Diastolic stress echocardiography in patients with normal resting diastolic function: prognostic utility in presence and absence of myocardial ischemia

Background

Abnormal diastolic response to exercise is reportedly associated with worse cardiovascular events. However, this has not been well studied in patients with normal diastolic function at rest.

Purpose

We sought to study diastolic response to exercise in patients referred for exercise stress echocardiography (ExE) and to explore its association with adverse outcomes in the presence and absence of exercise-induced myocardial ischemia.

Methods

In a retrospective study, patients referred for ExE to assess myocardial ischemia between April 2017 and December 2018 were enrolled. Patients were included if they had guideline-defined normal diastolic function at rest and availability of a full set of post exercise diastolic variables (post exercise tissue Doppler derived septal mitral annular early diastolic velocity (e'), ratio of pulsed Doppler derived mitral forward flow early diastolic velocity (E) over e' (E/e') and continuous wave Doppler derived maximum tricuspid regurgitation velocity (TRV)). The patients were followed for a median of 3.4 years for the occurrence of composite death, acute coronary syndrome, cardiac hospitalization, and need of follow-up ischemia testing. Abnormal exercise diastolic variables were defined as e' <7 cm/s, E/e' >15, and TRV >2.8 m/s.

Results

We studied 492 patients [age: 55.7±12.9 year, 268 (54%) women, EF: 61±5.8%]. Mean achieved metabolic equivalents of tasks (METs) was 9.7±3.1, and a total of 49 (10%) patients had evidence of exercise-induced ischemia. At rest, mean left atrial volume index was 25.4±12 ml, e' was 8±2 cm/s, E/e' was 9.5±2.4, and TRV was 2.1±0.44 m/s. Post exercise e' was 10±3 cm/s [<7cm/s in 63 (13%)], E/e' was 11.1±3.9 [>15 in 95 (19%)], and TRV was 2.37±0.68 m/s [>2.8 m/s in 152 (31%)]. Ischemic ExE was found to be strongly associated with the outcome (HR: 4.46, 95% CI: 2.8 to 7.1, p<0.001). In addition, all diastolic variables predicted the outcome in isolation if they were abnormal (e': 2.28, 95% CI: 1.4 to 3.7, p=0.001, E/e': 1.81; 95% CI: 1.15 to 2.84, p=0.01; TRV: 1.58, 95% CI: 1.17 to 2.13, p=0.003). When combined, however, association with the outcome was seen only when 2 or 3 of these variables were abnormal simultaneously (Figure 1A). When patients were stratified by ischemia and abnormal diastolic variables (figure 1B), patients with 2 or 3 abnormal variables were more likely to experience the outcome compared to patients with 0 or 1 abnormal variables in both absence of ischemia (p<0.001) and presence of ischemia (p=0.016). The stratified groups were different in their clinical and exercise profiles, with worse profiles in patients with both ischemia and 2 or 3 abnormal variables, and best profiles in patients with no ischemia and 0 or 1 abnormal variables.

Conclusions

In patients referred for ExE to assess ischemia with normal baseline diastolic function, exercise can unmask abnormal diastolic properties and stratify patients' risk regardless of the overt myocardial ischemia.

Funding Acknowledgement

Type of funding sources: None.

Molecular insights into the development of hepatic metastases in colorectal cancer: a metastasis prediction study

OBJECTIVE

Colorectal cancer is presently the third most commonly diagnosed cancer in the United States. In this study, we identified molecular differences between hepatic and non-hepatic metastases in colorectal cancer and evaluated their prognostic significance.

MATERIALS AND METHODS

We downloaded primary data from the NCBI Gene Expression Omnibus (GSE6988, GSE62321, GSE50760, and GSE28722). To identify the molecular differences, we used the Significance Analysis of Microarray method. We selected nine prognostic genes (SYTL2, PTPLAD1, CDS1, RNF138, PIGR, WDR78, MYO7B, TSPAN3, and ATP5F1) with hepatic metastasis prediction score in colorectal cancer (hereafter referred to as LASSO Score). We confirmed the prognostic significance of the LASSO Score by using Kaplan-Meier survival analysis, multivariate analysis, the time-dependent area under the curve (AUC) of Uno's C-index, and the AUC of the receiver operating characteristic curve at 1-5 years.

RESULTS

Survival analysis revealed that a high LASSO Score is associated with a poor prognosis in colorectal cancer patients with hepatic metastases (p = 0). Analysis of C-indices and AUC values from the receiver operating characteristic curve further supported this prediction by the LASSO Score. Multivariate analysis confirmed the prognostic significance of the LASSO Score (p = 1.13e-06).

CONCLUSIONS

This study reveals the biological mechanisms underlying hepatic metastases in colorectal cancer and will help in developing targeted therapies for colorectal cancer.

Association between immunotherapy biomarkers and glucose metabolism from F-18 FDG PET

OBJECTIVE

To assess associations between parameters derived from F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) and mRNA expression levels of immune checkpoint biomarkers such as programmed death receptor 1 (PD-1), programmed death-ligand 1 (PD-L1), cytotoxic T-lymphocyte antigen 4 (CTLA-4) as well as tumor mutation burden (TMB) in non-small cell lung cancer (NSCLC) patients.

