Normal-Incidence Germanium Photodetectors Integrated with Polymer Microlenses for Optical Fiber Communication Applications.

We present a novel photon-acid diffusion method to integrate polymer microlenses (MLs) on a four-channel, high-speed photo-receiver consisting of normal-incidence germanium (Ge) p-i-n photodiodes (PDs) fabricated on a 200 mm Si substrate. For a 29 µm diameter PD capped with a 54 µm diameter ML, its dark current, responsivity, 3 dB bandwidth (BW), and effective aperture size at -3 V bias and 850 nm wavelength are measured to be 138 nA, 0.6 A/W, 21.4 GHz, and 54 µm, respectively. The enlarged aperture size significantly decouples the tradeoff between aperture size and BW and enhances the optical fiber misalignment tolerance from ±5 µm to ±15 µm to ease the module packaging precision. The sensitivity of the photo-receiver is measured to be -9.2 dBm at 25.78 Gb/s with a bit error rate of 10-12 using non-return-to-zero (NRZ) transmission. Reliability tests are performed, and the results show that the fabricated Ge PDs integrated with polymer MLs pass the GR-468 reliability assurance standard. The demonstrated photo-receiver, a first of its kind to the best of our knowledge, features decent performance, high yield, high throughput, low cost, and compatibility with complementary metal-oxide-semiconductor (CMOS) fabrication processes, and may be further applied to 400 Gb/s pulse-amplitude modulation four-level (PAM4) communication.

The emergence of RAS mutations in patients with RAS wild-type mCRC receiving cetuximab as first-line treatment: a noninterventional, uncontrolled multicenter study.

ABSRTACT: BACKGROUND: Patients treated with anti-epidermal growth factor receptor (anti-EGFR) will ultimately develop acquired resistance promoted by clonal selection, mainly the emergence of mutations in the MAPK pathway (mostly RAS mutations). Baseline assessment of RAS mutations in the blood of patients correlates well with RAS tumour tissue testing and is currently an alternative option in routine clinical practice to guide first-line therapy. The aim of this study was the prevalence of acquired genomic alterations detected in the auxiliary tool of ctDNA testing and investigated the role of RAS ctDNA status for detecting tumour response and predicting benefit to anti-EGFR therapy. METHODS: Only patients with concordant wild-type formalin-fixed, paraffin-embedded (FFPE) tumour tissue and baseline ctDNA RAS wild-type were included. RAS mutations in plasma were evaluated using MassARRAY platform. Blood samples were collected at baseline, every 3 months during first-line treatment, and at disease progression. The primary endpoint was the detection rate of RAS mutations during cetuximab treatment. The correlation between response and survival outcomes and the emergence of circulating RAS mutations was also analysed. RESULTS: The detection rate of RAS mutations during treatment was 9.3% (10/108). RAS mutations detection occurred a median of 3 months prior to radiologic documentation. The subgroup of patients with RAS mutations exhibited significantly inferior progression-free survival and overall survival (P = 0.002 and 0.027, respectively) but the baseline characteristics, response rates, disease control rates, and metastatectomy were not significant (all P > 0.05). CONCLUSIONS: We demonstrated that RAS ctDNA status might be a valuable biomarker for detecting early tumour response and predicting benefit to anti-EGFR therapy. CLINICAL TRIAL REGISTRATION: NCT03401957 (January 17, 2018).

The Negative Prognostic Impact of Lymph Node Skip Metastasis in Stage III Colon Cancer With pN1 Disease: A Single-Center and Retrospective Cohort Study.

