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.

Empyema necessitans caused by methicillin-resistant Staphylococcus aureus: a case report and literature review

BACKGROUND

Empyema necessitans (EN) is a rare condition characterized by pleural infection with pus spreading into adjacent soft tissues. Although Mycobacterium tuberculosis and Actinomyces israelii are common causative agents, methicillin-resistant Staphylococcus aureus (MRSA) is relatively rare, but it is associated with high mortality in empyema cases. We aimed to report a unique case of EN caused by MRSA and present a literature review to better understand this rare condition.

CASE PRESENTATION

A 69-year-old man with a history of right ureteral stone presented with fever and left anterior thoracic pain. A physical examination revealed redness and swelling in the left thoracic region. Imaging studies confirmed EN with fluid accumulation around the sternocostal joint of the left first rib. MRSA was identified from blood and pleural fluid cultures. The patient received antimicrobial therapy, and a chest tube was inserted for drainage. Despite initial improvement, vertebral osteomyelitis was diagnosed on day 17. The antimicrobials were subsequently terminated after 6 weeks, but vertebral osteomyelitis recurred, and treatment was resumed and completed on day 215.

CONCLUSION

EN caused by MRSA is rare, and the literature review revealed 14 cases from human sources. Positive blood cultures were observed in 40% of cases, and metastatic infections were present in 30% of cases. Osteomyelitis was the most common type of metastatic lesion. All the patients underwent drainage. Patients with MRSA-associated EN frequently develop disseminated lesions and should therefore be carefully examined. Moreover, appropriate treatment with antibiotics and drainage is necessary for a good prognosis. Although the prognosis appeared to be favorable in our review, publication bias and treatment challenges for metastatic infections should be considered.

Characterization of DOM released from bacteria in response to chlorine in water based on indicator bacteria E. coli

ABSTRACTIn this study, Escherichia coli (E. coli) was used as an indicator bacterium treated with five different concentrations of chlorine (0.1; 0.5; 1.0; 2.0, and 5.0 mg/L) and without chlorine (0.0 mg/L) to evaluate the changes in the DOM characteristics. The dissolved organic carbon (DOC) concentration initially increased along with the chlorine concentrations and decreased after 24 h (0.0 and 0.1 mg/L) and 168 h (0.5; 1.0; 2.0 and 5.0 mg/L). Ultra-violet absorbance at 260 nm (UV260) showed that the absorbance decreased for control without chlorine (0.0 mg/L) and 0.1 mg/L chlorine, while increased for other concentrations of chlorine within 120 h. The DOC and UV260 results indicated that the high concentrations of chlorine initiated high contents of DOM which contained more humic-like molecules than the DOM released from E. coli without chlorine. Fluorescence excitation-emission matrix (EEM) analysis suggested that the DOM released from E. coli without chlorine enriched with protein-like substances, whereas the fulvic-like and humic-like substances more intensified in the DOM for the high concentrations of chlorine (>1.0 mg/L). The molecular weight distribution of DOM showed that the intensity of high molecular weight substances and polydispersity increased along with chlorine concentration and contact time, whereas the low molecular weight substances were relatively higher in the DOM for control without chlorine. The obtained results of this study would be useful for a better understanding of the variation of DOM during treatment and could be used as an important reference for optimizing the operation condition of the water treatment plants.

Hepatic Encephalopathy Caused by Long-Term Amiodarone Use

This case describes a 72-year-old Japanese woman with hypertrophic cardiomyopathy and non-sustained ventricular tachycardia who had received a total of 215 g of amiodarone over six years and presented with hepatic encephalopathy. The abdominal non-contrast computed tomography showed diffusely increased attenuation of the liver parenchyma. The liver biopsy revealed drug-induced steatohepatitis. No genetic variations in the urea cycle were found. She was ultimately diagnosed with drug-induced steatohepatitis and urea cycle abnormalities caused by long-term amiodarone use. Amiodarone may cause drug-induced steatohepatitis and urea cycle abnormalities, which could induce hyperammonemia. Although case reports of amiodarone-induced hyperammonemia and hepatic encephalopathy have already been reported, we present a typical picture of an amiodarone-induced bright liver, including the mechanism of amiodarone-induced hyperammonemia, to provide an educational learning point for many readers.

Secondary channel estimation in spatial active noise control systems using a single moving higher order microphone

Spatial active noise control (ANC) systems focus on minimizing unwanted acoustic noise over continuous spatial regions by generating anti-noise fields with secondary loudspeakers. Conventionally, error microphones are necessary inside the region to measure the channels from the secondary loudspeakers to the error microphones and record the residual sound field during the noise control. These error microphones highly limit the implementation of spatial ANC systems because of their impractical geometry and obstruction to the users from accessing the region. Recent advances, such as virtual sensing, focus on ANC with microphones placed away from the region. While these techniques relax the usage of error microphones during the noise control, an error microphone array remains necessary during the secondary channel estimation. In this paper, we propose a method to estimate secondary channels without using an error microphone array. Instead, a moving higher order microphone is applied to obtain the secondary channels from the secondary loudspeakers to the region of interest, which includes all desired error microphone locations. By simulation, we show that the proposed method is robust against various measuring errors introduced by the movement of the microphone and is suitable for the secondary channel estimation in spatial ANC systems.

