Hearing among male firefighters: a comparison with hearing data from screened and unscreened male population

We investigated whether hearing loss is associated with firefighting. We conducted cross-sectional study comparing hearing threshold levels (HTLs) of 912 male firefighters with two hearing databases obtained from an otologically normal male Korean population (KONP) and a non-industrial noise-exposed male Korean population (KNINEP), considering age and the main roles of firefighters. Firefighters' age-adjusted HTLs were significantly worse than those of KONP (prevalence ratio (PR)=5.29, P<0.001)but not different from those of KNINEP (PR=0.99, P=0.550). Rescuers (PR=1.005, P<0.001) had worse hearing than the KNINEP after age adjustment. Comparison of firefighters' HTLs (50th and 90th percentiles) with those of KONP and KNINEP by age and frequency showed that firefighters' HTLs had significant increases (poorer hearing) across most age groups and frequencies compared with KONP. Compared with KNINEP, firefighters' HTLs were worse in the younger age groups (<45 years) but not different in the older age groups (>45 years). In conclusion, the hearing thresholds of younger firefighters and rescuers were worse than expected by normal aging alone. Future research should include longitudinal studies to consider variable risk factors, such as military service, smoking, and so on.

Ventral segment-preserving right hepatectomy in patients with hepatocellular carcinoma

BACKGROUND

Transection along the anterior fissure was proposed as a mechanism by which to open the third door of the liver. In this study, we investigated surgical outcomes of a ventral segment-preserving right hepatectomy (VSPRH) compared with those of conventional right hepatectomy in patients with hepatocellular carcinoma (HCC).

METHODS

Between January 2007 and December 2010, 595 primary HCC patients underwent liver resection at the authors' institution. Among them, the 123 HCC patients who underwent a right hepatectomy were retrospectively analyzed. The patients were classified into two groups according to the type of resection: those who underwent a VSPRH (Group A; 27 cases) and those who underwent a conventional right hepatectomy (Group B; 96 cases).

RESULTS

In Group A, expected remnant liver volume after a right hepatectomy was calculated to be 32.1 ± 7.2% of functional total liver volume (FTLV); remnant liver volume increased up to 54.7 ± 7.2% of FTLV after a VSPRH. Clinicopathologic characteristics and intraoperative data did not differ between the two groups. The liver-related complication rate was higher in Group B (P = 0.02). Overall survival and disease-free survival rates were similar (3-year disease-free survival (Group A: 67.8%; Group B: 71.7%; P = 0.65); 3-year overall survival (Group A: 91.7%; Group B: 87.4%; P = 0.26). In regard to long-term synthetic function, the 1-year postoperative serum albumin level was higher in Group A.

CONCLUSIONS

A VSPRH yielded fewer liver-related complications and similar long-term oncologic outcomes, compared with conventional right hepatectomy in cirrhotic patients with a small left lobe volume. Therefore, VSPRH can be considered to be an alternative procedure for a right hepatectomy.

Precision Measurement of the (e^{+}+e^{-}) Flux in Primary Cosmic Rays from 0.5 GeV to 1 TeV with the Alpha Magnetic Spectrometer on the International Space Station

We present a measurement of the cosmic ray (e^{+}+e^{-}) flux in the range 0.5 GeV to 1 TeV based on the analysis of 10.6 million (e^{+}+e^{-}) events collected by AMS. The statistics and the resolution of AMS provide a precision measurement of the flux. The flux is smooth and reveals new and distinct information. Above 30.2 GeV, the flux can be described by a single power law with a spectral index γ=-3.170±0.008(stat+syst)±0.008(energy scale).

Concurrent chemoradiotherapy shows long-term survival after conversion from locally advanced to resectable hepatocellular carcinoma

PURPOSE

For locally unresectable hepatocellular carcinoma (HCC) patients, concurrent chemoradiotherapy (CCRT) has been applied as a loco-regional treatment. After shrinkage of tumors in selected patients, surgical resection is performed. The aim of this study was to evaluate prognostic factors and long-term survivors in such patients.

