Multiplexed flow cytometric approach for detection of anti-SARS-CoV-2 IgG, IgM and IgA using beads covalently coupled to the nucleocapsid protein.

Flow cytometry has emerged as a promising technique for detection of SARS-CoV-2 antibodies. In this study, we developed an innovative strategy for simultaneous detection of immunoglobulin G (IgG), IgM and IgA. The SARS-CoV-2 nucleocapsid protein was covalently bound to functional beads surface applying sulpho-SMCC chemistry. BUV395 anti-IgG, BB515 anti-IgM, biotinylated anti-IgA1/IgA2 and BV421 streptavidin were used as fluorophore conjugated secondary antibodies. Serum and antibodies reaction conditions were optimized for each antibody isotype detection and a multiplexed detection assay was developed. This new cell-free assay efficiently discriminate COVID-19 negative and positive samples. The simultaneous detection of IgG, IgM and IgA showed a sensitivity of 88·5-96·2% and specificity of 100%. This novel strategy opens a new avenue for flow cytometry-based diagnosis.

Development of polypyrrole (nano)structures decorated with gold nanoparticles toward immunosensing for COVID-19 serological diagnosis.

The rapid and reliable detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroconversion in humans is crucial for suitable infection control. In this sense, many studies have focused on increasing the sensibility, lowering the detection limits and minimizing false negative/positive results. Thus, biosensors based on nanoarchitectures of conducting polymers are promising alternatives to more traditional materials since they can hold improved surface area, higher electrical conductivity and electrochemical activity. In this work, we reported the analytical comparison of two different conducting polymers morphologies for the development of an impedimetric biosensor to monitor SARS-CoV-2 seroconversion in humans. Biosensors based on polypyrrole (PPy), synthesized in both globular and nanotubular (NT) morphology, and gold nanoparticles are reported, using a self-assembly monolayer of 3-mercaptopropionic acid and covalently linked SARS-CoV-2 Nucleocapsid protein. First, the novel hybrid materials were characterized by electron microscopy and electrochemical measurements, and the biosensor step-by-step construction was characterized by electrochemical and spectroscopic techniques. As a proof of concept, the biosensor was used for the impedimetric detection of anti-SARS-CoV-2 Nucleocapsid protein monoclonal antibodies. The results showed a linear response for different antibody concentrations, good sensibility and possibility to quantify 7.442 and 0.4 ng/mL of monoclonal antibody for PPy in the globular and NT morphology, respectively. The PPy-NTs biosensor was able to discriminate serum obtained from COVID-19 positive versus negative clinical samples and is a promising tool for COVID-19 immunodiagnostic, which can contribute to further studies concerning rapid, efficient, and reliable detections.

Techniques for the interruption of tubal patency for female sterilisation.