BACKGROUND: Lymph node skip metastasis is a subgroup of lymph node metastatic patterns with low incidence in node-positive colon cancer. Its clinical significance is still unclear. OBJECTIVE: This study aimed to investigate the prognostic impact of lymph node skip metastasis in stage III colon cancer. DESIGN: This is a retrospective observational analysis. SETTINGS: The study was conducted at the Taipei Veterans General Hospital. PATIENTS: This study included patients with stage III colon cancer who underwent D3 lymphadenectomy between 2006 and 2015. MAIN OUTCOME MEASURES: The patients were divided into a lymph node skip metastasis-positive group and a negative group. Recurrence-free survival and overall survival were compared using Kaplan-Meier curves and log-rank test. Cox regression was applied to identify related risk factors influencing survival. RESULTS: A total of 461 patients were reviewed, and lymph node skip metastasis-positive patients represented 13.2% of our sample. Patients with lymph node skip metastasis tended to present with a higher proportion of right-sided cancer, lower positive lymph nodes, lower lymph node ratio, and higher mean BMI. Liver recurrence was more prevalent in the lymph node skip metastasis group ( p = 0.028) than in the negative group. The presence of lymph node skip metastasis was a negative prognostic factor for 5-year recurrence-free survival (51.4% vs 68.7%; p = 0.002) and 5-year overall survival (66.4% vs 80.4%; p = 0.024) in Kaplan-Meier curves and multivariate Cox regression. Subgroup analysis revealed the survival significance of recurrence-free survival ( p = 0.001) and overall survival ( p = 0.011) in lymph node skip metastasis with pN1 disease. LIMITATIONS: This study was limited by its retrospective design, single-center nature, and sampling error. CONCLUSIONS: Lymph node skip metastasis is an independent negative prognostic factor in stage III colon cancer with pN1 disease. More intensive surveillance may be necessary for patients of this subgroup. See Video Abstract at https://links.lww.com/DCR/C60 . IMPACTO PRONSTICO NEGATIVO DE LAS METSTASIS DISCONTNUAS GANGLIONARES LINFTICAS EN CASOS DE CNCER DE COLON ESTADIO III CON ENFERMEDAD PN ESTUDIO DE COHORTES RETROSPECTIVO MONOCENTRICO: ANTECEDENTES:Las metástasis discontínuas ganglionares linfáticas, son un subgrupo de patrones metastásicos en los ganglios linfáticos con baja incidencia en el cáncer de colon con nódulos positivos. Su significado clínico aún no está claro.OBJETIVO:Estudio que tiene por objetivo el investigar el impacto pronóstico de las metástasis discontínuas de los ganglios linfáticos en el cáncer de colon de estadio III.DISEÑO:Análisis observacional retrospectivo.AJUSTES:El estudio se realizó en el Hospital General de Veteranos de Taipei.PACIENTES:Pacientes con cáncer de colon en estadio III que se sometieron a linfadenectomía D3 entre 2006 y 2015.PRINCIPALES MEDIDAS DE RESULTADO:Los pacientes se dividieron en un grupo positivo de metástasis discontínuas en los ganglios linfáticos y un otro grupo negativo. La sobrevida libre de recidiva y la sobrevida global, fueron comparadas mediante las curvas de Kaplan-Meier y la prueba de rango logarítmico. Se aplicó la regresión de Cox para identificar los factores de riesgo relacionados que influyeron en la sobrevida.RESULTADOS:Se revisaron un total de 461 casos, donde los pacientes positivos con metástasis en los ganglios linfáticos representaron el 13,2% de nuestra muestra. Los pacientes con metástasis discontínuas ganglionares linfáticas tendían a presentar una mayor proporción de cáncer localizado en el lado derecho del colon, presentar un menor numéro de ganglios linfáticos positivos y una proporción menor de ganglios linfáticos con un IMC promedio más alto. Las recidivas hepáticas fueron más prevalentes en el grupo de metástasis discontínuas ganglionares linfáticas ( p = 0,028) que en el grupo negativo. La presencia de metástasis discontínuas ganglionares linfáticas fué un factor de pronóstico negativo en la sobrevida libre de recidiva a 5 años (51,4% frente a 68,7%, p = 0,002) y la sobrevida general a 5 años (66,4% frente a 80,4%, p = 0,024) evaluada por las curvas de Kaplan-Meier y la regresión multivariada de Cox. El análisis de subgrupos reveló la importancia de la sobrevida libre de recidiva ( p = 0,001) y la sobrevida general ( p = 0,011) en los casos con metástasis discontínuas ganglionares linfáticas con enfermedad pN1.LIMITACIONES:Diseño retrospectivo, naturaleza de centro único y error de muestreo.CONCLUSIONES:Las metástasis discontínuas ganglionares linfáticas son un factor pronóstico negativo independiente en los casos de cáncer de colon estadio III con enfermedad pN1. Tal vez sea necesaria una mayor vigilancia de los pacientes en este subgrupo.Consulte Video Resumen en https://links.lww.com/DCR/C60 . (Traducción-Dr. Xavier Delgadillo ).

Impact of the COVID-19 pandemic on inflammatory bowel disease care in Taiwan: A multicenter study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic had a great impact on healthcare system and patients. This study aimed to evaluate the effect of the COVID-19 pandemic on the perceptions of patients with inflammatory bowel disease (IBD). METHODS: This prospective multicenter study was conducted between July 2021 and December 2021. Patients with IBD answered a structured questionnaire, and their degree of anxiety was assessed using a visual analogue scale (VAS) before and after reading educational materials. RESULTS: A total of 225 (47.67%) patients with Crohn's disease, 244 (51.69%) with ulcerative colitis and 3 (0.64%) with indeterminate colitis were enrolled. Common concerns were adverse events from vaccination (20.34%), and higher risks of developing severe COVID-19 (19.28%) and COVID-19 infection (16.31%) than the general population. Medications deemed by the patients to increase the risk of COVID-19 were immunomodulators (16.10%), anti-tumor necrosis factor-α antagonists (9.96%), and corticosteroids (9.32%). Thirty-five (7.42%) patients self-discontinued IBD medication, of whom 12 (34.28%) had worse symptoms. Older age (>50 years) (OR 1.10, 95% CI 1.01-1.19, p = 0.03), IBD-related complications (OR 1.16, 95% CI 1.04-1.28, p = 0.01), education status below senior high school (OR 1.22, 95% CI 1.08-1.37, p = 0.001), and residing in north-central Taiwan (OR 1.21, 95% CI 1.10-1.34, p < 0.001) were associated with more anxiety. None of the enrolled patients contracted COVID-19. The anxiety VAS score (mean ± SD) improved after reading the educational materials (3.84 ± 2.33 vs. 2.81 ± 1.96, p < 0.001). CONCLUSION: The medical behavior of IBD patients was influenced by the COVID-19 pandemic, and their anxiety could be mitigated after education.