Evaluation on Intestinal Permeability of Phlorotannins Using Caco-2 Cell Monolayers

Among the phlorotannins of seaweed polyphenols, eckols which have a dibenzodioxin linkage are known to have various physiological functions. The purpose of this study was to investigate the intestinal epithelial absorption of eckols using Caco-2 cell monolayers of the small intestinal membrane model. Each compound permeated from the apical (AP) side to the basolateral (BL) side in the monolayers was identified and quantitated by liquid chromatography-mass spectrometry with electrospray ionization. In the transport assays using five types of eckols (eckol, fucofuroeckol A, phlorofucofuroeckol A, dieckol, and 8,8'-bieckol), only the monomeric eckol showed limited transepithelial absorption with relatively small apparent permeability values (0.30  ±  0.04  ×  10−8 cm/s). Analyzing the Hanks’ balanced salt solution in the receiver on the BL side showed that phloroglucinol was detected in all experimental sections using eckols, and it's concentration increased with time over the course of the incubation. The other molecules corresponding to the unconjugated and conjugated metabolites of eckols were not detected in the AP and BL sides through the assays. These results suggest that eckols, including monomeric eckol, may be decomposed into phloroglucinol in the intestinal epithelium and the resulting phloroglucinol permeates to the BL side.

Diagnostic value of simultaneous 99mTc-sestamibi/123I-BMIPP imaging parameters for predicting the improvement of left ventricular wall motion after acute myocardial infarction using CZT SPECT system

Background

Although the presence of 99mTc-sestamibi/123I-BMIPP-mismatch, the reverse redistribution (RR) of 99mTc-sestamibi and RR of 123I-BMIPP in patients with acute myocardial infarction (AMI) are known to significant markers for predicting the improvement of LV wall motion in the infarcted territory in chronic phase, few studies were performed to analyze them by simultaneous dual-isotope imaging using cadmium-zinc-telluride (CZT) SPECT system.

Purpose

The purpose of this study was to evaluate whether the presence of 99mTc-sestamibi/123I-BMIPP-mismatch or RR of 99mTc-sestamibi, RR of 123I-BMIPP make better prediction of the improvement of LV wall motion in the infarcted territory.

Methods

We evaluated 42 consecutive patients with AMI who had undergone both dual-isotope SPECT in acute phase and stress myocardial SPECT using 99mTc-tracers in chronic phase by Discovery NM530c. The presence of 99mTc-sestamibi/123I-BMIPP-mismatch, RR of 99mTc-sestamibi and RR of 123I-BMIPP were determined using traditional definition. The improvement of LV wall motion in the infarcted territory from acute phase to chronic phase was assessed using QGS.

Results

Of 42 patients, the improvement of LV wall motion in the infarcted territory from acute phase to chronic phase was found in 29 patients. The presence of 99mTc-sestamibi/123I-BMIPP-mismatch and RR of 99mTc-sestamibi and RR of 123I-BMIPP were significantly linked to predict the improvement of LV wall motion (p=0.0001, p=0.0001 and p=0.002, respectively). To predict the improvement of LV wall motion in the infarcted territory in chronic phase, the presence of 99mTc-sestamibi/123I-BMIPP-mismatch showed sensitivity of 93%, specificity of 85% and accuracy of 91%, while RR of 99mTc-sestamibi and RR of 123I-BMIPP had sensitivities of 72%, 48%, specificities of 85%, 100% and accuracies of 76%, 64%, respectively. The multivariate discriminant analysis revealed that the combination of 99mTc-sestamibi/123I-BMIPP-mismatch, RR of 99mTc-sestamibi and RR of 123I-BMIPP best predicted the improvement of LV wall motion in the infarcted territory in chronic phase with sensitivity of 93%, specificity of 85% and accuracy of 91% (chi-square=40.6), compared with RR of 99mTc-sestamibi and RR of 123I-BMIPP only (sensitivity 79%, specificity 85% and accuracy of 81%, chi-square=16.9).

Conclusions

The addition of 99mTc-sestamibi/123I-BMIPP-mismatch on RR of 99mTc-sestamibi and RR of 123I-BMIPP in patients with AMI, help better predict the improvement of LV wall motion in the infarcted territory in chronic phase.

Funding Acknowledgement

Type of funding sources: None.

Prediction of the improvement of left ventricular wall motion after acute myocardial infarction by simultaneous dual-isotope imaging with 99mTc-sestamibi/123I-BMIPP using cadmium-zinc-telluride SPECT

Background/Introduction

Although both the presence of 99mTc-sestamibi/123I-BMIPP mismatch and the reverse redistribution of 99mTc-sestamibi in patients with acute myocardial infarction (AMI) are known to significant markers for predicting the improvement of left ventricular (LV) wall motion in the infarcted territory in chronic phase, few studies evaluated them by simultaneous dual-isotope (99mTc-sestamibi/123I-BMIPP) imaging using cadmium-zinc-telluride (CZT) SPECT system.

