Tumor immune microenvironment is influenced by frameshift mutations and tumor mutational burden in gastric cancer.

PURPOSE: Immunoscore can effectively predict prognosis in patients with colon cancer; however, its clinical application is limited. We modified the Immunoscore and created a tumor immune microenvironment (TIM) classification system for gastric carcinoma. Unlike previous studies that used small sample sizes or focused on particular immune-cell subtypes, our simplified system enables pathologists to classify gastric carcinomas intuitively using H&E-stained sections. METHODS: Samples from 326 patients with advanced gastric carcinoma were reviewed and analyzed by pathologists using simple determination and digital image analysis. Comprehensive results of cancer-panel sequencing, Epstein-Barr‒virus (EBV) status, and PD-L1, HER2, ATM, PTEN, MET, FGFR2, and EGFR immunohistochemistry were evaluated with respect to the TIM class. RESULTS: The TIM was classified as "hot" (n = 22), "immunosuppressed" (n = 178), "excluded" (n = 83), or "cold" (n = 43). TIM category was significantly associated with numbers of frameshift mutations (P < 0.001) and high tumor mutational burden (P < 0.004), and predicted overall survival. It was also significantly associated with age, histological type, degree of fibrosis, PD-L1 expression, loss of ATM and PTEN expression (P < 0.001), sex, EBV positivity, and HER2 overexpression (P < 0.04). "Hot" tumors were frequent in PD-L1 expressing and EBV-positive samples, and in those with ATM and PTEN loss. "Excluded" tumors were frequent in HER2-positive cases, whereas "cold" tumors were more frequent in younger patients with poorly cohesive histology and high fibrosis levels. CONCLUSIONS: TIM classification system for gastric carcinoma has prognostic significance and results in classes that are associated with molecular characteristics.

Short-term outcomes of a multicentre randomized clinical trial comparing laparoscopic pylorus-preserving gastrectomy with laparoscopic distal gastrectomy for gastric cancer (the KLASS-04 trial).

BACKGROUND: There remain concerns about the safety and functional benefit of laparoscopic pylorus-preserving gastrectomy (LPPG) compared with laparoscopic distal gastrectomy (LDG). This study evaluated short-term outcomes of a randomized clinical trial (RCT) comparing LPPG with LDG for gastric cancer. METHODS: The Korean Laparoendoscopic Gastrointestinal Surgery Study (KLASS)-04 trial was an investigator-initiated, open-label, parallel-assigned, superiority, multicentre RCT in Korea. Patients with cT1N0M0 cancer located in the middle third of the stomach at least 5 cm from the pylorus were randomized to undergo LPPG or LDG. Participants, care givers and those assessing the outcomes were not blinded to group assignment. Outcomes were 30-day postoperative morbidity rate and death at 90 days. RESULTS: Some 256 patients from nine institutions were randomized (LPPG 129 patients, LDG 127 patients) between July 2015 and July 2017 and outcomes for 253 patients were analysed. Postoperative complications within 30 days were seen in 19.3 and 15.5 per cent in the LPPG and LDG groups respectively (P = 0·419). Postoperative pyloric stenosis was observed in nine (7.2 per cent) and two (1·5 per cent) patients in the LPPG and LDG groups (P = 0·026) respectively. In multivariable analysis higher BMI was a risk factor for postoperative complications (odds ratio 1·17, 95 per cent c.i. 1·04 to 1·32; P = 0·011). Death at 90 days was zero in both groups. CONCLUSION: Postoperative complications and mortality was comparable in patients undergoing LPPG and LDG. Registration number: NCT02595086 (http://www.clinicaltrials.gov).

Preoperative MRI Evaluation of Thyroid Cartilage Invasion in Patients with Laryngohypopharyngeal Cancer: Comparison of Contrast-Enhanced 2D Spin-Echo and 3D T1-Weighted Radial Gradient Recalled-Echo Techniques.