BACKGROUND: Female sterilization is the most popular contraceptive method worldwide. Several techniques are described in the literature, however only few of them are commonly used and properly evaluated. OBJECTIVES: To compare the different tubal occlusion techniques in terms of major and minor morbidity, failure rates (pregnancies), technical failures and difficulties and women's and surgeons' views. SEARCH STRATEGY: The Cochrane Controlled Trials Register has been searched. A search of the reference lists of identified trials was performed. An additional MEDLINE search was done using an Internet search service Pub Med. SELECTION CRITERIA: All randomized controlled trials comparing different techniques for tubal sterilization, regardless of the way of entry in the abdominal cavity or the method of anesthesia. DATA COLLECTION AND ANALYSIS: Trials under consideration were evaluated for methodological quality and appropriateness for inclusion. Nine relevant studies were included and the results were stratified in five groups: tubal ring versus clip, modified Pomeroy versus electrocoagulation, tubal ring versus electrocoagulation, modified Pomeroy versus Filshie clip and Hulka versus Filshie clip. Results are reported as odds ratio for dichotomous outcomes and weighted mean differences for continuous outcomes. MAIN RESULTS: Tubal ring versus clip: Minor morbidity was higher in the ring group (Peto OR 2.15; 95% CI 1.22, 3.78). Technical difficulties were found less frequent in the clip group ( Peto OR 3.87; 95% CI 1.90, 7.89). There was no difference in failure rates between the two groups (Peto OR 0.70; 95% CI 0.28, 1.76). Pomeroy versus electrocoagulation: Women undergoing modified Pomeroy technique had higher major morbidity than with electrocoagulation technique (Peto OR 2.87; 95% CI 1.13, 7.25). Postoperative pain was more frequent in the Pomeroy group (Peto OR 3.85; 95% CI 2.91, 5.10). Tubal ring versus electrocoagulation: Post operative pain was more frequently reported in the tubal ring group. No pregnancies were reported. Pomeroy versus Filshie clip: In the trial comparing the two interventions only one pregnancy was reported in the Pomeroy group after follow-up for 24 months. No differences were found when comparing Hulka versus Filshie clip in the only study that compared these two devices (Toplis 1988). REVIEWER'S CONCLUSIONS: Electrocoagulation was associated with less morbidity when compared with tubal ring and other methods. However the risk of burns to the small bowel might be a serious criticism of the approach. The small sample size and the relative short period of follow-up in these studies limited the power to show clinical or statistical differences for rare outcomes such as failure rates. Aspects such as training, costs and maintenance of the equipment may be important factors in deciding which method to choose.

Techniques for the interruption of tubal patency for female sterilisation.

BACKGROUND: Female sterilization is the most popular contraceptive method worldwide. Several techniques are described in the literature, however only few of them are commonly used and properly evaluated. OBJECTIVES: To compare the different tubal occlusion techniques in terms of major and minor morbidity, failure rates (pregnancies), technical failures and difficulties and women's and surgeons' views. SEARCH STRATEGY: The Cochrane Controlled Trials Register has been searched. A search of the reference lists of identified trials was performed. An additional MEDLINE search was done using an Internet search service Pub Med. SELECTION CRITERIA: All randomized controlled trials comparing different techniques for tubal sterilization, regardless of the way of entry in the abdominal cavity or the method of anesthesia. DATA COLLECTION AND ANALYSIS: Trials under consideration were evaluated for methodological quality and appropriateness for inclusion. Nine relevant studies were included and the results were stratified in five groups: tubal ring versus clip, modified Pomeroy versus electrocoagulation, tubal ring versus electrocoagulation, modified Pomeroy versus Filshie clip and Hulka versus Filshie clip. Results are reported as odds ratio for dichotomous outcomes and weighted mean differences for continuous outcomes. MAIN RESULTS: Tubal ring versus clip: Minor morbidity was higher in the ring group (Peto OR 2.15; 95% CI 1.22, 3.78). Technical difficulties were found less frequent in the clip group ( Peto OR 3.87; 95% CI 1.90, 7.89). There was no difference in failure rates between the two groups (Peto OR 0.70; 95% CI 0.28, 1.76). Pomeroy versus electrocoagulation: Women undergoing modified Pomeroy technique had higher major morbidity than with electrocoagulation technique (Peto OR 2.87; 95% CI 1.13, 7.25). Postoperative pain was more frequent in the Pomeroy group (Peto OR 3.85; 95% CI 2.91, 5.10). Tubal ring versus electrocoagulation: Post operative pain was more frequently reported in the tubal ring group. No pregnancies were reported. Pomeroy versus Filshie clip: In the trial comparing the two interventions only one pregnancy was reported in the Pomeroy group after follow-up for 24 months. No differences were found when comparing Hulka versus Filshie clip in the only study that compared these two devices (Toplis 1988). REVIEWER'S CONCLUSIONS: Electrocoagulation was associated with less morbidity when compared with tubal ring and other methods. However the risk of burns to the small bowel might be a serious criticism of the approach. The small sample size and the relative short period of follow-up in these studies limited the power to show clinical or statistical differences for rare outcomes such as failure rates. Aspects such as training, costs and maintenance of the equipment may be important factors in deciding which method to choose.