Oncologic relevance of genetic alterations in sporadic synchronous and solitary colorectal cancer: a retrospective multicenter study.

BACKGROUND: Oncologic impact of genetic alteration across synchronous colorectal cancer (CRC) still remains unclear. This study aimed to compare the oncologic relevance according to genetic alteration between synchronous and solitary CRC with performing systematic review. METHODS: Multicenter retrospective analysis was performed for CRC patients with curative resection. Genetic profiling was consisted of microsatellite instability (MSI) testing, RAS (K-ras, and N-ras), and BRAF (v-Raf murine sarcoma viral oncogene homolog B1) V600E mutation. Multivariate analyses were conducted using logistic regression for synchronicity, and Cox proportional hazard model with stage-adjusting for overall survival (OS) and disease-free survival (DFS). RESULTS: It was identified synchronous (n = 36) and solitary (n = 579) CRC with similar base line characteristics. RAS mutation was associated to synchronous CRC with no relations of MSI and BRAF. During median follow up of 77.8 month, Kaplan-meier curves showed significant differences according to MSI-high for OS, and in RAS, and BRAF mutation for DFS, respectively. In multivariable analyses, RAS and BRAF mutation were independent factors (RAS, HR = 1.808, 95% CI = 1.18-2.77, p = 0.007; BRAF, HR = 2.417, 95% CI = 1.32-4.41, p = 0.004). Old age was independent factor for OS (HR = 3.626, 95% CI = 1.09-12.00, p = 0.035). CONCLUSION: This study showed that oncologic outcomes might differ according to mutation burden characterized by RAS, BRAF, and MSI between synchronous CRC and solitary CRC. In addition, our systematic review highlighted a lack of data and much heterogeneity in genetic characteristics and survival outcomes of synchronous CRC relative to that of solitary CRC.

Does the morphology of the umbilicus influence the incidence of surgical site infections in transumbilical single-incision laparoscopic appendectomy?

Background: Transumbilical laparoscopic appendectomy (TULA) may be a feasible alternative to conventional laparoscopic appendectomy. However, a transumbilical incision may increase incisional surgical site infections (SSIs) compared to conventional laparoscopic appendectomy. This study aimed to investigate the relationship between the morphology of the umbilicus and the incidence of SSIs in patients who underwent TULA. Patients and Methods: This retrospective study analysed the medical records of consecutive patients who underwent surgery for acute appendicitis at our institution from June 2016 to October 2020. The patients were assigned to the SSI group (those with an SSI) or the non-SSI group. The morphology of the umbilicus was calculated by measuring its width and depth on preoperative computed tomography images and was compared between the SSI and non-SSI groups. Results: The SSI group included 23 patients, while the non-SSI group included 252 patients. The width of the umbilicus was significantly shorter in the SSI group than in the non-SSI group (29 ± 10 mm vs. 34 ± 9 mm, P = 0.027). The umbilicus was slightly deeper in the SSI group than in the non-SSI group; however, the difference was not significant (16 mm vs. 15 mm, P = 0.384). Conclusions: This was the first study investigating the correlation between the morphology of the umbilicus and SSI development in TULA. SSIs tended to occur more commonly in a narrow and deep umbilicus. An extension of the umbilical incision may help prevent SSI in patients with this umbilical morphology.

Clinical and oncologic outcomes of laparoscopic versus open surgery in elderly patients with colorectal cancer: a retrospective multicenter study.