PATIENTS AND METHODS

Integrated data were downloaded from Genomic Data Common Data Portal. Clinical, mRNA-seq, and whole exome-seq data of lung adenocarcinoma and squamous cell carcinoma from The Cancer Genome Atlas (TCGA) database were analyzed. TMB was defined as the total number of somatic missense mutations per megabase of the genome examined. Expression levels of PD-1, PD-L1, CTLA4 mRNA and TMB were collected. Correlations between imaging parameters of glucose metabolism and the expression levels of genomic biomarkers from cancers were evaluated. Bonferroni correction (adjusted p<0.0027) was applied to reduce type 1 error.

RESULTS

Of 31 NSCLC cases, 11 cases were adenocarcinoma (LUAD) and 20 were squamous cell carcinoma (LUSC). In linear regression analysis, texture parameters such as low gray-level run emphasis (LGRE, R2=0.48, p<0.0001), short run low gray-level emphasis (SRLGE, R2=0.45, p<0.0001) and long run low gray-level emphasis (LRLGE, R2=0.41, p=0.0001) derived from gray-level run length matrix (GLRLM) showed remarkable correlation with PD-L1 mRNA expression. Expression of PD-1, CTLA-4, and TMB failed to show any significant correlation with parameters of the F-18 FDG PET/CT.

CONCLUSIONS

Texture parameters derived from PET, known to indicate glucose uptake distribution, were correlated with expression of PD-L1 mRNA but not with expression of PD-1, CTLA-4 and TMB. Thus, tumoral heterogeneity could be a surrogate marker for the identification of PD-L1 level in NSCLC.

Using lactic acid bacteria and packaging with grapefruit seed extract for controlling Listeria monocytogenes growth in fresh soft cheese

Various cheese products are involved in outbreaks of listeriosis worldwide due to high consumption and prolonged refrigerated storage. The objective of this study was to determine the efficacy of using lactic acid bacteria and packaging with grapefruit seed extract (GSE) for controlling Listeria monocytogenes growth in soft cheese. Leuconostoc mesenteroides and Lactobacillus curvatus isolated from kimchi were used as a starter culture to make a soft cheese, which was inoculated with a cocktail strain of L. monocytogenes. The soft cheese was packed with low-density polyethylene, biodegradable polybutylene adipate-co-terephthalate (PBAT), low-density polyethylene with GSE, or PBAT with GSE and stored at 10°C and 15°C. Leuconostoc mesenteroides (LcM) better inhibited the growth of L. monocytogenes than Lb. curvatus. The PBAT with GSE film showed the best control for the growth of L. monocytogenes. When both LcM and PBAT with GSE were applied to the soft cheese, the growth of L. monocytogenes was inhibited significantly more than the use of LcM or PBAT with GSE alone. In all test groups, water activity, pH, and moisture on a fat-free basis decreased, and titratable acidity increased compared with the control group. These results suggest that LcM isolated from kimchi and PBAT with GSE packaging film can be used as a hurdle technology to lower the risk of L. monocytogenes in soft cheese at the retail market.

P1535 Interventricular interaction can result in right ventricular dysfunction in interventricular septum involved myocardial infarction patient

Background

Previous studies revealed that interventricular septal thickness is related to right ventricular dysfunction after anterior myocardial infarction. This finding suggest that interventricular septal function can affect right ventricular function in myocardial infarction patients. We assumed that right ventricular free wall strain values measured using dedicated software can be affected in the setting of ischemic insult on interventricular septum in long-term follow up.

Methods

The patients diagnosed as acute myocardial infarction due to left anterior descending artery disease who underwent successful revascularization were enrolled. Echocardiographic exams were performed at least 2 times, within 72 hours and 1 year after the revascularization. Strain values of interventricular septum and right ventricular free wall were derived from the raw-dicom images. The analysis was performed using the dedicated software for the measurement of right ventricular strain.

Results

Total 65 patients were enrolled. The values of global left ventricular strain were increased after the follow up. There were no changes in global longitudinal strain of the right ventricle. But longitudinal stain values acquired from right ventricular free walls were decreased even the strain values measured at left ventricle and interventricular septum were improved.

Conclusion

Interventricular septal dysfunction due to ischemic injury can affect long term right ventricular dysfunction. This finding suggests the interventricular dependence between cardiac chambers and can provide the development of heart failure in myocardial infarction patient even after the successful revascularization.