BACKGROUND AND PURPOSE: Accurate assessment of thyroid cartilage invasion on preoperative imaging influences management in patients with laryngeal and hypopharyngeal cancers. We evaluated the clinical usefulness of contrast-enhanced 3D T1-weighted radial gradient recalled-echo for preoperative assessment of thyroid cartilage invasion in patients with laryngohypopharyngeal squamous cell carcinoma, compared with 2D spin-echo T1WI. MATERIALS AND METHODS: Preoperative MR images of 52 consecutive patients who were diagnosed with laryngeal or hypopharyngeal cancer and underwent partial or total laryngectomy were analyzed. Pathologic specimens served as reference standards. Two independent head and neck radiologists evaluated the presence of thyroid cartilage invasion in both contrast-enhanced 2D spin-echo T1WI and 3D gradient recalled-echo sequences. The sensitivity, specificity, and accuracy of the 2 modalities were compared. The area under the curve was a measure of diagnostic performance. RESULTS: Pathologic neoplastic thyroid cartilage invasion was identified in 24 (46.2%) of the 52 patients. The sensitivity (75.0%), specificity (96.4%), and accuracy (86.5%) of contrast-enhanced 3D gradient recalled-echo were significantly higher than those of 2D spin-echo T1WI (58.3%, 89.3%, and 75.0%; P = .017, .003, and .002, respectively). 3D gradient recalled-echo had significantly better diagnostic performance (area under the curve = 0.963) than 2D spin-echo T1WI (area under the curve = 0.862; P = .010). CONCLUSIONS: Contrast-enhanced 3D gradient recalled-echo was diagnostically superior in identifying neoplastic thyroid cartilage invasion compared with 2D spin-echo T1WI in patients with laryngohypopharyngeal cancer, and therefore, may provide more accurate preoperative staging.

Enhanced wound healing using a 3D printed VEGF-mimicking peptide incorporated hydrogel patch in a pig model.

There is a need for effective wound healing through rapid wound closure, reduction of scar formation, and acceleration of angiogenesis. Hydrogel is widely used in tissue engineering, but it is not an ideal solution because of its low vascularization capability and poor mechanical properties. In this study, gelatin methacrylate (GelMA) was tested as a viable option with tunable physical properties. GelMA hydrogel incorporating a vascular endothelial growth factor (VEGF) mimicking peptide was successfully printed using a three-dimensional (3D) bio-printer owing to the shear-thinning properties of hydrogel inks. The 3D structure of the hydrogel patch had high porosity and water absorption properties. Furthermore, the bioactive characterization was confirmed by cell culture with mouse fibroblasts cell lines (NIH 3T3) and human umbilical vein endothelial cells. VEGF peptide, which is slowly released from hydrogel patches, can promote cell viability, proliferation, and tubular structure formation. In addition, a pig skin wound model was used to evaluate the wound-healing efficacy of GelMA-VEGF hydrogel patches; the results suggest that the GelMA-VEGF hydrogel patch can be used for wound dressing.

Development and Validation of a Deep Learning-Based Model to Distinguish Glioblastoma from Solitary Brain Metastasis Using Conventional MR Images.

BACKGROUND AND PURPOSE: Differentiating glioblastoma from solitary brain metastasis preoperatively using conventional MR images is challenging. Deep learning models have shown promise in performing classification tasks. The diagnostic performance of a deep learning-based model in discriminating glioblastoma from solitary brain metastasis using preoperative conventional MR images was evaluated. MATERIALS AND METHODS: Records of 598 patients with histologically confirmed glioblastoma or solitary brain metastasis at our institution between February 2006 and December 2017 were retrospectively reviewed. Preoperative contrast-enhanced T1WI and T2WI were preprocessed and roughly segmented with rectangular regions of interest. A deep neural network was trained and validated using MR images from 498 patients. The MR images of the remaining 100 were used as an internal test set. An additional 143 patients from another tertiary hospital were used as an external test set. The classifications of ResNet-50 and 2 neuroradiologists were compared for their accuracy, precision, recall, F1 score, and area under the curve. RESULTS: The areas under the curve of ResNet-50 were 0.889 and 0.835 in the internal and external test sets, respectively. The area under the curve of neuroradiologists 1 and 2 were 0.889 and 0.768 in the internal test set and 0.857 and 0.708 in the external test set, respectively. CONCLUSIONS: A deep learning-based model may be a supportive tool for preoperative discrimination between glioblastoma and solitary brain metastasis using conventional MR images.

