SARS-CoV-2 infection and replication in human gastric organoids

COVID-19 typically manifests as a respiratory illness, but several clinical reports have described gastrointestinal symptoms. This is particularly true in children in whom gastrointestinal symptoms are frequent and viral shedding outlasts viral clearance from the respiratory system. These observations raise the question of whether the virus can replicate within the stomach. Here we generate gastric organoids from fetal, pediatric, and adult biopsies as in vitro models of SARS-CoV-2 infection. To facilitate infection, we induce reverse polarity in the gastric organoids. We find that the pediatric and late fetal gastric organoids are susceptible to infection with SARS-CoV-2, while viral replication is significantly lower in undifferentiated organoids of early fetal and adult origin. We demonstrate that adult gastric organoids are more susceptible to infection following differentiation. We perform transcriptomic analysis to reveal a moderate innate antiviral response and a lack of differentially expressed genes belonging to the interferon family. Collectively, we show that the virus can efficiently infect the gastric epithelium, suggesting that the stomach might have an active role in fecal-oral SARS-CoV-2 transmission.Several clinical reports have described gastrointestinal symptoms for COVID-19, though whether the virus can replicate within the stomach remains unclear. Here the authors generate gastric organoids from human biopsies and show that the virus can efficiently infect gastric epithelium, suggesting that the stomach might have an active role in fecal-oral transmission

Mutations of PIK3CA in gastric adenocarcinoma

BACKGROUND: Activation of the phosphatidylinositol 3-kinase (PI3K) through mutational inactivation of PTEN tumour suppressor gene is common in diverse cancer types, but rarely reported in gastric cancer. Recently, mutations in PIK3CA, which encodes the p110α catalytic subunit of PI3K, have been identified in various human cancers, including 3 of 12 gastric cancers. Eighty percent of these reported mutations clustered within 2 regions involving the helical and kinase domains. In vitro study on one of the "hot-spot" mutants has demonstrated it as an activating mutation. METHODS: Based on these data, we initiated PIK3CA mutation screening in 94 human gastric cancers by direct sequencing of the gene regions in which 80% of all the known PIK3CA mutations were found. We also examined PIK3CA expression level by extracting data from the previous large-scale gene expression profiling study. Using Significance Analysis of Microarrays (SAM), we further searched for genes that show correlating expression with PIK3CA. RESULTS: We have identified PIK3CA mutations in 4 cases (4.3%), all involving the previously reported hotspots. Among these 4 cases, 3 tumours demonstrated microsatellite instability and 2 tumours harboured concurrent KRAS mutation. Data extracted from microarray studies showed an increased expression of PIK3CA in gastric cancers when compared with the non-neoplastic gastric mucosae (p < 0.001). SAM further identified 2910 genes whose expression levels were positively associated with that of PIK3CA. CONCLUSION: Our data suggested that activation of the PI3K signalling pathway in gastric cancer may be achieved through up-regulation or mutation of PIK3CA, in which the latter may be a consequence of mismatch repair deficiency

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Profiling of gene expression changes in human colon crypt maturation and study of their dysregulation in tumourigenesis

published_or_final_versionPathologyDoctoralDoctor of Philosoph

May Measurement Month 2017–2019: A Community-Wide Opportunistic Blood Pressure Screening Campaign in Hong Kong