Strain values of both ventricles Left ventricle after revascularization (n = 65) 1 year later (n = 65) P values Global longitudinal strain (%) -12.84 ± 4.50 -15.62 ± 4.45 &lt;0.001 Septal longitudinal strain (%) -10.77 ± 5.96 -14.02 ± 5.26 &lt;0.001 Right ventricle Global longitudinal strain (%) -19.36 ± 4.57 -19.47 ± 4.83 0.872 Septal longitudinal strain (%) -14.82 ± 4.48 -16.43 ± 6.03 0.055 Free wall longitudinal strain (%) -20.23 ± 5.33 -17.82 ± 5.70 0.010

Abstract P1535 Figure. Right ventricular segmental strain

Analysis of 'Fuji' apple somatic variants from next-generation sequencing

The domesticated apple (Malus x domestica Borkh.) is a major fruit crop of temperate regions of the world. 'Fuji' apple (Ralls Genet x Delicious), a famous apple cultivar in Korea, has been very popular since its promotion in Japan in 1958. 'Fuji' and its bud mutant cultivars possess variable levels of genetic diversity. Nonetheless, the phenotypes of each group, which are classified into the bud mutation groups: early season, fruiting spur, and coloring, are similar. Despite attempts to identify these bud mutation cultivars, molecular markers, which were developed before the emergence of next-generation sequencing technology, have not been able to distinguish each cultivar easily. In this study, we adopted the resequencing technique using the 'Golden Delicious' (Grimes Golden x Unknown) apple genome as a reference. SNPs (single nucleotide polymorphisms) and InDels (insertions or deletions) of 'Fuji' apple and its bud mutant cultivar were detected and SNPs and unique InDels distinct to each cultivar were identified. Data from this study may be used to identify bud mutant cultivars of 'Fuji' apples and be useful for further breeding of apples.

Development of an E-learning System for the Endoscopic Diagnosis of Early Gastric Cancer: An International Multicenter Randomized Controlled Trial

Background

In many countries, gastric cancer is not diagnosed until an advanced stage. An Internet-based e-learning system to improve the ability of endoscopists to diagnose gastric cancer at an early stage was developed and was evaluated for its effectiveness.

Methods

The study was designed as a randomized controlled trial. After receiving a pre-test, participants were randomly allocated to either an e-learning or non-e-learning group. Only those in the e-learning group gained access to the e-learning system. Two months after the pre-test, both groups received a post-test. The primary endpoint was the difference between the two groups regarding the rate of improvement of their test results.

Findings

515 endoscopists from 35 countries were assessed for eligibility, and 332 were enrolled in the study, with 166 allocated to each group. Of these, 151 participants in the e-learning group and 144 in the non-e-learning group were included in the analysis. The mean improvement rate (standard deviation) in the e-learning and non-e-learning groups was 1·24 (0·26) and 1·00 (0·16), respectively (P < 0·001).

Interpretation

This global study clearly demonstrated the efficacy of an e-learning system to expand knowledge and provide invaluable experience regarding the endoscopic detection of early gastric cancer (R000012039).

•

This report establishes that an e-learning system on the Internet can improve the diagnostic ability of endoscopists.

•

Countless endoscopists worldwide can access the system to learn how to make an endoscopic diagnosis of early gastric cancer.

•

The e-learning system could be modified to provide education regarding endoscopic diagnosis in other organs.

This is the first report to demonstrate how an e-learning system based on the Internet can improve the diagnostic ability of gastrointestinal endoscopists worldwide. There is no limit to the number of endoscopists who can access the system and benefit from this opportunity to learn how to make an endoscopic diagnosis of early gastric cancer. This e-learning system could be modified to provide education regarding endoscopic diagnosis in other organs such as the large intestine and the esophagus, as well as the stomach. It may contribute to human welfare and health by reducing the mortality from gastrointestinal cancer.

Assessment of apple core collections constructed using phenotypic and genotypic data

Several types of information can be used to select core collections, including passport data, agronomic data, and molecular data. However, little is known about the ability of core collections to retain the genetic diversity and structure of the whole collection for characters that were not considered during the selection, particularly when molecular markers are used. In this study, two core subsets were established for the apple (Malus spp) germplasm bank curated at the Apple Research Station, National Institute of Horticultural and Herbal Science, Korea, based upon genetic diversity estimated with 14 simple sequence repeat markers, and phenotypic diversity based on 23 traits. Comparisons between these two subsets and with the whole collection were used to determine the effect of the data used in the selection on phenotypic and genetic diversity, and population structure. The two subsets had a similar diversity and did not differ from the original collection, according to the Nei and Shannon diversity indices. Allele and class frequencies were also maintained in the two subsets. Overall, the type of data used to construct the core collection had little influence on the phenotypic and genetic diversity retained. Therefore, in the case of apple collections, the use of molecular markers is preferable, because they allow rapid and reliable characterization.

Optimisation of bi-layer resist overhang structure formation and SiO2 sputter-deposition process for fabrication of gold multi-electrode array

In this paper we report the results on the optimization of the bi-layer lift-off resist (LOR) SiO₂ sputter-deposition technique which is ideal for obtaining damage-free multi-electrode array (MEA).

Serpin peptidase inhibitor clade A member 1 is a biomarker of poor prognosis in gastric cancer

Background:

In a previous study, we reported that serpin peptidase inhibitor clade A member 1 (serpinA1) is upregulated in Snail-overexpressing gastric cancer. Although serpinA1 has been studied in several types of cancer, little is known about its roles and mechanisms of action. In this study, we examined the role of serpinA1 in the migration and invasion of gastric cancers and determined its underlying mechanism.

Methods:

Expression levels were assessed by western blot analyses and real-time PCR. Snail binding to serpinA1 promoter was analysed by chromatin immunoprecipitation (ChIP) assays. The roles of serpinA1 were studied using cell invasion and migration assays. In addition, the clinicopathologic and prognostic significance of serpinA1 expression were validated in 400 gastric cancer patients using immunohistochemical analysis.