MRI Features May Predict Molecular Features of Glioblastoma in Isocitrate Dehydrogenase Wild-Type Lower-Grade Gliomas.

BACKGROUND AND PURPOSE: Isocitrate dehydrogenase (IDH) wild-type lower-grade gliomas (histologic grades II and III) with epidermal growth factor receptor (EGFR) amplification or telomerase reverse transcriptase (TERT) promoter mutation are reported to behave similar to glioblastoma. We aimed to evaluate whether MR imaging features could identify a subset of IDH wild-type lower-grade gliomas that carry molecular features of glioblastoma. MATERIALS AND METHODS: In this multi-institutional retrospective study, pathologically confirmed IDH wild-type lower-grade gliomas from 2 tertiary institutions and The Cancer Genome Atlas constituted the training set (institution 1 and The Cancer Genome Atlas, 64 patients) and the independent test set (institution 2, 57 patients). Preoperative MRIs were analyzed using the Visually AcceSAble Rembrandt Images and radiomics. The molecular glioblastoma status was determined on the basis of the presence of EGFR amplification and TERT promoter mutation. Molecular glioblastoma was present in 73.4% and 56.1% in the training and test sets, respectively. Models using clinical, Visually AcceSAble Rembrandt Images, and radiomic features were built to predict the molecular glioblastoma status in the training set; then they were validated in the test set. RESULTS: In the test set, a model using both Visually AcceSAble Rembrandt Images and radiomic features showed superior predictive performance (area under the curve = 0.854) than that with only clinical features or Visually AcceSAble Rembrandt Images (areas under the curve = 0.514 and 0.648, respectively; P < . 001, both). When both Visually AcceSAble Rembrandt Images and radiomics were added to clinical features, the predictive performance significantly increased (areas under the curve = 0.514 versus 0.863, P < .001). CONCLUSIONS: MR imaging features integrated with machine learning classifiers may predict a subset of IDH wild-type lower-grade gliomas that carry molecular features of glioblastoma.

Dynamic and subtype-specific interactions between tumour burden and prognosis in breast cancer.

We investigated the relationship between the prognostic importance of anatomic tumour burden and subtypes of breast cancer using data from the Korean Breast Cancer Registry Database. In HR+/HER2+ and HR-/HER2-tumours, an increase in T stage profoundly increased the hazard of death, while the presence of lymph node metastasis was more important in HR+/HER2+ and HR-/HER2+ tumours among 131,178 patients with stage I-III breast cancer. The patterns of increasing mortality risk and tumour growth (per centimetre) and metastatic nodes (per node) were examined in 67,038 patients with a tumour diameter ≤ 7 cm and < 8 metastatic nodes. HR+/HER2- and HR-/HER2- tumours showed a persistent increase in mortality risk with an increase in tumour diameter, while the effect was modest in HER2+ tumours. Conversely, an increased number of metastatic nodes was accompanied by a persistently increased risk in HR-/HER2+ tumours, while the effect was minimal for HR-/HER2- tumours with > 3 or 4 nodes. The interactions between the prognostic significance of anatomic tumour burden and subtypes were significant. The prognostic relevance of the anatomic tumour burden was non-linear and highly dependent on the subtypes of breast cancer.

Probing the Effects of Strong Electromagnetic Fields with Charge-Dependent Directed Flow in Pb-Pb Collisions at the LHC.

The first measurement at the LHC of charge-dependent directed flow (v_{1}) relative to the spectator plane is presented for Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV. Results are reported for charged hadrons and D^{0} mesons for the transverse momentum intervals p_{T}>0.2 GeV/c and 3

Airflow limitation as a risk factor for vascular stiffness.

