Abstract
Background
A novel coronavirus of zoonotic origin (2019-nCoV) has recently been identified in patients with acute respiratory disease. This virus is genetically similar to SARS coronavirus ...and bat SARS-like coronaviruses. The outbreak was initially detected in Wuhan, a major city of China, but has subsequently been detected in other provinces of China. Travel-associated cases have also been reported in a few other countries. Outbreaks in health care workers indicate human-to-human transmission. Molecular tests for rapid detection of this virus are urgently needed for early identification of infected patients.
Methods
We developed two 1-step quantitative real-time reverse-transcription PCR assays to detect two different regions (ORF1b and N) of the viral genome. The primer and probe sets were designed to react with this novel coronavirus and its closely related viruses, such as SARS coronavirus. These assays were evaluated using a panel of positive and negative controls. In addition, respiratory specimens from two 2019-nCoV-infected patients were tested.
Results
Using RNA extracted from cells infected by SARS coronavirus as a positive control, these assays were shown to have a dynamic range of at least seven orders of magnitude (2x10−4-2000 TCID50/reaction). Using DNA plasmids as positive standards, the detection limits of these assays were found to be below 10 copies per reaction. All negative control samples were negative in the assays. Samples from two 2019-nCoV-infected patients were positive in the tests.
Conclusions
The established assays can achieve a rapid detection of 2019n-CoV in human samples, thereby allowing early identification of patients.
Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), which has been characterized by fever, respiratory, and gastrointestinal ...symptoms as well as shedding of virus RNA into feces. We performed a systematic review and meta-analysis of published gastrointestinal symptoms and detection of virus in stool and also summarized data from a cohort of patients with COVID-19 in Hong Kong.
We collected data from the cohort of patients with COVID-19 in Hong Kong (N = 59; diagnosis from February 2 through February 29, 2020),and searched PubMed, Embase, Cochrane, and 3 Chinese databases through March 11, 2020, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We analyzed pooled data on the prevalence of overall and individual gastrointestinal symptoms (loss of appetite, nausea, vomiting, diarrhea, and abdominal pain or discomfort) using a random effects model.
Among the 59 patients with COVID-19 in Hong Kong, 15 patients (25.4%) had gastrointestinal symptoms, and 9 patients (15.3%) had stool that tested positive for virus RNA. Stool viral RNA was detected in 38.5% and 8.7% among those with and without diarrhea, respectively (P = .02). The median fecal viral load was 5.1 log10 copies per milliliter in patients with diarrhea vs 3.9 log10 copies per milliliter in patients without diarrhea (P = .06). In a meta-analysis of 60 studies comprising 4243 patients, the pooled prevalence of all gastrointestinal symptoms was 17.6% (95% confidence interval CI, 12.3–24.5); 11.8% of patients with nonsevere COVID-19 had gastrointestinal symptoms (95% CI, 4.1–29.1), and 17.1% of patients with severe COVID-19 had gastrointestinal symptoms (95% CI, 6.9–36.7). In the meta-analysis, the pooled prevalence of stool samples that were positive for virus RNA was 48.1% (95% CI, 38.3–57.9); of these samples, 70.3% of those collected after loss of virus from respiratory specimens tested positive for the virus (95% CI, 49.6–85.1).
In an analysis of data from the Hong Kong cohort of patients with COVID-19 and a meta-analysis of findings from publications, we found that 17.6% of patients with COVID-19 had gastrointestinal symptoms. Virus RNA was detected in stool samples from 48.1% patients, even in stool collected after respiratory samples had negative test results. Health care workers should therefore exercise caution in collecting fecal samples or performing endoscopic procedures in patients with COVID-19, even during patient recovery.
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We show that a high-energy electron bunch can be used to capture the instantaneous longitudinal and transverse field structures of the highly transient, microscopic, laser-excited relativistic wake ...with femtosecond resolution. The spatiotemporal evolution of wakefields in a plasma density up ramp is measured and the reversal of the plasma wake, where the wake wavelength at a particular point in space increases until the wake disappears completely only to reappear at a later time but propagating in the opposite direction, is observed for the first time by using this new technique.
AIMS: To investigate the medium‐pressure (MP) and low‐pressure (LP) Ultraviolet (UV) susceptibility and the repair potential of Enterococcus faecalis (DSM 20478) after UV treatment. METHODS AND ...RESULTS: A range of UV doses from 4 to 19 mJ cm⁻² was selected in this study. Photoreactivation and dark repair performance were investigated under fluorescent light or in the dark respectively. The inactivation and repair performance of UV disinfection under a range of salinities (0, 1%, 3%) and temperature (4 and 25°C) were compared. Results indicated that MP UV exposure resulted in higher inactivation efficiency against Ent. faecalis than LP UV exposure. For repair potential, LP UV resulted in a greater level of light repair than MP UV. Effect of salinity on the inactivation and repair of Ent. faecalis was correlated with UV sources, whereas low temperature generally adversely affected the inactivation efficiency and final repair levels after both MP and LP UV exposure. CONCLUSIONS: Both salinity and temperature demonstrated to play an important role in the inactivation and repair capability when UV light was used to treat ballast water. SIGNIFICANCE AND IMPACT OF THE STUDY: Considering that UV‐treated ballast water is exposed or discharged to marine water environment in many countries with various temperature and salinity conditions, results of this study provide significant implications for the management of public health associated with ballast water treatment and discharge.