Purpose

The purpose of this study was to evaluate whether the presence of 99mTc-sestamibi/123I-BMIPP mismatch or the reverse redistribution of 99mTc-sestamibi make better prediction of the improvement of LV wall motion in the infarcted territory.

Methods

We evaluated 30 consecutive patients with AMI who had undergone both dual-isotope (99mTc-sestamibi/123I-BMIPP) SPECT in acute phase and stress myocardial SPECT using 99mTc-tracers in chronic phase by Discovery NM530c. Both 99mTc-sestamibi/123I-BMIPP mismatch and reverse redistribution of 99mTc-sestamibi were determined using traditional definition. The improvement of LV wall motion in the infarcted territory from acute phase to chronic phase was assessed using QGS.

Results

Of 30 patients, the improvement of LV wall motion in the infarcted territory from acute phase to chronic phase was found in 20 patients. Both the presence of 99mTc-sestamibi/123I-BMIPP mismatch and reverse redistribution of 99mTc-sestamibi were significantly linked to predict the improvement of LV wall motion (p=0.0001, p=0.011, respectively). The respective sensitivities, specificities and accuracies in the prediction of the improvement of LV wall motion in the infarcted territory were 90%, 90% and 90% with 99mTc-sestamibi/123I-BMIPP mismatch, and 60%, 90%, 70% with reverse redistribution of 99mTc-sestamibi.

Conclusions

In the simultaneous 99mTc-sestamibi/123I-BMIPP dual-isotope imaging using CZT SPECT system, both the presence of 99mTc-sestamibi/123I-BMIPP mismatch and the reverse redistribution of 99mTc-sestamibi in acute phase are useful for predicting the improvement of LV wall motion in chronic phase, but the presence of 99mTc-sestamibi/123I-BMIPP mismatch is superior to the reverse redistribution of 99mTc-sestamibi for it.

Funding Acknowledgement

Type of funding source: None

Prediction of myocardial viability in chronic phase in patients with acute myocardial infarction by simultaneous dual-isotope imaging with 99mTc-sestamibi/123I-BMIPP SPECT using CZT camera system

Objectives

The objective of this study was to determine the optimal cut-off value of % uptake of simultaneous dual-isotope (99mTc-sestamibi/123I-BMIPP) SPECT in patients with acute myocardial infarction (AMI) for prediction of myocardial viability in chronic phase.

Methods

We evaluated 30 consecutive patients with AMI who had undergone both dual-SPECT in acute phase and stress myocardial SPECT using 99mTc-tracers in chronic phase by Discovery NM530c. Regional % uptake with a 17-segment model was obtained using QPS software. The presence of myocardial viability was defined when regional % uptake ≥50% in 99mTc SPECT at rest in chronic phase was observed. Receiver operating characteristic (ROC) curves were analyzed to determine the optimal cutoff values of regional % uptake in both left anterior descending artery (LAD) territory and non-LAD coronary territory in acute phase to predict the myocardial viability in chronic phase.

Results

The cutoff values for prediction of viable myocardium were %uptake ≥47% for 99mTc-sestamibi, %uptake ≥31% for 123I-BMIPP in acute phase in LAD territory and %uptake ≥52% for 99mTc-sestamibi, %uptake ≥48% for 123I-BMIPP in non-LAD territory. The respective sensitivities, specificities and the area under the ROC curve (AUC) values in the prediction of myocardial viability were 92%, 92% and 0.94 with 99mTc-sestamibi, 90%, 85%, 0.92 with 123I-BMIPP in LAD territory, and 81%, 93% and 0.92 with 99mTc-sestamibi, 81%, 90%, 0.92 with 123I-BMIPP in non-LAD territory. There were no significant differences in AUC values between 99mTc-sestamibi and 123I-BMIPP in both LAD territory and non-LAD coronary territory.

Conclusions

In the simultaneous 99mTc-sestamibi/123I-BMIPP dual-isotope imaging in patients with AMI, these results suggest that not only 99mTc-sestamibi SPECT, but also 123I-BMIPP SPECT may be possible to predict the presence of myocardial viability in chronic phase. But it should be noted that the optimal cutoff values of regional % uptake in acute phase to predict the myocardial viability may differ for LAD territory and non-LAD coronary territory.