Results:

Overexpression of Snail resulted in upregulation of serpinA1 in gastric cancer cell lines, AGS and MKN45, whereas knockdown of Snail inhibited serpinA1 expression. Chromatin immunoprecipitation analysis showed that overexpression of Snail increased Snail recruitment to the serpinA1 promoter. Overexpression of serpinA1 increased the migration and invasion of gastric cancer cells, whereas knockdown of serpinA1 decreased invasion and migration. Moreover, serpinA1 increased mRNA levels and release of metalloproteinase-8 in gastric cancer cells. Serpin peptidase inhibitor clade A member 1 was observed in the cytoplasm of tumour cells and the stroma by immunohistochemistry. Enhanced serpinA1 expression was significantly associated with increased tumour size, advanced T stage, perineural invasion, lymphovascular invasion, lymph node metastases, and shorter overall survival.

Conclusions:

Serpin peptidase inhibitor clade A member 1 induces the invasion and migration of gastric cancer cells and its expression is associated with the progression of gastric cancer. These results may provide a potential target to prevent invasion and metastasis in gastric cancer.

Cortical thickness and hippocampal shape in pure vascular mild cognitive impairment and dementia of subcortical type

BACKGROUND AND PURPOSE

The progression pattern of brain structural changes in patients with isolated cerebrovascular disease (CVD) remains unclear. To investigate the role of isolated CVD in cognitive impairment patients, patterns of cortical thinning and hippocampal atrophy in pure subcortical vascular mild cognitive impairment (svMCI) and pure subcortical vascular dementia (SVaD) patients were characterized.

METHODS

Forty-five patients with svMCI and 46 patients with SVaD who were negative on Pittsburgh compound B (PiB) positron emission tomography imaging and 75 individuals with normal cognition (NC) were recruited.

RESULTS

Compared with NC, patients with PiB(-) svMCI exhibited frontal, language and retrieval type memory dysfunctions, which in patients with PiB(-) SVaD were further impaired and accompanied by visuospatial and recognition memory dysfunctions. Compared with NC, patients with PiB(-) svMCI exhibited cortical thinning in the frontal, perisylvian, basal temporal and posterior cingulate regions. This atrophy was more prominent and extended further toward the lateral parietal and medial temporal regions in patients with PiB(-) SVaD. Compared with NC subjects, patients with PiB(-) svMCI exhibited hippocampal shape deformities in the lateral body, whilst patients with PiB(-) SVaD exhibited additional deformities within the lateral head and inferior body.

CONCLUSIONS

Our findings suggest that patients with CVD in the absence of Alzheimer's disease pathology can be demented, showing cognitive impairment in multiple domains, which is consistent with the topography of cortical thinning and hippocampal shape deformity.

Comparison of clinical outcomes in hepatitis B virus-positive kidney transplant recipients with or without pretransplantation antiviral therapy

BACKGROUND

Antiviral agents have improved the outcomes of hepatitis B virus (HBV)-positive kidney transplant recipients (KTRs). Preemptive therapy has been the main approach to forestall HBV reactivation. We sought to compare prophylactic and preemptive approaches.

METHODS

We divided the 69 HBV-positive KTRs into treatment and historical control groups, according to the time of starting pretransplantation antiviral therapy. The treatment group was further divided into prophylactic and preemptive therapy groups.

RESULTS

The treatment group showed a significant improvement in 10-year graft (82% vs 34%) and patient (91% vs 57%) survivals. Among the historical control group, the main causes of graft failure were patient deaths (68%), which were mostly caused by liver diseases. In contrast, there was no liver-related death in the treatment group. In addition, there was no difference in graft or patient survival between the prophylactic and preemptive groups, but the incidence of HBV reactivation was lower in the prophylactic group. Antiviral therapy was an independent factor for the improved patient survival (P = .005).

CONCLUSIONS

Pretransplantation antiviral therapy is essential to improve clinical outcomes. Prophylactic may be better than preemptive antiviral therapy to decrease HBV reactivation.

Management of gastric epithelial neoplasia in patients requiring esophagectomy for esophageal cancer

Esophageal squamous cell carcinoma is occasionally associated with malignancies located in other regions of the alimentary tract, as well as in the head, neck, and upper respiratory tract. The stomach is most commonly used for reconstruction of the alimentary tract after esophagectomy for esophageal cancer. When synchronous tumors are located in the stomach, it is often unsuitable for use in esophageal reconstruction. In such cases, an invasive procedure involving anastomosis between the esophagus and the colon must be performed. However, this procedure is associated with a high incidence of mortality and morbidity. Seven patients with synchronous esophageal cancer and gastric epithelial neoplasia were encountered. First, endoscopic submucosal dissection (ESD) was performed for the gastric epithelial neoplasia. Then, following successful ESD, Ivor-Lewis esophagectomy for esophageal cancer was planned 1 to 2 weeks later. A total of 11 gastric epithelial lesions were found in seven patients. En bloc resection by ESD was possible in all 11 lesions and histologically complete resection was achieved in all 11 lesions. Follow-up endoscopy was done 1-2 weeks after ESD; six patients with well-healing ulcers underwent esophagectomy the next day (8 or 15 days after ESD). In one patient with a poorly healed ulcer, a second follow-up endoscopy was done 1 week later and then esophagectomy was performed the next day (22 days after ESD). Post-surgical complications related to ESD, such as bleeding or mediastinal leak, were not seen in any of the seven patients. In patients with synchronous esophageal cancer and gastric epithelial neoplasia, ESD for gastric epithelial neoplasia followed by Ivor-Lewis esophagectomy 1 to 2 weeks later is an effective choice of treatment.