Since echinocandins are recommended as first line therapy for invasive candidiasis, detection of resistance, mainly due to alteration in FKS protein, is of main interest. EUCAST AFST recommends ...testing both MIC of anidulafungin and micafungin, and breakpoints (BPs) have been proposed to detect echinocandin-resistant isolates. We analyzed MIC distribution for all three available echinocandins of 2,787 clinical yeast isolates corresponding to 5 common and 16 rare yeast species, using the standardized EUCAST method for anidulafungin and modified for caspofungin and micafungin (AM3-MIC). In our database, 64 isolates of common pathogenic species were resistant to anidulafungin, according to the EUCAST BP, and/or to caspofungin, using our previously published threshold (AM3-MIC ≥ 0.5 mg/L). Among these 64 isolates, 50 exhibited 21 different FKS mutations. We analyzed the capacity of caspofungin AM3-MIC and anidulafungin MIC determination in detecting isolates with FKS mutation. They were always identified using caspofungin AM3-MIC and the local threshold while some isolates were misclassified using anidulafungin MIC and EUCAST threshold. However, both methods misclassified four wild-type C. glabrata as resistant. Based on a large data set from a single center, the use of AM3-MIC testing for caspofungin looks promising in identifying non-wild-type C. albicans, C. tropicalis and P. kudiravzevii isolates, but additional multicenter comparison is mandatory to conclude on the possible superiority of AM3-MIC testing compared to the EUCAST method.
Recent evidence suggests that a subpopulation of cancer cells, cancer stem cells (CSCs), is responsible for tumor growth in colorectal cancer. However, the role of CSCs in colorectal cancer ...metastasis is unclear. Here, we identified a subpopulation of CD26
+ cells uniformly present in both the primary and metastatic tumors in colorectal cancer patients with liver metastasis. Furthermore, in patients without distant metastasis at the time of presentation, the presence of CD26
+ cells in their primary tumors predicted distant metastasis on follow-up. Isolated CD26
+ cells, but not CD26
− cells, led to development of distant metastasis when injected into the mouse cecal wall. CD26
+ cells were also associated with enhanced invasiveness and chemoresistance. Our findings have uncovered a critical role of CSCs in metastatic progression of cancer. Furthermore, the ability to predict metastasis based on analysis of CSC subsets in the primary tumor may have important clinical implication as a selection criterion for adjuvant therapy.
► Metastatic colorectal cancers contain a subset of CD26
+ cancer stem cells ► Nonmetastatic tumors with CD26
+ CSCs frequently proceed to metastasis ► Isolated CD26
+ CSCs can initiate distant metastasis in a mouse model ► CD26
+ CSCs show enhanced invasiveness and migratory potential
Silver nanorod arrays with different lengths fabricated by oblique angle deposition at various vapor deposition angles have been studied systematically on their morphologies, optical reflections, and ...surface-enhanced Raman scattering (SERS) responses. The tilting angle β of Ag nanorods increases with the increase of the deposition angle θ, while the diameter D and density n of Ag nanorods grow as power laws of the length L, D ∼ L p and n ∼ L −γ, where the exponents are p ∼ 0.30−0.34 and γ ∼ 0.23−0.40 for different deposition angles, respectively. The optical reflectance from these substrates depends not only on the length of the Ag nanorods but also on the deposition angle. It is found that the SERS enhancement factor decreases nearly monotonically with the increase of the reflectance at SERS excitation wavelength, and the highest SERS enhancement factor can reach close to 109. We have developed a phenomenological model based on the assumption that the absorbance (reflection) of the nanorod array is directly linked to the local electric field, and it predicts a similar trend to that of the experimental observation. The empirical results can help us to design better Ag nanorod array SERS substrates, and can also be used as a quality control measurement method for SERS substrate production.
Summary
Background
Sleep–wake disturbances are common in patients with cirrhosis and have a considerable effect on health‐related quality of life; however, the underlying mechanism behind the ...phenomenon is unclear. Cytokines are involved in the mediation of signalling pathways regulating fibrogenesis, leading to cirrhosis. In addition, increased cytokines could contribute to sleep disturbances.
Aim
To determine the relationship between pro‐inflammatory cytokines and sleep disturbance in cirrhotic patients.