Funding Acknowledgement

Type of funding source: None

Coherence-based performance analysis on noise reduction in multichannel active noise control systems

Active noise control (ANC) over an extended spatial region using multiple microphones and multiple loudspeakers has become an important problem. The maximum noise reduction (NR) potential over the control area is a critical evaluation variable as it indicates the fundamental limitation of a given ANC system. In this paper, a method to mathematically formulate the NR potential for any given multichannel ANC systems is developed. First, the residual error in the multichannel feedforward ANC system is formulated, and then the multiple-input-multiple-output problem is decomposed into the parallel-channel problem. The total energy of the residual error is further decomposed into three different terms representing (i) the signal coherence between the reference signals and error signals, (ii) the filter, and (iii) the system null space. The experimental results validate the proposed evaluation method and illustrate the effectiveness on the maximum NR performance evaluation for given systems. Using the proposed analyzing method, more insight into the contribution of each component to the NR potential can be achieved.

Phlorotannins Remarkably Suppress the Formation of Nε-(Carboxymethyl)lysine in a Collagen-Glyoxal Environment

N ε-(Carboxymethyl)lysine (CML), which is formed by the glycation of collagen, is a skin-accumulating advanced glycation end product and has been shown to be deeply involved in diabetic osteopenia and skin aging. In this study, we prepared the phlorotannins of marine algal polyphenols from Japanese Lessoniaceae ( Ecklonia cava, Ecklonia kurome, cultured E. kurome, Ecklonia stolonifera, Eisenia nipponica, and Eisenia bicyclis) and evaluated their inhibitory activities against CML formation in a collagen-glyoxal environment. The level of CML formed from the glycation of collagen by glyoxal was detected using an enzyme-linked immunosorbent assay. Except for E. stolonifera, the level of CML formation in the treatment with crude phlorotannins at 0.16 µg/mL was found to be comparable to that in the treatment with 0.40 mM aminoguanidine hydrochloride (AG) which is a typical antiglycation agent. In the test using phloroglucinol and isolated eckols (eckol, fucofuroeckol A, phlorofucofuroeckol A, dieckol, and 8,8’-bieckol) at a concentration of 0.80 µg/mL, the level of CML formed was lower for each compound, except for phlorofucofuroeckol A, than the data obtained with the addition of 2.0 mM AG. The mass concentration of 0.80 µg/mL was converted to 6.3 µM for phloroglucinol, 2.2 µM for eckol, 1.7 µM for fucofuroeckol A, 1.3 µM for phlorofucofuroeckol A, and 1.1 µM for dieckol and 8,8’-bieckol. From a comparison of the molar concentrations, it was found that phloroglucinol and the eckols inhibited the formation of CML resulting from glycation of collagen by glyoxal at concentrations of approximately 317 to 1818 times lower than AG.

P1828Aortic calcification detected by computed tomography and aortic vulnerable plaques: aortic angioscopy study

Background

Aortic calcification is associated with atherosclerotic risk factors and an increased risk of death and cardiovascular disease. However, the relationships aortic calcification and aortic plaque instability are not yet elucidated. Recently, some reports showed non-obstructive aortic angioscopy seemed to visualize atherosclerotic changes of aortic wall more clearly compared with computed tomography (CT). The purpose of this study was to evaluate whether aortic calcification is associated with aortic vulnerable plaques in patients with cardiovascular disease.

Methods

We investigated 60 consecutive patients with confirmed or suspected coronary artery disease who underwent both aortic angioscopy and CT. The AC volume (ACV) was measured using the volume-rendering method by extracting the area >130 HU within the whole aorta. ACV index (ACVI) was defined as ACV divided by the body surface area. We evaluated the number of ruptured plaque (RP), ulceration and fissure by aortic angioscopy in the whole aorta. We excluded 4 hemodialysis patients. All patients were divided into the median value of ACVI.

Results

The mean age of patients was 68±10. The median of ACVI was 10.7 ml/m2 [3.9–22.7]. High ACVI patients had significantly greater number of RP, ulceration and atheromatous plaques detected by aortic angioscopy compared with those of low ACVI (2.2±2.7 vs 0.8±1.1, p=0.033, 1.6±1.2 vs 0.9±1.0, p=0.041, 4.0±3.1 vs 1.9±1.8, p=0.009, respectively). Furthermore, the patients without aortic calcification did not have RP at all. In a multivariate model, the number of the atheromatous plaques was independently associated with high ACVI (odds ratio 1.57, 95% confidence interval 1.07–2.69, p=0.018)

Conclusions

Aortic calcification detected by CT was related to aortic vulnerable plaques in patients with cardiovascular disease.

6125High wall shear stress predicts plaque rupture of the aortic arch: computational fluid dynamics model and non-obstructive general angioscopy study

Background

Wall shear stress (WSS) has been considered as a major determinant of aortic atherosclerosis. Recently, non-obstructive general angioscopy (NOGA) was developed to be able to visualize a variety of its atherosclerotic pathology, including in vivo ruptured plaque (RP) in the aorta. We, therefore, investigated the relationship between NOGA derived RP in the aortic arch and the stereographic distribution of WSS by using computational fluid dynamics modeling (CFD) on three-dimensional CT angiography (3D-CT).

Methods

We investigated 30 consecutive patients who underwent 3D-CT before and NOGA during coronary angiography. WSS in the aortic arch was measured with an application of CFD based on finite element method by using uniform inlet and outlet flow conditions. Aortic RP was detected by NOGA.