BACKGROUND: Laparoscopic surgery is commonly used in elderly patients over 80 years old. The purpose of this study was to compare the perioperative and oncologic outcomes between laparoscopic surgery and open surgery in elderly patients with colorectal cancer. METHODS: We retrospectively analyzed the medical records of patients aged ≥ 80 years who underwent curative resection of colorectal cancer at six Hallym University-affiliated hospitals. The perioperative outcomes and oncologic outcomes were compared between laparoscopic and open surgery RESULTS: Of 294 elderly patients, 104 (35.3%) underwent open surgery and 190 (64.7%) underwent laparoscopic surgery. The postoperative hospital stay (P = 0.019) and time to soft diet (P = 0.009) were shorter in the laparoscopic group than in the open group. Postoperative complications were less frequent in the laparoscopic group than in the open group (P < 0.001), including wound infection (P = 0.005), ileus (P = 0.005), and pneumonia (P = 0.001). The 3-year overall survival (OS) (P = 0.982) and recurrence-free survival rates (RFS) (P = 0.532) were similar in both groups. In multivariable analyses, positive lymph node status was the only independent factor associated with OS (P = 0.019) and RFS (P = 0.012). Laparoscopic surgery was not associated with OS (P = 0.874) and RFS (P = 0.772). CONCLUSION: Laparoscopic surgery offers several perioperative advantages over open surgery and similar long-term oncological outcomes for elderly patients with colorectal cancer. Therefore, we suggest that laparoscopic surgery can be safely performed for the treatment of elderly patients (≥ 80 years old) with colorectal cancer.

Clinical outcomes of sigmoid volvulus and risk factors for its recurrence: a multicenter study in Korea.

PURPOSE: Sigmoid volvulus is one of the leading causes of colonic obstruction. The aims of this study were to review the treatment characteristics and clinical outcomes of patients diagnosed with sigmoid volvulus over 10 years at five university-affiliated hospitals in Korea, and to identify possible risk factors for its recurrence. METHODS: Retrospective review was performed for medical records of patients who were diagnosed with sigmoid volvulus and managed surgically or conservatively at the five Hallym University-affiliated hospitals between January 2005 and July 2018. RESULTS: A total of 69 patients were diagnosed, of whom 11 patients underwent emergency surgery and 58 patients were conservatively managed. Non-operative management was successful in 53 of 58 patients (91.4%) at initial admission. Of the non-operative managed patients, six patients required emergency surgery due to unsuccessful decompression or recurrence whereas 23 patients underwent regular surgery for definitive treatment. And overall recurrence rate and mortality rate were 25.8% (15/58) and 1.7% (1/58), respectively. A total of 40 patients underwent surgery; 23 underwent regular surgery and 17 underwent emergency surgery. Restoration of bowel continuity was more frequently performed in the regular surgery group than in the emergency surgery group (87.0% vs 52.9%, P = 0.03). In multivariable analysis, only non-operative management at the initial admission (P = 0.029) was independently associated with recurrence. CONCLUSION: Although non-operative treatment can be initially attempted, surgery is required for preventing recurrence. Regular surgery should be considered to restore continuity of the bowel.

Transumbilical Single-Incision Laparoscopic-Assisted Appendectomy (TULAA) Is Useful in Adults and Young Adolescents: Comparison with Multi-Port Laparoscopic Appendectomy.

Background and objectives: Single-port laparoscopic appendectomy (SLA) in most previous studies has used intracorporeal excision of the appendix and needed a longer operative time than multi-port laparoscopic appendectomy (MLA), although SLA does have the potential benefit of an almost invisible scar within the umbilicus. Some studies have reported that extracorporeal transumbilical single-incision laparoscopic-assisted appendectomy (TULAA) in children took a considerably reduced operative time compared to MLA. We adopted TULAA in adults, adding routine dissection of the peritoneal attachment of the appendix. The aim was to compare the operative outcomes between TULAA and MLA. Materials and Methods: Between March 2013 and January 2016, 770 patients with acute uncomplicated and complicated appendicitis from 15 to 75 years of age were enrolled retrospectively. The operation was performed as early (EA) and interval appendectomy (IA). Results: Operative time was shorter in the TULAA group than in the MLA group, except for IA. No open conversion occurred in the TULAA group, except one case of ileocecal resection for IA. No intra-abdominal fluid collection was found in the TULAA group. Extended resection (especially partial cecectomy) was performed less frequently in the TULAA group than in the MLA group for IA. Mean postoperative hospital stay was shorter in the TULAA group for uncomplicated appendicitis. When the data of the EA group and the IA group were compared, operative time was significantly shorter in the IA group for both MLA and TULAA. The open conversion rate and the complication rate tended to be lower in the IA group. Confined to IA, the TULAA group tended to have shorter mean initial, postoperative, and total hospital stays. Conclusions: TULAA can be a useful surgical alternative to MLA in adults and young adolescents, because it lacks open conversion and provides both a shorter operative time and a shorter postoperative hospital stay. TULAA is feasible for IA in that it showed a lower rate of extended resection and complications.

