Long-term clinical outcomes of endoscopic submucosal dissection for colorectal neoplasia with or without the hybrid technique

AIM

The main aim of this study was to compare the long-term outcome of a conventional colorectal endoscopic submucosal dissection (ESD) in which submucosal dissection was continued throughout until the completion of resection (ESD-T) to hybrid endoscopic submucosal dissection (ESD-H) in the colorectum.

METHOD

Medical records of 836 colorectal neoplasia patients treated by ESD-T or ESD-H were reviewed. ESD-H was defined as colorectal ESD with additional snaring in the final stage of the procedure. Primary outcomes were the overall and metastatic recurrence rates. Secondary outcomes were short-term outcomes such as the en bloc resection rate, procedure time and adverse events.

RESULTS

The overall recurrence rate was higher in the ESD-H than in the ESD-T group (5.7% vs 0.7%, P = 0.001). The metastatic recurrence rate showed no significant difference between these groups (1.4% vs 1.4%, P = 1.000). Multivariate analysis revealed that a failed en bloc resection (hazard ratio 24.097; 95% CI 5.446-106.237; P < 0.001) and larger tumour size (hazard ratio 1.042; 95% CI 1.014-1.070; P = 0.003) were independently associated with overall recurrence. The ESD-H group showed a lower en bloc resection rate (56.8% vs 96.5%, P < 0.001), shorter procedure time (45.6 vs 54.3 min, P < 0.001) and higher perforation rate (10.3% vs 6.0%, P = 0.029).

CONCLUSION

Although long-term outcomes in terms of overall recurrence are inferior following ESD-H, a failed en bloc resection and large tumour size are the only independent risk factors for recurrence. Further investigations are warranted to improve the long-term outcomes of ESD-H.

Midkine Promotes Odontoblast-like Differentiation and Tertiary Dentin Formation

Autophagy is an intracellular self-degradation process that is essential for tissue development, cell differentiation, and survival. Nevertheless, the role of autophagy in tooth development has not been definitively identified. The goal of this study was to investigate how autophagy is involved in midkine (MK)-mediated odontoblast-like differentiation, mineralization, and tertiary dentin formation in a mouse tooth pulp exposure model. In vitro studies show that MK and LC3 have similar expression patterns during odontoblast-like cell differentiation. Odontoblast-like cell differentiation is promoted through MK-mediated autophagy, which leads to increased mineralized nodule formation. Subcutaneous transplantation of hydroxyapatite/tricalcium phosphate with rMK-treated human dental pulp cells led to dentin pulp-like tissue formation through MK-mediated autophagy. Furthermore, MK-mediated autophagy induces differentiation of dental pulp cells into odontoblast-like cells that form DSP-positive tertiary dentin in vivo. Our findings may provide 1) novel insight into the role of MK in regulating odontoblast-like differentiation and dentin formation in particular via autophagy and 2) potential application of MK in vital pulp therapy.

Salivary microbiota in periodontal health and disease and their changes following nonsurgical periodontal treatment

Purpose

The aims of this study were to examine the salivary microbiota in conditions of periodontal health and disease and to explore microbial changes following nonsurgical periodontal treatment.

Methods

Non-stimulated saliva samples were collected from 4 periodontally healthy participants at baseline and from 8 patients with chronic periodontitis at baseline and 3 months following nonsurgical periodontal therapy. The V3 and V4 regions of the 16S rRNA gene from the DNA of saliva samples were amplified and sequenced. The salivary microbial compositions of the healthy participants and patients with periodontitis prior to and following nonsurgical treatment of periodontitis were compared based on the relative abundance of various taxa.

Results

On average, 299 operational taxonomic units were identified in each sample. The phylogenetic diversity in patients with periodontitis was higher than that in healthy participants and decreased following treatment. The abundance of the phylum Spirochaetes and the genus Treponema in patients with periodontitis was 143- and 134-fold higher than in the healthy control group, respectively, but decreased significantly following treatment. The species that were overabundant in the saliva of patients with periodontitis included the Peptostreptococcus stomatis group, Porphyromonas gingivalis, the Fusobacterium nucleatum group, Parvimonas micra, Porphyromonas endodontalis, Filifactor alocis, and Tannerella forsythia. The phylum Actinobacteria, the genus Streptococcaceae_uc, and the species Streptococcus salivarius group were more abundant in healthy participants than in those with periodontitis. There was a trend toward a decrease in disease-associated taxa and an increase in health-associated taxa following treatment.

Conclusions

Our results revealed differences in the taxa of salivary microbiota between conditions of periodontal health and disease. The taxa found to be associated with health or disease have potential for use as salivary biomarkers for periodontal health or disease.

P1526Pre-dialysis left atrial function assessed by two-dimensional speckle tracking echocardiography as a predictor of upcoming heart failure in hemodialysis patients

Background

Left atrial global longitudinal strain (LA GLS) by 2-dimensional speckle tracking echocardiography is a useful tool to assess LA function and left ventricular (LV) diastolic function. The authors assessed prognostic value of LA GLS, and other diastolic functional parameters in patients undergoing hemodialysis.

Methods

A total of 78 (49 male) patients undergoing hemodialysis who checked echocardiography due to heart failure (HF) symptoms were included for this analysis. Echocardiography wasperformed at the same day of, and before hemodialysis session. Besides conventional echocardiographic measurements, GLS of the LA and the LV were checked and compared. Incidence of rehospitalization due to HF symptoms during mean follow up duration of 381.4±197.5 days was investigated and echocardiographic parameters were compared between patients who experienced rehospitalization and who did not.

Results

16 (20.1%) patients experienced rehospitalization due to HF. HF rehospitalization group had significantly low baseline LV ejection fraction (55.7±7.2 vs. 61.3±7.1%, p=0.006) and LV GLS (14.7±3.4 vs. 18.2±3.9%, p=0.002), while LV geometry (LV end-diastolic volume index and LV wall thickness) did not show significant differences. In HF rehospitalization group, baseline LA function and diastolic function were significantly impaired as reflected by LA GLS (18.8±2.6 vs. 23.8±3.6%, p<0.001), E/E' ratio (20.8±3.3 vs. 15.8±4.6%, p<0.001), and right ventricular systolic pressure (61.4±9.6 vs. 53.4±12.8%, p=0.022). LA end-systolic volume index was not significantly different between the 2 groups. Among various echocardiographic parameters, receiver operation characteristic curve analysis revealed that LA GLS had the strongest power (cutoff value 20.6%, sensitivity 0.813 and specificity 0.790, area under curve 0.849) in prediction of future rehospitalization due to HF.

Predictor of future HF: ROC analysis

Conclusions

The present study demonstrated that functional changes of the LA as measured by LA GLS before hemodialysis session can be used as an echocardiographic parameter to predict future rehospitalization due to HF. Further studies are required to evaluate prognostic value of LA function in predicting other cardiovascular events in hemodialysis patients.