Results

The maximum and mean values of WSS were 67.2±29.2 Pa and 2.4±0.6 Pa. A total of 18 RPs was detected by NOGA. The patients with a distinct RP showed a significantly higher maximum WSS in the whole aortic arch, and the greater and lesser curvature of the aortic arch than those without it (73.3±29.0 Pa vs 50.4±15.2 Pa, p=0.035, 95.0±27.5 Pa vs 42.8±25.2 Pa, p=0.003, 70.8±29.3 Pa vs 46.1±11.9 Pa, p=0.013, respectively), whereas there was no significant difference in the mean WSS between those with and without it. In a multivariate analysis, the maximum value of WSS was an independent predictor of RP in the aortic arch (odds ratio 1.05, 95% confidence interval 1.01–1.13, p=0.019).

Representative picture of WSS and NOGA

Conclusions

Aortic RP detected by NOGA was strongly associated with the higher maximum WSS in the aortic arch derived by CFD using 3D-CT. Maximum WSS may explain the underlying mechanism of not only aortic atherosclerosis, but also aortic RP.

Classification of 3097 patients from the Japanese melanoma study database using the American joint committee on cancer eighth edition cancer staging system

BACKGROUND

The American Joint Committee on Cancer (AJCC) 8^th Edition Cancer Staging System was implemented in 2018; however, it has not been validated in an Asian melanoma population.

OBJECTIVE

The purpose of this study was to validate the new system using a cohort of Japanese melanoma patients.

METHODS

The AJCC 7^th and 8^th Editions were used for TNM classification of patients in a database established by the Japanese Melanoma Study Group. Patient data with sufficient information to be applicable to the AJCC 8^th staging were selected. The Kaplan-Meier method was used to estimate disease-specific survival and relapse-free survival.

RESULTS

In total, data for 3097 patients were analyzed. The 5-year disease-specific survival according to the 7^th and 8^th Edition staging system were as follows: IA = 98.5%/97.9%; IB = 95.4%/96.2%; IIA = 94.2%/94.1%; IIB = 84.6%/84.4%; IIC = 72.2%/72.2%; IIIA = 76.2%/87.5%; IIIB = 60.7%/72.6%; IIIC = 42.0%/55.3% and IIID = none/26.0%. The 5-year relapse-free survival according to the 7^th and 8^th Edition staging was as follows: IA = 94.5%/92.7%; IB = 85.4%/85.3%; IIA = 80.1%/79.4%; IIB = 71.4%/70.6%; IIC = 56.8%/55.7%; IIIA = 56.8%/69.4%; IIIB = 42.6%/56.8%; IIIC = 20.0%/33.3% and IIID = none/6.5%.

CONCLUSION

The results show that new staging system could efficiently classify our Japanese melanoma cohort. Although there was no difference in Stage I and II disease between the 7^th and 8^th Edition systems, we should be careful in managing Stage III disease since the survival curves of the 8^th Edition staging were completely different from the 7^th Edition. Moreover, our results indicate that adjuvant therapies for Stage IIB and IIC should be developed, since the relapse-free survival for these stages were equivalent to Stage IIIA and IIIB, respectively.

Sparse sound field decomposition for super-resolution in recording and reproduction

A sound field recording and reproduction method based on sparse sound field decomposition is proposed. Most current methods are based on plane-wave or harmonic decomposition of the pressure distribution obtained by microphones, which leads to spatial aliasing artifacts with severe effects. This paper proposes a method for sound field decomposition based on a generative model of the sound field consisting of near-field source components and far-field plane-wave components. Since the distribution of the near-field source components can be assumed to be spatially sparse, the pressure distribution obtained by the microphones can be decomposed into these two components using sparse decomposition algorithms. Using the proposed method, the sound field can be more accurately interpolated and super-resolution in recording and reproduction can be achieved. Experimental results show that the reproduction accuracy above the spatial Nyquist frequency determined by the microphone intervals was improved compared with that of the current methods.

Differences in behaviour of three biopolymer constituents in coagulation with polyaluminium chloride: Implications for the optimisation of a coagulation-membrane filtration process

Coagulation is often applied as a pre-treatment for membrane processes to reduce dissolved organic matter and to prevent membrane fouling. Biopolymers (BPs) have repeatedly been reported as major organic foulants, and coagulation conditions such as pH or dose have been optimised to minimise the remaining BPs. Optimisation however remains problematic because of the complex and heterogenetic nature of BP. In this study, the behaviour of several BP fractions in a coagulation process was investigated by excitation-emission matrix-parallel factor analysis (EEM-PARAFAC) following liquid chromatography (LC)-fractionation. Using a series of jar tests, we found that BP removal depends on the type of source water, reflecting differences in charge neutralisation conditions in three samples of natural water despite nearly identical processes for removing humic substances. This result demonstrates the complexity of optimisation for BP coagulation. Fractionation of EEM-PARAFAC to BP by LC showed that at least three organic component groups (C1, C2 and C3) constitute BP. C1 is tryptophan-like organic matter that is often found in wastewater effluent, C2 is tyrosine-like organic matter that has a phenolic chemical structure, and C3 is a humic-like substance. C1 was removed thoroughly at acidic pH but not at neutral pH, while the removal of C2 was inefficient even with a significant change in pH or dose, indicating similar difficulties in a coagulation process. The difference in components C1 and C2 may partly explain the difference in efficiencies of removal of BP in water from different sources. Our investigation suggests that the optimisation or selection of appropriate pre-treatment processes for membrane systems should be substantially based on the composition of BPs (e.g., C1 and C2 components).