BACKGROUND: Cardiovascular disease is one of the main causes of mortality in patients with chronic obstructive pulmonary disease (COPD), and atherosclerosis is a cause of cardiac comorbidities in COPD. However, it is not clear whether airflow limitation is associated with atherosclerosis irrespective of smoking.OBJECTIVE: To investigate whether airflow limitation is independently associated with vascular stiffness.METHODS: We enrolled 18 893 participants (male 70.5%; mean age 47.5 ± 9.8 years; never smokers 44.2%) who underwent spirometry and brachial-ankle pulse wave velocity (baPWV) as part of a standard health examination at Ajou University Hospital, Suwon, South Korea, from January 2010 to December 2015.We defined vascular peripheral atherosclerosis as baPWV ≥ 1400 cm/s and airflow limitation as pre-bronchodilator ratio of forced expiratory volume in 1 sec (FEV1) to forced vital capacity (FVC) <70%.RESULTS: Mean baPWV was higher in subjects with airflow limitation (1477.6 ± 331.7 cm/sec, n = 638) than in those without airflow limitation (1344.1 ± 231.8 cm/sec, n = 18255, P < 0.001). In multivariate logistic regression analysis, the following were independent predictors associated with peripheral atherosclerosis (P < 0.05): age, male sex, fasting serum glucose, mean blood pressure, serum leukocyte count, serum low density lipoprotein level and FEV1.CONCLUSION: Airflow limitation was an independent predictor of vascular stiffness irrespective of smoking history, which suggests that airflow limitation is linked with atherosclerosis.

Targetoid hepatic observations on gadoxetic acid-enhanced MRI using LI-RADS version 2018: emphasis on hepatocellular carcinomas assigned to the LR-M category.

AIM: To determine useful imaging features for differentiating hepatocellular carcinoma (HCC) categorised as LR-M from non-HCC malignancies in using the Liver Imaging-Reporting and Data System (LI-RADS) version 2018 on gadoxetic acid-enhanced magnetic resonance imaging (MRI). MATERIALS AND METHODS: Patients at high-risk for HCC with surgically confirmed HCCs (n=131) and non-HCC malignancies (n=90) and who had undergone gadoxetic acid-enhanced MRI were included. LI-RADS categories were assigned to identify hepatic observations defined as LR-M by two radiologists. Major and ancillary imaging features of hepatic observation with targetoid appearance including intratumoural septa were compared between HCCs and non-HCC malignancies. A classification tree analysis (CTA) was applied to differentiate high-risk HCCs from non-HCC malignancies in the LR-M category. RESULTS: A total of 36 HCCs (27.5%) and 70 non-HCC malignancies (77.8%) were assigned as LR-M. An enhancing capsule (p=0.0293), blood products in the mass (p=0.0393), non-targetoid restriction (p=0.018), and a septum (p=0.0053) were significantly predictive of HCC. On CTA, the presence of a septum was an initial predictor for a high probability of HCC followed by non-targetoid restriction. The CTA model has a sensitivity of 63.9%, specificity of 90%, and accuracy of 81.1% for differentiating HCC assigned LR-M from non-HCC malignancy. CONCLUSION: A considerable proportion of HCCs could have been categorised as LR-M as they had a targetoid appearance on gadoxetic acid-enhanced MRI. An intratumoural septum and non-targetoid restriction as well as enhancing capsule and blood products in the mass may be useful for differentiating HCC assigned to LR-M from non-HCC malignancy on gadoxetic acid-enhanced MRI.

Comparison of the diagnostic performance of the 2017 and 2018 versions of LI-RADS for hepatocellular carcinoma on gadoxetic acid enhanced MRI.

AIM: To compare the diagnostic performance of the 2017 (v2017) and 2018 versions (v2018) of the Liver Imaging-Reporting and Data System (LI-RADS) for hepatocellular carcinoma (HCC) using gadoxetic acid-enhanced magnetic resonance imaging (Gd-EOB-MRI) and to evaluate the effect in v2018. MATERIALS AND METHODS: Treatment-naive patients at high-risk for HCC who underwent Gd-EOB-MRI were included. The LI-RADS categories were assigned according to v2017 and v2018. The diagnostic performances were compared between v2017 and v2018 according to the size and combination of imaging features. RESULTS: A total of 117 patients with 137 observations were identified, including 89 HCCs; 76.2% (64/84) of observations with threshold growth were re-classified as subthreshold growth when using v2018 instead of v2017. The final categories changed in nine (14%) cases. For the combination of LR-5/LR-5V, there were no significant differences in sensitivity and specificity between the two versions (sensitivity, 64% versus 58.4%; specificity, 87.5% versus 85.4%; all p>0.05). For the combination of LR-4 and LR-5/5V, the diagnostic performance of v2018 was inferior to that of v2017 when considering only major features (accuracy, 86.1% versus 80.3%, respectively; p=0.013), particularly in observations measuring 10-20 mm, but was comparable after adding the ancillary features (accuracy, 86.9% versus 86.1%, respectively; p=1.00). CONCLUSION: In LI-RADS v2018, although a considerable number of observations re-classified subthreshold growth, changes in the assigned categories were insignificant; overall diagnostic performance was comparable to that of v2017, but v2018 might emphasise the value of ancillary features in combination with major features for determining the probability of HCC.