Safety and feasibility of laparoscopic surgery for appendiceal mucocele: a multicenter study.

BACKGROUND: Although laparoscopic appendectomy has been widely performed since 1987, concerns over potential spillage of mucus into the peritoneal cavity during laparoscopic manipulation have prevented the use of laparoscopic surgery (LS) for appendiceal mucocele. The purpose of the present study was to evaluate the safety, feasibility, and short-term perioperative outcomes of LS for appendiceal mucocele. METHODS: A retrospective review was performed to identify patients diagnosed with appendiceal mucocele based on their imaging studies and who underwent surgery at one of six Hallym-University-affiliated hospitals between January 2007 and June 2016. Patient demographics, surgical outcomes, and postoperative outcomes were retrospectively analyzed. RESULTS: A total of 96 patients were evaluated, of whom 58 underwent LS (LS group) and 38 underwent open surgery (OS; OS group). There were no significant differences in patient characteristics between groups. The operation time was similar in both groups (P = 0.399). Intraoperative rupture occurred in two patients in each group (no significant difference, P = 0.647). Time to flatus, time to soft food intake, and length of hospital stay were shorter in the LS group than in the OS group (2.4 vs. 3.2 days, P = 0.003; 3.6 vs. 4.5 days, P = 0.024; 6.5 vs. 8.8 days, P = 0.011, respectively). The rate of postoperative complications was similar between the groups (P = 0.786). Univariate analysis revealed that rupture of appendiceal mucocele was associated with white blood cell count > 10,000/µL (P = 0.032) but not with LS (P = 0.647). CONCLUSIONS: The results showed that LS is safe and feasible for the surgical treatment of appendiceal mucocele. An elevated WBC count was associated with a risk of appendiceal mucocele rupture.

Poorly Differentiated Clusters in Colorectal Adenocarcinomas Share Biological Similarities with Micropapillary Patterns as well as Tumor Buds.

In colorectal carcinoma, poorly differentiated clusters (PDCs) are a poor prognostic indicator and show morphological continuity and behavioral similarities to micropapillary patterns (MPPs) as well as tumor buds (TBs). Epithelial-mesenchymal transition (EMT) and inhibition of cancer-stromal interactions may contribute to the development of PDCs. To clarify the biological nature of PDCs, we examined immunohistochemical stainings for ß-catenin, Ki-67, E-cadherin, epithelial cell adhesion molecule (EpCAM), MUC1, and epithelial membrane antigen (EMA), which are associated with EMT and cancer-stromal interactions. The expression frequencies and patterns of PDCs, TBs, and differentiated neoplastic glands from the tumor center (TC) were compared. In the study group (117 cases), the nuclear ß-catenin staining index was higher in PDCs (37.3%) and TBs (43.3%) than in neoplastic glands from TC (8.9%, P < 0.001). The mean Ki-67 labeling index in TC was 71.5%, whereas it was decreased in PDCs (31.2%) and TBs (10.2%, P < 0.001). E-cadherin and EpCAM displayed a tendency to be found along the cell membrane in TC samples (91.5% and 92.3%, respectively), whereas they showed loss of membranous staining in PDC (44.4% and 36.8%, respectively) and TB samples (60.7% and 68.4%, respectively). An inside-out pattern for MUC1 and EMA was frequently observed in PDC (48.7% and 45.3%, respectively) and TB samples (46.2% and 45.3%, respectively), but not in TC samples. Our data demonstrate that there is a pathogenetic overlap among PDCs, TBs, and MPPs and suggest that they might represent sequential growth patterns that branch from common biological processes such as dedifferentiation and alteration in cancer-stromal interactions.