MATERIALS AND METHODS

From January 2000 to January 2009, 264 patients with HCC were treated with CCRT (45 Gy with fractional dose of 1.8 Gy), and intra-arterial chemotherapy was administered during radiotherapy. Eighteen of these patients (6.8%) underwent hepatic resection after showing a response to CCRT. Cases were considered resectable when tumor-free margins and sufficient remnant volumes were obtained without extrahepatic metastasis. Prior to operation, there were six patients with complete remission, 11 with partial remission, and six with stable disease according to modified Response Evaluation Criteria in Solid Tumors.

RESULTS

In pathologic review, four patients (22.2%) showed total necrosis and seven patients (38.9%) showed 70-99% necrosis. A high level of necrosis (≥80%) was correlated with low risk for extrahepatic metastasis and long-term survival. In univariate analyses, vessel invasion and capsular infiltration were significantly correlated with disease free survival (DFS) (p=0.017 and 0.013, respectively), and vessel invasion was significantly correlated with overall survival (OS) (p=0.013). In multivariate analyses, capsule infiltration was a significant factor for DFS (p=0.016) and vessel invasion was significant for OS (p=0.015).

CONCLUSION

CCRT showed favorable responses and locally advanced HCC converted into resectable tumor after CCRT in selected patients. Long-term survivors showed the pathological features of near total necrosis, as well as negative capsule and vessel invasion.

Angle-resolved photoemission spectroscopy of tetragonal CuO: evidence for intralayer coupling between cupratelike sublattices

We investigate by angle-resolved photoemission the electronic structure of in situ grown tetragonal CuO, a synthetic quasi-two-dimensional edge-sharing cuprate. We show that, in spite of the very different nature of the copper oxide layers, with twice as many Cu in the CuO layers of tetragonal CuO as compared to the CuO(2) layers of the high-T(c) cuprates, the low-energy electronic excitations are surprisingly similar, with a Zhang-Rice singlet dispersing on weakly coupled cupratelike sublattices. This system should thus be considered as a member of the high-T(c) cuprate family, with, however, interesting differences due to the intralayer coupling between the cupratelike sublattices.

The effect of statin on epithelial-mesenchymal transition in peritoneal mesothelial cells

Background

Statins have recently been highlighted for their pleiotropic actions distinct from cholesterol-lowering effects. Despite this interest, it is currently unknown whether statin therapy inhibits peritoneal dialysis (PD)-related epithelial-mesenchymal transition (EMT).

Methods

In vitro, human peritoneal mesothelial cells (HPMCs) were exposed to 5.6 mM glucose (NG) or 100 mM glucose (HG) with or without simvastatin (1 µM). In vivo, PD catheters were inserted into 32 Sprague-Dawley rats, and saline (C, n = 16) or 4.25% peritoneal dialysis fluid (PDF) (PD, n = 16) was infused for 4 weeks. Eight rats from each group were treated with 5 mg/kg/day of simvastatin intraperitoneally. Changes in the protein expression of EMT markers such as E-cadherin, α-SMA, Snail, and fibronectin in HPMCs and the peritoneum were evaluated by Western blot analysis and immunofluorescence or immunohistochemical staining. We also explored whether activation of the mevalonate pathway and its downstream small GTPases were involved in dialysis-related peritoneal EMT and could be inhibited by statin treatment.

Results

Compared to NG cells, E-cadherin expression was significantly decreased, while α-SMA, Snail, and fibronectin expression were significantly increased in HPMCs exposed to HG, and these changes were abrogated by simvastatin (p<0.05). In addition, the cobblestone-like appearance of normal HPMCs was converted into a fibroblast-like morphology after HG treatment, which was reversed by simvastatin. These EMT-like changes were also observed in HPMCs treated with geranyl-geranyl pyrophosphate (5 µM). HG significantly increased the protein expression of RhoA and Rac1 in the membrane fractions, and these increases were ameliorated by simvastatin (p<0.05). In PD rats, E-cadherin in the peritoneum was significantly decreased, whereas α-SMA, Snail, and fibronectin expression were significantly increased (p<0.05) compared to C rats. The thickness of the mesothelial layer in the peritoneum were also significantly greater in PD rats than in C rats (p<0.05). These changes of the peritoneum in PD rats were significantly attenuated by simvastatin.