Questionable correlation of the apparent diffusion coefficient with the histological grade and microvascular invasion in small hepatocellular carcinoma.

AIM: To evaluate the correlation between the apparent diffusion coefficient (ADC) and various histopathological parameters in small hepatocellular carcinomas (HCCs). MATERIALS AND METHODS: In 143 surgically resected small HCCs, the mean and minimum ADC values, tumour-to-liver ADC ratio, and normalised ADC (ADC of the HCC/ADC of the spleen) were correlated to the tumour grade, microvascular invasion (MVI), cellularity, fatty change, degree of fibrosis, and lymphocytic infiltration using linear regression analysis, the Wilcoxon rank sum test, or Spearman's rank correlation. RESULTS: No significant correlation was found between the ADC parameters and tumour grade. In the univariate analysis, the ADC ratio of the tumour was significantly correlated with MVI as well as the degree of fibrosis and lymphocyte infiltration of the HCC (p=0.017, 0.042, and 0.002, respectively). The ADC of the tumour was significantly correlated with the degree of lymphocyte infiltration of the HCC (p=0.049). In the multivariate analysis, the ADC ratio of the tumour was an independent parameter for MVI and the degree of lymphocyte infiltration of the HCC (p=0.034 and <0.001, respectively), and the ADC of the tumour was an independent parameter for the degree of lymphocyte infiltration of the HCC (p=0.009). There was no significant correlation between the other ADCs and pathological tumour parameters. CONCLUSION: The tumour grade of small HCCs was not correlated with ADC parameters. The tumour-to-liver ADC ratio was a significant independent parameter for the degree of lymphocyte infiltration and MVI of small HCCs.

The effects of cortisol and adrenal androgen on bone mass in Asians with and without subclinical hypercortisolism.

Analyses using the largest Korean cohort of adrenal incidentaloma (AI) revealed that subtle cortisol excess in premenopausal women and reduced dehydroepiandrosterone-sulfate (DHEA-S) in postmenopausal women and men are associated with bone mineral density (BMD) reduction in Asian patients with subclinical hypercortisolism (SH). INTRODUCTION: Few studies evaluated bone metabolism in Asians with SH. We investigated associations of cortisol and DHEA-S, an adrenal androgen, with BMD in Asians with AI, with or without SH. METHODS: We used cross-sectional data of a prospective multicenter study from Korea. We measured BMD, bone turnover markers, cortisol levels after 1-mg dexamethasone suppression test (1-mg DST), DHEA-S, and baseline cortisol to DHEA-S ratio (cort/DHEA-S) in 109 AI patients with SH (18 premenopausal, 38 postmenopausal women, and 53 men) and 686 with non-functional AI (NFAI; 59 premenopausal, 199 postmenopausal women, and 428 men). RESULTS: Pre- and postmenopausal women, but not men, with SH had lower BMDs at lumbar spine (LS) than those with NFAI (P = 0.008~0.016). Premenopausal women with SH also had lower BMDs at the hip than those with NFAI (P = 0.009~0.012). After adjusting for confounders, cortisol levels after 1-mg DST demonstrated inverse associations with BMDs at all skeletal sites only in premenopausal women (ß = - 0.042~- 0.033, P = 0.019~0.040). DHEA-S had positive associations with LS BMD in postmenopausal women (ß = 0.096, P = 0.001) and men (ß = 0.029, P = 0.038). The cort/DHEA-S had inverse associations with LS BMD in postmenopausal women (ß = - 0.081, P = 0.004) and men (ß = - 0.029, P = 0.011). These inverse associations of cort/DHEA-S remained significant after adjusting for cortisol levels after 1-mg DST (ß = - 0.079~- 0.026, P = 0.006~0.029). In postmenopausal women, the odds ratios of lower BMD by DHEA-S and cort/DHEA-S was 0.26 (95% CI, 0.08-0.82) and 3.40 (95% CI, 1.12-10.33), respectively. CONCLUSION: Subtle cortisol excess in premenopausal women and reduced DHEA-S in postmenopausal women and men may contribute to BMD reduction in Asians with SH.

