Exploring the role of sporadic BRAF and KRAS mutations during colorectal cancer pathogenesis: A spotlight on the contribution of the endosome-lysosome system.

The highly heterogenous nature of colorectal cancer can significantly hinder its early and accurate diagnosis, eventually contributing to high mortality rates. The adenoma-carcinoma sequence and serrated polyp-carcinoma sequence are the two most common sequences in sporadic colorectal cancer. Genetic alterations in adenomatous polyposis coli (APC), v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) and tumour protein 53 (TP53) genes are critical in adenoma-carcinoma sequence, whereas v-Raf murine sarcoma viral oncogene homolog B (BRAF) and MutL Homolog1 (MLH1) are driving oncogenes in the serrated polyp-carcinoma sequence. Sporadic mutations in these genes contribute differently to colorectal cancer pathogenesis by introducing distinct alterations in several signalling pathways that rely on the endosome-lysosome system. Unsurprisingly, the endosome-lysosome system plays a pivotal role in the hallmarks of cancer and contributes to specialised colon function. Thus, the endosome-lysosome system might be distinctively influenced by different mutations and these alterations may contribute to the heterogenous nature of sporadic colorectal cancer. This review highlights potential connections between major sporadic colorectal cancer mutations and the diverse pathogenic mechanisms driven by the endosome-lysosome system in colorectal carcinogenesis.

Insights into Melanoma Clinical Practice: A Perspective for Future Research.

BACKGROUND: Early diagnosis is the key to improving outcomes for patients with melanoma, and this requires a standardized histological assessment approach. The objective of this survey was to understand the challenges faced by clinicians when assessing melanoma cases, and to provide a perspective for future studies. METHODS: Between April 2022 and February 2023, national and international dermatologists, pathologists, general practitioners, and laboratory managers were invited to participate in a six-question online survey. The data from the survey were assessed using descriptive statistics and qualitative responses. RESULTS: A total of 54 responses were received, with a 51.4% (n = 28) full completion rate. Of the respondents, 96.4% reported ambiguity in their monthly melanoma diagnosis, and 82.1% routinely requested immunohistochemistry (IHC) testing to confirm diagnosis. SOX10 was the most frequently requested marker, and most respondents preferred multiple markers over a single marker. Diagnostic and prognostic tests, as well as therapeutic options and patient management, were all identified as important areas for future research. CONCLUSIONS: The respondents indicated that the use of multiple IHC markers is essential to facilitate diagnostic accuracy in melanoma assessment. Survey responses indicate there is an urgent need to develop new biomarkers for clinical decision making at multiple critical intervention points.

First Report of Root Rot on Paris polyphylla var. yunnanensis caused by Fusarium solani in Yunnan, China.