Could laparoscopic appendectomy in pregnant women affect obstetric outcomes? A multicenter study.

PURPOSE: The purpose of this study was to compare the perioperative and obstetric outcomes of pregnant women between laparoscopic surgery and open surgery and to evaluate the predictive factors for overall obstetric outcomes. METHODS: We retrospectively reviewed the medical records of pregnant women who underwent appendectomy between January 2008 and June 2015 at six hospitals affiliated to Hallym University. RESULTS: Eighty patients were evaluated. Twenty-four underwent laparoscopic appendectomy (LA) and 56 underwent open appendectomy (OA). There were no significant differences in the patients' characteristics and gestational age at surgery between the two groups. Operation time, time to flatus, and time to soft food intake were similar in both groups. The length of stay was shorter in the LA group than in the OA group (5.1 vs 8.1 days, P = 0.044). Gestational age at delivery, birth weight, and delivery type were similar in both groups. There was no significant difference in overall obstetric poor outcome (20.8 vs 14.3 %, P = 0.516), including preterm delivery (8.3 vs 7.1 %, P = 1.000) and fetal loss (12.5 vs 7.1 %, P = 0.350). Multivariable analysis revealed that fever >38 °C (P = 0.022) and maternal age (P = 0.044) were independent predictors for the overall poor outcomes. CONCLUSIONS: LA was associated with shorter length of stay compared with OA, but perioperative and obstetric outcomes were similar with both procedures. LA can be safely performed in pregnant women in any trimester.

Single-lesion measurement per organ for assessing tumor response in advanced gastric cancer.

OBJECTIVE: The criterion of two target lesions per organ in the revised Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1) is an arbitrary decision. We assumed that measuring the single largest lesion per organ (modified RECIST 1.1, hereafter referred to as mRECIST 1.1) instead of two (RECIST 1.1) might be enough to assess tumor responses. METHODS: We compared tumor response using computed tomography according to the RECIST 1.1 and mRECIST 1.1 in patients with advanced gastric cancer (AGC) who received first-line chemotherapy. RESULTS: A total of 51 patients who had at least two target lesions in any organ according to the RECIST 1.1 were included in the study. The level of concordance in the tumor response between the RECIST 1.1 and mRECIST 1.1 was excellent (k = 0.904). Only 3 patients (5.9%) showed a disagreement of tumor responses between the two criteria. The overall response rate was not significantly different between the two criteria (45.1% by RECIST 1.1 vs. 49.0% by mRECIST 1.1, p = 0.692). CONCLUSION: The mRECIST 1.1 showed a high concordance with the original RECIST 1.1 in the assessment of tumor response for patients with AGC. Our result suggests that it may be possible to measure the single largest target lesion per organ for assessing tumor response in clinical practice.

Caproiciproducens galactitolivorans gen. nov., sp. nov., a bacterium capable of producing caproic acid from galactitol, isolated from a wastewater treatment plant.

A strictly anaerobic, Gram-stain-positive, non-spore-forming, rod-shaped bacterial strain, designated BS-1T, was isolated from an anaerobic digestion reactor during a study of bacteria utilizing galactitol as the carbon source. Its cells were 0.3-0.5 µm × 2-4 µm, and they grew at 35-45 °C and at pH 6.0-8.0. Strain BS-1T produced H2, CO2, ethanol, acetic acid, butyric acid and caproic acid as metabolic end products of anaerobic fermentation. Phylogenetic analysis, based on the 16S rRNA gene sequence, showed that strain BS-1T represented a novel bacterial genus within the family Ruminococcaceae, Clostridium Cluster IV. The type strains that were most closely related to strain BS-1T were Clostridium sporosphaeroides KCTC 5598T (94.5 %), Clostridium leptum KCTC 5155T (94.3 %), Ruminococcus bromii ATCC 27255T (92.1 %) and Ethanoligenens harbinense YUAN-3T (91.9 %). Strain BS-1T had 17.6 % and 20.9 % DNA-DNA relatedness values with C. sporosphaeroides DSM 1294T and C. leptum DSM 753T, respectively. The major components of the cellular fatty acids were C16 : 0 dimethyl aldehyde (DMA) (22.1 %), C16 : 0 aldehyde (14.1 %) and summed feature 11 (iso-C17 : 0 3-OH and/or C18 : 2 DMA; 10.0 %). The genomic DNA G+C content was 50.0 mol%. Phenotypic and phylogenetic characteristics allowed strain BS-1T to be clearly distinguished from other taxa of the genus Clostridium Cluster IV. On the basis of these data, the isolate is considered to represent a novel genus and novel species within Clostridium Cluster IV, for which the name Caproiciproducens galactitolivorans gen. nov., sp. nov. is proposed. The type species is BS-1T ( = JCM 30532T and KCCM 43048T).