High average-power ultrafast CPA Yb:KYW laser system with dual-slab amplifier

A diode-pumped, ultrafast Yb:KYW laser system utilizing chirped-pulse amplification in a dual-slab regenerative amplifier with spectral shaping of seeding pulse from a master oscillator has been developed. A train of compressed pulses with pulse length of 181 fs, repetition rate up to 200 kHz, and average power exceeding 8 W after compression and pulse picker was achieved.

Autophagy deficiency in beta cells leads to compromised unfolded protein response and progression from obesity to diabetes in mice

AIMS/HYPOTHESIS

The unfolded protein response (UPR) in endoplasmic reticulum (ER) and autophagy are known to be related. We investigated the role of autophagy in UPR of pancreatic beta cells and the susceptibility of autophagy-deficient beta cells to the ER stress that is implicated in the development of diabetes.

METHODS

Rat insulin promoter (RIP)-Cre(+);autophagy-related 7 (Atg7)(F/W) mice were bred with ob/w mice to derive RIP-Cre(+);Atg7(F/F)-ob/ob mice and to induce ER stress in vivo. GFP-LC3(+)-ob/ob mice were generated to examine in vivo autophagic activity. Real-time RT-PCR was performed to study the expression of the genes of the UPR machinery. Proteolysis was assessed by determining release of incorporated radioactive leucine.

RESULTS

Production of UPR machinery was reduced in autophagy-deficient beta cells, which was associated with diminished production of p85α and p85β regulatory subunits of phosphoinositide 3-kinase. Because of compromised UPR machinery, autophagy-deficient beta cells were susceptible to ER stressors in vitro. When mice with beta cell-specific autophagy deficiency, which have mild hyperglycaemia, were bred with ob/ob mice to induce ER stress in vivo, severe diabetes developed, which was accompanied by an increase in beta cell death and accumulation of reactive oxygen species. The increased demand for UPR present in obesity was unmet in autophagy-deficient beta cells. Autophagy level and autophagic activity were enhanced by lipid, while proteolysis was reduced.

CONCLUSIONS/INTERPRETATION

These results suggest that autophagy is important for intact UPR machinery and appropriate UPR in response to lipid injury that increases demand for UPR. Autophagy deficiency in pancreatic beta cells may contribute to the progression from obesity to diabetes.

Preoperative anxiety and pain sensitivity are independent predictors of propofol and sevoflurane requirements in general anaesthesia

BACKGROUND

Psychological factors are thought to drive inter-patient variations in anaesthetic and analgesic requirements. This cross-sectional study investigated whether preoperative psychological factors can predict anaesthetic requirements and postoperative pain.

METHODS

Before total thyroidectomy, 100 consecutive women completed the Spielberger's State-Trait Anxiety Inventory (STAI) and the pain sensitivity questionnaire (PSQ). Target-controlled propofol was administered for induction of anaesthesia, and sevoflurane-oxygen-air was given to maintain equal depths of anaesthesia, as determined by bispectral index (BIS) monitoring.

RESULTS

Patients with higher anxiety scores (state and trait) required greater amounts of propofol to reach light (BIS=85) and moderate (BIS=75) levels of sedation, but only trait anxiety was significantly associated with propofol requirements in reaching a deep level of sedation (BIS=65). The MAC-hour of sevoflurane was significantly correlated only with PSQ scores. The postoperative pain intensity was significantly correlated with both STAI and PSQ.

CONCLUSIONS

Preoperative anxiety and pain sensitivity are independent predictors of propofol and sevoflurane requirements in general anaesthesia. Anaesthetic and analgesic doses could be modified based on the patient's preoperative anxiety and pain sensitivity.

Endoscopic submucosal resection of esophageal subepithelial lesions using band ligation

Subepithelial lesions (SELs) are occasionally found in the esophagus during upper endoscopy. Sometimes endoscopic resection is needed for accurate diagnosis or in the rare cases of malignant transformation of SELs. In this case series, we evaluated the usefulness of endoscopic submucosal resection with a ligation device (ESMR-L) in esophageal SELs. Twenty-three patients with 25 esophageal SELs that were no larger than 13 mm and were localized within the muscularis mucosae or submucosa were enrolled. ESMR-L was successfully performed in all 25 SELs. The en bloc resection rate was 100% (25/25), and histologically complete resection was achieved in 24 lesions (24/25, 96%). After resection of the lesion by snare, minor immediate bleeding occurred in four cases, but there was no delayed bleeding or perforation.

