Ultra-Sensitive Detection of the SARS-CoV-2 Nucleocapsid Protein via a Clustered Regularly Interspaced Short Palindromic Repeat/Cas12a-Mediated Immunoassay.

Tracking trace protein analytes in precision diagnostics is an ongoing challenge. Here, we developed an ultrasensitive detection method for the detection of SARS-CoV-2 nucleocapsid (N) protein by combining enzyme-linked immunosorbent assay (ELISA) with the clustered regularly interspaced short palindromic repeat/CRISPR-associated protein (CRISPR/Cas) system. First, the SARS-CoV-2 N protein bound by the capture antibody adsorbed on the well plate was sequentially coupled with the primary antibody, biotinylated secondary antibody, and streptavidin (SA), followed by biotin primer binding to SA. Subsequently, rolling circle amplification was initiated to generate ssDNA strands, which were targeted by CRISPR/Cas12a to cleave the FAM-ssDNA-BHQ1 probe in trans to generate fluorescence signals. We observed a linear relationship between fluorescence intensity and the logarithm of N protein concentration ranging from 3 fg/mL to 3 × 107 fg/mL. The limit of detection (LOD) was 1 fg/mL, with approximately nine molecules in 1 µL of the sample. This detection sensitivity was 4 orders magnitude higher than that of commercially available ELISA kits (LOD: 5.7 × 104 fg/mL). This method was highly specific and sensitive and could accurately detect SARS-CoV-2 pseudovirus and clinical samples, providing a new approach for ultrasensitive immunoassay of protein biomarkers.

High Selectivity of A Novel Pillar[5]arene with Ester Units as a Gas Chromatographic Stationary Phase toward Aromatic Isomers.

This work reports the first example of employing ester-functionalized pillar[5]arene (P5A-C10-OAc) stationary phase for gas chromatography (GC) separations. The as-fabricated P5A-C10-OAc column achieved improved column efficiency of 4270 plates/m and separation performance in contrast to the P5-C10-Br column. The P5A-C10-OAc column showed good separation performance for a wide range of analytes such as alkanes, bromoalkanes, ketones, fatty acid methyl esters, aldehydes, alcohols, halobenzenes, anilines, phenols, naphthalenes, and showed sharp and symmetrical peak shapes for analytes that are liable to peak-tailing in GC analysis. As testified by the challenging isomer mixtures (bromonitrobenzene, chloronitrobenzene, bromobenzaldehyde, chlorobenzaldehyde, nitrobenzaldehyde), the P5A-C10-OAc column exhibited comprehensively higher separation capability than the P5A-C10-Br, P5A-C10 and commercial HP-35 columns. This work demonstrates the great potential of pillararene-based stationary phases as a new type of stationary phases for GC separations.

Development of dual-mode ELISA based on ALP-catalyzed APP hydrolysis for IL-6 detection.

Sensitive and accurate detection of interleukin 6 (IL-6) is crucial for the early diagnosis of cerebral infarction to improve patient survival rates. However, the low-abundance of IL-6 in cerebral infarction presents a significant challenge in developing effective diagnosis method. Herein, we studied and analyzed the strong fluorescence property of 4-aminophenol phosphate (APP) and developed an enzyme-linked immunosorbent assay (ELISA) for IL-6 detection. The detection was based on the integration of optical signal change induced by alkaline phosphatase (ALP)-catalyzed APP hydrolysis and ALP-mediated ELISA. The generated colorimetric signal of 4-aminophenol, APP hydrolysis product, was used for ELISA of IL-6 with a detection limit of 0.1 ng/mL, and the visual detection of IL-6 was achieved. The changes in APP fluorescence have a good linear relationship with the logarithm of IL-6 concentration in the range of 0.005 ng/mL to 5.0 ng/mL, with a detection limit of 0.001 ng/mL, which was 100 times lower than that of conventional pNPP-based ELISA. Furthermore, the constructed ELISA effectively distinguished between samples from patients with cerebral infarction and volunteers with non-cerebral infarction, and the severity of symptoms was well distinguished based on IL-6 measurement. The dual-mode ELISA demonstrated high feasibility of low-abundance biomarker detection and displayed good potential for accurate in vitro diagnosis.

Advances in Recombinant Adeno-Associated Virus Vectors for Neurodegenerative Diseases.

