73.7%), and the mean age was 72.2±12.4 years. Among these patients, cannulation was successfully performed in 89 patients (93.7%). A 5-, 6-, or 7-French sheath (conventional or slender) was used in this study. Cannulation was performed using a forearm radial artery approach in patients in whom dTRA failed.

PCI was successfully performed in all patients. The meantime to achieve haemostasis was 6.3±5.3 hours, and no major bleeding complications occurred. Based on The Early Discharge After Transradial Stenting of Coronary Arteries trial haematoma scale, grade I, II, and III subcutaneous haemorrhages were observed in 16 (16.8%), 4 (4.2%), and 1 patient (1.1%), respectively. No patient developed a haematoma > grade IV.

In patients with STEMI, the mean door-to-balloon time was 39.4±31.9 min, and the mean puncture-to-balloon time was 19.7±14.2 min.

Conclusions

The distal radial approach is feasible and safefor primary PCI in selected patients with AMI.The application of the dTRA may serve as a less invasive strategy for the treatment of patients with AMI.

P303Prognostic value of diastolic wall strain in patients with asymptomatic severe aortic stenosis

Background

Diastolic wall strain (DWS) has been reported to be associated with left ventricular (LV) stiffness and worse clinical outcomes. We sought to assess the utility of this new index for prediction of prognosis in asymptomatic patients with severe aortic stenosis (AS).

Methods

Asymptomatic severe AS patients [peak flow velocity (PFV) ≥4.0m/s, mean pressure gradient (mPG) ≥40mmHg, aortic valve area (AVA) ≤1.0cm2, or indexed AVA ≤0.6cm2/m2)] diagnosed between July 2007 and April 2016 were included in this study. Patients with significant mitral valve disease, posterior wall motion abnormality, prior cardiac surgery, hypertrophic cardiomyopathy, and LV ejection fraction <50% were excluded. DWS was calculated with a validated formula [DWS = (posterior wall thickness at end-systole − posterior wall thickness at end-diastole)/posterior wall thickness at end-systole]. All study patients were prospectively followed up to last visit or death until November 2017, and predictive value of all-cause death was assessed using Cox-proportional hazards modeling. Patients who underwent aortic valve replacement (AVR) during the study period were censored on the date of surgery.

Results

A total of 184 asymptomatic severe AS, 138 (age 76±9year-old, men 41%, PFV 3.9±1.0m/s, mPG 38±19mmHg, AVA 0.83±0.18cm2, indexed AVA 0.56±0.13cm2/m2) met all study criteria. Of whom, 43 (31%) underwent AVR and 28 (20%) died during a mean follow-up of 25±28months. In a multivariable model after adjusting for clinical and echocardiographic variables, advancing age (per10yrs; HR=2.19, 95% CI=1.19–4.03, P<0.05), history of hemodialysis (HR=4.31, 95% CI=1.30–14.35, P<0.05), and low-DWS (DWS <0.30) (HR=2.83, 95% CI=1.25–6.40, P<0.05) were independent predictors of all-cause death. In the Kaplan-Meier estimates of cumulative survival stratified by DWS status were shown (Figure).

The Kaplan-Meier estimates of survival

Conclusion

Low-DWS provides prognostic information in patients with asymptomatic severe AS.

Observation of Ξ(1620)^{0} and Evidence for Ξ(1690)^{0} in Ξ_{c}^{+}→Ξ^{-}π^{+}π^{+} Decays

We report the first observation of the double strange baryon Ξ(1620)^{0} in its decay to Ξ^{-}π^{+} via Ξ_{c}^{+}→Ξ^{-}π^{+}π^{+} decays based on a 980  fb^{-1} data sample collected with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. The mass and width are measured to be 1610.4±6.0(stat)_{-4.2}^{+6.1} (syst)  MeV/c^{2} and 59.9±4.8(stat)_{-7.1}^{+2.8}(syst)  MeV, respectively. We obtain 4.0σ evidence of the Ξ(1690)^{0} with the same data sample. These results shed light on the structure of hyperon resonances with strangeness S=-2.

Prospective predictors of exacerbation status in severe asthma over a 3-year follow-up

BACKGROUND

A predisposition to exacerbations is being recognized as a distinct phenotype with "previous exacerbations" representing the strongest clinical factor associated with future exacerbation. Thus, to identify additional novel biomarkers associated with asthma exacerbations, "past exacerbation status" must be included as a confounding factor.

OBJECTIVE

This study aimed to characterize the clinical and biomarker features associated with asthma exacerbations in severe asthma.