Methods
Ninety‐eight nonalcoholic cirrhotic patients without overt hepatic encephalopathy were enrolled in this cross‐sectional study. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality. The Psychometric Hepatic Encephalopathy Score (PHES) was used to examine cognitive performance and define minimal hepatic encephalopathy (MHE). The Hospital Anxiety and Depression Scale (HADS) was used to evaluate the mood status of the patients. Pro‐inflammatory cytokines that include interleukin 6 (IL‐6) and tumour necrosis factor‐α, as well as HBV‐DNA or HCV‐RNA levels were determined in patients.
Results
A total of 56 (57%) cirrhotic patients were identified as ‘poor’ sleepers (PSQI > 5). After multivariate analysis, IL‐6 (P = 0.001) and HADS scores (P = 0.002) were found to be independent predictive factors of poor sleep quality. No significant relationships were observed between the sleep indices and the presence of MHE. HCV‐RNA, but not HBV‐DNA, viraemia was associated with sleep disturbance in cirrhotic patients.
Conclusions
Sleep disturbance is found commonly in cirrhotic patients and a high serum IL‐6 level is predictive of poor sleep quality. Minimal hepatic encephalopathy by itself may not contribute to sleep dysfunction in cirrhotic patients.
Background
There is increasing use of anti‐osteoporotic agents (AOA) worldwide for prevention or management of patients with osteoporosis. However, there have been reports of severe cutaneous adverse ...reactions (SCAR) induced by AOA. A recent study showed weak association between HLA and strontium ranelate (SR)‐SCAR.
Objective
To characterize patients with AOA‐SCAR and investigate the HLA association and utility of in vitro diagnostic methods.
Methods
We enrolled 16 cases with AOA‐cutaneous adverse drug reactions (cADR), including SCAR (n = 10: 8 with Stevens–Johnson syndrome SJS and 2 with drug rash with eosinophilia and systemic symptoms DRESS) and maculopapular exanthema (MPE) (n = 6) from Taiwan and Hong Kong. We analysed the clinical characteristics, outcomes, HLA alleles and in vitro testing of AOA‐SCAR, and tolerability to alternative drugs. We further performed literature review and meta‐analysis on the HLA association of AOA‐SCAR.
Results
Our data showed strontium ranelate is the most common causality of AOA‐SCAR in Asian populations. There was no cross‐hypersensitivity of SR‐SCAR with other AOA. HLA genotyping showed that SR‐SJS was most significantly associated with HLA‐A*33:03 (Pc = 5.17 × 10−3, OR: 25.97, 95% CI: 3.08–219.33). Meta‐analysis showed that HLA‐A*33:03 was associated with SR‐SJS (P = 5.01 × 10−5; sensitivity: 85.7%) in Asians. The sensitivity of lymphocyte activation test (LAT) for identifying the culprit drug of SR‐SJS was 83.3%.
Conclusions
Strontium ranelate is identified as the most notorious AOA associated with SCAR. The HLA‐A*33:03 genetic allele and LAT testing may add benefits to the diagnosis of SR‐SCAR in patients whose reaction developed while taking multiple drugs.
Linked Commentary: T. Shiohara. J Eur Acad Dermatol Venereol 2021; 35: 567‐568. https://doi.org/10.1111/jdv.17138.
Middle East respiratory syndrome coronavirus (MERS-CoV) causes a zoonotic respiratory disease of global public health concern, and dromedary camels are the only proven source of zoonotic infection. ...Although MERS-CoV infection is ubiquitous in dromedaries across Africa as well as in the Arabian Peninsula, zoonotic disease appears confined to the Arabian Peninsula. MERS-CoVs from Africa have hitherto been poorly studied. We genetically and phenotypically characterized MERS-CoV from dromedaries sampled in Morocco, Burkina Faso, Nigeria, and Ethiopia. Viruses from Africa (clade C) are phylogenetically distinct from contemporary viruses from the Arabian Peninsula (clades A and B) but remain antigenically similar in microneutralization tests. Viruses from West (Nigeria, Burkina Faso) and North (Morocco) Africa form a subclade, C1, that shares clade-defining genetic signatures including deletions in the accessory gene ORF4b. Compared with human and camel MERS-CoV from Saudi Arabia, virus isolates from Burkina Faso (BF785) and Nigeria (Nig1657) had lower virus replication competence in Calu-3 cells and in ex vivo cultures of human bronchus and lung. BF785 replicated to lower titer in lungs of human DPP4-transduced mice. A reverse genetics-derived recombinant MERS-CoV (EMC) lacking ORF4b elicited higher type I and III IFN responses than the isogenic EMC virus in Calu-3 cells. However, ORF4b deletions may not be the major determinant of the reduced replication competence of BF785 and Nig1657. Genetic and phenotypic differences in West African viruses may be relevant to zoonotic potential. There is an urgent need for studies of MERS-CoV at the animal–human interface.
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