Conclusion

This study demonstrated that PD-related EMT was mediated via the mevalonate pathway, and statin treatment inhibited the EMT changes in HG-treated HPMCs and PDF-stimulated PD rats. These findings suggest that statins may be a promising therapeutic strategy for preservation of peritoneal membrane integrity in long-term PD patients.

Practical guidelines for the surgical treatment of gallbladder cancer

At present, surgical treatment is the only curative option for gallbladder (GB) cancer. Many efforts therefore have been made to improve resectability and the survival rate. However, GB cancer has a low incidence, and no randomized, controlled trials have been conducted to establish the optimal treatment modalities. The present guidelines include recent recommendations based on current understanding and highlight controversial issues that require further research. For T1a GB cancer, the optimal treatment modality is simple cholecystectomy, which can be carried out as either a laparotomy or a laparoscopic surgery. For T1b GB cancer, either simple or an extended cholecystectomy is appropriate. An extended cholecystectomy is generally recommended for patients with GB cancer at stage T2 or above. In extended cholecystectomy, a wedge resection of the GB bed or a segmentectomy IVb/V can be performed and the optimal extent of lymph node dissection should include the cystic duct lymph node, the common bile duct lymph node, the lymph nodes around the hepatoduodenal ligament (the hepatic artery and portal vein lymph nodes), and the posterior superior pancreaticoduodenal lymph node. Depending on patient status and disease severity, surgeons may decide to perform palliative surgeries.

Surgical resection after down-staging of locally advanced hepatocellular carcinoma by localized concurrent chemoradiotherapy

BACKGROUND

This study evaluated the down-staging efficacy and impact on resectability of concurrent chemoradiotherapy (CCRT) followed by hepatic arterial infusion chemotherapy (HAIC) in locally advanced hepatocellular carcinoma, and identified prognostic factors of disease-free survival (DFS) and overall survival (OS) after curative resection.

METHODS

DFS and OS were investigated using clinicopathologic variables. Functional residual liver volume (FRLV) was assessed before CCRT and again before surgery in patients with major hepatectomy. Tumor marker response was defined as elevated tumor marker levels at diagnosis but levels below cutoff values before surgery (α-fetoprotein < 20 ng/mL, protein induced by vitamin K absence or antagonist-II < 40 mAU/mL).

RESULTS

Of 243 patients who received CCRT followed by HAIC between 2005 and 2011, 41 (16.9 %) underwent curative resection. Tumor down-staging was demonstrated in 32 (78 %) of the resected patients. FRLV significantly increased from 47.5 to 69.9 % before surgery in patients who underwent major hepatectomy. In addition, the OS of the curative resection group was significantly higher than the OS of the CCRT followed by HAIC alone group (49.6 vs. 9.8 % at 5-year survival; p < 0.001). By multivariate analysis, the poor prognostic factors for DFS after curative resection were tumor marker non-response and the presence of a satellite nodule; however, tumor marker non-response was the only independent poor prognostic factor of OS.

CONCLUSIONS

CCRT followed by HAIC increased resectability by down-staging tumors and increasing FRLV. Curative resection may provide good long-term survival in tumor marker responders who undergo CCRT followed by HAIC.

Electron and positron fluxes in primary cosmic rays measured with the alpha magnetic spectrometer on the international space station

Precision measurements by the Alpha Magnetic Spectrometer on the International Space Station of the primary cosmic-ray electron flux in the range 0.5 to 700 GeV and the positron flux in the range 0.5 to 500 GeV are presented. The electron flux and the positron flux each require a description beyond a single power-law spectrum. Both the electron flux and the positron flux change their behavior at ∼30  GeV but the fluxes are significantly different in their magnitude and energy dependence. Between 20 and 200 GeV the positron spectral index is significantly harder than the electron spectral index. The determination of the differing behavior of the spectral indices versus energy is a new observation and provides important information on the origins of cosmic-ray electrons and positrons.