METHODS

We evaluated clinical parameters from 105 severe asthmatics yearly for 3 years, as well as their exacerbation status. We classified the subjects into 3 groups: (i) consistent non-exacerbators (CNE, subjects who did not experience any exacerbation over the 3-year period); (ii) consistent frequent exacerbators (CFE, subjects with frequent exacerbation, defined as those who had 2 or more exacerbations within 1 year, throughout the 3-year period); and (iii) intermittent exacerbators (IE). We conducted multivariate analysis for comparisons among the groups for multiple factors, including several Th2-related biomarkers, in addition to the "past exacerbation status."

RESULTS

Thirty-nine subjects were classified as CNE, 15 as CFE, and 51 as IE. Frequent exacerbations in the previous year predicted exacerbations for the following year (P < .001). Among the several Th2-related biomarkers, only FeNO was associated with exacerbation status. When we analysed the data after the second visit, the impact of FeNO on predicting future exacerbation remained significant, even after considering the exacerbation status during the first year (P < .05).

CONCLUSIONS AND CLINICAL RELEVANCE

Measurement of FeNO has a significant potential to predict future asthma exacerbation, which is independent of the "past exacerbation history."

Do screws and screw holes affect osteolysis in cementless cups using highly crosslinked polyethylene? A 7 to 10-year follow-up case-control study

BACKGROUND

The use of screws and the presence of screw holes may cause acetabular osteolysis and implant loosening in cementless total hip arthroplasty (THA) using conventional polyethylene. In contrast, this issue is not fully understood using highly crosslinked polyethylene (HXLPE), particularly in large comparative study. Therefore, we performed a case-control study to assess the influence of screw usage and screw holes on: (1) implant fixation and osteolysis and (2) polyethylene steady-state wear rate, using cases with HXLPE liners followed up for 7-10 years postoperatively.

HYPOTHESIS

The screw usage and screw holes adversely affect the implant fixation and incidence of wear-related osteolysis in THA with HXLPE.

PATIENTS AND METHODS

We reviewed 209 primary cementless THAs performed with 26-mm cobalt-chromium heads on HXLPE liners. To compare the effects of the use of screws and the presence of screw holes, the following groups were established: (1) with-screw (n=140); (2) without-screw (n=69); (3) no-hole (n=27) and (4) group in which a cup with screw holes, but no screw was used (n=42). Two adjunct groups (no-hole cups excluded) were established to compare the differences in the two types of HXLPE: (5) remelted group (n=100) and (6) annealed group (n=82). Implant stability and osteolysis were evaluated by plain radiography and computed tomography. The wear rate from 1 year to the final evaluation was measured using plain X-rays and PolyWare Digital software.

RESULTS

All cups and stems achieved bony fixation. On CT-scan, no acetabular osteolysis was found, but there were 3 cases with a small area of femoral osteolysis. The mean steady-state wear rate of each group was (1) 0.031±0.022, (2) 0.033±0.035, (3) 0.031±0.024, (4) 0.029±0.018, (5) 0.030±0.018 and (6) 0.034±0.023mm/year, respectively. A comparison of the effects of screw usage or screw holes found no significant between-group differences in the implant stability, prevalence of osteolysis [no acetabular osteolysis and 3/209 at femoral side (1.4%)] and steady-state wear rate.

DISCUSSION

This study suggests that there are no adverse effects on the results of THA with HXLPE from the use of cups with screw holes and the use of screws for cup fixation.

LEVEL OF EVIDENCE

Level III retrospective case-control study.

Measurement of the Direct CP Asymmetry in B¯→X(s+dγ) Decays with a Lepton Tag

We report the measurement of the direct CP asymmetry in the radiative B¯→X(s+dγ) decay using a data sample of (772 ± 11)×10(6) BB[over ¯] pairs collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. The CP asymmetry is measured as a function of the photon energy threshold. For Eγ*≥2.1  GeV, where Eγ* is the photon energy in the center-of-mass frame, we obtain A(CP)(B¯→X(s+dγ))=(2.2±3.9±0.9)%, consistent with the standard model prediction.

Circulating soluble receptor for advanced glycation end products is inversely correlated to oxidized low-density lipoproteins in asymptomatic subjects

OBJECTIVE

There is growing evidence that circulating soluble receptor for advanced glycation end products (sRAGE) exerts antiatherogenic effects as a decoy receptor that abolishes RAGE signalling. A previous study reported that oxidized low-density lipoprotein (oxLDL) can be one of the RAGE ligands. The present cross-sectional study investigated the clinical association between sRAGE and oxLDL in humans.