Association of blood n-3 fatty acid with bone mass and bone marrow TRAP-5b in the elderly with and without hip fracture.

The plasma n-3 fatty acid level was 26.2% lower in patients with osteoporotic hip fracture than in those with osteoarthritis. In all patients, n-3 fatty acid was positively associated with bone mineral density and inversely associated with tartrate-resistant acid phosphatase-5b level in bone marrow aspirates, reflecting the bone microenvironment. INTRODUCTION: Despite the potential beneficial role of n-3 fatty acid (FA) on bone metabolism, the specific mechanisms underlying these effects in humans remain unclear. Here, we assessed whether the plasma n-3 level, as an objective indicator of its status, is associated with osteoporosis-related phenotypes and bone-related markers in human bone marrow (BM) samples. METHODS: This was a case-control and cross-sectional study conducted in a clinical unit. n-3 FA in the blood and bone biochemical markers in the BM aspirates were measured by gas chromatography/mass spectrometry and immunoassay, respectively. BM fluids were collected from 72 patients who underwent hip surgery because of either osteoporotic hip fracture (HF; n = 28) or osteoarthritis (n = 44). RESULTS: After adjusting for confounders, patients with HF had 26.2% lower plasma n-3 levels than those with osteoarthritis (P = 0.006), and each standard deviation increment in plasma n-3 was associated with a multivariate-adjusted odds ratio of 0.40 for osteoporotic HF (P = 0.010). In multivariate analyses including all patients, a higher plasma n-3 level was associated with higher bone mass at the lumbar spine (ß = 0.615, P = 0.002) and total femur (ß = 0.244, P = 0.045). Interestingly, the plasma n-3 level was inversely associated with the tartrate-resistant acid phosphatase-5b level (ß = - 0.633, P = 0.023), but not with the bone-specific alkaline phosphatase level, in BM aspirates. CONCLUSIONS: These findings provide clinical evidence that n-3 FA is a potential inhibitor of osteoclastogenesis that favors human bone health.

Urinary Neutrophil Gelatinase-Associated Lipocalin as a Biomarker for Renal Injury in Liver Transplant Recipients Using Calcineurin Inhibitors.

BACKGROUND: Urinary neutrophil gelatinase-associated lipocalin (uNGAL) is an early biomarker of renal injury. We examined the feasibility of using uNGAL as an early predictor of renal impairment in patients under calcineurin inhibitors in liver transplant recipients. METHODS: From urine samples obtained from liver transplant recipients, the glomerular filtration rate (GFR) at the time of urine sampling was compared with that at 5 to 7 months later. Patients were divided into 3 groups according to initial GFR and then divided into 2 groups according to the uNGAL level of 25 ng/mL. Progression of renal injury (PRI) was defined as a decrease in the GFR of more than 5 mL/min/1.73 m2 in the mild or moderate groups, or if a normal group patient shifted to the mild or moderate group. RESULTS: Fifty-one patients were enrolled. The mean uNGAL level was higher in the moderate group than in the normal and mild groups (18.38 ± 14.31 vs 7.74 ± 8.13; P < .01). A proportion of uNGAL-high was also higher in the moderate group than in the mild group (40% vs 5%; P = .03). uNGAL-high was a risk factor for 6-month PRI (odds ratio, 60.375; 95% confidence interval, 1.283-4088.25; P = .037) and 1-year PRI (odds ratio, 21.311; % confidence interval, 0.947-479.578; P = .054). CONCLUSIONS: A uNGAL of >25 ng/mg can be a marker for moderate renal impairment (GFR of 30-59 mL/min/1.73 m2) and a predictor of PRI at 6 months in patients using calcineurin inhibitors. Renal protection strategies should be considered in liver transplant recipients with a uNGAL of >25 ng/mg in spot urine sampling.

