Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 5 de 5
Filter
1.
Diagnostics (Basel) ; 12(7)2022 Jun 27.
Article in English | MEDLINE | ID: covidwho-1911244

ABSTRACT

BACKGROUND: Rapid diagnosis of COVID-19 is essential in order to restrict the spread of the pandemic, and different approaches for SARS-CoV-2 testing have been proposed as cost-effective and less time-consuming alternatives. For virus detection, the real-time reverse transcriptase-polymerase chain reaction (RT-PCR) technique is still the "gold standard" for accuracy and reliability, but its performance is affected by the efficiency of nucleic acid extraction methods. OBJECTIVE: In order to improve the SARS-CoV-2 diagnostic workflow, we compared a "standard" commercially available kit, based on viral RNA extraction from human swab samples by magnetic beads, with its technological evolution. The two methods differ mainly in their time consumption (9 vs. 35 min). METHODS: We adopted the MAGABIO PLUS VIRUS DNA/RNA PURIFICATION KIT II (BIOER), defined as "standard", with the automatic extractor BIOER (GenePure Pro fully automatic nucleic acid purification system) to isolate RNA from nasopharyngeal swabs for the detection of SARS-CoV-2 by RT-PCR. We tested this kit with a new faster version of the first one, defined as "rapid" (MAGABIO PLUS VIRUS RNA PURIFICATION KIT II). RESULTS AND CONCLUSION: The two evaluated procedures provided similar analytical results, but the faster method proved to be a more suitable tool for the detection of SARS-CoV-2 from nasopharyngeal swabs, due to a more rapid availability of results, which may contribute to improving both clinical decision making and patient safety.

2.
Data Brief ; 38: 107432, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1439972

ABSTRACT

Since the association of SARS-Cov-2 infection with Nervous System (NS) manifestations, we performed RNA-sequencing analysis in Frontal Cortex of COVID-19 positive or negative individuals and affected or not by Dementia individuals. We examined gene expression differences in individuals with COVID-19 and Dementia compared to Dementia only patients by collecting transcript counts in each sample and performing Differential Expression analysis. We found eleven genes satisfying our significance criteria, all of them being protein coding genes. These data are suitable for integration with supplemental samples and for analysis according to different individuals' classification. Also, differential expression evaluation may be implemented with other scientific purposes, such as research of unannotated genes, mRNA splicing and genes isoforms. The analysis of Differential Expressed genes in COVID-19 positive patients compared to non-COVID-19 patients is published in: S. Gagliardi, E.T. Poloni, C. Pandini, M. Garofalo, F. Dragoni, V. Medici, A. Davin, S.D. Visonà, M. Moretti, D. Sproviero, O. Pansarasa, A. Guaita, M. Ceroni, L. Tronconi, C. Cereda, Detection of SARS-CoV-2 genome and whole transcriptome sequencing in frontal cortex of COVID-19 patients., Brain. Behav. Immun. (2021). https://doi.org/10.1016/j.bbi.2021.05.012.

3.
Brain Pathol ; 31(5): e12997, 2021 09.
Article in English | MEDLINE | ID: covidwho-1273078

ABSTRACT

The actual role of SARS-CoV-2 in brain damage remains controversial due to lack of matched controls. We aim to highlight to what extent is neuropathology determined by SARS-CoV-2 or by pre-existing conditions. Findings of 9 Coronavirus disease 2019 (COVID-19) cases and 6 matched non-COVID controls (mean age 79 y/o) were compared. Brains were analyzed through immunohistochemistry to detect SARS-CoV-2, lymphocytes, astrocytes, endothelium, and microglia. A semi-quantitative scoring was applied to grade microglial activation. Thal-Braak stages and the presence of small vessel disease were determined in all cases. COVID-19 cases had a relatively short clinical course (0-32 days; mean: 10 days), and did not undergo mechanical ventilation. Five patients with neurocognitive disorder had delirium. All COVID-19 cases showed non-SARS-CoV-2-specific changes including hypoxic-agonal alterations, and a variable degree of neurodegeneration and/or pre-existent SVD. The neuroinflammatory picture was dominated by ameboid CD68 positive microglia, while only scant lymphocytic presence and very few traces of SARS-CoV-2 were detected. Microglial activation in the brainstem was significantly greater in COVID-19 cases (p = 0.046). Instead, microglial hyperactivation in the frontal cortex and hippocampus was clearly associated to AD pathology (p = 0.001), regardless of the SARS-CoV-2 infection. In COVID-19 cases complicated by delirium (all with neurocognitive disorders), there was a significant enhancement of microglia in the hippocampus (p = 0.048). Although higher in cases with both Alzheimer's pathology and COVID-19, cortical neuroinflammation is not related to COVID-19 per se but mostly to pre-existing neurodegeneration. COVID-19 brains seem to manifest a boosting of innate immunity with microglial reinforcement, and adaptive immunity suppression with low number of brain lymphocytes probably related to systemic lymphopenia. Thus, no neuropathological evidence of SARS-CoV-2-specific encephalitis is detectable. The microglial hyperactivation in the brainstem, and in the hippocampus of COVID-19 patients with delirium, appears as a specific topographical phenomenon, and probably represents the neuropathological basis of the "COVID-19 encephalopathic syndrome" in the elderly.