A Label-Free Fluorescent Array Sensor Utilizing Liposome Encapsulating Calcein for Discriminating Target Proteins by Principal Component Analysis

A new fluorescent arrayed biosensor has been developed to discriminate species and concentrations of target proteins by using plural different phospholipid liposome species encapsulating fluorescent molecules, utilizing differences in permeation of the fluorescent molecules through the membrane to modulate liposome-target protein interactions. This approach proposes a basically new label-free fluorescent sensor, compared with the common technique of developed fluorescent array sensors with labeling. We have confirmed a high output intensity of fluorescence emission related to characteristics of the fluorescent molecules dependent on their concentrations when they leak from inside the liposomes through the perturbed lipid membrane. After taking an array image of the fluorescence emission from the sensor using a CMOS imager, the output intensities of the fluorescence were analyzed by a principal component analysis (PCA) statistical method. It is found from PCA plots that different protein species with several concentrations were successfully discriminated by using the different lipid membranes with high cumulative contribution ratio. We also confirmed that the accuracy of the discrimination by the array sensor with a single shot is higher than that of a single sensor with multiple shots.

Canstatin stimulates migration of rat cardiac fibroblasts via secretion of matrix metalloproteinase-2

Type IV collagen, a nonfibrillar type, is ubiquitously expressed in the basement membrane around cardiomyocytes. Canstatin, a cleaved product of α2 chain of type IV collagen, is an antiangiogenic factor. Because it has not been clarified whether canstatin exerts other biological activities in heart, we investigated the effects of canstatin on adult rat cardiac fibroblasts. Cell migration was determined by Boyden chamber assay. Western blotting was performed to detect secretion of matrix metalloproteinase-2 (MMP-2) and MMP-9 and phosphorylation of extracellular signal-regulated kinase (ERK). Localization of MMP-2 was detected by immunofluorescence staining. Canstatin (250 ng/ml) significantly increased migration, secretion, and activity of MMP-2 but not MMP-9. CTTHWGFTLC peptide, an MMP inhibitor and small interfering RNA (siRNA) against MMP-2 suppressed the canstatin-induced (250 ng/ml, 24 h) migration. Canstatin (250 ng/ml, 30 min) significantly increased phosphorylation of ERK. PD98059, a MEK inhibitor, significantly suppressed the canstatin-induced (250 ng/ml, 24 h) migration but not secretion of MMP-2. An increase in MMP-2 expression was observed in cytoplasm of the canstatin-treated (250 ng/ml) cardiac fibroblasts (within 30 min). Canstatin induced actin stress fiber formation, which was inhibited by Y-27632, a Rho-associated kinase inhibitor. Y-27632 also suppressed the canstatin-induced (250 ng/ml, 24 h) MMP-2 secretion. Canstatin (250 ng/ml, 30 min) failed to induce ERK phosphorylation in MMP-2 siRNA-treated cardiac fibroblasts. In conclusion, this study revealed a novel function of canstatin for inducing cell migration of adult rat cardiac fibroblasts at least in part by ERK phosphorylation through MMP-2 secretion, possibly via actin cytoskeletal change.

Characteristics of meso-particles formed in coagulation process causing irreversible membrane fouling in the coagulation-microfiltration water treatment

In coagulation-membrane filtration water treatment processes, it is still difficult to determine the optimal coagulation condition to minimize irreversible membrane fouling. In microfiltration (MF), meso-particles (i.e., 20 nm-0.5 μm) are thought to play an important role in irreversible membrane fouling, especially their characteristics of particle number (PN) and zeta potential (ZP). In this study, a new nanoparticle tracker combined a high-output violet laser with a microscope was developed to identify the physicochemical characteristics of these microscopic and widely dispersed meso-particles. The effects of pH and coagulant dose on ZP and PN of micro-particles (i.e., >0.5 μm) and meso-particles were investigated, and then coagulation-MF tests were conducted. As the result, irreversible membrane fouling was best controlled for both types of membranes, while meso-particle ZP approached zero at around pH 5.5 for both types of natural water. Since PN was greatest under these conditions, ZP is more important in determining the extent of irreversible membrane fouling than PN. However, the acidic condition to neutralize meso-particles is not suitable for actual operation, as considering residual aluminum concentration, pipe corrosion, and chlorination efficiency. It is therefore necessary to investigate coagulants or other methods for the appropriate modification of meso-particle characteristics.