Recombinant adeno-associated virus (rAAV) vectors are gene therapy delivery tools that offer a promising platform for the treatment of neurodegenerative diseases. Keeping up with developments in this fast-moving area of research is a challenge. This review was thus written with the intention to introduce this field of study to those who are new to it and direct others who are struggling to stay abreast of the literature towards notable recent studies. In ten sections, we briefly highlight early milestones within this field and its first clinical success stories. We showcase current clinical trials, which focus on gene replacement, gene augmentation, or gene suppression strategies. Next, we discuss ongoing efforts to improve the tropism of rAAV vectors for brain applications and introduce pre-clinical research directed toward harnessing rAAV vectors for gene editing applications. Subsequently, we present common genetic elements coded by the single-stranded DNA of rAAV vectors, their so-called payloads. Our focus is on recent advances that are bound to increase treatment efficacies. As needed, we included studies outside the neurodegenerative disease field that showcased improved pre-clinical designs of all-in-one rAAV vectors for gene editing applications. Finally, we discuss risks associated with off-target effects and inadvertent immunogenicity that these technologies harbor as well as the mitigation strategies available to date to make their application safer.

Atypical thymic carcinoid tumor with ectopic ACTH syndrome in a 33-year-old male patient: A rare case report and literature review.

RATIONALE: Atypical thymic carcinoid tumor is an exceedingly rare thymic neuroendocrine tumor derived from the cells of neuroendocrine system. Misdiagnosis or delayed diagnosis may result in disease progression to advanced stages and eventually leads to a poor prognosis. It is therefore necessary to make a correct diagnosis and provide an adequate treatment. PATIENT CONCERNS: A 33-year-old Chinese male presented with numbness in bilateral lower extremities and general fatigue for a month. Chest computed tomography revealed a superior anterior mediastinal mass. Thymoma was initially considered, given the location of the mass and radiographic presentation. DIAGNOSIS: Microscopic findings showed that the tumor cells are arranged in pseudoepitheliomatous growth or irregular nested growth pattern in a background of fibroconnective tissue, with focal infiltration into adipose tissue. The chrysanthemum-like structure or beam-like structure seen often in typical carcinoid tumor was not identified in this case. The tumor cells are spindled or oval, with focal active mitosis. The immunohistochemical staining showed strong positivity for CD56, CgA and Syn, positivity for CK, ACTH, and TTF-1, negativity for Vimentin, and ki67 labeled proliferation index was up to 10% in focal areas. According to the radiological and pathological findings, the diagnosis of atypical thymic carcinoid was made. INTERVENTIONS: The patient underwent surgical resection of the mass. OUTCOME: No recurrence or metastasis was identified during the follow up. LESSONS: Because of its low incidencen, onspecific clinical symptoms, tissue location, and radiological findings, atypical thymic carcinoid tumor may sometimes be misdiagnosed as thymoma. Attention should be paid to avoid misdiagnosis.

Endometrioid adenofibroma of ovary: A case report and review of literature.

RATIONALE: Endometrioid adenofibroma is a benign epithelial neoplasm of the ovary, most of which are often unilateral. The symptoms of endometrioid adenofibroma are often nonspecific and misleading. Therefore, a full understanding of the characteristics, diagnosis, and treatment methods of this disease is of great importance. In this study, we report a 34-year-old woman who was found with an unidentified mass on the right ovary during the physical examination 3 years ago with nosymptoms or signs. PATIENT CONCERNS: A 34-year-old Chinese female was found with an unidentified 6 cm mass on the right ovary for 3 years that presented with no symptoms or signs. DIAGNOSIS: Pelvic ultrasound revealed a 6 cm cystic solid mixed mass on the right ovary. Through histological and immunohistochemical examinations, the tumor mass was finally diagnosed as endometrioid adenofibroma of ovary. INTERVENTIONS: To confirm the diagnosis, the ovarian tumor was laparoscopically resected. OUTCOMES: The patient returned to hospital after 3 months with no recurrence or postoperative complications. LESSONS: Endometrioid adenofibroma is a benign epithelial neoplasm of the ovary. Complete surgical resection is required and rare cases can recur. Postsurgical pathologic and immunohistochemical testing can confirm a diagnosis of endometrioid adenofibroma. It is important to understand of the key points of differential diagnosis of the disease due to the different prognosis and clinical treatment.

Intra-tumoral angiogenesis correlates with immune features and prognosis in glioma.

Gliomas are the most common malignant tumor in the brain. As with other tumors, the progression of glioma depends on intra-tumoral angiogenesis. However, the effect of angiogenesis on gliomas is still not fully understood. In this study, we developed an angiogenesis pathway score using Gene Set Variation Analysis (GSAV) in R to assess the status of intra-glioma angiogenesis in The Cancer Genome Atlas (TCGA), Chinese Glioma Genome Atlas (CGGA mRNAseq_325, CGGA mRNA-array), and GSE16011 datasets. We found that the angiogenesis pathway score not only accurately predicted the prognosis of glioma patients, but also accurately distinguished the malignant phenotype and immune characteristics of gliomas. In addition, as an independent prognostic factor, the score could predict glioma sensitivity to radiotherapy and chemotherapy. In summary, we used the angiogenesis pathway score to reveal the relationship between glioma angiogenesis and the malignant phenotype, immune characteristics, and prognosis of glioma.

