Pathology, research and practice
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Pathol. Res. Pract. · May 2021
ReviewRecent advances and challenges of RT-PCR tests for the diagnosis of COVID-19.
Since the outbreak of the novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the control of virus spread has remained challenging given the pitfalls of the current diagnostic tests. Nevertheless, RNA amplification techniques have been the gold standard among other diagnostic methods for monitoring clinical samples for the presence of the virus. ⋯ We discuss the barriers to the widespread use of the RT-PCR test, and some technical advances, such as RT-LAMP (reverse-transcriptase-loop mediated isothermal amplification). We also address how other molecular techniques, such as immunodiagnostic tests can be used to avoid incorrect interpretation of RT-PCR tests.
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Pathol. Res. Pract. · Apr 2021
RNase in the saliva can affect the detection of severe acute respiratory syndrome coronavirus 2 by real-time one-step polymerase chain reaction using saliva samples.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a single-stranded RNA virus that causes coronavirus disease 2019, which spread worldwide immediately after the first patient infected with this virus was discovered in Wuhan, China, in December 2019. Currently, polymerase chain reaction (PCR) specimens for the detection of SARS-CoV-2 include saliva, nasopharyngeal swabs, and lower respiratory tract-derived materials such as sputum. Initially, nasopharyngeal swab specimens were applied mainly to the PCR detection of SARS-CoV-2. ⋯ Interestingly, SARS-CoV-2 (5 × 103 copies/mL) could be detected in saliva supplemented with an RNase inhibitor. Concerning the saliva samples supplemented with an RNase inhibitor, the optimal temperature for sample storage was -20 °C, and PCR detection was maintained within 48 h without problems under these conditions. These finding suggest that RNase in the saliva can affect the detection of SARS-CoV-2 by PCR using saliva samples.
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The novel coronavirus disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), first appeared in December 2019, in Wuhan, China and evolved into a pandemic. As Angiotensin-Converting Enzyme 2 (ACE2) is one of the potential target receptors for SARS-CoV-2 in human body, which is expressed in different tissues, multiple organs might become affected. In the initial phase of the current pandemic, a handful of post-mortem case-series revealed COVID-19-related pathological changes in various organs. ⋯ Herein, we thoroughly reviewed multiple organs including lung, gastrointestinal tract, liver, kidney, skin, heart, blood, spleen, lymph nodes, brain, blood vessels, and placenta in terms of COVID-19-related pathological alterations. Also, these findings were compared with SARS and MERS infection, wherever applicable. We found a diverse range of pathological changes, some of which resemble those found in SARS and MERS.
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Pathol. Res. Pract. · Apr 2020
RAS/RAF mutations and their associations with epigenetic alterations for distinct pathways in Vietnamese colorectal cancer.
KRAS, NRAS, and BRAF are potential tumor-driven genes that are involved in the RAS/RAF/MAPK signaling pathway. RAS/RAF mutations importantly contribute to colorectal tumorigenesis since they remain the activated status of downstream pathways without regulation of the upstream EGFR signal. However, it has not been unclear how epigenetic alterations involved in colorectal tumorigenesis mediated by KRAS, NRAS, or BRAF mutations. ⋯ In addition, the frequency of having KRAS mutations was significantly higher in MGMT (p = 0.035) or RASSF1A (p = 0.043) methylated cases than in those without methylation. BRAF mutations were positively associated with MLH1 hypermethylation (p = 0.028) but were inversely associated with APC hypermethylation (p = 0.032). Overall, our results show specific interactions of genetic and epigenetic alterations and suggest the presence of independent oncogenic pathways in tumorigenesis of CRC.
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Pathol. Res. Pract. · Feb 2020
Molecular diagnostic characteristics based on the next generation sequencing in lung cancer and its relationship with the expression of PD-L1.
Next generation sequencing (NGS) is a massively parallel sequencing technique that can be used to detect many forms of DNA variation, including point mutations, small fragment insertion deletions, gene recombination, and copy number variations. It can simultaneously analyze multiple genes and mutations, quantitatively detect gene mutation rate, and provide comprehensive information for clinicians. More and more lung cancer patients have benefited from studies on programmed death-1igand l (PD-L1) and immunocheckpoint inhibitors. The relationship between gene mutation and PD-L1 is also a focus of current research. Therefore, we collected a large number of cases to describe the molecular diagnostic characteristics of NGS in lung cancer and the relationship between NGS and PD-L1 expression. ⋯ In the 15-gene panel, in addition to EGFR, ALK and ROS1, MET, KRAS, PIK3CA, KIT, ESR1 and NRAS also had their own characteristics in sex, age, smoking history, histopathology, sample type and PD-L1, showing different clinicopathological tendencies. Understanding this information can help us optimize stratified lung cancer patients. Furthermore, it provides patients with a variety of diagnostic needs and a large number of unique clinical data worthy of clinical recognition.