Biomimetic Processing of Ceramics and Ceramic-Metal Composites

Biomimetic design and processing of laminated B4C-Al cermets, based on knowledge gained from the microstructure-property characterization of abalone shells, is described. In the nacre section of the shell, the microstructure is highly organized as CaCO3(aragonite) crystals, with a thickness of 0.25 μm, separated by a layer of organic matter 300–500 Å thick. This organization forms a miniature “brick and mortar” microstructure. The resultant strength and fracture toughness of the nacre, i.e., 180 MPa and 7 MPa-m1/2, are many orders of magnitude higher than those of monolithic CaCO3. The processing of laminated B4C-Al cermets, based on the microstructure of the nacre, was performed by a combination of tape casting of the ceramic and infiltration of the metal. The resultant cermets displayed a 40% increase in both fracture toughness and strength over monolithic B4C-Al cermets.

A case of a giant mucocoele of the appendiceal stump presented with a palpable mass in the right thigh: pre-operative diagnosis based on characteristic multidetector CT findings

The pre-operative diagnosis of a mucocoele of the appendiceal stump (MAS) may be difficult owing to rarity and non-specific clinical presentation. However, a pre-operative diagnosis of a MAS is important to prevent widespread dissemination by inadvertent spillage of mucous contents. We describe a case of a MAS presenting with a palpable mass in the right thigh in which a pre-operative diagnosis was made by characteristic multidetector CT (MDCT) findings.

Improvement of transmittance by fabricating broadband subwavelength anti-reflection structures for polycarbonate

We report on how to increase transmittance of a 0.2 mm thick polycarbonate (PC) film by periodic subwavelength anti-reflection structures in the visible spectral range. Subwavelength anti-reflection structures like moth-eyes are fabricated into the polycarbonate substrate itself by thermal nano-imprinting lithography (TH-NIL), which uses silicon stamps that have periodic structures such as gratings (lines and spaces) and pillared dots, and are fabricated by laser interference lithography (LIL) and transformer coupled plasma etching. To increase transmittance of a polycarbonate film, we control the periods and shapes of patterns, the number of patterned surfaces, and the overlapping direction of patterns that are fabricated into its surfaces. As a result of this, we show that average transmittance improves as the pattern period gets shorter and as both surfaces of the film are patterned. We also show that the spectrum range gets larger as the pattern period gets shorter and is determined by the longer pattern period in the case of designing a film to have different pattern period on its surfaces. The maximum average transmittance of a polycarbonate film increases up to approximately 6% compared to a bare sample in the 470-800 nm spectral range.

Does propofol and alfentanil-induced sedation cause periodic apnoea in chronic renal failure patients?

AIMS

There is evidence suggesting that the respiratory response to sedation is different in patients with sleep apnoea, which is common in patients with chronic renal failure (CRF). This study examined the respiratory response of sedation with propofol and alfentanil, whose pharmacokinetics are not affected by the renal function, in CRF patients.

METHODS

Chronic renal failure patients who underwent arteriovenous-fistular surgery (CRF group) and patients who underwent chemoport insertion (control group) were enrolled in this study. Sedation was induced by infusing propofol 1.5 micro/ml and alfentanil 0.2 micro/kg/min continuously in both groups. In the desaturation study, the respiratory rate and peripheral oxygen saturation in room air were checked. In the apnoea-hypopnoea study, the patient's sedation (Observer's Assessment of Alertness/Sedation) score, apnoea-hypopnoea index (AHI) was recorded using a portable ventilation effort recorder (microMesam) while applying 5 l/min of oxygen through a facial mask.

RESULTS

The desaturation event was more common (21.5/h vs. 2/h, p = 0.001) in the CRF patients. Apnoea and hypopnoea (AHI: 13.0 vs. 1.6, p = 0.012, per cent of patients with an AHI > 5: 53.3% vs. 7.1%, p = 0.014) occurred more frequently in the CRF patients but the sedation score was not different.

CONCLUSION

Chronic renal failure patients have a higher risk of developing apnoea and hypopnoea during sedation, which highlights the need for careful monitoring and management in these patients.

Identification of glutathione conjugates and mercapturic acids of 1,2-dibromopropane in female BALB/c mice by liquid chromatography-electrospray ionization tandem mass spectrometry

Based on recent results that 1,2-dibromopropane (1,2-DBP) causes hepatotoxicity and immunotoxicity in female BALB/c mice as well as a reduction of hepatic glutathione levels, the possible formation of glutathione conjugates and mercapturic acids of 1,2-DBP was investigated in vivo in the present studies. The following four metabolites were identified in the liver at 12 h after treatment with 1,2-DBP, by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI/MS): M1, 2-hydroxypropylglutathione; M2, 2-oxopropylglutathione; M3, N-acetyl-S-(2-hydroxypropyl)-L-cysteine; and M4, N-acetyl-S-(2-oxopropyl)-L-cysteine. Ions of individual conjugates were observed at m/z 366, 364, 222 and 220, respectively. Characteristic product ions at m/z 237, 217, 204 and 202 for the identification of M1, M2, M3 and M4 were observed, respectively. In the sera isolated from the same animals, only mercapturic acids (M3 and M4) were observed by LC-ESI/MS. When female BALB/c mice were treated orally with 1,2-DBP at doses of 150, 300 and 600 mg kg(-1) once for 12 h, the production of glutathione conjugates and mercapturic acids in liver was apparently dose dependent, as were the concentrations of them in sera. When the production of metabolites from 1,2-DBP was investigated in liver following oral treatment with 600 mg kg(-1) 1,2-DBP for 6, 12, 24 and 48 h, metabolite concentrations were greatest at the first time point (6 h). The results explain the authors' previous studies that oral treatment with 1,2-DBP reduces the hepatic content of glutathione.