Comparison of short- and long-term outcomes of an early experience with robotic and laparoscopic-assisted resection for rectal cancer.

BACKGROUND/AIMS: Robotic surgery is increasingly used for rectal cancer. We compared the short- and long-term outcomes between robotic- and laparoscopic-assisted resection for rectal cancer. METHODOLOGY: A retrospective chart review was performed between 2006 and 2010. RESULTS: Seventeen robotic and 61 laparoscopic surgeries were performed consecutively. Median follow-up time was 58.2 months. No operation was converted to open surgery. No difference was observed between the groups for types of operations, diverting ileostomy rate, operation time, blood loss, and postoperative hospital stay, tumor diameter, distal margin, circumferential margin, tumor stage, differentiation, lymphovascular, or perineural invasion. However, the number of harvested lymph nodes was higher in the robot than that in the laparoscopy group (p = 0.017). Overall morbidity and reoperation rates were similar between the groups. The 5-yr overall and disease-free survival rates of all patients were 82.5% and 81.3%, respectively. The 5-yr overall and disease-free survival rates of the robotic and the laparoscopy groups were 94.1% and 79.7% (p = 0.241), and 94.1% and 77.9% (p = 0.159), respectively. CONCLUSIONS: Robot-assisted resection for rectal cancer resulted in harvesting more lymph nodes without increasing morbidity and showed a comparable survival rate, compared with those of laparoscopy.

Clinicopathologic impacts of poorly differentiated cluster-based grading system in colorectal carcinoma.

Differentiation-based histologic grading of colorectal carcinoma (CRC) is widely used, but its clinical impact is limited by insufficient prognostic value, interobserver disagreement, and the difficulty of its application to CRC with specific histologic types such as mucinous and medullary carcinoma. A recently proposed novel grading system based on quantifying poorly differentiated clusters (PDCs) claims to have the advantages of reproducibility and improved prognostic value, and might apply to heterogeneous CRC. We aimed to validate the clinicopathologic significance of the PDCs-based grading system and to determine the relationship between this grading system and microsatellite instability (MSI). Two hundred and one patients who had undergone radical surgery were reviewed. Based on the number of PDCs, 85, 58, and 58 tumors were classified as grade (G) 1 (42.3%), G2 (28.9%), and G3 (28.9%), respectively. PDCs-based grade was significantly associated with T, N, and M stages; lymphovascular invasion; conventional histologic grade; and frequent tumor budding (all P <0.001). In multivariate analysis, PDCs-based grade was found to be an independent prognostic factor for disease-free survival (P = 0.022; hazard ratio, 3.709 [G2], 7.461 [G3]). G3 CRC significantly correlated with high MSI (MSI-H) compared to G1 and G2 (P = 0.002; odds ratio, 5.750). In conclusion, this novel grading would provide valuable prognostic information to a greater number of patients and would require continued verification. PDCs-based grading is feasible for CRCs with heterogeneous morphology, and we propose that the association between G3 and MSI-H be further evaluated in different histological subtypes of CRC.

Clostridium vulturis sp. nov., isolated from the intestine of the cinereous vulture (Aegypius monachus).