Clinical outcome of local treatment and radical resection for pT1 rectal cancer.

BACKGROUND: Rectal cancer is mainly cured by radical resection with neoadjuvant chemoradiation or adjuvant chemotherapy. Pathological T1 lesions can be managed by local treatment and radiotherapy thereafter. Lower morbidity is the key benefit of these local treatments. Since nodal metastasis is important for staging, radical resection (RR) is suggested. Rectal cancer has higher surgical morbidity than colon cancer; local treatment has been the preferred choice by patients. METHODS: We retrospectively enrolled data of 244 patients with pT1 rectal adenocarcinoma. A total of 202 patients (82.8%) underwent RR, including low anterior resection (LAR) and abdomino-perineal resection (APR), and 42 patients (17.2%) underwent LT, including transanal excision and colonoscopic polypectomy. RESULTS: In our study, seven patients (16.7%) had loco-regional recurrence and distant metastasis from the LT group while eight patients (4.0%) had distant metastasis without loco-regional recurrence from the RR group. The lymph node metastasis rate in RR group was 8.4%. Forty-seven patients (24.2%) underwent LAR with temporary stoma, and its reversal rate was 100%. In the RR group, postoperative complication rate was 10.4% with a mortality rate of 0.5%. Recurrence-free survival (RFS) was 95.7% for RR and 80.2% for LT (P = 0.001), and overall survival (OS) was 93.7% for RR and 70.0% for LT (P = 0.001). CONCLUSION: This study found that RFS and OS in patients of pT1 rectal adenocarcinoma that had received RR were better than receiving LT. Further adjuvant chemotherapy was possible for some RR patients. A higher recurrence rate after LT must be balanced against the morbidity and mortality associated with RR.

Surveillance of Rice Blast Resistance Effectiveness and Emerging Virulent Isolates in Taiwan.

Rice blast caused by Magnaporthe oryzae is a dangerous threat to rice production and food security worldwide. Breeding and proper deployment of resistant varieties are effective and environmentally friendly strategies to manage this notorious disease. However, a highly dynamic and quickly evolved rice blast pathogen population in the field has made disease control with resistance germplasms more challenging. Therefore, continued monitoring of pathogen dynamics and application of effective resistance varieties are critical tasks to prolong or sustain field resistance. Here, we report a team project that involved evaluation of rice blast resistance genes and surveillance of M. oryzae field populations in Taiwan. A set of International Rice Research Institute-bred blast-resistant lines (IRBLs) carrying single blast resistance genes was utilized to monitor the field effectiveness of rice blast resistance. Resistance genes such as Ptr (formerly Pita2) and Pi9 exhibited the best and most durable resistance against the rice blast fungus population in Taiwan. Interestingly, line IRBLb-B harboring the Pib gene with good field protection has recently shown susceptible lesions in some locations. To dissect the genotypic features of virulent isolates against the Pib resistance gene, M. oryzae isolates were collected and analyzed. Screening of the AvrPib locus revealed that the majority of field isolates still maintained the wild-type AvrPib status but eight virulent genotypes were found. Pot3 insertion appeared to be a major way to disrupt the AvrPib avirulence function. Interestingly, a novel AvrPib double-allele genotype among virulent isolates was first identified. Pot2 repetitive element-based polymerase chain reaction (rep-PCR) fingerprinting analysis indicated that mutation events may occur independently among different lineages in different geographic locations of Taiwan. This study provides our surveillance experience of rice blast disease and serves as the foundation to sustain rice production.

Three-dimensional versus conventional two-dimensional laparoscopic colectomy for colon cancer: A 3-year follow-up study.