Resin bonding using an all-etch or self-etch adhesive to enamel after carbamide peroxide and/or CPP-ACP treatment

BACKGROUND

Limited evidence exists regarding the effect of carbamide peroxide and casein phosphopeptide amorphous calcium phosphate (CPP-ACP) on composite-enamel bonding. Microshear bond strengths, using either a total-etch or self-etching adhesive, to enamel treated with carbamide peroxide and/or CPP-ACP were investigated.

MATERIALS AND METHODS

Twenty-six extracted human third molars were sectioned into four parts, each being allocated into one of the four groups (n=26): bleach (Polanight, 16% carbamide peroxide), CPP-ACP (GC Tooth Mousse), bleach and then CPP-ACP, or untreated (control). The surfaces were bonded with a total-etch bonding system (Single Bond) or a self-etching primer system (Clearfil SE Bond) and tested using a microshear test.

RESULTS

A significant difference in bond strength was found between bonding systems. SE Bond showed the highest bond strength to untreated enamel (p < 0.05). The microshear bond strength of SE Bond decreased when the enamel was treated with carbamide peroxide, CPP-ACP or both (p < 0.05). Only combined use of carbamide peroxide and CPP-ACP significantly affected microshear bond strength with Single Bond.

CONCLUSION

These findings suggest the shear bond strength of resin to enamel using a self-etching priming adhesive may be affected if the enamel is treated with a bleaching agent or CPP-ACP.

Evaluation of the biliary tract: The value of performing magnetic resonance cholangiopancreatography in conjunction with a 3-D spoiled gradient-echo gadolinium enhanced dynamic sequence

The 3-D gradient-echo (GRE) sequence allows thinner sections and better resolution of biliary obstruction. When the presence of biliary obstruction is identified using magnetic resonance cholangiopancreatography, the addition of the 3-D GRE sequence may be helpful for diagnosing biliary obstruction. By showing the changes in the bile duct wall, within the duct lumen and around the bile duct, this technique can be helpful for distinguishing benign from malignant stricture as well as a stone from an enhancing intraluminal mass.

A mechanical spike accompanies the action potential in Mammalian nerve terminals

Large and rapid changes in light scattering accompany secretion from nerve terminals of the mammalian neurohypophysis (posterior pituitary). In the mouse, these intrinsic optical signals are intimately related to the arrival of the action potential E-wave and the release of arginine vasopressin and oxytocin (S-wave). Here we have used a high bandwidth atomic force microscope to demonstrate that these light-scattering signals are associated with changes in terminal volume that are detected as nanometer-scale movements of a cantilever positioned on top of the neurohypophysis. The most rapid mechanical response ("spike"), having a duration shorter than the action potential but comparable to that of the E-wave, represents a transient increase in terminal volume due to water movement associated with Na(+)-influx. The slower mechanical event ("dip"), on the other hand, depends upon Ca(2+)-entry as well as on intraterminal Ca(2+)-transients and, analogously to the S-wave, seems to monitor events associated with secretion.

Changes in FAD and NADH fluorescence in neurosecretory terminals are triggered by calcium entry and by ADP production

We measured changes in the intrinsic fluorescence (IF) of the neurosecretory terminals of the mouse neurohypophysis during brief (1-2 s) trains of stimuli. With fluorescence excitation at either 350 +/- 20 or 450 +/- 50 nm, and with emission measured, respectively, at 450 +/- 50 or > or = 520 nm, DeltaF/F(o) was approximately 5-8 % for a 2 s train of 30 action potentials. The IF changes lagged the onset of stimulation by approximately 100 ms and were eliminated by 1 microM tetrodotoxin (TTX). The signals were partially inhibited by 500 microM Cd(2+), by substitution of Mg(2+) for Ca(2+), by Ca(2+)-free Ringer's with 0.5 mM EGTA, and by 50 microM ouabain. The IF signals were also sensitive to the mitochondrial metabolic inhibitors CCCP (0.3 microM), FCCP (0.3 microM), and NaN(3) (0.3 mM), and their amplitude reflected the partial pressure of oxygen (pO(2)) in the bath. Resting fluorescence at both 350 nm and 450 nm exhibited significant bleaching. Flavin adenine dinucleotide (FAD) is fluorescent, while its reduced form FADH(2) is relatively non-fluorescent; conversely, NADH is fluorescent, while its oxidized form NAD is non-fluorescent. Thus, our experiments suggest that the stimulus-coupled rise in [Ca(2+)](i) triggers an increase in FAD and NAD as FADH(2) and NADH are oxidized, but that elevation of [Ca(2+)](i), alone cannot account for the totality of changes in intrinsic fluorescence.