High statistics measurement of the positron fraction in primary cosmic rays of 0.5-500 GeV with the alpha magnetic spectrometer on the international space station

A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This measurement extends the energy range of our previous observation and increases its precision. The new results show, for the first time, that above ∼200  GeV the positron fraction no longer exhibits an increase with energy.

Histological subclassification of cirrhosis can predict recurrence after curative resection of hepatocellular carcinoma

BACKGROUND

Recurrence of hepatocellular carcinoma (HCC) after curative resection continues to be a major cause of death. This prospective study is designed to investigate whether histological subclassification of cirrhosis using the Laennec system could predict recurrence in patients with hepatitis B virus (HBV)-related HCC after curative resection.

METHODS

Patients with HBV-related HCC who underwent curative resection and showed Laennec stage 3 to 4 were enrolled and the cases with stage 4 were subclassified histologically into three groups (stages 4A, 4B and 4C) according to the Laennec system. Between February 2006 and August 2009, 92 patients were recruited.

RESULTS

Stage 3, 4A, 4B and 4C were identified in 24 (26.1%), 15 (16.3%), 43 (46.7%) and 10 (10.9%) patients respectively. The cumulative incidence rates of recurrence at 1, 2 and 3 years were 24.2%, 40.5% and 55.1% respectively. On multivariate analysis, serum albumin [hazard ratio (HR), 0.528; 95% confidence interval (CI), 0.312-0.891; P=0.017] and Edmondson-Steiner grade III-IV (HR, 3.456; 95% CI, 1.123-10.517; P=0.031) were significantly correlated with early recurrence (<1 year), whereas stage 4C (HR, 5.426; 95% CI, 1.030-28.598; P=0.046) was the only independent risk factor for late recurrence (≥1 year).

CONCLUSIONS

Histological subclassification of cirrhosis using the Laennec system is a significant predictor of late recurrence in patients with HBV-related HCC after curative resection.

A numerical study on the charge transport in TPD/Alq3-based organic light emitting diodes

We report our simulation study on the charge transport characteristic of the multi-layer structure for organic light emitting diodes (OLEDs). We performed a numerical simulation on a multilayer structure comprising a hole transport layer (HTL), an emission layer (EML), and an electron transport layer (ETL) between both electrodes. The material of the HTL is TPD (N,N'-Bis (3-methylphenyl)-N,N'-bis(phenyl) benzidine), and the ETL includes Alq3 (Tris (8-hyroxyquinolinato) aluminium). Here, we investigated the parameters such as recombination rates which influence the efficiency of the charge transport between layers in bilayer OLEDs. We also analyzed a transient response during the turn on/off period and the carrier transport in accordance with the variation of the injection barrier and applied voltage. In addition, our numerical simulation revealed that the insertion of the EML affects the photonic characteristics in bilayer structure and also the efficiency due to the difference in the internal barrier height.

The impact of group B Streptococcus prophylaxis on early onset neonatal infections

OBJECTIVE

To determine if changes have occurred in the causative pathogens and/or antibiotic susceptibility profiles in early onset neonatal infections since initiation of group B Streptococcus (GBS) prophylaxis and to determine risk factors for ampicillin/penicillin resistant microorganisms.

STUDY DESIGN

Data on 220 infants with positive blood, urine, or cerebrospinal fluid cultures for bacteria or fungi at ≤seven days of age from 1990-2007 were examined and divided into three epochs, based on intrapartum antibiotic prophylactic (IAP) practices. Pathogens and antibiotic resistance were compared among epochs.

RESULTS

A significant decrease in the incidence of GBS infections occurred over time, with no change in the incidence of other pathogens or the emergence of antibiotic resistance, including the very low-birthweight population. In regression analysis, ampicillin resistance was associated with male gender (OR 3.096).

CONCLUSIONS

No emergence of antibiotic resistant pathogens was found following IAP use. Changing microorganisms and increasing antibiotic resistance found in prior studies are likely multifactorial. Further study is needed to continue to reduce the rates of common early onset pathogens.