A Gram-stain positive, strict anaerobe, spore-forming, motile rod-shaped bacterial strain with peritrichous flagella, designated YMB-57(T), was isolated from the intestine of a cinereous vulture (Aegypius monachus) in Korea. Strain YMB-57(T) was found to show optimal growth at 37 °C, pH 7.5 and 1.0 % (w/v) NaCl. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain YMB-57(T) belongs to the genus Clostridium and is most closely related to the type strains of Clostridium subterminale (96.9 % sequence similarity), Clostridium thiosulfatireducens (96.7 %) and Clostridium sulfidigenes (96.6 %). The main fermentation end-products identified following growth in PYG medium were acetate, butyrate, ethanol, propanol, carbon dioxide and hydrogen. Peptone was converted to ethanol, and butanol, whereas glucose was fermented to ethanol. The major cellular fatty acids were identified as C16:0, C18:1 ω9c, and C18:1 ω9c DMA and the DNA G+C content was determined to be 34.0 mol%. Phenotypic and phylogenetic differences indicate that strain YMB-57(T) is distinct from other Clostridium species. It is proposed that strain YMB-57(T) be classified as the type strain of a novel species of the genus Clostridium, with the name Clostridium vulturis sp. nov. The type strain is YMB-57(T) (=KCTC 15114(T) = JCM 17998(T)).

Investigation of out-of-distribution detection across various models and training methodologies.

Machine learning-based algorithms demonstrate impressive performance across numerous fields; however, they continue to suffer from certain limitations. Even sophisticated and precise algorithms often make erroneous predictions when implemented with datasets having different distributions compared to the training set. Out-of-distribution (OOD) detection, which distinguishes data with different distributions from that of the training set, is a critical research area necessary to overcome these limitations and create more reliable algorithms. The OOD issue, particularly concerning image data, has been extensively studied. However, recently developed OOD methods do not fulfill the expectation that OOD performance will increase as the accuracy of in-distribution classification improves. Our research presents a comprehensive study on OOD detection performance across multiple models and training methodologies to verify this phenomenon. Specifically, we explore various pre-trained models popular in the computer vision field with both old and new OOD detection methods. The experimental results highlight the performance disparity in existing OOD methods. Based on these observations, we introduce Trimmed Rank with Inverse softMax probability (TRIM), a remarkably simple yet effective method for model weights with newly developed training methods. The proposed method could serve as a potential tool for enhancing OOD detection performance owing to its promising results. The OOD performance of TRIM is highly compatible with the in-distribution accuracy model and may bridge the efforts on improving in-distribution accuracy to the ability to distinguish OOD data.

Multicenter analysis of risk factors for anastomotic leakage after laparoscopic rectal cancer excision: the Korean laparoscopic colorectal surgery study group.

OBJECTIVE: To assess the risk factors for clinical anastomotic leakage (AL) in patients undergoing laparoscopic surgery for rectal cancer. BACKGROUND: Little data are available about risk factors for AL after laparoscopic rectal cancer resection. METHODS: This was a retrospective analysis of 1609 patients with rectal cancer who had undergone laparoscopic surgery for rectal cancer with sphincter preservation. Clinical data related to AL were collected from 11 institutions. Univariate and multivariate analyses were performed to determine the risk factors for AL. RESULTS: AL was noted in 101 (6.3%) of the patients. The leakage rate ranged from 2.0% to 10.3% for each hospital (P = 0.04). In patients without protective stomas (n = 1187), male sex [hazard ratio (HR), 3.468], advanced tumor stage (HR, 2.520), lower tumor level (HR, 2.418), preoperative chemoradiation (HR, 6.284), perioperative transfusion (HR, 10.705), and multiple firings of the linear stapler (HR, 6.181) were significantly associated with AL. Our theoretical model suggested that the HR for patients with 2 risk factors was significantly higher than that the HR for patients with no or only 1 risk factor. CONCLUSIONS: Male sex, low anastomosis, preoperative chemoradiation, advanced tumor stage, perioperative bleeding, and multiple firings of the linear stapler increased the risk of AL after laparoscopic surgery for rectal cancer. A diverting stoma might be mandatory in patients with 2 or more of the risk factors identified in this analysis.