Characterization of the Phase II metabolites of rutaecarpine in rat by liquid chromatography-electrospray ionization-tandem mass spectrometry

From the authors' previous studies on the Phase I metabolism of rutaecarpine, nine metabolites formed were identified as products of hydroxylation on the aromatic rings in rat liver microsomes. In order to determine the possible metabolic fate of rutaecarpine, the Phase II metabolites of rutaecarpine were characterized in the present study by using liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS). When male Sprague-Dawley rats were treated intravenously with 4 mg kg(-1) rutaecarpine, 16 different Phase I and II metabolites were identified in urine including four sulfate and four glucuronide conjugates. Phase I metabolites of rutaecarpine were identified as four mono-hydroxylated metabolites (M2-5) and four isobaric di-hydroxylated metabolites (M6-9). These metabolites were identical to the in vitro metabolites except one, which was hydroxylated in the aliphatic moiety. In addition, Phase II metabolites were identified as conjugated with sulfate (S1-4) and glucuronide (G1-4). In faeces, 11 different metabolites were identified. The metabolites M8 and glucuronide conjugated (G1-4) were not detected. Structures of all metabolites were confirmed with CID fragmentation spectra of MS(2), MS(3) and retention times by LC/ESI-MS.

Quasimonoenergetic electron beam generation by using a pinholelike collimator in a self-modulated laser wakefield acceleration

A relativistic electron bunch with a large charge (>2 nC) was produced from a self-modulated laser wakefield acceleration configuration. For this experiment, an intense laser beam with a peak power of 2 TW and a duration of 700 fs was focused in a supersonic He gas jet, and relativistic high-energy electrons were observed from the strong laser-plasma interaction. By passing the electron bunch through a small pinholelike collimator, we could generate a quasimonoenergetic high-energy electron beam, in which electrons within a cone angle of 0.25 mrad (f/70) were selected. The beam clearly showed a narrow-energy-spread behavior with a central energy of 4.3 MeV and a charge of 200 pC. The acceleration gradient was estimated to be about 30 GeV/m. Particle-in-cell simulations were performed for comparison study and the result shows that both the experimental and simulation results are in good agreement and the electron trapping is initiated by the slow beat wave of the Raman backward wave and the incident laser pulse.

Duration curve analysis for the assessment of pathogen loading from diffuse sources

Pathogen level of surface waters has received great attention for protecting public health. In this study, total coliform, fecal coliform and Escherichia coli concentrations were monitored as the pathogen indicator organisms at six monitoring stations in the Geum River, Korea. Rainfall runoff from two agricultural-forestry watersheds was analyzed for their microbial aspect as well. Total coliform concentration of the Geum River showed high correlation with the flow rate. To estimate total coliform loading on the Geum River in probability scale, the duration curve method was applied. In addition, a standard duration curve reflecting the water quality criteria was constructed to determine water quality compliance. Under the assumption of linearity between flow rate and total coliform concentration of the Geum River, total coliform duration curve revealed that total coliform concentrations exceed the desired criteria mainly due to pollutants from diffuse sources.

Smad4 expression in gastric adenoma and adenocarcinoma: frequent loss of expression in diffuse type of gastric adenocarcinoma

Smads are signal transducers for the members of the TGF-beta superfamily. Of these Smads, Smad4 is essential for TGF-beta signaling. The purpose of this study was to elucidate Smad4 expression and localization in 65 gastric adenomas, 49 intestinal-type and 39 diffuse type of gastric adenocarcinomas (including 12 cases of fresh frozen tissue) using Real-time RT-PCR and immunohistochemistry. Real-time RT-PCR showed that intestinal type gastric adenocarcinomas have higher Smad4 mRNA expression than diffuse type gastric adenocarcinomas. Immunohistochemical stain for Smad4 revealed that expression of Smad4 was significantly lower in diffuse-type gastric adenocarcinoma than intestinal-type gastric adenocarcinomas. Also, higher Smad4 protein expression in intestinal type gastric adenocarcinomas than overall gastric adenoma was noted. The rate of reduced Smad4 expression was higher in advanced gastric cancer than early gastric cancer. These results suggest that Smad4 might play different roles in human gastric carcinogenesis, especially between intestinal type and diffuse type of gastric adenocarcinoma.

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.

Serum keratan sulphate as a cartilage metabolic marker in horses: the effect of exercise

Keratan sulphate (KS) concentration in sera from resting horses and horses training daily on a racetrack was measured by an inhibition enzyme-linked immunosorbent assay (ELISA) using anti-equine KS antibody 1/14/16H9. For the in-training horses, serum KS concentrations in 2-year-old-horses was significantly higher than 3- or 4-year-old-horses. A higher concentration of serum KS was found in the in-training group than in the long-term resting group in 2-year-old-horses. Serum KS concentration increased remarkably immediately after training in healthy horses, and at 1, 5, 9 and 24 h after training remained at similar levels to the pre-training concentration. The results suggest that serum KS concentration could represent the situation of joint loading, induced by daily racetrack training, affecting the metabolic activities in joint cartilage.