P688Cardiac dysfunction as a predictor of hepatic sinusoidal obstruction syndrome after hematopoietic cell transplantation

Background

Hepatic sinusoidal obstruction syndrome (HSOS) is a well-known fatal complication of hematopoietic cell transplantation (HCT), but the impact of cardiac abnormalities on the occurrence of HSOS has been poorly evaluated. Therefore, the authors investigated whether the structural changes or dysfunction of the heart before HCT is associated with the future occurrence of HSOS.

Methods

A total of 92 patients who underwent HCT were divided into 2 groups; HSOS group (n=11, 6 males, 53.8±15.9 years) vs no HSOS group (n=81, 51 males, 48.6±14.7 years). According to the modified Seattle criteria, HSOS was defined as otherwise unexplained occurrence of 2 or more of the following events within 20 days of HCT; serum total bilirubin >2 mg/dL, hepatomegaly or right upper quadrant pain, sudden weight gain due to fluid accumulation (>2% of baseline body weight). Echocardiography examinations were performed 1 month before HCT, and echocardiographic findings were compared between the groups.

Results

HSOS was developed in 11 patients (12.0%). HSOS group had significantly larger left ventricular end-diastolic volume index (LVEDVI) (65.2±4.9 vs 53.2±6.9 ml/m2, p<0.001) and relatively worse systolic function than no HSOS group (LV ejection fraction: 56.4±3.4 vs 65.1±5.9%, p<0.001, LV global longitudinal strain: −17.9±1.4 vs −20.1±2.0%, p=0.001). LV diastolic functional parameters were also significantly worse in HSOS group than in no HSOS group (E/E' ratio: 11.3±1.8 vs 9.1±2.0, p=0.002, left atrial global longitudinal strain: 27.7±3.3 vs 34.9±5.9%, p<0.001). However, left atrial volume index was not different between the groups (30.8±2.8 vs 29.0±3.3 ml/m2, p=0.078). By receiver operation characteristic curve analysis, among significantly different variables, LVEDVI was the most powerful predictor for HSOS, and the optimal cutoff value was 59.25 mL/m2. (81.8% sensitivity and 77.8% specificity, AUC 0.909).

Predictor of HSOS: ROC analysis

Conclusions

The present study demonstrated that structural changes or dysfunction of the heart are more prevalent in patients with HSOS after HCT and larger LVEDVI, among them, can be a useful predictor of upcoming HSOS. Routine echocardiographic study before HCT would be useful to identify high risk group for HSOS, and the development of HSOS should be carefully monitored in HCT patients with cardiac structural changes or dysfunction on echocardiography.

P671Impacts of echocardiography-defined pulmonary hypertension on clinical outcome in patients with multiple myeloma

Background

Pulmonary hypertension (PH) is a rarely reported complication of multiple myeloma (MM). PH of MM is usually mild to moderate and can be secondary to a variety of conditions, including left ventricular dysfunction, diastolic dysfunction, chronic heart failure, treatment-related toxicity, thrombophilic condition and precapillary involvement. However, only few reports regarding PH in MM incidence and prognosis exist up to now.

Purpose

The purpose of this study was to investigate the risk factors of transthoracic echocardiography-defined PH and its impact on clinical outcome in patients with MM.

Methods

A total of 277 MM patients was included and divided into 2 groups–those non-pulmonary hypertension (PH) or those with PH, based on the results of the transthoracic echocardiography (TTE); PH group (n=143, 60.9±9.2 years, 68 males) versus non-PH group (n=134, 55.9±11.5 years, 72 males). We analyzed propensity score matching and multiple imputation method were used to deal with the missing data in echocardiographic characteristics.

Results

During the follow-up period (median 618 days), all-cause death occurred in 79 (28.5%) patients and 41 patients (14.8%) died from cardiovascular causes (including acute decompensated heart failure, fatal MI, sudden cardiac arrest). In the Kaplan-Meier survival analysis of crude population and propensity-matched population, cumulative overall survival and cardiovascular death (CVD)-free survival were significantly lower in the PH group than in the non-PH group (p<0.001). In propensity-matched population, estimated pulmonary artery pressure >35mmHg in TTE, congestive heart failure, and DM were significant independent predictors of all-cause death.

KM curves in MM stratified by PH

Conclusion

This study demonstrates that the presence of PH, congestive heart failure, and DM is an independent prognostic factor for all-cause death in MM patients with MM. These results highlight the risk associated cardiovascular disease in MM patients and emphasize that management strategies that prevent deterioration of cardiac function are essential.

Dental Stem Cells and Their Applications

Stem cells are unspecialised cells that can divide, renew, and differentiate into more specialised cells. Due to their unique properties, stem cells are known for their use in therapies and treatments for missing tissues and damaged parts of the body. However, due to the invasive nature and other ethical issues with the retrieval process and usage of stem cells, stem cells are clinically being used in a limited manner. Furthermore, due to the invasive nature of the retrieval process elsewhere, dental tissues are one of the most preferred sources for stem cells. This review covers all of the characteristics of dental tissue-derived stem cells and their potential future uses.

Genetic driver mutations define the expression signature and microenvironmental composition of high-grade gliomas

High-grade gliomas (HGG), including glioblastomas, are characterized by invasive growth, resistance to therapy, and high inter- and intra-tumoral heterogeneity. The key histological hallmarks of glioblastoma are pseudopalisading necrosis and microvascular proliferation, which allow pathologists to distinguish glioblastoma from lower-grade gliomas. In addition to being genetically and molecularly heterogeneous, HGG are also heterogeneous with respect to the composition of their microenvironment. The question of whether this microenvironmental heterogeneity is driven by the molecular identity of the tumor remains controversial. However, this question is of utmost importance since microenvironmental, non-neoplastic cells are key components of the most radiotherapy- and chemotherapy-resistant niches of the tumor. Our work demonstrates a versatile, reliable, and reproducible adult HGG mouse model with NF1-silencing as a driver mutation. This model shows significant differences in tumor microenvironment, expression of subtype-specific markers, and response to standard therapy when compared to our established PDGFB-overexpressing HGG mouse model. PDGFB-overexpressing and NF1-silenced murine tumors closely cluster with human proneural and mesenchymal subtypes, as well as PDGFRA-amplified and NF1-deleted/mutant human tumors, respectively, at both the RNA and protein expression levels. These models can be generated in fully immunocompetent mixed or C57BL/6 genetic background mice, and therefore can easily be incorporated into preclinical studies for cancer cell-specific or immune cell-targeting drug discovery studies.