Subject(s)
COVID-19/pathology , Dementia/virology , Microglia/pathology , Nervous System Diseases/virology , Aged , Aged, 80 and over , Astrocytes/pathology , Brain/pathology , COVID-19/psychology , Case-Control Studies , Dementia/pathology , Dementia/psychology , Female , Humans , Male , Nervous System Diseases/pathology , Nervous System Diseases/psychology , SARS-CoV-2/isolation & purification
4.
Brain Behav Immun ; 97: 13-21, 2021 10.
Article in English | MEDLINE | ID: covidwho-1233366

ABSTRACT

SARS-Cov-2 infection is frequently associated with Nervous System manifestations. However, it is not clear how SARS-CoV-2 can cause neurological dysfunctions and which molecular processes are affected in the brain. In this work, we examined the frontal cortex tissue of patients who died of COVID-19 for the presence of SARS-CoV-2, comparing qRT-PCR with ddPCR. We also investigated the transcriptomic profile of frontal cortex from COVID-19 patients and matched controls by RNA-seq analysis to characterize the transcriptional signature. Our data showed that SARS-CoV-2 could be detected by ddPCR in 8 (88%) of 9 examined samples while by qRT-PCR in one case only (11%). Transcriptomic analysis revealed that 11 genes (10 mRNAs and 1 lncRNA) were differential expressed when frontal cortex of COVID-19 patients were compared to controls. These genes fall into categories including hypoxia, hemoglobin-stabilizing protein, hydrogen peroxide processes. This work demonstrated that the quantity of viral RNA in frontal cortex is minimal and it can be detected only with a very sensitive method (ddPCR). Thus, it is likely that SARS-CoV-2 does not actively infect and replicate in the brain; its topography within encephalic structures remains uncertain. Moreover, COVID-19 may have a role on brain gene expression, since we observed an important downregulation of genes associated to hypoxia inducting factor system (HIF) that may inhibit the capacity of defense system during infection and oxigen deprivation, showing that hypoxia, well known multi organ condition associated to COVID-19, also marked the brain.


Subject(s)
COVID-19 , SARS-CoV-2 , Frontal Lobe , Humans , Transcriptome , Whole Exome Sequencing
5.
Sensors (Basel) ; 21(7)2021 Apr 03.
Article in English | MEDLINE | ID: covidwho-1167703

ABSTRACT

A new coronavirus (SARS-CoV-2) caused the current coronavirus disease (Covid-19) epidemic. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) is used as the gold standard for clinical detection of SARS-CoV-2. Under ideal conditions, RT-qPCR Covid-19 assays have analytical sensitivity and specificity greater than 95%. However, when the sample panel is enlarged including asymptomatic individuals, the sensitivity decreases and false negatives are reported. Moreover, RT-qPCR requires up to 3-6 h with most of the time involved in RNA extraction from swab samples. We introduce CovidArray, a microarray-based assay, to detect SARS-CoV-2 markers N1 and N2 in the nasopharyngeal swabs. The method is based on solid-phase hybridization of fluorescently-labeled amplicons upon RNA extraction and reverse transcription. This approach combines the physical-optical properties of the silicon substrate with the surface chemistry used to coat the substrate to obtain a diagnostic tool of great sensitivity. Furthermore, we used an innovative approach, RNAGEM, to extract and purify viral RNA in less than 15 min. We correctly assigned 12 nasopharyngeal swabs, previously analyzed by RT-qPCR. Thanks to the CovidArray sensitivity we were able to identify a false-negative sample. CovidArray is the first DNA microarray-based assay to detect viral genes in the swabs. Its high sensitivity and the innovative viral RNA extraction by RNAGEM allows the reduction of both the amount of false-negative results and the total analysis time to about 2 h.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , RNA, Viral/genetics , Real-Time Polymerase Chain Reaction , Sensitivity and Specificity
SELECTION OF CITATIONS
SEARCH DETAIL