Effect of Allergen Sensitization on External Root Resorption

In orthodontic tooth movement (OTM), we should be concerned about external root resorption (ERR) as an undesirable iatrogenic problem, but its mechanisms are not fully understood. Since our previous epidemiologic studies found that patients with allergic diseases showed higher rates of ERR during orthodontic treatment, we explored the possible effect of allergic sensitization on ERR. In ovalbumin (OVA)-sensitized Brown–Norway rats, the amounts of ERR and OTM were greater than those in animals subjected to orthodontic force alone. The expression levels of RANKL and pro-inflammatory cytokines were increased in the periodontal tissues of sensitized rats with OTM, compared with control rats. Furthermore, leukotriene B4 (LTB4), a potent lipid mediator of allergic inflammation, and enzymes of the 5-lipoxygenase pathway, the biosynthetic pathway of leukotrienes, were also up-regulated. We found that low doses of aspirin suppressed ERR in allergen-sensitized rats, as well as the expressions of RANKL, pro-inflammatory cytokines, and LTB4. The present findings indicate that allergen sensitization has adverse effects on ERR under OTM, and that aspirin is a potential therapeutic agent for combating ERR.

A robust approach to independent component analysis of signals with high-level noise measurements

We propose a robust approach for independent component analysis (ICA) of signals where observations are contaminated with high-level additive noise and/or outliers. The source signals may contain mixtures of both sub-Gaussian and super-Gaussian components, and the number of sources is unknown. Our robust approach includes two procedures. In the first procedure, a robust prewhitening technique is used to reduce the power of additive noise, the dimensionality and the correlation among sources. A cross-validation technique is introduced to estimate the number of sources in this first procedure. In the second procedure, a nonlinear function is derived using the parameterized t-distribution density model. This nonlinear function is robust against the undue influence of outliers fundamentally. Moreover, the stability of the proposed algorithm and the robust property of misestimating the parameters (kurtosis) have been studied. By combining the t-distribution model with a family of light-tailed distributions (sub-Gaussian) model, we can separate the mixture of sub-Gaussian and super-Gaussian source components. Through the analysis of artificially synthesized data and real-world magnetoencephalographic (MEG) data, we illustrate the efficacy of this robust approach.

Genetic decrease in fatty acid unsaturation of phosphatidylglycerol increased photoinhibition of photosystem I at low temperature in tobacco leaves

Leaves of transgenic tobacco plants with decreased levels of fatty acid unsaturation in phosphatidylglycerol (PG) exhibited a slightly lower level of the steady state oxidation of the photosystem I (PSI) reaction center P700 (P700(+)) than wild-type plants. The PSI photochemistry of wild-type plants was only marginally affected by high light treatments. Surprisingly, all plants of transgenic lines exhibited much higher susceptibility to photoinhibition of PSI than wild-type plants. This was accompanied by a 2.5-fold faster re-reduction rate of P700(+) in the dark, indicating a higher capacity for cyclic electron flow around PSI in high light treated transgenic leaves. This was associated with a much higher intersystem electron pool size suggesting over-reduction of the PQ pool in tobacco transgenic lines with altered PG unsaturation compared to wild-type plants. The physiological role of PG unsaturation in PSI down-regulation and modulation of the capacity of PSI-dependent cyclic electron flows and distribution of excitation light energy in tobacco plants under photoinhibitory conditions at low temperatures is discussed. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial.

Retrospective analysis of an efficient peripheral blood stem cell collection and the relation between infused cell dose and clinical outcome in patients with malignant lymphoma and multiple myeloma

INTRODUCTION

Etoposide (VP16) is a drug used not only for the treatment of lymphoma but also for the collection of peripheral blood stem cells (PBSCs). We analysed the efficacy and adverse effects of collecting PBSCs and the relation between the infused cell dose and the clinical outcome in lymphoid malignancies.

METHOD

Investigating 30 patients with non-Hodgkin's lymphoma, one patient with Hodgkin's lymphoma, and five patients with multiple myeloma, we compared the effects of several doses of etoposide with those of CHOP or CHOP-like treatments or salvage treatments. We also analysed the relation between the amount of CD34(+) cells collected (above or below 5.0 × 10(6) /kg/day) and prognosis of these patients.

RESULTS

We found the collected cell count to be highest in patients treated with 500 mg/m(2) of VP16 and lowest in those not treated with VP16 (P = 0.0073). A CD34(+) cell count above 100/μL on the collection day indicates that the target amount of CD34(+) cells (4.0 × 10(6) /kg) can be readily obtained and was reached most rapidly by the patients who had received 500 mg/m(2) of VP16 (P = 0.01). The longer duration of neutropenia in those patients (P = 0.000006) resulted in longer antibiotic treatment (P = 0.0052). Both progression-free survival (PFS) and overall survival (OS) were better for the patients who yielded more than 5.0 × 10(6) CD34(+) cells/kg/day (P = 0.087 for PFS and P < 0.033 for OS).