Background: Three-dimensional (3D) laparoscopy was developed to overcome the drawbacks of two-dimensional (2D) laparoscopy, namely lack of depth perception. However, the benefit of 3D laparoscopy in colorectal surgery is inconclusive. Here, we compare the 3-year follow-up outcomes of 3D and 2D laparoscopic colectomy. Patients and Methods: A total of 91 consecutive patients who underwent either 3D or 2D laparoscopy colectomy from October 2015 to November 2017 by a single surgical team for colon cancer were enrolled. Data were collected from a prospectively constructed database, including clinico-pathological features and operative parameters. The pathological results, recurrence, survival and systemic treatment were collected from the Taiwan Cancer Database. Results: There were 47 patients in the 3D group and 44 in the 2D group. There were no significant differences in characteristics of patients, operation data, pathological results, complications, operative time, blood loss or the number of lymph node harvested between the two groups. In addition, disease-free survival and overall survival were equal between the two groups. Conclusions: This is the first long-term result of a 3D laparoscopic colectomy. In our 3-year follow-up, there was no difference in long-term outcomes between 2D and 3D laparoscopy for colorectal surgery in an experienced centre.

The efficacy of anti-EGFR therapy in treating metastatic colorectal cancer differs between the middle/low rectum and the left-sided colon.

BACKGROUND: Clinically, metastatic rectal cancer has been considered a subset of left-sided colon cancer. However, heterogeneity has been proposed to exist between high and middle/low rectal cancers. We aimed to examine the efficacy of anti-epidermal growth factor receptor (EGFR) treatment for middle/low rectal and left-sided colon cancers. METHODS: This study enrolled 609 patients with metastatic colorectal cancer who were treated with anti-EGFR therapy. They were divided into groups based on primary tumour locations: the right-sided colon, the left-sided colon or the middle/low rectum. The efficacy of first-line and non-first-line anti-EGFR treatment was analysed. Genomic differences in colorectal cancer data from The Cancer Genome Atlas (TCGA) were investigated and visualised with OncoPrint and a clustered heatmap. RESULTS: On first-line anti-EGFR treatment, patients with middle/low rectal tumours had significantly lower progression-free survival, overall survival, and overall response rates (6.8 months, 27.8 months and 43%, respectively) than those with left-sided colon cancer (10.1 months, 38.3 months and 66%, respectively). Similar outcomes were also identified on non-first-line anti-EGFR treatment. In TCGA analysis, rectal tumours displayed genetic heterogeneity and shared features with both left- and right-sided colon cancer. CONCLUSIONS: Anti-EGFR treatment has lower efficacy in metastatic middle/low rectal cancer than in left-sided colon cancer.

Alternative conformations of a major antigenic site on RSV F.

The respiratory syncytial virus (RSV) fusion (F) glycoprotein is a major target of neutralizing antibodies arising from natural infection, and antibodies that specifically bind to the prefusion conformation of RSV F generally demonstrate the greatest neutralization potency. Prefusion-stabilized RSV F variants have been engineered as vaccine antigens, but crystal structures of these variants have revealed conformational differences in a key antigenic site located at the apex of the trimer, referred to as antigenic site Ø. Currently, it is unclear if flexibility in this region is an inherent property of prefusion RSV F or if it is related to inadequate stabilization of site Ø in the engineered variants. Therefore, we set out to investigate the conformational flexibility of antigenic site Ø, as well as the ability of the human immune system to recognize alternative conformations of this site, by determining crystal structures of prefusion RSV F bound to neutralizing human-derived antibodies AM22 and RSD5. Both antibodies bound with high affinity and were specific for the prefusion conformation of RSV F. Crystal structures of the complexes revealed that the antibodies recognized distinct conformations of antigenic site Ø, each diverging at a conserved proline residue located in the middle of an α-helix. These data suggest that antigenic site Ø exists as an ensemble of conformations, with individual antibodies recognizing discrete states. Collectively, these results have implications for the refolding of pneumovirus and paramyxovirus fusion proteins and should inform development of prefusion-stabilized RSV F vaccine candidates.

Taiwan Society of Colon and Rectal Surgeons (TSCRS) Consensus for Cytoreduction Selection in Metastatic Colorectal Cancer.

BACKGROUND: Taiwan has witnessed a surge in the incidence of colorectal cancer (CRC), of which 40-60% metastasize. Continuous updating of cytoreductive strategies in metastatic CRC (mCRC) has contributed to median overall survival reaching 40 months. In this changing scenario, to standardize the approaches across Taiwan, a group of experts from the Taiwan Society of Colon and Rectal Surgeons (TSCRS) convened to establish evidence- and opinion-based recommendations for defining the criteria of "resectability" in mCRC. METHODS: Over the course of one-on-one consultations, lasting 30-40 min each, with 30 medical specialists (19 colorectal surgeons, 4 general surgeons, and 7 medical oncologists) from 16 hospitals in Taiwan followed by a 2-h meeting with 8 physician experts (3 general surgeons, 4 colorectal surgeons, and 1 thoracic surgeon), 12 key questions on cytoreduction were addressed. This was further contextualized based on published literature. RESULTS: The final consensus includes eight recommendations regarding the criteria for metastasis resection, role of local control treatment in liver potentially resectable patients, management of synchronous liver metastases, approach for peritoneal metastasis, place for resection in multiple-organ metastasis, and general criteria for resectability. CONCLUSIONS: mCRC patients undergoing R0 resection have the greatest survival advantage following surgery. Our role as a multidisciplinary team (MDT) should be to treat potentially resectable mCRC patients as rapidly and safely as possible, and achieve R0 resection as far as possible and for as long as possible (continuum of care). This TSCRS consensus statement aims to help build clinical capacity within the MDTs, while making better use of existing healthcare resources.

