Objective To develop a catalytic hairpin assembly(CHA)-based fluorescent assay for the detection of the target RNA of severe acute respiratory syndrome coronavirus-2(SARS-CoV-2),so as to realize the rapid nucleic acid testing of SARS-CoV-2.Methods A 24-nt segment of the SARS-CoV-2 nucleocapsid protein gene(N gene,NC_045512.2)was chosen as the target RNA and the hairpin motif 1(H1)and hairpin motif 2(H2)were designed based on the principle of CHA reaction.The H1 motif was labelled with a fluorophore group as well as a quencher group.When the target RNA was added to the hairpin motifs,CHA reaction was triggered at room temperature(25℃),which led to the amplification of fluorescence signal,thereby enabling the rapid detection of the target RNA.After the optimization of the hairpin motifs and the experimental conditions,the sensitivity and the specificity of the testing method were measured to evaluate its performance.Results We successfully constructed a CHA-based fluorescent assay specifically for the target RNA of SARS-CoV-2.With this method,testing could be completed at room temperature within 30 min.This testing method exhibited excellent specificity and could be used to accurately distinguish the perfectly-matched target RNA from the target RNA with single-base mutations.In addition,the testing method demonstrated good sensitivity,with a detection limit of 50 pmol/L.Conclusion The proposed assay enables the simple and rapid detection of the SARS-CoV-2 target RNA with excellent sensitivity and specificity,showing great promise for further optimization and subsequent clinical application for the rapid detection of SARS-CoV-2 nucleic acid.

Objective:To investigate the role of glycoprotein A repetitions predominant (GARP) in the pathogenesis of tuberculosis through regulatory T cell (Treg), in order to provide new targets for the treatment of tuberculosis.Methods:Sixty patients with active pulmonary tuberculosis (ATB) admitted to Huashan Hospital, Fudan University and Wuxi Fifth People′s Hospital from January to September 2021 were included. And six individuals with latent tuberculosis infection (LTBI), and 16 healthy controls (HC) were recruited during the same period. Flow cytometry was performed to detect the proportion of Treg in the peripheral blood, and the expressions of GARP and transforming growth factor-β1 (TGF-β1) on Treg in different groups. Mann-Whitney U test was used for statistical analysis. Results:Among the 60 patients with ATB, 23 patients did not receive anti-tuberculosis drug therapy, 17 patients were treated for less than three months, ten patients were treated for three to less than six months, and ten patients were treated for greater than or equal to six months. The percentage of CD4 + CD25 + forkhead box protein 3 (Foxp3) + Treg in untreated ATB patients was 7.50%(5.67%, 9.00%), which was higher than that in HC (5.57%(5.03%, 6.09%)), and the difference was statistically significant ( U=95.00, P=0.010). The percentage of GARP expressing in CD4 + CD25 + Foxp3 + Treg in untreated ATB patients was 10.37%(7.79%, 12.90%), which was higher than that in LTBI (7.02%(5.15%, 8.81%)) and HC (5.33%(4.26%, 6.67%)), respectively, and the differences were both statistically significant ( U=31.00, P=0.040; U=36.00, P<0.001, respectively), while there was no significant difference between LTBI and HC ( U=25.00, P=0.095). The percentage of CD4 + CD25 + Foxp3 + Treg expressing TGF-β1 in untreated ATB patients was 7.13%(4.25%, 8.89%), which was higher than that in HC (3.59%(2.10%, 5.17%)), and the difference was statistically significant ( U=71.00, P=0.001). The expressions of GARP in CD4 + CD8 -CD25 + Foxp3 + Treg in patients with ATB treated for less than three months group, three to less than six months group and greater than or equal to six months group were 7.82%(3.94%, 13.17%), 6.92%(5.61%, 9.47%) and 7.26%(5.82%, 9.64%), respectively. The expressions of TGF-β1 in CD4 + CD8 -CD25 + Foxp3 + Treg in the above three treatment groups were 11.16%(7.91%, 15.23%), 8.66%(5.43%, 12.54%) and 7.82%(6.01%, 9.53%), respectively, and the expression of TGF-β1 in CD4 + CD8 -CD25 + Foxp3 + Treg in the patients with ATB treated for less than three months group was higher than that in the greater than or equal to six months group, the difference was statistically significant ( U=37.50, P=0.024). Conclusions:Foxp3/GARP/TGF-β1 pathway may be involved in the immune mechanism of Treg regulating the pathogenesis of tuberculosis, and GARP may be a new target for anti-tuberculosis therapy.

Objective To investigate the clinical and histopathologic features , diagnosis and differential diagnosis of eccrine angiomatous hamartoma ( EAH ).Methods Four cases of eccrine angiomatous hamartoma were studied by light microscopy and immunohistochemical staining along with review of the literature.Results There were 3 male and 1 female patients at diagnosis in age of 4 months, 3.5 years, 5.5 years and 14.0 years, respectively.Tumor sites included the left little finger (1 case), right index finger (1 case), lower back (1 case) and knee (1 case).Clinically, most cases presented as a solitary, flesh or reddish papule , plaque or nodule with size of 0.4-6.0 cm in diameter.The skin lesions in 3 cases enlarged commensurate with the growth of the patients , and local hyperhidrosis in one case.Histologically, EAH was characterized by proliferation of well-differentiated eccrine secretory and ductal elements closely associated with thin-walled angiomatous channels in the middle or deep dermis and subcutaneous tissue.By immunohistochemistry , the vascular components were positive for CD 31, CD34 and factorⅧrelated antigen while the eccrine glands were positive for S-100 protein, CEA, EMA, CAM5.2 and GCDFP15.Local surgical resection was performed in 4 cases and follow-up data (0.5 to 4.5 years) showed no recurrence.Conclusion EAH is a rare, benign cutaneous hamartoma.Combination of clinical manifestations , histological changes and immunohistochemical findings is useful for the diagnosis and differential diagnosis .