The association of cortisol and adrenal androgen with trabecular bone score in patients with adrenal incidentaloma with and without autonomous cortisol secretion.

Despite ethnic differences in cortisol sensitivity, only one study in Caucasians has assessed trabecular bone score (TBS) in patients with subclinical hypercortisolism (SH). We showed that both subtle cortisol excess and reduced adrenal androgen may contribute to impaired bone quality in Asian women with SH. INTRODUCTION: One study in Caucasians has assessed trabecular bone score (TBS), an index of bone microstructure, in adrenal incidentaloma (AI) patients with subclinical hypercortisolism (SH). There are ethnic differences in cortisol sensitivities between Caucasian and Asian populations. We investigated the associations of cortisol and the adrenal androgen dehydroepiandrosterone-sulfate (DHEA-S) with TBS in AI patients with SH, adrenal Cushing's syndrome (CS), and nonfunctional AI (NFAI). METHODS: We measured TBS, cortisol levels after the overnight 1 mg dexamethasone suppression test (1 mg DST), and cortisol/DHEA-S in 61 patients with SH (30 men; 31 women), 19 with adrenal CS (4 men; 15 women), and 355 with NFAI (213 men; 142 women). RESULTS: After adjusting for confounders, the serum cortisol level after 1 mg DST was inversely correlated with TBS in men (ß = -0.133, P = 0.045) and women (ß = - 0.140, P = 0.048). Higher cortisol/DHEA-S ratio was associated with lower TBS in women (ß = - 0.252, P < 0.001), but not men. This inverse association of cortisol/DHEA-S ratio in women remained statistically significant after adjusting for the serum cortisol level after 1 mg DST (ß = - 0.221, P = 0.008). Compared with women with NFAI, women with SH had 2.2% lower TBS (P = 0.040). Deteriorated bone microstructure (TBS < 1.230) was associated with the serum cortisol level after 1 mg DST (odds ratio [OR], 2.18; 95% confidence interval [CI], 1.04-4.53) and cortisol/DHEA-S ratio (OR, 2.05; 95% CI, 1.03-4.08). CONCLUSIONS: Subtle cortisol excess in both genders and reduced DHEA-S, especially in women, may contribute to impaired bone quality in Asian patients with SH.

Threshold regulation and stochasticity from the MecA/ClpCP proteolytic system in Streptococcus mutans competence.

Many bacterial species use the MecA/ClpCP proteolytic system to block entry into genetic competence. In Streptococcus mutans, MecA/ClpCP degrades ComX (also called SigX), an alternative sigma factor for the comY operon and other late competence genes. Although the mechanism of MecA/ClpCP has been studied in multiple Streptococcus species, its role within noisy competence pathways is poorly understood. S. mutans competence can be triggered by two different peptides, CSP and XIP, but it is not known whether MecA/ClpCP acts similarly for both stimuli, how it affects competence heterogeneity, and how its regulation is overcome. We have studied the effect of MecA/ClpCP on the activation of comY in individual S. mutans cells. Our data show that MecA/ClpCP is active under both XIP and CSP stimulation, that it provides threshold control of comY, and that it adds noise in comY expression. Our data agree quantitatively with a model in which MecA/ClpCP prevents adventitious entry into competence by sequestering or intercepting low levels of ComX. Competence is permitted when ComX levels exceed a threshold, but cell-to-cell heterogeneity in MecA levels creates variability in that threshold. Therefore, MecA/ClpCP provides a stochastic switch, located downstream of the already noisy comX, that enhances phenotypic diversity.

Evolution and persistence of resistance-associated substitutions of hepatitis C virus after direct-acting antiviral treatment failures.

Daclatasvir plus asunaprevir (DCV+ASV) treatment is an all-oral direct-acting antiviral (DAA) therapy for the genotype 1b HCV-infected patients. In this study, we investigated how resistance-associated substitutions (RASs) evolved after treatment failures and assessed the effect of those substitutions on viral fitness. Sequencing of NS5A and NS3 revealed typical RASs after treatment failures. Interestingly, the RASs of NS3 reverted to the wild-type amino acid within 1 year after treatment failures. However, the RASs of NS5A were stable and did not change. The effect of NS5A and NS3 RASs on viral RNA replication was assessed after mutagenic substitution in the genotype 1b HCV RNA. Among single substitutions, the effect of D168V was more substantial than the others and the effect of the triple mutant combination (D168V+L31V+Y93H) was the most severe. The RAS at NS5A Y93 affected both viral RNA replication and virus production. Finally, the effect of trans-complementation of NS5A was demonstrated in our co-transfection experiments and these results suggest that such a trans-complementation effect of NS5A may help maintain the NS5A RASs for a long time even after cessation of the DAA treatment. In conclusion, the results from this investigation would help understand the emergence and persistence of RASs.