Paris polyphylla var. yunnanensis is a perennial herb with diverse chemical components having wide-ranging pharmacological effects. The demand for P. polyphylla var. yunnanensis as a raw material increases greatly and currently exceeds 1,000 tons per year (Zhou et al. 2021). In September 2021, root rot was observed on P. polyphylla var. yunnanensis in Mangshi, Yunnan province, China. Average disease incidences in the fields reached 15%, with diseased plants exhibiting yellowing and wilting leaves, as well as browning and rotting roots. Cross sections (5 × 5 mm2) cut from the margin of symptomatic and asymptomatic root tissues were surface-sterilized for 30 s with 75% ethanol, followed by 180 s with 1% sodium hypochlorite. After rinsing thrice with sterile distilled water, the fragments were transferred to potato dextrose agar (PDA) plates and incubated at 28°C in the dark. Ten isolates were obtained, and single spore isolation was performed. These isolates showed similar morphological characters, with colonies ranging in color from white to pale cream and sparse mycelia. Conidia were produced on the top or side of phialides. Microconidia were oval or reniform, 0- or 1-septate, with a diameter of 5.1-10.7 µm × 1.6-3.9 µm (average 7.6 µm × 2.8 µm) (n=30). The macroconidia were straight to slightly curved or sickle-shaped, 3- to 5-septate, with a diameter of 15.1-27.9 µm × 2.8-4.0 µm (average 21.0 µm × 3.6 µm). Chlamydospores were smooth, nearly round, and 3.3-6.6 (average 4.9) µm in diameter. Genomic DNA were extracted from mycelia of the two isolates. The nuclear ribosomal internal transcribed spacer (ITS), translation elongation factor 1 alpha (EF1α), and the second largest subunit of nuclear DNA-directed RNA polymerase II (RPB2) were amplified with the primer pairs of ITS1/ITS4 (White et al. 1990), EF1-728F/EF1-986R (Carbone and Kohn 1999), and fRPB2-5F/fRPB2-7cR (Liu et al. 1999), respectively. These two isolates exhibited the same nucleotide sequences (ITS, OP646781; EF1α, OP661172; RPB2, OP661173), with BLASTn analyses showing 100%, 99.66%, and 99.65% identity, respectively, with Fusarium solani (syn. Neocosmospora solani) (Crespo et al. 2019) strain NRRL 43474 (ITS, EF453097; EF1α, EF452945; RPB2, EF469984). A phylogenetic tree was constructed using MEGAX based on the nucleotide sequences of ITS, EF1α, and RPB2, using the maximum likelihood method. The isolate was classified into the F. solani clade. According to the morphology and sequence analyses, the isolate was identified as F. solani (Chehri et al. 2015), and named PpFs1. To test the pathogenicity of the isolate PpFs1, the roots of four years old P. polyphylla var. yunnanensis plants were dipped in 107 spore/mL suspension filtered from potato dextrose broth (PDB) for 30 min, while control roots were dipped in sterile water. After inoculation, all plants were transplanted in pots filled with sterile soil and kept at 25°C with a 12/12-h light/darkness photoperiod. Six plants were used for each treatment, and repeated thrice. Two months after inoculation, the infected plants showed wilted leaves and rotted roots, while controls remained asymptomatic. PpFs1, identified by morphology and ITS, was re-isolated from infected plants, and was found to comply with Koch's postulates. To the best of our knowledge, F. oxysporum and F. concentricum causes Paris polyphylla var. Chinensis stem rot in China. But this is the first report of root rot on P. polyphylla var. yunnanensis being caused by F. solani in Yunnan, China.

First report of Didymella curtisii causing leaf scorch on spider lily (Hymenocallis littoralis) in China.

Hymenocallis littoralis (Jacq.) Salisb, commonly known as spider lily, is a Amaryllidaceae species widely cultivated in southern China for ornamental and medicinal purposes (Anusha et al., 2016). In 2020, there was a devastating outbreak of leaf scorch of H. littoralis from July to September in Kunming city, Yunnan province of China (E102.8268°, N24.8371°), with 97% disease incidence. The initial spots were small and reddish-brown but gradually expanded to large irregular lesions with yellow centers. The leaves then turned yellow and withered from tip towards the petiole in the severely infected plants. For identification, leaf sections (5 × 5 mm2) cut from the margins of the lesions were surface-sterilized for 3 min with 1% sodium hypochlorite, rinsed three times with sterile distilled water, placed on potato dextrose agar (PDA), and incubated at 28°C at a 12-h photoperiod for three days. One fungus was isolated from 90% of the samples, of which three monosporic isolates were selected using a method of agar dilution lineation separation. After 4 days of incubation, colonies were white-yellowish, and changed to beige-mustard after 7 days. The pycnidia were produced after 10 days incubation on oatmeal agar (OA), and they were black-brown, subglobose, and ostiolate. Chlamydospores mainly formed in the aerial mycelia, globose, often in chains, brown or pale. The conidia were ellipsoidal or clavate, (0-)1-3-septate, 2.1 to 10.8 × 1.0 to 3.2 µm (n=60). The total genomic DNA of three isolates was extracted from mycelia. The nuclear ribosomal internal transcribed spacer region (ITS), the second largest subunit of nuclear DNA-dependent RNA polymerase II (rpb2), the 28S nuclear ribosomal large subunit rRNA gene (LSU), and beta-tubulin gene (tub2) were amplified using the ITS1/ITS4 (White et al., 1990), fRPB2-5F/fRPB2-7cR (Liu et al., 1999), LR0R/LR5 (Schoch et al., 2012), and Btub2Fd/Btub4Rd (Woudenberg et al., 2009) primer pairs, respectively. The amplicons were cloned in the pMD19-T vector (Code No. 6013, Takara, Kusatsu, Japan) and sequenced bi-directionally. These three isolates had the same nucleotide sequences, one of which was submitted to NCBI (ITS, OM279485; rpb2, OM304305; LSU, OP800249; tub2, OQ108870). BLASTn analyses showed that ITS, rpb2, LSU, and tub2 were genetically 100%, 98.49%, 99.89%, and 97.89%, respectively, identical with MN973518, MT018130, MN943724, and MT005618 genes of Didymella curtisii strain CBS 288.29. Phylogenetic tree was constructed with MEGAX based on the nucleotide sequences of ITS, rpb2, LSU, and tub2 using the maximum likelihood method. The fungus isolated from diseased leaves of H. littoralis was grouped into the same clade with D. curtisii. According to the morphology and sequence analyses, the isolate was D. curtisii (Chen et al., 2015) and was named isolate HlDc1. To confirm the causal agent of the disease, a spore suspension with 106 spores of HlDc1/mL was smeared on healthy leaves of six months old with brushes. Leaves in the control group were smeared with sterile water. All inoculated plants were incubated at 28°C under a 12-h photoperiod in a moisture chamber. The pathogenicity tests were conducted three times with six plants each time. Fifteen days post-inoculation, the leaves inoculated with HlDc1 developed red-brown lesions, whereas the control leaves remained asymptomatic. Isolate HlDc1 was re-isolated from infected leaves. To our knowledge, this is the first report of leaf scorch on H. littoralis in Yunnan province, China, caused by D. curtisii. The results laid the foundation for epidemiological forecasting and scientific control of this disease.