METHODS

Serum levels of the conventional atherosclerotic risk factors, sRAGE and malondialdehyde-modified low-density lipoprotein (MDA-LDL) were analysed in asymptomatic subjects; MDA-LDL was measured as a biomarker of oxLDL.

RESULTS

Mean serum levels of sRAGE and MDA-LDL were 1101 ng/l and 57.6 IU/l, respectively, in 33 subjects of mean age 65 years. Simple linear regression analysis showed a significant inverse correlation between sRAGE and MDA-LDL. Stepwise multiple linear regression analysis confirmed MDA-LDL to be independently, significantly and inversely correlated with sRAGE.

CONCLUSIONS

An independent, significant and inverse correlation was shown to exist between circulating levels of sRAGE and oxLDL (MDA-LDL), which suggests that part of the antiatherosclerotic effects of sRAGE may be related to oxLDL quenching.

γ-Glutamyl Transpeptidase Activity Assay

Gamma-glutamyl transpeptidase catalyzes the transfer of a gamma-glutamyl bond and is of importance in glutathione metabolism. The most common assay methods for this enzyme, in which gamma-glutamyl derivatives of p-nitroaniline are used as a gamma-glutamyl donor, are described in this unit.

Development of Mathematical Models for Long-Term Prediction of Corrosion Behaviour of Carbon Steel Overpacks for Radioactive Waste Disposal

Mathematical models to enable long-term prediction of the corrosion behaviour of carbon steel overpacks for radioactive waste have been developed. An existing model of the growth of pits, implemented in the CAMLE software, has been extended and used to investigate the sensitivity of the predictions to input parameters, including cathodic reaction kinetics and the relative position of the anode and cathode. Predictions have also been made of the aeration period of the repository, during which localised corrosion is possible.

The association between circulating secreted protein acidic and rich in cysteine (SPARC) and glycosylated haemoglobin (HbA(1c)) during lifestyle-modified weight reduction intervention in obese male subjects

The physiological role and clinical relevance of circulating secreted protein acidic and rich in cysteine (SPARC, or osteonectin) is still poorly understood. This study investigated the correlation between circulating SPARC and metabolic variables, including glucose and glycosylated haemoglobin (HbA(1c)), during a diet and exercise modified weight reduction intervention programme. Changes in plasma SPARC levels and several metabolic variables were analysed in asymptomatically obese, nondiabetic, male subjects before and after weight reduction intervention. Body mass index and blood pressure, serum cholesterol and HbA(1c) levels were all significantly reduced after weight reduction intervention. Multiple regression analysis demonstrated that changes in SPARC levels were significantly and positively correlated with HbA(1c). The relationship between SPARC and HbA(1c) may merit further investigation with regard to its association with postprandial or long-term glucose variation in obese male subjects.

Correlation between Ischaemia-Modified Albumin and Intermediate-Density Lipoprotein in Haemodialysis Patients with End-Stage Renal Disease

This study investigated the association between ischaemia-modified albumin (IMA), a biomarker of cardiac ischaemia, and increases in the levels of intermediate-density lipoprotein (IDL), an atherogenic particle that can cause oxidative stress, in haemodialysis patients with end-stage renal disease (ESRD). Fasting levels of serum IMA and lipids/lipoproteins were analysed in 15 patients and 15 healthy control subjects. There was a close positive correlation between IMA and IDL levels in ESRD patients but no significant correlation between IMA and lipids/lipoproteins in control subjects. This suggests a possible link between the characteristic dyslipo-proteinaemia found in ESRD and levels of IMA and, if confirmed in studies with larger sample sizes, may lead to further studies on the potential of the relationship between IMA and IDL as a biomarker in haemodialysis patients with ESRD.

A Modelling and Experimental Study for Long-Term Prediction of Localised Corrosion in Carbon Steel Overpacks for High-Level Radioactive Waste

This paper describes a joint modelling and experimental study for investigation of pit growth in carbon steel High-Level Radioactive Waste overpacks under consideration in Japan. A mathematical model of the growth of corrosion pits in metals has been developed. This model is implemented in the computer program CAMLE, and includes representation of the chemical, electrochemical and migration processes that control pit-growth rates. Experiments to provide key input data for the model are described, in addition to experiments to measure ‘short-term’ pit growth. Predictions from the model are compared with these data. Overall, the comparisons are encouraging and the model shows good potential as a tool for assessment of the long-term corrosion behaviour of overpacks under repository conditions. Future developments of the model to improve agreement are discussed.