First report of Agrobacterium tumefaciens causing crown gall disease of roselle (Hibiscus sabdariffa L.) in Taiwan.

Roselle (Hibiscus sabdariffa L.) plants, whose calyces are used for production of beverages or jams, are mainly cultivated in Taitung County of eastern Taiwan. Since 2016, large crown galls were observed on the roselle plants in the commercial plantations at Taimali and Jinfong Townships of Taitung County. A follow-up survey in July and August of 2017 revealed spreading of this disease to the neighboring areas including Beinan and Dawu Townships. Disease incidence was estimated to be 0.6-10%. Galls of varying sizes (2-15 cm in diameter) were usually found on the roots and crowns of the roselle plants, starting with small swellings at the infection sites. Galls were light-colored, and smooth and tender in texture at the early stage, but later turned dark-colored, and appeared rough and woody. In some cases, adventitious roots extruding from the larger crown galls could be seen. Isolation of the causal agent was performed by quadrantally streaking bacterial suspension made from surface-sterilized, macerated galls on trypticase soy agar (TSA). After incubating at 28°C for 5 days, single colonies were transferred onto new TSA plates for further cultivation at 28°C. Finally, circular, convex, viscous and milky white colonies with smooth surface similar to colony morphology of Agrobacterium tumefaciens C58 were obtained for further identification. First, all six candidate isolates (TZ-1, TL1-2, TL2-1, TD1-1, TD1-24 and TD2-1) were identified as Agrobacterium spp. using the partial sequences of the 16S rRNA gene (accession numbers MW205820 to MW205825 in the GenBank database). The selected isolates also showed some biochemical and physiological characteristics similar to A. tumefaciens, including oxidase positive, growth at 35°C and in 2% NaCl, and alkalinity from litmus milk. Moreover, they were tested negative for utilization of citrate and acid production on potato dextrose agar (PDA) supplemented with calcium carbonate. Under a transmission electron microscope, the bacterium was rod-shaped and possessed peritrichous flagella. By means of multiplex PCR using primers designed for differentiation of Agrobacterium rubi, Agrobacterium vitis and Agrobacterium biovars 1 and 2, a 184 bp product was detected in all six isolates, indicating that they all belong to Agrobacterium biovar 1. Furthermore, the recA allele of each isolate was PCR amplified using primers F2898/F2899, and recA sequence analysis assigned all six isolates to A. tumefaciens genomospecies G7 (GenBank accession numbers MZ570905-MZ570910). Pathogenicity assay was carried out by inoculating the stems of 2-week-old roselle seedlings through wounds made with a sterile needle with bacteria on it. The inoculated seedlings were kept in plastic bags to maintain high humidity. Symptoms similar to those observed in the field developed at the inoculation sites after 7 days, and Koch's postulates were fulfilled when the bacteria re-isolated from the galls were also identified as A. tumefaciens genomospecies G7 using recA gene sequence analysis. To our knowledge, this is the first report of crown gall disease caused by A. tumefaciens on Hibiscus sabdariffa in Taiwan. This disease may potentially damage the roselle industry if no action is taken to stop its spreading. Identification of the causal agent of roselle crown gall disease could help us further investigate its ecology and develop integrated pest management strategies for prevention of this disease in the future.

Insulin-Like Growth Factor 2 mRNA-Binding Protein 1 (IGF2BP1) Is a Prognostic Biomarker and Associated with Chemotherapy Responsiveness in Colorectal Cancer.

Insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) is an RNA-binding protein and serves as a post-transcriptional fine-tuner regulating the expression of mRNA targets. However, the clinicopathological roles of IGF2BP1 in colorectal cancer (CRC) remains limited. Thus, we aimed to elucidate the clinical significance and biomarker potentials of IGF2BP1 in CRC. A total of 266 specimens from two sets of CRC patients were collected. IGF2BP1 expression was studied by immunohistochemical (IHC) staining. The Kaplan-Meier survival plot and a log-rank test were used for survival analysis. The Cox proportional hazards model was applied to determine the survival impact of IGF2BP1. Public datasets sets from The Cancer Genome Atlas (TCGA) and Human Cancer Metastasis Database (HCMDB), receiver operating characteristic (ROC) plotter, and two CRC cell lines, HCT-116 and DLD-1, were used for validating our findings. We showed that IGF2BP1 was overexpressed in tumor specimens compared to 13 paired normal parts by examining the immunoreactivity of IGF2BP1 (p = 0.045). The increased expression of IGF2BP1 in primary tumor parts was observed regardless of metastatic status (p < 0.001) in HCMDB analysis. IGF2BP1 expression was significantly associated with young age (59.6% vs. 46.7%, p-value = 0.043) and advanced stage (61.3% vs. 40.0%, p-value = 0.001). After controlling for confounding factors, IGF2BP1 remained an independent prognostic factor (HR = 1.705, p-value = 0.005). TCGA datasets analysis indicated that high IGF2BP1 expression showed a lower 5-year survival rate (58% vs. 65%) in CRC patients. The increased expression of IGF2BP1 in chemotherapy non-responder rectal cancer patients was observed using a ROC plotter. Overexpression of IGF2BP1 promoted the colony-forming capacity and 5-fluorouracil and etoposide resistance in CRC cells. Here, IGF2BP1 was an independent poor prognostic marker in CRC patients and contributed to aggressive phenotypes in CRC cell lines.

Invasion and Colonization Pattern of Fusarium fujikuroi in Rice.

Bakanae disease in rice can cause abnormal elongation of the stem and leaves, development of adventitious roots, a larger leaf angle, and even death. Little is known about the infection, colonization, and distribution of Fusarium fujikuroi in rice plants across different growth stages. In this study, microscopic observation and quantitative real-time PCR were combined to investigate the pathogenesis of bakanae, using artificially inoculated seedlings of a susceptible rice cultivar, Zerawchanica karatals (ZK), a resistant cultivar, Tainung 67 (TNG67), naturally infected adult field plants (cultivars Kaohsiung 139, Taikeng 2, and Tainan 11), and an F. fujikuroi isolate expressing green fluorescent protein. In rice seedlings, F. fujikuroi hyphae were found to directly penetrate the epidermis of basal stems and roots, then extend inter- and intracellularly to invade the vascular bundles. Occlusion of vascular bundles and radial hyphal expansion from vascular bundles to surrounding parenchyma were observed in adult plants. Analysis of consecutive 3-cm segments of the whole plant revealed that F. fujikuroi was largely confined to the embryo, basal stem, and basal roots in seedlings, and distributed unevenly in the lower aerial parts (including nodes and internodes) of adult plants. The elongation and development of adventitious roots did not necessarily correlate with the amount of F. fujikuroi in diseased plants. Treatment of rice seeds with gibberellic acid-3 (GA3) at 0.5 mg/liter resulted in significantly more elongation of ZK than TNG67 seedlings, suggesting that the susceptibility of ZK to bakanae is associated with its higher sensitivity to GA3.

RAB27B-activated secretion of stem-like tumor exosomes delivers the biomarker microRNA-146a-5p, which promotes tumorigenesis and associates with an immunosuppressive tumor microenvironment in colorectal cancer.

The dynamic cell-cell communication is essential for tissue homeostasis in normal physiological circumstances and contributes to a diversified tumor microenvironment. Although exosomes are extracellular vesicles that actively participate in cell-cell interaction by shutting cellular components, impacts of tumor exosomes in the context of cancer stemness remain elusive. Here, we expand colorectal cancer stem cells (CRCSCs) as cancer spheroids and demonstrate that the ß-catenin/Tcf-4-activated RAB27B expression is required for the secretion of CRCSC exosomes. In an exosomal RNA sequencing analysis, a switch of exosomal RNA species from retrotransposons to microRNAs (miRNAs) is identified upon expanding CRCSCs. miRNA-146a-5p (miR-146a) is the major miRNA in CRCSC exosomes and exosomal miR-146a promotes stem-like properties and tumorigenicity by targeting Numb in recipient CRC cells. Among 53 CRC patients, those with abundant exosomal miR-146a expression in serum exhibits higher miR-146aHigh /NumbLow CRCSC traits, an increased number of tumor-filtrating CD66(+) neutrophils and a decreased number of tumor-infiltrating CD8(+) T cells. Our study elucidates a unique mechanism of tumor exosome-mediated stemness expansion.

Combined Microsatellite Instability and Elevated Microsatellite Alterations at Selected Tetranucleotide Repeats (EMAST) Might Be a More Promising Immune Biomarker in Colorectal Cancer.