Self-expandable metal stents for malignant esophageal obstruction: a comparative study between extrinsic and intrinsic compression

Self-expandable metal stents (SEMSs) are effective for malignant esophageal obstruction, but usefulness of SEMSs in extrinsic lesions is yet to be elucidated. This study is aimed at evaluating the clinical usefulness of SEMSs in the extrinsic compression compared with intrinsic. A retrospective review was conducted for 105 patients (intrinsic, 85; extrinsic, 20) with malignant esophageal obstruction who underwent endoscopic SEMSs placement. Technical and clinical success rates were evaluated and clinical outcomes were compared between extrinsic and intrinsic group. Extrinsic group was mostly pulmonary origin. Overall technical and clinical success rate was 100% and 91%, respectively, without immediate complications. Extrinsic and intrinsic group did not differ significantly in clinical success rate. The median stent patency time was 131.3 ± 85.8 days in intrinsic group while that of extrinsic was 54.6 ± 45.1 due to shorter survival after stent insertion. The 4-, 8-, and 12-week patency rates were 90.5%, 78.8%, and 64.9% respectively in intrinsic group, while stents of extrinsic group remained patent until death. Uncovered, fully covered, and double-layered stent were used evenly and the types did not influence patency in both groups. In conclusion, esophageal SEMSs can safely and effectively be used for malignant extrinsic compression as well as intrinsic.

Panoramic measures for oral bone mass in detecting osteoporosis: a systematic review and meta-analysis

Different quantitative and qualitative indices calculated on oral panoramic radiographs have been proposed as useful tools to screen for reduced skeletal bone mineral density (BMD). Our aim was to systematically review the literature on linear and qualitative panoramic measures and to assess the accuracy of these indices by performing a meta-analysis of their sensitivity and specificity. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement was followed. Fifty studies were included in the qualitative appraisal and 19 were considered for meta-analysis. The methodological quality of the retrieved studies, assessed with the QUADAS-2 tool, was on average low. Three indices were reported by most of the studies: mandibular cortical width, panoramic mandibular index, and the Klemetti index. Mandibular cortical width presented with a better accuracy in excluding osteopenia/osteoporosis (specificity), since patients with a cortical width more than 4 mm had a normal BMD in 90% of the cases. Almost all studies used a cutoff of 0.3 for the panoramic mandibular index, resulting in an estimated sensitivity and specificity in detecting reduced BMD, respectively, of 0.723 (SE 0.160; 95% confidence interval [CI], 0.352-0.926) and 0.733 (SE 0.066; 95% CI, 0.587-0.841). The presence of any kind of mandibular cortical erosion gave an estimated sensitivity and specificity in detecting reduced BMD, respectively, of 0.789 (SE 0.031; 95% CI, 0.721-0.843) and 0.562 (SE 0.047; 95% CI, 0.47-0.651) and a sensitivity and specificity in detecting osteoporosis, respectively, of 0.806 (SE 0.105; 95% CI, 0.528-0.9200) and 0.643 (SE 0.109; 95% CI, 0.417-0.820). The mandibular cortical width, panoramic mandibular index, and Klemetti index are overall useful tools that potentially could be used by dentists to screen for low BMD. Their limitations are mainly related to the experience/agreement between different operators and the different image quality and magnification of the panoramic radiographs.

Effect of vitamin levels and different stocking densities on performance, nutrient digestibility, and blood characteristics of growing pigs

This study was conducted to evaluate the effects of dietary vitamin levels and stocking densities on growth performance, nutrient digestibility, and blood characteristics in growing pigs. A 2×3 factorial (two vitamin levels, three regimens of stocking densities) arrangement was utilized with 96 pigs (23.10×0.95 kg initial body weight and 63 d of age) for 36 d. The pigs were allocated to pens with different stocking density (0.64, 0.48, and 0.38 m(2)/pig, respectively). The diets used in this study were a normal diet (based on NRC) and a high level of vitamin diet (2-fold higher than normal diet). The ADG and ADFI of pigs were decreased as the stocking density increased (p = 0.03 and p = 0.01, respectively). The G/F of pigs was 5% lower in the high vitamin treatment (p = 0.03) as compared with the control treatment. The apparent total tract digestibility (ATTD) of DM and N digestibility was negatively affected by the high level of vitamin in diets (p = 0.05 and p = 0.04, respectively). Moreover, a significant and negative effect on the ATTD of N was detected in the large groups (linear, p = 0.02). Blood cortisol concentration was increased with increasing stocking density (linear, p = 0.05), and was decreased by high level of vitamin (p = 0.04) at the end of this experiment. Stocking density also caused a linear reduction in WBC concentration (p = 0.05). Our data indicated that the principal effect of stocking density was not reliant on dietary vitamin levels. In conclusion, results indicated that doubling the vitamin supplementation did not improve the growth performance of pigs in high density. However, the blood cortisol concentration was decreased but the ATTD of N digestibility was impaired by high level of vitamin diet.

Effect of dietary supplementation of procyanidin on growth performance and immune response in pigs

This study was performed to determine the effect of dietary supplementation of procyanidin on growth performance, blood characteristics, and immune function in growing pigs. In experiment 1 (Exp. 1), thirty-two crossbred pigs with an initial BW of 19.2±0.3 kg were allocated into 4 treatments for an 8-wk experiment: i) CON (basal diet), ii) MOS 0.1 (basal diet+0.1% mannanoligosaccharide), iii) Pro-1 (basal diet+0.01% procyanidin), and iv) Pro-2 (basal diet+0.02% procyanidin). Pigs fed Pro-1 and Pro-2 diets had greater (p<0.05) gain:feed ratio compared with those fed CON or MOS 0.1 diets. Serum creatinine concentration was less (p<0.05) in Pro-2 treatment than those in CON, MOS 0.1 and Pro-1 treatments. In Exp. 2, twelve pigs (BW 13.4±1.3 kg) received basal diet with i) 0 (CON), ii) 0.02% (Pro-0.02%), and iii) 0.04% procyanidin (Pro-0.04%) for 4 wk. Concentration of platelets was lower (p<0.05) in the Pro-0.04% group compared to CON at 24 h after lipopolysaccharide (LPS) challenge. In addition, secretion of cytokines from cultured peripheral blood mononuclear cells (PBMC) in the presence or absence of procyanidin was examined. The levels of interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α were lower (p<0.05) in Pro (LPS-stimulated PBMCs+procyanidin) than those in CON (LPS-stimulated PBMCs+PBS) at 4 h after LPS challenge. These data suggest that dietary addition of procyanidin improves feed efficiency and anti-inflammatory cytokines of pigs.