Initial experience with purely laparoscopic living-donor right hepatectomy.

BACKGROUND: There may be concerns about purely laparoscopic donor right hepatectomy (PLDRH) compared with open donor right hepatectomy, especially when performed by surgeons accustomed to open surgery. This study aimed to describe technical tips and pitfalls in PLDRH. METHODS: Data from donors who underwent PLDRH at Seoul National University Hospital between December 2015 and July 2017 were analysed retrospectively. Endpoints analysed included intraoperative events and postoperative complications. All operations were performed by a single surgeon with considerable experience in open living donor hepatectomy. RESULTS: A total of 26 donors underwent purely laparoscopic right hepatectomy in the study interval. No donor required transfusion during surgery, whereas two underwent reoperation. In two donors, the dissection plane at the right upper deep portion of the midplane was not correct. One donor experienced portal vein injury during caudate lobe transection, and one developed remnant left hepatic duct stenosis. One donor experienced remnant portal vein angulation owing to a different approach angle, and one experienced arterial damage associated with the use of a laparoscopic energy device. One donor had postoperative bleeding due to masking of potential bleeding foci owing to intra-abdominal pressure during laparoscopy. Two donors experienced right liver surface damage caused by a xiphoid trocar. CONCLUSION: Purely laparoscopic donor hepatectomy differs from open donor hepatectomy in terms of angle and caudal view. Therefore, surgeons experienced in open donor hepatectomy must gain adequate experience in laparoscopic liver surgery and make adjustments when performing PLDRH.

Predictors of failure to detect early hepatocellular carcinoma in patients with chronic hepatitis B who received regular surveillance.

BACKGROUND: A proportion of chronic hepatitis B (CHB) patients are diagnosed with advanced hepatocellular carcinoma (HCC) despite regular surveillance. AIMS: To determine predictors for HCC detection failure in CHB patients who underwent regular surveillance. METHODS: CHB patients with well-preserved liver function, who underwent ultrasonography and alpha-foetoprotein (AFP) analysis every 6 months, were enrolled. Cox regression analysis was used to identify predictors for detection failure, defined as HCC initially diagnosed at Barcelona Clinic Liver Cancer (BCLC) stage B or C. RESULTS: Of the 4590 CHB patients (mean age, 52.1 years; men, 61.6%), 169 patients were diagnosed with HCC (3.68%) and 35 (20.7%) HCC patients were initially diagnosed with HCC BCLC stage B or C. The cumulative incidence of HCC detection failure was 0.2% at year 1 and 1.3% at year 5. Multivariate analyses indicated that cirrhosis (hazard ratio [HR], 3.078; 95% CI, 1.389-6.821; P = 0.006), AFP levels ≥9 ng/mL (HR, 5.235; 95% CI, 2.307-11.957; P = 0.010), and diabetes mellitus (HR, 3.336; 95% CI, 1.341-8.296; P = 0.010) were independent predictors of HCC detection failure. Another model that incorporated liver stiffness (LS) values identified LS values ≥11.7 kPa (HR, 11.045; 95% CI, 2.066-59.037; P = 0.005) and AFP levels ≥9 ng/mL (HR, 4.802; 95% CI, 1.613-14.297; P = 0.005) as predictors of detection failure. CONCLUSIONS: In CHB patients undergoing regular surveillance with ultrasonography and alpha-foetoprotein (AFP) analysis every 6 months, the HCC detection failure rate was not high (0.8% per person; 0.1% per test). However, careful attention should be paid in patients with advanced liver fibrosis (clinical cirrhosis or LS value >11.7 kPa), high AFP levels, or diabetes mellitus, who are prone to surveillance failure.