β-Catenin activated hepatocellular adenoma: a report of three cases in Korea

Hepatocellular adenoma (HCA) is an uncommon benign hepatic tumor, and the use of oral contraceptives is known to contribute to the development of HCA. Recently, a genotype and phenotype classification system for HCA was suggested, and malignant transformation to hepatocellular carcinoma (HCC) was shown to be strongly associated with activating mutations in β-catenin. Here, we report three cases of HCA in Korean patients: 7-cm, inflammatory and β-catenin-activated HCA with HCC transformation in a 46-year-old man; 13-cm, β-catenin-activated HCA with cytological atypia in a 23-year-old woman; and 10-cm, pigmented, inflammatory and β-catenin-activated HCA in a 36-year-old man. All cases exhibited the nuclear expression of β-catenin and diffuse cytoplasmic expression of glutamine synthetase upon immunohistochemical staining. All tumors were completely resected, and the patients were followed for 3 to 6 years with no evidence of local recurrence or metastasis.

Lesson from 610 liver resections of hepatocellular carcinoma in a single center over 10 years

Background

Recent advances in surgical techniques and perioperative management have led to improved surgical outcomes, especially perioperative outcomes. The aim of this study was to review our experience with hepatic resection for hepatocellular carcinoma (HCC) over a ten-year period to determine how to improve long-term surgical outcomes.

Methods

From January 1996 to December 2007, 610 patients underwent curative resection for HCC at Yonsei University Health System, Seoul, Korea. Prognostic factors for disease-free and overall survival were identified, and surgical outcomes were compared between two time periods: before 2003 and after 2003.

Results

The 1-, 3-, and 5-year overall survival rates were 90.1%, 74.9% and 64.4%, respectively. The patients after 2003 tended to have improved overall survival. The survival rate after recurrence in patients with tumors > 3 cm was significantly greater after 2003. (P = 0.044).

Conclusions

The improved survival rates after 2003 may be explained by better selection of surgical candidates, a reduced perioperative transfusion rate due to improved surgical techniques, and active multimodal treatment for recurrent HCC.

Impact of internal spermatic artery preservation during laparoscopic varicocelectomy on recurrence and the catch-up growth rate in adolescents

OBJECTIVE

To investigate the effectiveness of laparoscopic varicocelectomy (LV) in adolescents with varicocele and analyze the impact of internal spermatic artery (ISA) preservation on surgical outcomes.

MATERIALS AND METHODS

Data on 92 adolescents with left varicocele who underwent LV between December 1998 and January 2011 were retrospectively analyzed. The mean age of the patients was 13.2 ± 2.1 years. Age, grade of disease, number of ligation veins, recurrence rates, and catch-up growth were analyzed in patients who underwent ISA preservation and ligation. The median duration of the follow-up was 21 months.

RESULTS

ISA preservation was performed on 50 patients (54%). There were no significant inter-group differences in terms of age, varicocele grade, number of ligation veins, and catch-up growth (93% vs. 90%). The patients who received artery preservation demonstrated a higher recurrence rate (22%) than those who received artery ligation (5%; p = 0.032). Among 13 patients who had persistent or recurrent varicocele, nine were treated with embolization and one was treated with magnification-assisted subinguinal varicocelectomy. None of these 10 patients demonstrated recurrence or testicular atrophy.

CONCLUSIONS

LV with ISA ligation can reduce the recurrence rate and results in the same catch-up growth rate in comparison with LV with ISA preservation.

Pre-S mutations of hepatitis B virus affect genome replication and expression of surface antigens

BACKGROUNDS AND AIMS

In chronic hepatitis B virus (HBV) infection, quantitative HBV surface antigen (qHBsAg) is useful for monitoring viral replication and treatment responses. We aimed to determine whether pre-S mutations have any effect on circulating qHBsAg.

METHODS

Plasmids expressing 1–8 amino acid deletion in pre-S1 ("pre-S1Δ1-8") and 3-25 amino acid deletion in pre-S2 ("pre-S2Δ3-25") were constructed. At 72 h posttransfection into Huh7 cells, qHBsAg were measured using electrochemiluminescence immunoassay analyzer. To mimic milieus of quasispecies, we co-transfected either pre-S1Δ1-8 or pre-S2Δ3-25 with wild type (WT).