Effects of Dietary Fat Types on Growth Performance, Pork Quality, and Gene Expression in Growing-finishing Pigs

This study was performed to determine the effects of dietary fat sources, i.e., beef tallow, soybean oil, olive oil and coconut oil (each 3% in feed), on the growth performance, meat quality and gene expression in growing-finishing pigs. A total of 72 crossbred pigs (Landrace×Large White×Duroc) were used at 71±1 kg body weight (about 130 d of age) in 24 pens (320×150 cm) in a confined pig house (three pigs per pen) with six replicate pens per treatment. The growing diet was given for periods of 14±3 d and the finishing diet was given for periods of 28±3 d. The fat type had no significant effect either on growth performance or on chemical composition or on meat quality in growing-finishing pigs. Dietary fat type affected fatty acid composition, with higher levels of unsaturated fatty acids (UFAs) and monounsaturated fatty acids (MUFAs) in the olive oil group. Microarray analysis in the Longissimus dorsi identified 6 genes, related to insulin signaling pathway, that were differentially expressed among the different feed groups. Real time-PCR was conducted on the six genes in the longissimus dorsi muscle (LM). In particular, the genes encoding the protein kinase, cAMP-dependent, regulatory, type II, alpha (PRKAR2A) and the catalytic subunit of protein phosphatase 1, beta isoform (PPP1CB) showed the highest expression level in the olive oil group (respectively, p<0.05, p<0.001). The results of this study indicate that the type of dietary fat affects fatty acid composition and insulin signaling-related gene expression in the LM of pigs.

Evaluation of Houttuynia cordata and Taraxacum officinale on Growth Performance, Nutrient Digestibility, Blood Characteristics, and Fecal Microbial Shedding in Diet for Weaning Pigs

A total of 144 pigs ((Landrace×Yorkshire)×Duroc] with an average initial BW of 8.45±0.57 kg were used in a 5-wk growth trial. Pigs were randomly allocated to 4 treatments with 9 replications per pen in a randomized complex block design. Dietary treatments included: i) CON (basal diet), ii) ANT (CON+tylosin 1 g/kg), iii) H1 (CON+H. cordata 1 g/kg) and iv) T1 (CON+T. officinale 1 g/kg). In this study, pigs fed the ANT and T1 treatment had a higher (p<0.05) average daily gain (ADG) and gain:feed (G:F) ratio than those fed CON and H1 treatment. Dietary ANT and T1 treatment led to a higher energy digestibility than the CON group. No difference (p>0.05) was observed on the growth performance and apparent total tract digestibility with H1 supplementation compared with the CON treatment. The inclusion of ANT treatment led to a higher (p<0.05) lymphocyte concentration compared with the CON treatment. Dietary supplementation of herbs did not affect (p>0.05) the blood characteristics (white blood cell (WBC), red blood cell (RBC), IgG, lymphocyte). No difference was observed on (p<0.05) fecal microbial shedding (E. coli and lactobacillus) between ANT and CON groups. Treatments H1 and T1 reduced the fecal E. coli concentration compared with the CON treatment, whereas the fecal lactobacillus concentration was not affected by the herb supplementation (p>0.05). In conclusion, the inclusion of T. officinale (1 g/kg) increased growth performance, feed efficiency, energy digestibility similarly to the antibiotic treatment. Dietary supplementation of T. officinale and H. cordata (1 g/kg) reduced the fecal E. coli concentration in weaning pigs.

Heterogeneity of mucosal mast cell infiltration in subgroups of patients with esophageal chest pain

BACKGROUND

Although there is growing evidence that an increase in mucosal mast cells (MMCs) in the small and large intestine is associated with visceral hypersensitivity, few studies have evaluated MMCs in humans with esophageal symptoms. The aim of this study was to investigate esophageal MMC distribution in patients with non-cardiac chest pain (NCCP) and to examine the association between the number of gut MMCs and other functional gastrointestinal disorders.

METHODS

Forty-two consecutive NCCP patients and 10 healthy controls completed a questionnaire for bowel symptoms, chest pain intensity score, and psychologic depression. Esophageal, duodenal, and rectal MMCs were identified immunohistochemically and quantified by image analysis.

KEY RESULTS

Numbers of MMCs were significantly higher in NCCP patients vs healthy controls (11.8 ± 5.6 vs 7.6 ± 3.7 MMCs/high-power field, p = 0.026). In comparison of subgroups classified by 24-h impedance-pH monitoring, esophageal MMC counts were highest in the hypersensitive esophagus group (p < 0.01) and were also significantly increased in the functional chest pain group (p < 0.05). A positive correlation between esophageal and duodenal MMC counts was observed in patients with functional dyspepsia (FD; Spearman ρ = 0.604, p = 0.037). In particular, patients with clinical overlap with irritable bowel syndrome showed a strong positive correlation between esophageal and rectal MMC numbers (Spearman ρ = 0.857, p = 0.010).

CONCLUSIONS & INFERENCES

Among NCCP patients, increased MMC infiltration occurs in subgroups with hypersensitive esophagus and functional chest pain. In subpopulations with overlap with FD or irritable bowel syndrome, esophageal MMC counts demonstrated significant positive correlations with duodenal or rectal MMC counts.

Esophageal mucosal mast cell infiltration and changes in segmental smooth muscle contraction in noncardiac chest pain

Mast cells release potent mediators that alter enteric nerve and smooth muscle functions and may contribute to the pathogenesis of functional gastrointestinal disorders. The goal of this study was to determine if mucosal mast cell infiltration was associated with smooth muscle segmental changes in esophageal contraction. All patients with noncardiac chest pain (NCCP) were divided into two groups consisting of patients with non-erosive reflux disease or functional chest pain (FCP) according to the results of ambulatory 24 hours esophageal pH monitoring and high-resolution manometry. Pressure-volume (PV) was calculated by multiplying the length of the esophageal segment, duration of the contraction, and mean pressure over the entire space-time box (P mean). Quantification of mast cells was performed in five consecutive nonoverlapping immunostained sections. Spearman correlation analysis showed that the distal segment PV correlated with the mast cell count in all of the patients combined and in patients with FCP with correlation coefficients of 0.509 and 0.436, respectively (P = 0.004 and P = 0.042). Similar findings were observed for the segmental ratio of distal to proximal smooth muscle PV in all patients and in patients with FCP (correlation coefficients 0.566; P = 0.001 and correlation coefficients 0.525; P = 0.012, respectively). Mucosal mast cell infiltration was associated with distal esophageal contraction as a key pathophysiologic factor of NCCP.