Exonic Circular RNAs Are Involved in Arabidopsis Immune Response Against Bacterial and Fungal Pathogens and Function Synergistically with Corresponding Linear RNAs.

Circular RNAs (circRNAs) are a group of covalently closed RNAs, and their biological function is largely unknown. In this study, we focused on circRNAs that are generated from exon back-splicing (exonic circRNAs). The linear RNA counterparts encode functional proteins so that we can compare and investigate the relationship between circular and linear RNAs. We compared circRNA expression profiles between untreated and Pseudomonas syringae-infected Arabidopsis and identified and experimentally validated differentially expressed exonic circRNAs by multiple approaches. We found that exonic circRNAs are preferentially enriched in biological processes that associate with biotic and abiotic stress responses. We discovered that circR194 and circR4022 are involved in plant response against P. syringae infection, whereas circR11208 is involved in response against Botrytis cinerea infection. Intriguingly, our results indicate that these exonic circRNAs function synergistically with their corresponding linear RNAs. Furthermore, circR4022 and circR11208 also play substantial roles in Arabidopsis tolerance to salt stress. This study extends our understanding of the molecular functions of plant circRNAs.

A dual-luciferase reporter system for characterization of small RNA target genes in both mammalian and insect cells.

MicroRNAs (miRNAs) are regulatory RNA molecules that bind to target messenger RNAs (mRNAs) and affect the stability or translational efficiency of the bound mRNAs. Single or dual-luciferase reporter systems have been successfully used to identify miRNA target genes in mammalian cells. These reporter systems, however, are not sensitive enough to verify miRNA-target gene relationships in insect cell lines because the promoters of the target luciferase (usually Renilla) used in these reporter systems are too weak to drive sufficient expression of the target luciferase in insect cells. In this study, we replaced the SV40 promoter in the psiCHECK-2 reporter vector, which is widely used with mammalian cell lines, with the HSV-TK or AC5.1 promoter to yield two new dual-luciferase reporter vectors, designated psiCHECK-2-TK and psiCHECK-2-AC5.1, respectively. Only psiCHECK-2 and psiCHECK-2-AC5.1 had suitable target (Renilla)/reference (firefly) luciferase activity ratios in mammalian (HeLa and HEK293) and insect (Sf9, S2, Helicoverpa zea fat body and ovary) cell lines, while psiCHECK-2-TK had suitable Renilla/firefly luciferase activity ratios regardless of the cell line. Moreover, psiCHECK-2-TK successfully detected the interaction between Helicoverpa armigera miRNA9a and its target, the 3'-untranslated region of heat shock protein 90, in both mammalian and H. zea cell lines, but psiCHECK-2 failed to do so in H. zea cell lines. Furthermore, psiCHECK-2-TK with the target sequence, HzMasc (H. zea Masculinizer), accurately differentiated between H. zea cell lines with or without the negative regulation factor (miRNA or piRNA) of HzMasc. These data demonstrate that psiCHECK-2-TK can be used to functionally characterize small RNA target genes in both mammalian and insect cells.

Identification and Characterization of MicroRNAs in Gonads of Helicoverpa armigera (Lepidoptera: Noctuidae).

The high fecundity of the most destructive pest Helicoverpa armigera and its great resistance risk to insecticides and Bt crops make the reproductive-destruction-based control of this pest extremely appealing. To find suitable targets for disruption of its reproduction, we observed the testis and ovary development of H. armigera and conducted deep sequencing of the ovary and testis small RNAs of H. armigera and quantitative RT-PCR (RT-qPCR) validation to identify reproduction-related micro RNAs (miRNAs). A total of 7,592,150 and 8,815,237 clean reads were obtained from the testis and ovary tissue, respectively. After further analysis, we obtained 173 novel and 74 known miRNAs from the two libraries. Among the 74 known miRNAs, 60 miRNAs existed in the ovary and 72 existed in the testis. Further RT-qPCR validation of 5 miRNAs from the ovary and 6 miRNAs from the testis confirmed 8 of them were indeed ovary- (miR-989a, miR-263-5p, miR-34) or testis-biased (miR-2763, miR-998, miR-2c, miR-2765, miR-252a-5p). The 8 ovary- or testis-biased miRNAs had a total of 30,172 putative non-redundant target transcripts, as predicted by miRanda and RNAhybrid. Many of these target transcripts are assigned to reproduction-related GO terms (e.g., oocyte maturation, vitellogenesis, spermatogenesis) and are members of multiple reproduction-related KEGG pathways, such as the JAK-STAT signaling pathway, oocyte meiosis, the insulin signaling pathway, and insect hormone biosynthesis. These results suggest that the 8 gonad-biased miRNAs play important roles in reproduction and may be used as the targets for the development of reproductive-destruction-based control of H. armigera and, possibly, other lepidopteran pests.