Power of fecal DNA methylation analysis: Does it lead to development of a noninvasive screening tool for pancreatic cancer?

187

Background: The development of noninvasive screening tests is important to reduce mortality from gastrointestinal neoplasia, especially given that there is no noninvasive screening test for pancreatic cancer. We sought to develop such a test by analysis of DNA methylation from exfoliated cancer cells in feces.

Methods: We had reported a novel strategy that uses single-step modification of DNA with sodium bisulfite and fluorescence polymerase chain reaction methodology to measure aberrant methylation in fecal DNA. We increased number of biomarkers from 4 to 8 that were analyzed in 144 fecal samples obtained from a variety of patients, including colorectal tumors, hepatic tumors, and pancreatic tumors.

Results: The assay successfully identified one or more methylated markers in fecal DNA from patients with colorectal cancer, polyps, hepatocellular carcinoma, metastatic colorectal cancer at liver, and pancreatic cancer.

Conclusions: Methylation of 8 biomarkers in fecal DNA is associated with the presence of gastroenterological tumors relative to non-neoplastic conditions. Our fecal DNA methylation assay provides a possible means to noninvasively screen not only for colorectal tumors but also for pancreatic tumors.

No significant financial relationships to disclose.

Sorption and desorption of 17β-estradiol to natural sediment

The sorption and desorption of 17β-estradiol (E2) to various natural sediment were investigated. First, the quantitative solvent-water partition indices were measured. Significant differences were found between the n-octanol-water partition coefficient (K(OW)) and the n-hexane-water partition coefficient (K(HW)) of E2. The value of K(HW) (Log K(HW) = 0.07) is lower than those of two to four ring polyaromatic hydrocarbons (PAHs), while the value of K(OW) (Log K(OW) = 3.99) and that of organic matter-water partition coefficient (K(OC)) onto humic acid (Log K(OC) = 4.30) were similar to those of the PAHs. Five natural sediments of various characteristics and origins were selected for sorption and desorption experiments. Linear isotherms were obtained for sorption and desorption. The equilibrium partitioning coefficients of E2 were well-correlated with their values of weight fraction of organic carbon in sediments (f(OC)). Results suggest that E2 is sorbed mainly onto the organic portion of sediments and that its sorption coefficient can be estimated from K(OW) and f(OC), as in the case of non-polar PAHs. However, because of its polarity, the sorption mechanism of E2 onto sediments cannot be explained solely by the hydrophobic interaction.

Molecular characterization of Streptococcus mutans strains containing the cnm gene encoding a collagen-binding adhesin

OBJECTIVE

Streptococcus mutans, known to be a major pathogen of dental caries, is also considered to cause infective endocarditis. Its 120-kDa Cnm protein binds to type I collagen, which may be a potential virulence factor. In this study, we characterized S. mutans clinical strains focusing on the cnm gene encoding Cnm.

DESIGN

A total of 528 S. mutans strains isolated from Japanese, Finnish, and Thai subjects were investigated. Using molecular techniques, the distribution frequency of cnm-positive strains and location of the inserted cnm were analyzed. Furthermore, isogenic mutant strains were constructed by inactivation of the cnm gene, then their biological properties of collagen-binding and glucan-binding were evaluated. Southern hybridization of the genes encoding glucan-binding proteins was also performed.

RESULTS

The distribution frequency of cnm-positive strains from Thai subjects was 12%, similar to that previously reported for Japanese and Finnish subjects. Furthermore, the location of insertion of cnm was the same in all cnm-positive clinical isolates. As for the cnm-inactivated mutant strains constructed from 28 clinical isolates, their collagen-binding activity was negligible. In addition, glucan-binding activity in the cnm-positive clinical isolates was significantly reduced and corresponded to a lack of gbpA encoding glucan-binding protein A.

CONCLUSIONS

Our results indicate that strains with cnm genes, the most crucial factor for the collagen-binding property of S. mutans, are detectable at similar frequencies over several different geographic locations. In addition, the common properties of these strains are a high level of collagen-binding activity and tendency for a low level of glucan-binding activity.