A macrophage-specific synthetic promoter for therapeutic application of adiponectin

Foam cell formation from macrophage is a major cause of atherosclerosis. An efficient macrophage-specific promoter is required for the targeting to macrophages. In this study, we develop a macrophage-specific synthetic promoter for the therapeutic application of adiponectin (APN), an antiatherogenic gene. Synthetic promoter-146 (SP146), registered on the NCBI website (http://www.ncbi.nlm.nih.gov/nuccore/DQ107383), was tested for promoter activities in two non-macrophage cell lines (293 T, HeLa) and a macrophage cell line (RAW264.7, bone marrow-derived macrophages). To enforce macrophage specificity, partial elements of p47(phox) including the PU.1 site with various lengths (-C1, -C2 and -C3) were inserted next to the synthetic promoters. SP146-C1 showed the highest specificity and efficacy in RAW264.7 cells and was selected for development of an APN-carrying macrophage-specific promoter. Green fluorescent protein (GFP)- or APN-expressing lentivirus under SP146-C1 (Lenti-SP-GFP or Lenti-SP-APN, respectively) showed the highest expression efficacy in RAW264.7 cells compared with the non-macrophage cell lines. APN overexpression in RAW264.7 cells successfully inhibited intracellular lipid accumulation, and atherosclerotic lesions and lipid accumulation were significantly reduced by Lenti-SP-APN in ApoE-/- atherosclerosis mice. In conclusion, the synthetic promoter SP146-C1, combined with a p47(phox) promoter element, was successfully developed to target macrophage, and macrophage-specific introduction of APN under SP146-C1 was shown to ameliorate the atherosclerotic pathology.

The effects of statins on the clinical outcomes of Clostridium difficile infection in hospitalised patients

BACKGROUND

An association between exposure to statin drugs and favourable treatment outcomes for various types of infections has been established.

AIM

To determine the clinical characteristics and treatment outcomes of Clostridium difficile infection (CDI) among hospitalised patients taking statin drugs.

METHODS

The medical records were reviewed for consecutive in-patients with CDI confirmed by positive toxin assay (A or B), C. difficile culture, or the presence of pseudomembrane on endoscopy. Treatment success was defined as the resolution of diarrhoea within 6 days of therapy. The primary end points were assessed by average symptom recovery time and treatment response (success or failure).

RESULTS

Among 949 patients, the overall response to metronidazole was 91.9%. The baseline characteristics showed some differences between statin users and statin non-users with respect to mean disease severity score. In the multivariate analysis, successful treatment response was significantly associated with the absence of exposure to proton pump inhibitors (PPIs) (OR = 0.690, 95% CI = 0.513-0.929, P = 0.014) and with exposure to statins (OR = 1.449, 95% CI = 1.015-2.070, P = 0.041). Contrary to the treatment response, univariate and multivariate analyses failed to show that exposure to PPIs or statins affected symptom recovery times. Sixty-day CDI recurrence rates for those patients with statin exposure were significantly lower compared with those patients without statin exposure (3% vs. 7.3%, respectively; RR = 0.393, 95% CI = 0.167-0.926, P = 0.033).

CONCLUSION

Prior statin exposure in patients with C. difficile infection is associated with a successful response to treatment.

Socioeconomic disparities of periodontitis in Koreans based on the KNHANES IV

OBJECTIVES

The aim of this study was to identify the socioeconomic factors associated with the prevalence of periodontitis in Koreans.

METHODS

Cross-sectional data from 12 763 subjects, 15 years old and above, who underwent periodontal examinations were obtained from the Korean National Health and Nutrition Examination Survey IV (2007-209). Multivariate linear and logistic regression analyses were applied to estimate the association between socioeconomic indicators and prevalence of periodontitis.

RESULTS

A significant association was found between increasing age and periodontitis. Participants with higher income were less likely to have periodontitis (aOR = 0.9 and 95% CI = 0.78-0.98, and aOR = 0.7 and 95% CI = 0.60-0.80 in the middle and highest quintiles of monthly household income, respectively). In addition, participants living in rural areas were less likely to have periodontitis (aOR = 0.9 and 95% CI = 0.81-0.99), and current smokers were more likely to have periodontitis (aOR = 1.7 and 95% CI = 1.49-1.89). The analysis of comorbidities revealed that individuals with diabetes mellitus (DM) were significantly more likely to have periodontitis (aOR = 1.4 and 95% CI = 1.18-1.68).

CONCLUSIONS

In a rapidly increasing Korean population, the lower socioeconomic groups as well as individuals with DM were significantly more likely to present with periodontitis.

Single-stage extracranial carotid artery stenting and intracranial aneurysm coiling: technical feasibility and clinical outcome

The coexistence of carotid artery stenosis and cerebral aneurysm in a patient presents challenges for treatment decision-making. The purpose of this study was to evaluate the technical feasibility and clinical outcome after single-stage extracranial carotid artery stenting (CAS) and ipsilateral intracranial aneurysm coiling in a single institution. From March 2005 to February 2011, 17 patients with 21 aneurysms underwent single-stage CAS and coiling for ipsilateral aneurysms. There were symptomatic atherosclerotic carotid stenoses with unruptured aneurysms in eight, ruptured or symptomatic aneurysms with simultaneous asymptomatic carotid stenoses in two and asymptomatic lesions in seven. CAS was followed by aneurysm coiling in all 17 patients. Clinical and radiological data were reviewed. There were two procedure-related complications: acute in-stent thrombosis in one and premature aneurysmal rupture in the other. After aneurysm coiling, complete occlusion was demonstrated in 17 aneurysms and near-total occlusion in four. No neurological deficit was found at discharge and follow-up outcomes were excellent in all the patients (mean, 32.9 months). Follow-up imaging studies were performed in all the patients, including neck CT angiography in 14 (mean, 26.1 months), brain MR angiography in 14 (mean, 31.2 months), and conventional angiography in three (mean, 14.7 months). They revealed two asymptomatic, mild carotid re-stenoses and one major aneurysmal recanalization requiring re-coiling. A single-stage CAS and coiling procedure appears to be feasible and the complication rate seems to be reasonable. We suggest that there is no need for separate therapeutic procedures when a patient has carotid artery stenosis and accompanying ipsilateral intracranial aneurysm.

Lipopolysaccharide-induced indoleamine 2,3-dioxygenase expression in the periodontal ligament

BACKGROUND AND OBJECTIVE

Indoleamine 2,3-dioxygenase (IDO) is a tryptophan-oxidizing enzyme with immune-inhibitory effects. The aim of this study was to investigate the expression of IDO by lipopolysaccharide (LPS), a component of gram-negative bacteria, in human periodontal ligament (PDL) cells.

MATERIAL AND METHODS

Human PDL cells and gingival fibroblasts (GFs) were prepared from explants of human PDLs and from gingival tissues of clinically healthy donors, respectively. Real-time RT-PCR, western blotting and the IDO enzyme assay were performed to determine the expression of IDO following LPS treatment of cells. LPS was injected into mice tail veins to evaluate the effects of LPS in vivo in the maxillary first molar. Immunofluorescence staining and histological analysis were followed to localize IDO in mouse PDL.

RESULTS

The level of expression of IDO mRNA in primary human PDL cells after LPS treatment was increased in a dose-dependent manner, reaching a peak 8 h after LPS treatment. The expression and activities of IDO protein were significantly increased in comparison with those of the control. In addition, the increased production of kynurenine in culture medium was observed 72 h after LPS treatment. In the immunofluorescence findings, stronger immunoreactivities were shown in PDL than in gingival tissues in the maxillae. In accordance with the immunofluorescence findings, LPS treatment induced a strong up-regulation of IDO mRNA in human PDL cells, whereas human GFs showed only a weak response to LPS.