Pedobacter luteus sp. nov., isolated from soil.

Two strains of Gram-staining-negative, rod-shaped bacteria that were motile by gliding, N7d-4(T) and B4a-b5, were isolated during a study of culturable bacteria in soil cultivated with potatoes. These isolates grew at 15-37 °C and at pH 6.5-7.0. The major cellular fatty acids were summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c), anteiso-C15 : 0, iso-C15 : 0, iso-C17 : 0 3-OH and iso-C17 : 1ω9c. The major polar lipids were phosphatidyl-N-methylethanolamine and phosphatidylethanolamine. The strains contained d-18 : 0 and d-19 : 0 sphingosines. The DNA G+C contents of strains N7d-4(T) and B4a-b5 were 48.5 and 46.9 mol% (HPLC), respectively. A phylogenetic analysis based on 16S rRNA gene sequences showed that strains N7d-4(T) and B4a-b5 were affiliated with Pedobacter species in the family Sphingobacteriaceae. Strains N7d-4(T) and B4a-b5 shared 99.9 % sequence similarity, and the most closely related Pedobacter type strains were Pedobacter composti TR6-06(T) (96.5 and 96.7 % sequence similarity, respectively), P. oryzae N7(T) (95.4 and 95.6 %) and P. caeni LMG 22862(T) (94.0 and 94.4 %). Phenotypic data and phylogenetic inference clearly distinguished the two isolates from other Pedobacter species. Based on these data, the isolates are considered to represent a novel species of the genus Pedobacter, for which the name Pedobacter luteus sp. nov. is proposed. The type strain is N7d-4(T) ( = KCTC 22699(T)  = DSM 22385(T)).

Polaribacter sejongensis sp. nov., isolated from Antarctic soil, and emended descriptions of the genus Polaribacter, Polaribacter butkevichii and Polaribacter irgensii.

A Gram-staining-negative, catalase- and oxidase-positive, non-motile bacterium, designated strain KOPRI 21160(T), was isolated from Antarctic soil. Based on 16S rRNA gene sequence analysis, strain KOPRI 21160(T) was found to belong to the genus Polaribacter. Sequence similarity between strain KOPRI 21160(T) and the type strains of species of the genus Polaribacter was 94.2-98.3 %. The nearest phylogenetic neighbours of strain KOPRI 21160(T) were Polaribacter butkevichii KCTC 12100(T) (98.3 % similarity) and Polaribacter irgensii KCTC 23136(T) (97.5 %). DNA-DNA relatedness was 50.6 %, between strain KOPRI 21160(T) and P. butkevichii KCTC 12100(T), and 45.2 % between strain KOPRI 21160(T) and P. irgensii KCTC 23136(T). Strain KOPRI 21160(T) grew at 4-37 °C and at pH 7.0-8.5. It could hydrolyse DNA, starch and Tweens 20, 40, 60 and 80. Menaquinone-6 (MK-6) was the only respiratory quinone, and iso-C15 : 0, iso-C15 : 0 3-OH and C15 : 1ω6c were the major cellular fatty acids. The major polar lipids were phosphatidylethanolamine, two unidentified aminolipids and one unidentified lipid. The DNA G+C content was 30.0 mol%. Based on data from our polyphasic study, the organism is considered to represent a novel species of the genus Polaribacter, for which we propose the name Polaribacter sejongensis sp. nov. The type strain is KOPRI 21160(T) ( = KCTC 23670(T) = JCM 18092(T)). Emended descriptions of the genus Polaribacter, Polaribacter butkevichii Nedashkovskaya et al. 2005 and Polaribacter irgensii Gosink et al. 1998 are also proposed.

Comparison of the bacterial communities in anaerobic, anoxic, and oxic chambers of a pilot A(2)O process using pyrosequencing analysis.