BACKGROUND: The form of microsatellite instability (MSI) affecting tetranucleotide repeats known as elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) has emerged as a new potential biomarker in multiple cancers. In colorectal cancer (CRC), the correlation between EMAST and MSI mutations remain inconclusive. MATERIALS AND METHODS: We evaluated 1,505 patients with CRC using five EMAST markers (D20S82, D20S85, D8S321, D9S242, and MYCL1) and the Bethesda panel of MSI markers. Most commonly, mutations involved in CRCs were identified by MassArray Assay, and DNA repair genes were analyzed by next-generation sequencing. Clinical characteristics and prognostic relevance were correlated with EMAST and MSI. RESULTS: Tumors that were EMAST positive and MSI high (MSI-H) were detected in 159 (10.6%) and 154 (10.2%) of 1,505 patients with CRC. Patients were divided into four groups according to EMAST and MSI status (EMAST-positive and MSI-H, EMAST-positive and microsatellite-stable [MSS], EMAST-negative and MSI-H, and EMAST-negative and MSS). The EMAST-positive and MSI-H group was associated with female predominance, higher prevalence of proximal colon tumors, early stage tumors, poorly differentiated tumors, mucinous histology, and higher incidence of mutations in PI3KCA, BRAF, TGFBR, PTEN, and AKT1 compared with other groups. Furthermore, compared with only EMAST-positive tumors or only MSI-H tumors, tumors that were both EMAST-positive and MSI-H had a higher frequency of MLH1, MSH3, MSH6, PMS2, and EXO1 gene mutations. Finally, the presence of EMAST-positive and MSI-H tumors was a good prognostic indicator in CRC. CONCLUSION: High mutations in several DNA repair genes in EMAST-positive and MSI-H tumors suggest that this subtype of CRC might be more suitable for treatment with immune therapy. IMPLICATIONS FOR PRACTICE: Elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) is a unique molecular subtype of colorectal cancer (CRC). The current study demonstrated that the EMAST-positive and MSI-high (MSI-H) group was associated with female predominance, higher prevalence of proximal colon tumors, early stage tumors, poorly differentiated tumors, mucinous histology, and higher incidence of mutations in PI3KCA, BRAF, TGFBR, PTEN, and AKT1 compared with other groups. Most importantly, high mutations in DNA repair genes and MSI-related genes in EMAST-positive and MSI-H tumors suggest that this subtype of CRC might be more suitable for treatment with immune therapy compared with MSI-H tumors alone.

Prognosticators of Long-Term Outcomes of TNM Stage II Colorectal Cancer: Molecular Patterns or Clinicopathological Features.

BACKGROUND: Patients with stage II colorectal cancer (CRC) have a higher risk of recurrence when they have certain risk factors, including clinical and pathological patterns. However, as the prognostic role of molecular patterns for stage II disease is still unclear, this study aimed to investigate it. METHODS: A total of 509 patients with stage II CRC were enrolled, and all clinical, pathological, and molecular data were collected. Molecular patterns included microsatellite instability (MSI); elevated microsatellite alterations at selected tetranucleotides (EMAST) status; and expression of RAS/RAF genes, genes of the APC pathway, and other gene mutations. The endpoints were oncological outcomes, including overall survival (OS), cancer-specific survival (CSS), disease-free survival (DFS), local recurrence (LR), and distant recurrence (DR). Cox regression analysis was used. RESULTS: Numerous molecular patterns influenced the oncological outcomes on univariate analysis, but no variable reached significance in LR. On multivariate analysis, a mucinous component (MC) > 50% (P < 0.01) was significant for OS and CSS. Lymphovascular invasion (LVI; P< 0.01), MC > 50% (P < 0.01), and EMAST-H (P = 0.02) significantly influenced DFS, whereas LVI (P < 0.01), MC > 50% (P < 0.01), and TP53 mutation (P = 0.02) were significant for DR. CONCLUSIONS: In this study, MSI, EMAST, and RAS/RAF alterations did not influence the oncological outcomes. Overall, LVI and MC were two significant prognostic factors for DFS and DR. Thus, the histopathology, rather than the genes, plays a major role in the prognosis of patients with stage II CRC.

Risk factors for delayed perineal wound healing and its impact on prolonged hospital stay after abdominoperineal resection.

BACKGROUND: Perineal wound complications are a long-lasting issue for abdominoperineal resection (APR) patients. Complication rates as high as 60% have been reported, with the most common complication being delayed perineal wound healing. The aim of this study was to identify risk factors for delayed perineal wound healing and its impact on prolonged hospital stay. METHODS: We included low rectal tumor patients who underwent APR at a referral medical center from April 2002 to December 2017; a total of 229 patients were included. The basic characteristics and surgical outcomes of the patients were analyzed to identify risk factors for delayed perineal wound healing (> 30 days after APR) and prolonged hospital stay (post-APR hospital stay > 14 days). RESULTS: All patients received primary closure for their perineal wound. The majority of patients were diagnosed with adenocarcinoma (N = 213, 93.1%). In the univariate analysis, patients with hypoalbuminemia (albumin < 3.5 g/dL) had an increased risk of delayed wound healing (39.5% vs. 60.5%, P = 0.001), which was an independent risk factor in the multivariable analysis (OR 2.962, 95% CI 1.437-6.102, P = 0.003). Patients with delayed wound healing also had a significantly increased risk of prolonged hospital stay (OR 6.404, 95% CI 3.508-11.694, P < 0.001). CONCLUSIONS: Hypoalbuminemia was an independent risk factor for delayed wound healing, which consequently led to a prolonged hospital stay. Further clinical trials are needed to reduce the incidence of delayed perineal wound healing by correcting albumin levels or nutritional status before APR.