Introduction. Hypertension is a modifiable risk factor for multiple cardiovascular diseases. Early identification and intervention of new cases are crucial to improve patients’ outcomes. May Measurement Month (MMM) is an annual global synchronised blood pressure (BP) screening campaign. Participants can have their BP measured at the screening sites. It may be a possible way to identify undiagnosed hypertensive patients in the population. Methods. It was a cross-sectional study of BP among Hong Kong adults. Multiple screening sites were set in local community pharmacies and on the campus of the Chinese University of Hong Kong. Participants were asked to fill in a questionnaire regarding their demographics, medical history, and social history. Then, they took at least one BP reading using an automated sphygmomanometer after sitting at for 5 minutes. Up to three BP readings were taken and recorded for each participant, with one-minute intervals between readings. Results. A total of 3224 adults participated in MMM between 2017 and 2019. The average BP among the 3224 participants was 139.8/75.5 mmHg. The prevalence of hypertension was 2282 (70.8%), of which 635 (27.8%) were undiagnosed before MMM. Among the 1647 participants previously diagnosed with hypertension, 1007 (61.1%) had uncontrolled hypertension. Conclusion. A high number of cases can be identified with untreated, or treated but uncontrolled, hypertension from MMM. Citizens should be encouraged to check BP regularly and take follow-up actions if hypertension is suspected

Additional file 1 of Feasibility of a telephone-delivered educational intervention for knowledge transfer of COVID-19-related information to older adults in Hong Kong: a pre–post-pilot study

Additional file 1

Current and future molecular diagnostics in non-small-cell lung cancer

© 2015 Informa UK, Ltd.. The molecular investigation of lung cancer has opened up an advanced area for the diagnosis and therapeutic management of lung cancer patients. Gene alterations in cancer initiation and progression provide not only information on molecular changes in lung cancer but also opportunities in advanced therapeutic regime by personalized targeted therapy. EGFR mutations and ALK rearrangement are important predictive biomarkers for the efficiency of tyrosine kinase inhibitor treatment in lung cancer patients. Moreover, epigenetic aberration and microRNA dysregulation are recent advances in the early detection and monitoring of lung cancer. Although a wide range of molecular tests are available, standardization and validation of assay protocols are essential for the quality of the test outcome. In this review, current and new advancements of molecular biomarkers for non-small-cell lung cancer will be discussed. Recommendations on future development of molecular diagnostic services will also be explored.Link_to_subscribed_fulltex

(a) Sequence chromatogram from a case of gastric cancer with H1047R (A3140G) mutation within exon 20 of

<p><b>Copyright information:</b></p><p>Taken from "Mutations of in gastric adenocarcinoma"</p><p>BMC Cancer 2005;5():29-29.</p><p>Published online 23 Mar 2005</p><p>PMCID:PMC1079799.</p><p>Copyright © 2005 Li et al; licensee BioMed Central Ltd.</p> Site of mutation is denoted by the red arrow. (b) Sequence chromatogram of the corresponding normal mucosa from the same case showing the absence of mutation (red arrow), and thus confirming the somatic nature of the mutation

MAPK pathway mutations in head and neck cancer affect immune microenvironments and ErbB3 signaling.

MAPK pathway mutations affect one-fifth of head and neck squamous cell carcinoma (HNSCC). Unexpectedly, MAPK pathway aberrations are associated with remarkably long patient survival, even among patients with TP53 mutations (median ∼14 yr). We explored underlying outcome-favoring mechanisms with omics followed by preclinical models. Strikingly, multiple hotspot and non-hotspot MAPK mutations (A/BRAF, HRAS, MAPK1, and MAP2K1/2) all abrogated ErbB3 activation, a well-established HNSCC progression signal. Inhibitor studies functionally defined ERK activity negatively regulating phospho-ErbB3 in MAPK-mutants. Furthermore, pan-pathway immunoprofiling investigations identified MAPK-mutant tumors as the only "CD8+ T-cell-inflamed" tumors inherently bearing high-immunoreactive, constitutive cytolytic tumor microenvironments. Immunocompetent MAPK-mutant HNSCC models displayed active cell death and massive CD8+ T-cell recruitment in situ. Consistent with CD8+ T-inflamed phenotypes, MAPK-mutant HNSCC patients, independent of tumor-mutational burden, survived 3.3-4 times longer than WT patients with anti-PD1/PD-L1 immunotherapies. Similar prognosticity was noted in pan-cancers. We uncovered clinical, signaling, and immunological uniqueness of MAPK-mutant HNSCC with potential biomarker utilities predicting favorable patient survival