RESULTS

Pre-S mutations affected transcription and replication ability of HBV because of altered overlapping polymerase. Compared with WT, extracellular qHBsAg in pre-S1Δ1-8 and pre-S2Δ3-25 were on average 3.87-fold higher and 0.92-fold lower, respectively, whereas intracellular qHBsAg in pre-S1Δ1-8 and pre-S2Δ3-25 were 0.57-fold lower and 1.60-fold higher, respectively. Immunofluorescence staining of cellular HBsAg showed that pre-S1Δ1-8 had less staining and that pre-S2Δ3-25 had denser staining. As ratios of either pre-S1Δ1-8 or pre-S2Δ3-25:WT increased from 0:10 to 10:0 gradually, relative extracellular qHBsAg increased from 1.0 to 3.85 in pre-S1Δ1-8 co-transfection, whereas those decreased from 1.0 to 0.88 in pre-S2Δ3-25 co-transfection.

CONCLUSION

Pre-S mutations exhibit different phenotypes of genome replication and HBsAg expression according to their locations. Thus, qHBsAg level for diagnosis and prognostification in chronic HBV infection should be used more cautiously, considering emergences of pre-S deletion mutants.

Inhibition of tumour angiogenesis and growth by small hairpin HIF-1α and IL-8 in hepatocellular carcinoma

BACKGROUND & AIMS

Hypoxia-inducible factor-1α (HIF-1α), a key transcription factor in the cellular response to hypoxia, and interleukin 8 (IL-8), a key mediator of angiogenesis, are important in cancerous tumour growth. In this study, we evaluated the effects of HIF-1α and IL-8 knockdown on angiogenesis and tumour growth in hepatocellular carcinoma (HCC).

METHODS

Hepatocellular carcinoma cell lines were infected with adenoviruses expressing small-hairpin RNA (shRNA) specific for HIF-1α or IL-8, cultured under hypoxic conditions (1% O2), and examined for their levels of HIF-1α, IL-8, and angiogenesis factors using immunoblot. The effects of adenovirus-mediated shRNA-induced HIF-1α and IL-8 knockdown on tumour growth and angiogenesis were also investigated in a subcutaneous Hep3B-tumour mouse model.

RESULTS

Hypoxia-inducible factor-1α knockdown directly repressed tumour growth, whereas IL-8 knockdown indirectly repressed tumour growth. Combined knockdown of HIF-1α and IL-8 increased survival rates of mice. HIF-1α and IL-8 knockdown also decreased microvessel density and tumour volume in vivo. Similarly, HIF-1α and IL-8 knockdown inhibited the angiogenic effects of HCC cell-conditioned media on tube formation and invasion by endothelial cells in vitro.

CONCLUSION

These findings indicate that shRNA-induced HIF-1α and IL-8 knockdown inhibit angiogenesis and tumour growth in HCC. Further development of HIF-1α and IL-8 shRNA technologies could lead to effective therapies for HCC.

Association between BMP-2 and COL6A1 gene polymorphisms with susceptibility to ossification of the posterior longitudinal ligament of the cervical spine in Korean patients and family members

COL6A1 and BMP-2 genes have been implicated in ossification of the posterior longitudinal ligament (OPLL) susceptibility in Japanese and Chinese Han populations. However, no study has yet investigated the DNA of unaffected family members of patients with OPLL. This study investigated differences in genetic polymorphisms of BMP-2 and COL6A1 between Korean patients with OPLL and their family members (with and without OPLL). A total of 321 subjects (110 patients with OPLL and 211 family members) were enrolled in the study. Associations between two single nucleotide polymorphisms (SNPs) of the BMP-2 gene (Ser37Ala and Ser87Ser) and two SNPs of COL6A1 [promoter (-572) and intron 33 (+20)] with susceptibility to OPLL of the cervical spine were investigated between the two groups (OPLL+ and OPLL-). Of the 321 subjects, 162 had cervical OPLL (50.4%; 110 patients, 52 family members). There was a familial tendency of OPLL in 34 of the 110 families (30.9%). Allele and haplotype frequencies of the four SNPs in the BMP-2 and COL6A1 genes did not differ significantly between the OPLL+ and OPLL- groups, even when excluding participants over 50 years of age. This is the first report identifying SNPs of COL6A1 and BMP-2 in Korean patients and family members with OPLL. Although allele and haplotype frequencies were similar with those of a previous study in Japanese and Chinese patients, unaffected family members also showed similar rates of these SNPs in the present study. These results suggest that these SNPs may not directly influence the expression of OPLL.