CONCLUSION

These results clearly show that IDO was induced by LPS in primary human PDL cells, suggesting that PDL might be involved in the regulation of oral inflammatory disease.

SHP is involved in BMP2-induced odontoblast differentiation

Small Heterodimer Partner (SHP) interacts with diverse transcription factors such as Runx2 and regulates many cellular events including differentiation, proliferation, and energy metabolism. SHP is reported to be a positive regulator of BMP2-induced bone formation. This study aimed to clarify the role of SHP in odontoblast differentiation and matrix mineralization. Rat tooth germs were isolated, and gene expression was determined by RT-PCR and real-time PCR. Localization of SHP protein expression was identified by immunofluorescent analysis. Primary human dental pulp cells (HDPCs) were cultured with BMP2 and/or Ad-siSHP. Matrix mineralization was evaluated by Alizarin red staining. Transient transfection experiment was performed with the SHP or Dlx5 expressional plasmids and the DSPP gene. In tooth germs from post-natal days 3 to 9, BMP-2 and SHP expression increased with DSPP and DMP1 mRNA expression. In an immunostaining study, SHP was expressed in odontoblasts and surrounding osteoblasts. When HDPCs were cultured with BMP2 in mineralization-inducing medium, SHP expression also increased with an increase in DSPP expression. Down-regulation of SHP by Ad-siSHP inhibited matrix mineralization. In transient transfection experiments, overexpression of SHP was shown to enhance DSPP promoter activity through interactions between SHP and Dlx5. These results suggest that SHP may mediate BMP2 signaling to promote mineralization of the dentin matrix.

Efficacy of leukotriene receptor antagonist for erosive esophagitis: a preliminary retrospective comparative study

While diagnostic overlap exists between gastroesophageal reflux disease and eosinophilic esophagitis especially on histological findings, therapeutic approaches for the two disease entities are very different. Recently, anti-inflammatory treatment, in addition to acid suppressants, has been investigated for gastroesophageal reflux disease. This study investigated whether the incidence of endoscopic erosive esophagitis was lower in recipients of long-term leukotriene receptor antagonist (LTRA) treatment. This retrospective comparative study included 207 recipients of an LTRA and an equal number of controls who underwent screening upper endoscopic examination. Twenty-two (10.6%) and 51 (24.6%) cases of erosive esophagitis were detected in the LTRA and control groups, respectively (P < 0.001). A significantly higher incidence of minimal change esophagitis was also found in the controls compared with the LTRA group (14.5% vs. 2.4%, P < 0.001). On multivariate analysis, LTRA treatment was significantly and inversely associated with erosive esophagitis (odds ratio [OR], 0.25; 95% confidence interval [CI], 0.13 to 0.46). Within the LTRA treatment group, an increased risk of erosive esophagitis was strongly associated with the presence of hiatal hernia (OR, 5.89; 95% CI, 2.20-15.73, P < 0.001) and short duration of LTRA treatment (OR, 0.64; 95% CI, 0.37-0.89, P= 0.022). In conclusion, this preliminary retrospective analysis demonstrated that patients who underwent long-term treatment with a LTRA had low incidence of endoscopic minimal change esophagitis.

Unexpected synchronous follicular lymphoma of paraaortic and pelvic lymph nodes in a patient with endometrial carcinoma: a case report

BACKGROUND

Multiple neoplasms in a patient occur rarely. There has only been one case report about synchronous endometrial carcinoma and follicular lymphoma of the paraaortic and pelvic lymph node (LN) until now.

CASE REPORT

The patient was 64 years old and had vaginal spotting for four months. She was diagnosed with endometrioid endometrial carcinoma by endometrial biopsy. In intraoperative inspection, the whole paraaortic and pelvic LN had formed into a massive tumor bundle following the aorta and iliac vessels. The diagnosis was endometrial carcinoma FIGO Stage IB with synchronous follicular lymphoma Stage III. We performed adjuvant chemotherapy and radiotherapy. Currently, the patient has no evidence of recurrence for either carcinoma.

CONCLUSION

Lymph node dissection was included in the staging and debulking operation of the endometrial carcinoma. An inaccurate result of the frozen section can not rule out metastasis of endometrial carcinoma and surgeons can fall into a dilemma regarding treatment.

Wear performance of self-mating contact pairs of TiN and TiAlN coatings on orthopedic grade Ti-6Al-4V

Both titanium nitride (TiN) and titanium aluminum nitride (TiAlN) have shown great wear resistance potential in metallic medical devices as protective, hard thin film coatings. In the present study, the effects of TiN and TiAlN coating layers on the wear performance of Ti-6Al-4V were compared and analyzed. TiN and TiAlN coatings with a thickness of 3 microm were deposited by a cathodic vacuum arc ion plating technique on the surface of Ti-6Al-4V. Wear tests were conducted by using a pin-on-disk-type tribotester with a point contact self-mating pair in a linear reciprocal motion. A sliding distance of 20 mm per cycle at 1 Hz was used under a load of 15 N under ambient conditions with no lubricant. The wear resistance of TiN and TiAlN coatings is superior to that of uncoated Ti-6Al-4V at the early stage of sliding contact. Until a measurable amount of wear was detected, the number of sliding cycles of the TiAlN coating pair was longer than TiN. After the first detection of wear from the coating layers, the rate of wear of the TiN coating pairs was significantly higher than that of TiAlN (p < 0.05), and it was close to that of the uncoated pairs. In conclusion, the TiAlN coating is superior to TiN from the viewpoint of wear resistance under the test conditions used in this study.

Histologic diagnosis based on forceps biopsy is not adequate for determining endoscopic treatment of gastric adenomatous lesions

BACKGROUND AND STUDY AIMS

Controversy persists around the treatment of gastric low-grade dysplasia (LGD). The aim of this study was to investigate possible indications for the endoscopic resection of gastric LGD through analysis of the histologic discrepancies between specimens of gastric LGD obtained by forceps biopsy and by endoscopic mucosal resection (EMR), and of their clinicopathologic characteristics.

PATIENTS AND METHODS

The study involved 293 gastric LGD that were histologically proven on the basis of forceps biopsy in Severance Hospital between January 2004 and December 2007. Twenty cases were regularly followed up, and the remaining 273 were resected by EMR. We performed univariate and multivariate analyses of clinical and endoscopic characteristics including lesion size, number of biopsy fragments, and endoscopic appearance, in order to analyze the factors affecting histologic discrepancies.