Protein antigen in serotype k Streptococcus mutans clinical isolates

Streptococcus mutans, a major pathogen of dental caries and infective endocarditis, is classified into serotypes c, e, f, and k, with serotype k strains recently reported to be frequently detected in persons with infective endocarditis. Thus, we hypothesized that common properties associated with infective endocarditis are present in those strains. Fifty-six oral S. mutans strains, including 11 serotype k strains, were analyzed. Western blotting analysis revealed expression of the 3 types of glucosyltransferases in all strains, while expression of the approximately 190-kDa cell-surface protein (PA) was absent in 12 strains, among which the prevalence of serotype k (7/12) was significantly high. Furthermore, cellular hydrophobicity and phagocytosis susceptibility were lower in the group of serotype k strains. These results indicate that the absence of PA expression, low cellular hydrophobicity, and phagocytosis susceptibility are common bacterial properties associated with serotype k strains, which may be associated with virulence for infective endocarditis.

Measurement of branching fractions, isospin, and CP-violating asymmetries for exclusive b-->dgamma modes

We report new measurements of the decays B+-->rho+gamma, B0-->rho0gamma, and B0-->omegagamma using a data sample of 657x10(6) B meson pairs accumulated with the Belle detector at the KEKB e+e- collider. We measure branching fractions B(B+-->rho+gamma)=(8.7_-2.7-1.1;+2.9+0.9)x10(-7), B(B0-->rho0gamma)=(7.8_-1.6-1.0;+1.7+0.9)x10(-7), and B(B0-->omegagamma)=(4.0_-1.7;+1.9+/-1.3)x10(-7). We also report the isospin asymmetry Delta(rhogamma)=-0.48_-0.19-0.09;+0.21+0.08 and the first measurement of the direct CP-violating asymmetry ACP(B+-->rho+gamma)=-0.11+/-0.32+/-0.09, where the first and second errors are statistical and systematic, respectively.

Hole localization in the one-dimensional doped Anderson-Hubbard model

We study an interplay of disorder and correlation in the one-dimensional hole-doped Hubbard-model with disorder (Anderson-Hubbard model) by using the density-matrix renormalization group method. Concentrating on the doped-hole-density profile, we find in a large U/t regime that the clean system exhibits a simple fluidlike behavior whereas finite disorders create locally Mott regions which expand their area with increasing the disorder strength contrary to the conventional sense. We propose that such an anomalous Mott phase formation assisted by disorder is easily observable in atomic Fermi gases by setting up the box-shape trap.

Time-dependent CP-violating asymmetry in B0-->rho0gamma decays

We report the first measurement of CP-violation parameters in B0-->rho0gamma decays based on a data sample of 657x10(6)BB pairs collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. We obtain the time-dependent and direct CP-violating parameters, Srho0gamma=-0.83+/-0.65(stat)+/-0.18(syst) and Arho0gamma=-0.44+/-0.49(stat)+/-0.14(syst), respectively.

Binding and signal transduction characteristics of the nonpeptide vasopressin V1A receptor-selective antagonist YM218 in cultured rat mesangial cells

Vasopressin (AVP) causes mesangial cell contraction, proliferation and hypertrophy. The present study investigated the effects of YM218, a potent, nonpeptide AVP V(1A) receptor-selective antagonist, on rat mesangial cells using binding, signal transduction and cell growth assays. Specific binding of (3)H-AVP to rat mesangial cell plasma membranes was dependent upon time, temperature and membrane protein concentration. Scatchard plot analysis of equilibrium binding data revealed the existence of a single class of high-affinity binding sites with the expected V(1A) receptor profile. YM218 showed high affinity for V(1A) receptors, exhibiting a K(i) value of 0.19 nmol/l. AVP concentration-dependently increased intracellular Ca(2+) ([Ca(2+)](i)) levels, stimulated mitogen-activated protein (MAP) kinase and induced hyperplasia. Conversely, YM218 potently suppressed [Ca(2+)](i) elevation, activation of MAP kinase and hyperplasia induced by AVP. These results indicate that YM218 displays both high affinity for rat mesangial cell V(1A) receptors and high potency in inhibiting AVP-induced signal transduction and growth response. Therefore, YM218 is a useful pharmacologic tool for investigating the physiologic and pathophysiologic roles of AVP in kidney, and may have clinical application in the prevention or regression of mesangial cell growth.

A role of androgen receptor protein in cell growth of an androgen-independent prostate cancer cell line

Prostate cancer, which develops due to androgen and is initially responsive to androgen deprivation therapy, often comes to acquire androgen deprivation therapy resistance in short order. We investigated the role of androgen receptor (AR) protein in an androgen-independent prostate cancer cell line using AR ligands and AR siRNA. Although the androgen-independent cell line scarcely responded to AR ligands, their growth was attenuated by ablation of AR protein by siRNA.