Postoperative radiotherapy dose correlates with locoregional control in patients with extra-hepatic bile duct cancer

Purpose

To evaluate the results of postoperative radiotherapy in patients with extra-hepatic bile duct cancer (EHBDC) and identify the prognostic factors for local control and survival.

Materials and Methods

Between January 2001 and December 2010, we retrospectively reviewed the cases of 70 patients with EHBDC who had undergone curative resection and received postoperative radiotherapy. The median radiation dose was 50.4 Gy (range, 41.4 to 54 Gy). The resection margin status was R0 in 30 patients (42.9%), R1 in 25 patients (35.7%), and R2 in 15 patients (21.4%).

Results

The 5-year rates of overall survival (OS), event-free survival (EFS), and locoregional control (LRC) for all patients were 42.9%, 38.3%, and 61.2%, respectively. The major pattern of failure was distant relapses (33 patients, 47.1%). A multivariate analysis showed that the postradiotherapy CA19-9 level, radiation dose (≥50 Gy), R2 resection margins, perineural invasion, and T stage were the significant prognostic factors for OS, EFS, and LRC. OS was not significantly different between the patients receiving R0 and R1 resections, but was significantly lower among those receiving R2 resection (54.6%, 56.1%, and 7.1% for R0, R1, and R2 resections, respectively).

Conclusion

In patients with EHBDC who had undergone curative resection, a postoperative radiotherapy dose less than 50 Gy was suboptimal for OS and LRC. Higher radiation doses may be needed to obtain better LRC. Further investigation of novel therapy or palliative treatment should be considered for patients receiving R2 resection.

[Efficacy of feeding pump for patients on enteral tube feeding: a systematic literature review and analysis]

BACKGROUND/AIMS

This study was conducted to establish a guideline on the utilizing of feeding pump in patients requiring enteral tube feeding.

METHODS

As a first step, textbooks on nutrition and guidelines from regional clinical nutrition societies were analyzed. Afterwards, data on the efficacy, safety, and practicality of feeding pump application were collected and evaluated by systematically reviewing the related literature. As data sources, 8 domestic databases including KoreaMed and global databases such as Ovid-MEDLINE, Ovid-EMBASE, and Cochrane Library were utilized. A total of 2,016 related articles was selected by applying the keyword "(enteral feeding.mp AND pump.mp)".

RESULTS

Textbooks and guidelines were not able to draw conclusions on the effects of the feeding pump because the injection speed, tube size, and etcetera were different for enteral feeding. Feeding pump assisted enteral tube feeding was an efficient, safe, and practical procedure for reducing maladjustment-related complications of enteral tube feeding, which are obvious obstacles for maintaining nutritional balances in patients requiring tube feeding.

CONCLUSIONS

Feeding pump application can be considered an efficient and safe measure that is acceptable in patients on small intestinal tube feeding, critically-ill patients on gastro-intestinal tube feeding, premature babies, and critically-ill or severely malnourished children (recommendation grade D).

Statistical mechanics model for the dynamics of collective epigenetic histone modification

Epigenetic histone modifications play an important role in the maintenance of different cell phenotypes. The exact molecular mechanism for inheritance of the modification patterns over cell generations remains elusive. We construct a Potts-type model based on experimentally observed nearest-neighbor enzyme lateral interactions and nucleosome covalent modification state biased enzyme recruitment. The model can lead to effective nonlocal interactions among nucleosomes suggested in previous theoretical studies, and epigenetic memory is robustly inheritable against stochastic cellular processes.