CONCLUSION

We show here that 3 days of VP16 at 500 mg/m(2) was useful for the collection of PBSCs and that patients who yielded more than 5.0 × 10(6) CD34(+) cells/kg/day survived longer than those who yielded less.

High-flow Neonatal Macrocerebral Arteriovenous Fistulas in Hereditary Hemorrhagic Telangiectasia

Although some cases of vein of Galen aneurysmal malformation (VGAM) present initial clinical symptoms such as cardiopulmonary disturbance in the neonatal period, pial arteriovenous fistula is very seldom present as a clinical symptom immediately after birth. A neonatal patient, the first-born to his family, presented with tachypnea postpartum. This baby had a family history of hereditary hemorrhagic telangiectasia. A cerebral MR image revealed multiple macrocerebral arteriovenous fistulas (MCAVFs), resulting in a large partially thrombosed venous pouch within the cerebral cortex. Trans-arterial embolizations of the main two fistulas were performed using N-butyl cyanoacrylate (NBCA) with tantalum powder six months after birth. Post-embolization angiography confirmed the obliteration of the fistulas and magnetic resonance imaging (MRI) revealed thrombosis and reduction in size of the venous component. His tachypnea disappeared completely. There were no neurological complications due to the treatment. The prognosis of multiple MCAVFs mainly depends on the presence of medullar signs and symptoms and a delay before treatment. Pure glue endovascular intervention, as used in our case, is considered to be the first therapeutic choice to decrease the risk of neurological consequences.

Isolation and characterization of an ether-type polyurethane-degrading micro-organism and analysis of degradation mechanism by Alternaria sp

AIMS

To degrade ether-type polyurethane (ether-PUR), ether-PUR-degrading micro-organism was isolated. Moreover, ether-PUR-degrading mechanisms were analysed using model compounds of ether-PUR.

METHODS AND RESULTS

A fungus designated as strain PURDK2, capable of changing the configuration of ether-PUR, has been isolated. This isolated fungus was identified as Alternaria sp. Using a scanning electron microscope, the grid structure of ether-PUR was shown to be melted and disrupted by the fungus. The degradation of ether-PUR by the fungus was analysed, and the ether-PUR was degraded by the fungus by about 27.5%. To analyse the urethane-bond degradation by the fungus, a degraded product of ethylphenylcarbamate was analysed using GC/MS. Aniline and ethanol were detected by degradation with the supernatant, indicating that the fungus secreted urethane-bond-degrading enzyme(s). PURDK2 also degraded urea bonds when diphenylmethane-4,4'-dibutylurea was used as a substrate.

CONCLUSIONS

The enzyme(s) from PURDK2 degraded urethane and urea bonds to convert the high molecular weight structure of ether-PUR to small molecules; and then the fungus seems to use the small molecules as an energy source.

SIGNIFICANCE AND IMPACT OF THE STUDY

Ether-PUR-degrading fungus, strain PURDK2, was isolated, and the urethane- and urea-bonds-degrading enzymes from strain PURDK2 could contribute to the material recycling of ether-PUR.

Superconductivity in thin films of boron-doped carbon nanotubes

Superconductivity in carbon nanotubes (CNTs) is attracting considerable attention. However, its correlation with carrier doping has not been reported. We report on the Meissner effect found in thin films consisting of assembled boron (B)-doped single-walled CNTs (B-SWNTs). We find that only B-SWNT films consisting of low boron concentration leads to evident Meissner effect with Tc=12 K and also that a highly homogeneous ensemble of the B-SWNTs is crucial. The first-principles electronic-structure study of the B-SWNTs strongly supports these results.

A double three-step theory of brain metastasis in mice: the role of the pia mater and matrix metalloproteinases

The brain is frequently affected by the spread of lung cancer, and haematogenous metastasis is a common route to brain metastasis. We therefore developed an isogenic brain metastasis model of lung cancer to use the Lewis lung carcinoma cell line and analysed dynamics of neoplastic cells after extravasation. Histological analysis revealed two characteristic patterns: metastatic foci exhibiting an angiocentric pattern were designated 'perivascular proliferations'; neoplastic cells infiltrating the brain parenchyma were designated 'invasive proliferations'. Electron microscopic observation of perivascular proliferations showed that neoplastic cells were confined to the perivascular space. In invasive proliferations, however, fragments of collagen fibre were observed in the gaps between neoplastic cells, indicating that the neoplastic cells had disintegrated the pia-glial membrane. We analysed the expressions of matrix metalloproteinase-2 (MMP-2) and MMP-9 by using both immunohistochemical analysis and real-time polymerase chain reaction analysis. MMP-2 expression was significantly higher in invasive proliferations. MMP-9 expression was significantly higher in day 7, but there was no significant difference in day 11. The pia-glial membrane and perivascular space are the barriers that neoplastic cells must overcome to infiltrate the brain. In conclusion, our findings suggest that brain metastasis requires two distinct processes.