RESULTS

Of the 273 lesions resected by EMR, 207 (75.8 %) showed concordant histology, whereas for 51 (18.7 %) the histology was upgraded after endoscopic resection. Lesion size, absence of whitish discoloration, and the presence of spontaneous bleeding were found by univariate analysis to be statistically significant factors predicting an upgraded histology after EMR ( P = 0.026, P < 0.001, and P = 0.025, respectively). Multivariate analysis also showed absence of whitish discoloration to be a statistically significant factor influencing histologic discrepancies ( P = 0.001, odds ratio 5.29, 95 % confidence interval 1.95 - 14.37). Perforation and bleeding rates associated with EMR for LGD were 0.7 % and 6.2 %, respectively. Twenty patients who did not undergo EMR were followed up for a mean of 22 months, and 3 were revealed to have adenocarcinoma and 1 high-grade dysplasia on the latest histologic exam.

CONCLUSIONS

We should consider endoscopic resection for gastric LGD that are 2 cm or more in size and do not have whitish discoloration.

Evaluation of a new cataract surgery referral pathway

AIMS

To compare the quality of referrals and listing rates of direct optometric referrals vs traditional GP referrals for cataract surgery.

METHODS

A retrospective cohort of 124 patients referred for cataract surgery was identified (62 via optometric pathway and 62 via GP pathway). The quality of the referral was assessed by establishing if it contained adequate information relating to the College of Optometrists' referral framework document. Age, sex, drug history, listing rate, operative rate, and visual acuity (best corrected) at referral and at the postoperative visit were recorded and compared between the two referral pathways using the Fisher's exact test.

RESULTS

Optometric referrals, relative to GP referrals, were more likely to include information relating to objective visual loss (100 vs 87%, P=0.0061) and to counsel the patient (97 vs 18%, P=0.0001). GP referrals, relative to optometric referrals, were more likely to comment on personal circumstances (32 vs 3%, P=0.0001), past medical history (95 vs 68%, P=0.0001), and drug history (94 vs 69%, P=0.0009). Operative rates were higher for the optometric direct referrals relative to GP referrals (87 vs 69%, P=0.0284). There was no difference in the visual acuity before or after surgery between the pathways.

CONCLUSIONS

Optometric direct cataract referrals provide better information on objectively measured vision and better delivery of preoperative counselling. Traditional GP referrals contain better medical history, drug information, and details of personal circumstances. Rates of surgery were slightly higher with optometric referrals.

Completion sleeve pneumonectomy for suture line recurrence of lung cancer after sleeve lobectomy

The most appropriate treatment for suture line recurrence of lung cancer after bronchial sleeve lobectomy is completion pneumonectomy. While completion pneumonectomy may not be justified from an oncological point of view due to the positive bronchial resection margin, completion tracheal sleeve pneumonectomy is an optimal surgical procedure. We carried out two cases of completion tracheal sleeve pneumonectomy for suture line recurrence of lung cancer after bronchial sleeve lobectomy of the right upper lobe and achieved good results, which suggests that completion tracheal sleeve pneumonectomy for suture line recurrence after bronchial sleeve lobectomy is a good treatment modality for selected patients.

Expression of L-type amino acid transporter 1 (LAT1) and 4F2 heavy chain (4F2hc) in oral squamous cell carcinoma and its precusor lesions

BACKGROUND

Amino acid transporters play an important role in supplying organic nutrients to cells. The expression of L-type amino acid transporter 1 (LAT1) and its subunit 4F2 heavy chain (4F2hc) was evaluated to determine the alterations of these transporters in oral normal mucosa (ONM), oral precancerous lesion (OPL) and oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

Sections from formalin-fixed, paraffin-embedded samples of ONM, OPL or OSCC were examined using immunohistochemical staining to detect L4T1 and 4F2hc proteins.

RESULTS

The LAT1 and 4F2hc expression increased progressively from ONM to hyperplastic and to dysplastic lesions and OSCC. In particular, LAT1 may be a more specific indicator of tumor progression than 4F2hc.

CONCLUSION

LAT1 and 4F2hc may have an important role in the early stages of multistep oral carcinogenesis. In addition, the specific inhibition of LAT1 and 4F2hc might be a new rationale to suppress oral cancer progression.

Expression and functional characterization of the system L amino acid transporter in KB human oral epidermoid carcinoma cells

We have examined the expression and function of system l amino acid transporter in KB human oral epidermoid carcinoma cells. The KB cells express l-type amino acid transporter 1 (LAT1) in plasma membrane, but not l-type amino acid transporter 2 (LAT2). The [14C]l-leucine uptake by KB cells is inhibited by system l selective inhibitor BCH. The majority of [14C]l-leucine uptake is, therefore, mediated by LAT1. These results suggest that the transport of neutral amino acids including several essential amino acids into the KB cells mediated by LAT1 and the specific inhibition of LAT1 in oral cancer cells will be a new rationale for anti-cancer therapy.

Protective effects of green tea polyphenol against reactive oxygen species-induced oxidative stress in cultured rat calvarial osteoblast

The injurious effects of reactive oxygen species on osteoblasts and the potential protective role played by green tea polyphenols (GtPP) were investigated using primarily cultured rat calvarial osteoblasts. Oxidative stress was induced in cultured osteoblasts, either by adding 100 mmol/L H2O2 or by the action of 40 U/L xanthine oxidase (XO) in the presence of xanthine (250 micromol/L). After incubation, the cellular viability, function and morphology were evaluated. Both treatments produced a significant reduction in osteoblast viability, as assessed by a two-colored fluorescence staining method combined with flow cytometric analysis and MTT assay. A significant reduction in the alkaline phosphatase activity was observed after H2O2 addition, whereas XO did not have the same effect. On the microscopic observations, the morphological changes and intracellular ultrastructural damages were remarkably induced by both treatments. The H2O2-induced alterations were prevented by pre-incubating the osteoblasts with 200 microg/ml GtPP for 1 h. When the oxidative stress was induced by XO, the cellular viability and morphology was also maintained at the same polyphenol concentration. These results demonstrate that GtPP can act as a biological antioxidant in a cell culture experimental model and protect cells from oxidative stress-induced toxicity.

Oxygen dynamics in petroleum hydrocarbon contaminated salt marsh soils: III. A rate model

A model describing oxygen dynamics due to crude oil biodegradation under flooded conditions in saltwater wetlands was developed. The model is composed of three non-linear ordinary differential equations (ODEs) that simulate oxygen uptake, cell growth, and oil degradation simultaneously. The model equations were solved by using a stiff version of ODE solver, ODEPACK, which employs a multistep method and allows the change of step sizes and order of methods (ie., Gear's method). The results of model simulation were compared with experimental data obtained from a fully aerated microcosm study. The results of model simulation indicate that dissolved oxygen concentration in the overlying water rapidly depleted below 3 mg l(-1) unless the reaeration coefficient was higher than 2.0 day(-1). Active aerobic biodegradation of crude oil did not occur under flooded conditions because (i) dissolved oxygen is rapidly depleted, (ii) reaeration is not sufficient enough to replenish dissolved oxygen and (iii) the oil dissolution rate constant decreases over time. The model may lead to better understanding of oxygen demand for a long bioremediation period. The results of this study may be applicable for the establishment of an engineered bioremediation strategy.