Pulmonary artery intimal sarcoma mimicking pulmonary thromboembolism: A case report.

RATIONALE: Pulmonary artery intimal sarcoma is a rare tumor with exceptionally high mortality and easily misdiagnosed as pulmonary thromboembolism pulmonary thromboembolism (PTE) due to the nonspecific clinical presentation and symptom. Misdiagnosis or untimely diagnosis makes the disease progress to an advanced stage and eventually leads to a poor prognosis. PATIENT CONCERNS: A 37-year-old Chinese female presented with chest tightness and dyspnea for 3 months. Echocardiography and chest computed tomography revealed an intraluminal obstruction of the pulmonary arteries. Tests of serum tumor makers showed slight elevation for carbohydrate antigen-125, and α-fetoprotein. PTE was suspected according to the radiological and laboratory findings. DIAGNOSIS: Microscopic findings of the presumed thrombus showed prominent myxoid and edematous background with atypical spindled cells and curvilinear vascularity. Immunohistochemical staining demonstrated that the atypical spindled cells were positive for vimentin but negative for CK, S100, SMA, desmin, CD68, STAT6, CD34, ß-catenin, ALK-p80, p53, and MDM2. According to the radiological and pathological findings, the diagnosis of fibrosarcoma of pulmonary artery was made. INTERVENTIONS: The patient underwent surgical resection and the mass was excised as completely as possible. OUTCOME: Follow-up information showed no evidence of recurrence or metastasis after 3 months postresection. LESSONS: Because of the low incidence rate, nonspecific clinical symptoms, and radiological findings, primary fibrosarcoma of the pulmonary artery is commonly misdiagnosed as PTE. Pathological examination is necessary to confirm the diagnosis.

Inductive and synergistic interactions between plant allelochemical flavone and Bt toxin Cry1Ac in Helicoverpa armigera.

Genetically engineered crops simultaneously produce defensive allelochemicals and Bacillus thuringiensis (Bt) toxin proteins to kill some of the world's most devastating insect pests. How the two types of toxins, when ingested sequentially or simultaneously, interact at both lethal and sublethal doses in these pests remains underexplored. Here, we examined the toxicological interactions between the Bt toxin Cry1Ac and the flavonoid allelochemical flavone in Helicoverpa armigera. Simultaneous exposure of H. armigera neonates to lethal doses (LC25 ) of Cry1Ac and flavone caused a mortality significantly higher than that of either toxin alone and their expected additive mortality. Preexposure for 24 h to a sublethal dose (LC10 ) of Cry1Ac followed by 6-d simultaneous exposure to the same dose of Cry1Ac plus a lethal dose (1.6 mg/g diets, LC50 ) of flavone resulted in a mortality significantly higher than that of the LC50 dose of flavone alone and the expected additive mortality of the LC50 dose of flavone plus the LC10 dose of Cry1Ac. One-day preexposure to the sublethal dose (LC10 ) of flavone followed by 6-d simultaneous exposure to the LC50 dose (6 ng/cm2 ) of Cry1Ac plus the LC10 dose of flavone yielded a mortality significantly higher than that of the LC50 dose of Cry1Ac but similar to the expected additive mortality of the LC50 dose of Cry1Ac plus the LC10 dose of flavone. The results suggest that Cry1Ac induces and synergizes the toxicity of flavone against H. armigera larvae.

Novel nonapeptide GLP (28-36) amide derivatives with improved hypoglycemic and body weight lowering effects.

Glucagon-like peptide-1 (GLP-1) has emerged as a major therapeutic target for the treatment of type 2 diabetes. The nonapeptide GLP-1 (28-36) amide is one of the biological C-terminal products of GLP-1 modified by the neutral endopeptidase (NEP) 24.11 with limited hypoglycemic activity. In this study, we focused on the modification of GLP-1 (28-36) amide for the first time and synthesized a series of GLP-1 (28-36) amide analogues. Results of biological activity evaluation in INS-1 cell, STZ-induced diabetic and diet induced obesity (DIO) mice indicated that S3 as a promising candidate to treat type 2 diabetes and obesity.