Development of a random forest model for hypotension prediction after anesthesia induction for cardiac surgery.

BACKGROUND: Hypotension after the induction of anesthesia is known to be associated with various adverse events. The involvement of a series of factors makes the prediction of hypotension during anesthesia quite challenging. AIM: To explore the ability and effectiveness of a random forest (RF) model in the prediction of post-induction hypotension (PIH) in patients undergoing cardiac surgery. METHODS: Patient information was obtained from the electronic health records of the Second Affiliated Hospital of Hainan Medical University. The study included patients, ≥ 18 years of age, who underwent cardiac surgery from December 2007 to January 2018. An RF algorithm, which is a supervised machine learning technique, was employed to predict PIH. Model performance was assessed by the area under the curve (AUC) of the receiver operating characteristic. Mean decrease in the Gini index was used to rank various features based on their importance. RESULTS: Of the 3030 patients included in the study, 1578 (52.1%) experienced hypotension after the induction of anesthesia. The RF model performed effectively, with an AUC of 0.843 (0.808-0.877) and identified mean blood pressure as the most important predictor of PIH after anesthesia. Age and body mass index also had a significant impact. CONCLUSION: The generated RF model had high discrimination ability for the identification of individuals at high risk for a hypotensive event during cardiac surgery. The study results highlighted that machine learning tools confer unique advantages for the prediction of adverse post-anesthesia events.

Experimental and theoretical studies on the morphogenesis of bacterial biofilms.

Biofilm morphogenesis not only reflects the physiological state of bacteria but also serves as a strategy to sustain bacterial survival. In this paper, we take the Bacillus subtilis colony as a model system to explore the morphomechanics of growing biofilms confined in a defined geometry. We find that the growth-induced stresses may drive the occurrence of both surface wrinkling and interface delamination in the biofilm, leading to the formation of a labyrinthine network on its surface. The wrinkles are perpendicular to the boundary of the constraint region. The variation in the surface undulations is attributed to the spatial stress field, which is isotropic in the inner regime but anisotropic in the vicinity of the boundary. Our experiments show that the directional surface wrinkles can confer biofilms with anisotropic wetting properties. This study not only highlights the role of mechanics in sculpturing organisms within the morphogenetic context but also suggests a promising route toward desired surfaces at the interface between synthetic biology and materials sciences.