A new method for rapid screening of bacterial species- or subspecies-specific DNA probes

A simple assay for the rapid screening of bacterial species- or subspecies-specific DNA probes for the random cloning method is presented, involving the use of genomic DNAs as probes and recombinant plasmid DNAs containing genomic DNA digested with HindIII as targets. The optimal amount of target DNAs and the concentration of digoxigenin-labeled genomic DNA probes were 20 ng and 100 ng ml(-1) (or 10 ng and 200 ng ml(-1)), respectively. The method was applied to the development of Fusobacterium nucleatum subspecies-specific probes. Our results showed that four out of 96 probes were F. nucleatum subspecies-specific, which was confirmed by Southern blot analysis. Our results indicate that the new method can be used for the rapid screening of species- or subspecies-specific probes.

Effects of environmental endocrine disruptors on the sex differentiation in Korean rockfish, Sebastes schlegeli

The effects of estradiol-17beta, methyltestosterone, tributyltin, bisphenol A and 2,4-dinitrophenol on sex differentiation were investigated in the Korean rockfish, Sebastes schlegeli. The 51 day-old fry with undifferentiated gonads were fed with food containing the chemicals at 0.05, 0.5, 5, 50 and 100 micro/g diet for 29 days. Sex ratio and gonadal abnormality after the chemical treatment were determined by histological examination of gonads. In control group, the sex ratio of fry was 1:1.3 (female:male), and more males than females appeared. The sex of fry fed with estradiol-17beta at 5, 50 and 100 micro/g diet was all females. Feminization of the fry was induced by exogenic estradiol-17beta. In the methyltestosterone group, sex ratio of fry was 1:10.2 in 0.05 micro/g diet, 1:2.4 in 0.5 micro/g diet, 1:3.1 in 5 micro/g diet, 1:1.2 in 50 micro/g diet and 1:2.3 in 100 micro/g diet. Masculinization of the fry was induced by methyltestosterone at the lowest concentration. Furthermore, intersex of the fry was observed. The number of intersex fry was 23.3, 25.0 and 35.3 at 0.5, 5 and 50 micro/g diet of methyltestosterone, respectively. Sex ratio of bisphenol A group showed no difference with that of the control. The sex of fry fed with 2,4-dinitrophenol at 5, 50 and 100 micro/g diet was all females. 2,4-dinitrophenol should be considered as a new member of endocrine disruptors. In tributyltin group, the sex ratio of fry at 100 micro/g diet of tributyltin was 5.4:1. Tributyltin induced the feminization of the fry at the highest dose. Tributyltin showed an estrogenic effect in the Korean rockfish in contrast to an androgenic effect in gastropods.

Antibiotic selective pressure for the maintenance of antibiotic resistant genes in coliform bacteria isolated from the aquatic environment

Coliform bacteria isolated from the aquatic environment were investigated for antibiotic susceptibility and detailed structures of class 1 integrons. A high proportion of isolates were found to be resistant to sulfamethoxazole, aminoglycosides, and beta-lactams. The 750 (53.6%) isolates were resistant to one or more of the antibiotics tested out of 1,400 coliform bacteria. Based on the MIC of antibiotics and antibiogram, 150 isolates were selected and further studied for class 1 integrons. The intI1 gene was found in 36 (24.0%) of the 150 isolates. Twelve isolates carried the gene cassettes responsible for antibiotic resistance, while no gene cassettes were found in 24 isolates. Seven different genes, dfrA5, dfrA7, dfrA12, dfrA17, aaA2, aaA5, and aad(3'), were detected in gene cassettes. The dfrA and aad genes located on class 1 integrons were responsible for resistance to trimethoprim and aminoglycosides. The remaining 24 coliform bacteria had the incomplete or non-functional class 1 integrons. These results indicated that antibiotic selective pressures may play an important role to maintain gene cassettes of class 1 integrons and in the absence of sustained antibiotic pressures, such as the aquatic environment, coliform bacteria may carry empty or non-functional class 1 integrons.

EDTA-induced activation of Ca-regulated proteins in the vaginal mucosa

The effects of EDTA on the expression and topologic localization of mitogen-activated protein (MAP) kinases (ERK, JNK, and p38), along with nitric oxide synthase (NOS), I-KappaB, and p53 were examined to elucidate the host response provoked by the intravaginal application of a female controlled drug delivery system (FcDDS) containing a spermicidal/microbicidal agent and EDTA. Immunohistochemical and immunoblotting studies were conducted to identify and quantitate the EDTA-inducible proteins in vaginal mucosa. The content of nitrite, which is one of the primary stable breakdown products of nitric oxide (NO), was determined to correlate the expression of NOS with NO formation in HeLa cervical carcinoma cell line. The immunohistochemical study demonstrated that the modulation of the calcium gradient by EDTA activated MAP kinases (ERK and JNK) in the rabbit vaginal mucosa. The results of Western immunoblot study demonstrated differential expression of MAP kinases (ERK and JNK) with EDTA treatment, whereas the expression of NOS and NF-KappaB was not affected by EDTA. There was no significant difference in nitrite production in the HeLa cell line upon exposure to EDTA compared with the control, which was consistent with the results of the Western blot study. The results of this work support that the regulation of MAP kinase was affected by calcium, which is controlled by chelation activity of EDTA. The specific tissue responses exerted by the loading components of a biomaterial-based system should be fully taken into consideration for its intravaginal application.

Study on the inhibitory effects of Korean medicinal plants and their main compounds on the 1,1-diphenyl-2-picrylhydrazyl radical

A 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-generating system was used to evaluate the antioxidant properties of Korean medicinal plants that have been used widely as folk medicines for several disorders, as well as compounds isolated from them. Among the Rosaceae, Rosa rugosa and Rosa davurica showed strong DPPH radical-scavenging activity. The most effective medicinal plant from families other than Rosaceae was Cedrela sinensis, followed in order by Nelumbo nucifera, Eucommia ulmoides, Zanthoxylum piperitum, Cudrania tricuspidata and Houttuynia cordata. These results serve as a good index of the free radical-scavenging activities of Korean medicinal plants. Furthermore, the polyphenols isolated from these plants, procyanidin B-3, (+)-catechin, gallic acid, methyl gallate, quercetin, quercetin-3-O-beta-D-glucoside, quercetin-3-O-beta-galactoside, quercetin-3-O-rutinose and kaempferol, exerted strong DPPH radical-scavenging activity. These results suggest that the Korean medicinal plants and the polyphenols isolated from them that exhibited effective radical-scavenging activity may be promising agents for scavenging free radicals and treating diseases associated with excess free radicals.