Metastatic Malignancy to the Colon and Rectum: A Report of 14 Cases from One Single Institute.

BACKGROUND: Metastatic malignancy occurs rarely in the colon or rectum. We presented 14 patients with colorectal metastasis (CRM). METHODS: A retrospective review was conducted on a computerized colorectal tumor database at the Taipei Veterans General Hospital from January 2000 to June 2013. RESULTS: The incidence of CRM was 0.19% (14 in 7,524 patients). There were 6 males and 8 females with a mean age of 66.9 ± 13.6 years. Origins of the CRM included lung cancers (n = 3), prostate cancers (n = 2), and others (n = 1, respectively). Clinical presentations were not specific and colonoscopic pictures were indistinguishable from primary colorectal cancers; 5 of the 9 biopsies identified metastasis. Eight patients had extracolonic metastasis and 6 patients had CRM only. Significantly better survival was observed in the CRM-only group (p = 0.037). The mean interval from the treatment of primary tumor to the diagnosis of CRM was 30.2 ± 49.0 months. The mean survival time after CRM was 24.9 ± 30.8 months. CONCLUSION: Clinical features and colonoscopic findings of CRM were indistinguishable from primary colorectal cancer. Histopathological review of the biopsy could be helpful in identifying the primary lesion. Surgical resection with curative intent provided longer survival in CRM-only patients.

Differences in gene mutations according to gender among patients with colorectal cancer.

BACKGROUND: The incidence, site distribution, and mortality rates of patients with colorectal cancer differ according to gender. We investigated gene mutations in colorectal patients and wanted to examine gender-specific differences. METHODS: A total of 1505 patients who underwent surgical intervention for colorectal cancer were recruited from March 2000 to January 2010 at Taipei Veterans' General Hospital and investigated for gene mutations in K-ras, N-ras, H-ras, BRAF, loss of 18q, APC, p53, SMAD4, TGF-ß, PIK3CA, PTEN, FBXW7, AKT1, and MSI. RESULTS: There were significant differences between male and female patients in terms of tumor location (p < 0.0001) and pathological stage (p = 0.011). The female patients had significantly more gene mutations in BRAF (6.4 vs. 3.3%, OR 1.985, p = 0.006), TGF-ß (4.7 vs. 2.5%, OR 1.887, p = 0.027), and revealed a MSI-high status (14.0 vs. 8.3%, OR 1.800, p = 0.001) than male patients. Male patients had significantly more gene mutations in N-ras (5.1 vs. 2.3%, OR 2.227, p = 0.012); however, the significance was maintained only for mutations in BRAF (OR 2.104, p = 0.038), MSI-high status (OR 2.003 p = 0.001), and N-ras (OR 3.000, p = 0.010) after the groups were divided by tumor site. CONCLUSION: Gene mutations in BRAF, MSI-high status, and N-ras differ according to gender among patients with colorectal cancer.

Molecular and Clinicopathological Differences by Age at the Diagnosis of Colorectal Cancer.

We compared the clinicopathological and molecular profiles between different age groups of sporadic colorectal cancer (CRC) patients (age <50, 56-60, 60-70, 70-80, and >80); 1475 CRC patients were enrolled after excluding 30 individuals with Lynch syndrome. The mutation spectra for APC, TP53, KRAS, PIK3CA, FBXW7, BRAF, NRAS, HRAS, TGFbR, Akt1, and PTEN were analyzed using polymerase chain reaction (PCR), followed by MassArray and microsatellite (MSI-high) analysis by performing genotyping. Male patients (74.1%) were significantly predominant to females (25.9%) in the older age group (70-80, >80). There was an insignificantly linear trend between TNM staging and age-onset of CRC diagnosis. Patients aged < 50 had 58.7% diseases in the advanced stages (Stage III: 36.5% and IV: 22.2% respectively), while this decreased to 40.2% (Stage III: 26.2% and IV; 14.0% respectively) in patients >80. The distributions of mutation frequency were similar in majority of the genes studied among different age groups. Additionally, patients aged <50 had significantly higher frequency of MSI-high, PTEN, and HRAS mutations than those of other groups. Age-onset at diagnosis significantly affected overall survival (HR = 1.46; 95% CI: 1.35-1.58), but not cancer-specific survival (HR = 1.08; 95% CI: 0.99-1.18) in multivariate analysis. In conclusion, molecular and clinicopathological differences were not as significant among different age groups of CRC patients as previously suspected.