A(2)O process is a sequential wastewater treatment process that uses anaerobic, anoxic, and oxic chambers for nitrogen and phosphorus removal. In this study, the bacterial communities among these chambers were compared, and the diversity of the bacteria involved in nitrogen and phosphorus removal was surveyed. A pilot-scale A(2)O process (50 m(3) day(-1)) was operated for more than 6 months, and bacterial 16S rRNA gene diversity was analyzed using pyrosequencing. A total of 7,447 bacterial sequence reads were obtained from anaerobic (1,546), anoxic (2,158), and oxic (3,743) chambers. Even though there were differences in the atmospheric condition and functionality, no prominent differences could be found in the bacterial community of the three chambers of the pilot A(2)O process. All sequence reads, which were taxonomically analyzed using the Eztaxon-e database, were assigned into 638 approved or tentative genera. Among them, about 72.2 % of the taxa were contained in the phyla Proteobacteria and Bacteroidetes. Phosphate-accumulating bacteria, Candidatus Accumulibacter phosphatis, and two other Accumulibacter were found to constitute 3.1 % of the identified genera. Ammonia-oxidizing bacteria, Nitrosomonas oligotropha, and four other phylotypes in the same family, Nitrosomonadaceae, constituted 0.2 and 0.9 %, respectively. Nitrite-oxidizing bacteria, Nitrospira defluvii, and other three phylotypes in the same family, Nitrospiraceae, constituted 2.5 and 0.1 %, respectively. In addition, Dokdonella and a phylotype of the phylum Chloroflexi, function in nitrogen and/or phosphate removal of which have not been reported in the A(2)O process, constituted the first and third composition among genera at 4.3 and 3.8 %, respectively.

A Retrospective Multicenter Study of the Clinicopathological Characteristics and Prognosis of Young Adult Patients with Colorectal Cancer: Effects of Chemotherapy on Prognosis.

BACKGROUND: The objective of this study was to evaluate clinicopathologic features of young patients with colorectal cancer (CRC) and to compare their prognosis with those of older patients Methods: We retrospectively reviewed the medical records of patients who underwent surgery for stage 0-III CRC at four university-affiliated hospitals between January 2011 and December 2020. The patients were divided into two groups, the young adult group (≤45 years) and the older group (>45 years). RESULTS: Of 1992 patients, 93 (4.6%) were young adults and 1899 (95.3%) were older patients. Young patients showed more symptoms (p = 0.014) and more poorly or undifferentiated adenocarcinoma (p = 0.047) than older patients. The young adult patients were more likely to receive adjuvant chemotherapy (p < 0.001) and multidrug agents (p = 0.029), and less likely to cease chemotherapy (p = 0.037). The five-year RFS (recurrence-free survival) rate was better in the young adults than in the older patients (p = 0.009). In the multivariable analysis, young age was a significant prognostic factor for better RFS (p = 0.015). CONCLUSIONS: Young patients with CRC had more symptoms, aggressive histological features than older patients. They received more multidrug agents and discontinued chemotherapy less often, resulting in better prognosis.

Self-expandable metallic stents as a bridge to surgery in obstructive right- and left-sided colorectal cancer: a multicenter cohort study.

The insertion of a self-expandable metal stent (SEMS) has been proposed as an alternative to emergent surgery (ES) for obstructive colorectal cancer (CRC). We aimed to evaluate the perioperative and oncologic outcomes of SEMS as a bridge to surgery in obstructive CRC, as compared with ES. We retrospectively reviewed the medical records of patients who underwent curative resection of obstructive CRC at four Hallym University-affiliated hospitals between January 2010 and December 2019. All patients were analyzed overall colon, then according to the side of obstruction (overall, right or left). Of 167 patients, 52 patients underwent ES and 115 underwent SEMS insertion and surgery (SEMS group). The postoperative hospital stay and time to soft diet were shorter in the SEMS group than in the ES group for overall and both sided cancer. The SEMS group had lower rates of stoma formation and severe complications for overall and for left-sided cancer. The 5-year overall survival (P = 0.682) and disease-free survival (P = 0.233) rates were similar in both groups. SEMS insertion as a bridge to surgery was associated with faster recovery, a lower rate of stoma formation with similar oncologic outcomes to those of ES.