Efficacy and safety of antimicrobial de-escalation of treatment for sepsis: A protocol for systematic review and meta-analysis.

BACKGROUND: Sepsis has become a global healthcare problem and continues to be one of the leading causes of death due to infection. In essence, early recognition and diagnosis of sepsis is needed to inhibit the transition into septic shock, which is correlated with higher mortality. Many studies have suggested antimicrobial de-escalation as one of the strategies to replace the empirical broad-spectrum antimicrobial treatment using a narrower antimicrobial therapy, especially among patients with sepsis. However, antimicrobial de-escalation therapeutic effects in sepsis remains unclear. We therefore performed the present study in an attempt to assess efficacy and safety of antimicrobial de-escalation therapy in patients with sepsis. METHODS: We will carry out a systematic literature search to establish the potentially eligible trials from electronic databases, including EMBASE (1980 to October 16, 2020), MEDLINE via PubMed (1966 to October 16, 2020), Web of Science (1965 to October 16, 2020), Cochrane Library (CENTRAL; 2020, Issue 10), WanFang databases (last searched October 16, 2020), and China National Knowledge Infrastructure (CNKI; last searched October 16, 2020). For this study, the language restrictions are English or Chinese. Two authors independently examined quality based on the Cochrane Risk of Bias Tool V.2.0 and extracted data. Data obtained from the study will be synthesised using applicable statistical methods. RESULTS: The results of the present study will systematically assess efficacy and safety of antimicrobial de-escalation therapy among patients with sepsis. CONCLUSION: The results of the present study will help to establish the efficacy and safety of antimicrobial de-escalation to treat patients with sepsis. It can also help to identify the most efficient and safe therapeutically-relevant method. ETHICS AND DISSEMINATION: The present study is a meta-analysis and the pooled results are based on published evidence. Therefore, ethics approval is not necessary. OSF REGISTRATION NUMBER: October 22, 2020.osf.io/93wym. (https://osf.io/93wym/).

A direct competitive enzyme linked immunosorbent assay for progesterone using monoclonal antibody.

A direct competitive enzyme-linked immunosorbent assay (ELISA) with monoclonal antibody (MAb) was diagnosed with progesterone (P) level of human serum. In high concentrations and large amounts of displacer effect, this monoclonal antibody (MAb) can retain biological activity so that it can be specially combined with progesterone. Under conditions of the existing displaced agent, monoclonal antibody 11F8(3)H5 can maintain high specificity and affinity and can specifically bind progesterone in serum. Progesterone ELISA standard curve was calculated according to the following formula: Logit(y) = -1.358Log(x) + 0.4961, r = 0.9944. The serum progesterone values obtained by this method correlated well with those obtained by chemiluminescent immunoassay (CLIA): the correlative equation was y = 0.7804x + 0.7600, r = 0.9126.

Chemiluminescence immunoassay for chloramphenicol.

In recent years, various chemiluminescent clinical immunoassay kits have been widely applied to the detection of hormones. However, a kit for chloramphenicol (CAP) is often absent from most commercial product lists, even though it is important to control the levels of CAP residues in foodstuffs too. Therefore, we describe a simple, solid-phase chemiluminescence immunoassay (CLIA) for the measurement of CAP in foodstuffs. A rabbit anti-CAP IgG is passively adsorbed onto the walls of polypropylene plates. The labeled antigen is horseradish peroxidase (HRP) conjugate of CAP. Luminol solution is used as the substrate of HRP. The light yield is inversely proportional to the concentration of CAP. The method has a similar sensitivity (0.05 ng/ml), specificity, precision, and accuracy to a conventional enzyme immunoassay (EIA). The intra-assay and inter-assay CVs of ten samples were <8% and <20%, respectively, and the analytical recovery of the method was 87-100%. The experimental correlation coefficient of dilution was found to be 0.999 using milk supernatant as buffer. The detection limit for the method was 0.1-10 ng/ml, and it displayed good linearity.

Sensitive time-resolved fluoroimmunoassay for simultaneous detection of serum thyroid-stimulating hormone and total thyroxin with Eu and Sm as labels.

Based on a novel cocoating strategy and dissociation enhancement lanthanide fluorescence immunoassay technique, a sensitive time-resolved fluoroimmunoassay (TRFIA) has been developed for simultaneous quantification of human serum thyroid-stimulating hormone (TSH) and thyroxin (T4) in a one-and-the-same assay procedure. The new cocoating strategy for preparing highly active surface anti-TSH and anti-T4 monoclonal antibodies (McAbs) was performed by a three-step protocol. Namely, anti-TSH McAb at high concentration (10 micro g/ml) and extensively biotinylated bovine serum albumin (BSA) at low concentration (0.5 micro g/ml) were coated on microwells by passive adsorption, then streptavidin was captured by the surface BSA-biotin, and finally biotinylated anti-T4 McAb was immobilized by the remnant binding sites of the bound streptavidin. In the present TSH/T4 TRFIA, both sandwich- and competitive-type configurations were involved, and Eu(3+) and Sm(3+) were used as labels for TSH and T4 detection, respectively. The method showed rapid kinetics; the equilibrium was reached within 30min at 37 degrees C due to the use of high concentrations of reaction reagents, rapid agitation, and small reaction volume. The lower limits of detection of the method were 0.028 mIU/L for TSH and 4.1 nmol/L for T4 with 20 micro L of sample volume. The assay ranges for TSH and T4 were 0.21-80.00 mIU/L and 20-300 nmol/L, respectively. The correlation between the TSH/T4 values obtained by the present TSH/T4 TRFIA and those obtained by commercial chemiluminescence immunoassay was satisfactory.

Synthesis of a highly fluorescent beta-diketone-europium chelate and its utility in time-resolved fluoroimmunoassay of serum total thyroxine.

A new highly fluorescent beta-diketone-europium chelate was synthesized and employed as a tracer to develop a time-resolved fluoroimmunoassay (TRFIA) for detection of serum total thyroxine (T4). The tetradentate beta-diketone chelator, 1,10-bis(thiophene-2'-yl)-4,4,5,5,6,6,7,7-octafluorodecane-1,3,8,10-tetraone (BTOT), was structurally composed of two units of thenoyltrifluoroacetone (TTA) derivatives but expressed fluorescence that was greatly enhanced, as compared to the original TTA molecules, in the presence of excess amount of Eu3+. The luminescence properties of the europium chelate of BTOT werestudied in aqueous solution. Chlorosulfonylation of BTOT afforded 1, 10-bis(5'-chlorosulfo-thiophene-2'-yl)-4,4,5,5,6,6,7,7-octafluorodecane-1,3,8,10-tetraone (BCTOT), which could be coupled to proteins (i.e., streptavidin or the BSA-T4 conjugate) and used as a tracer for TRFIA. Although the BCTOT-Eu complex could be detected at a very low level (approximately 1.07 x 10(-12) mol/L) in buffered aqueous solution (50 mmoVLTris-HCl; pH, 8.0), the application of the chelate label in direct serum T4 TRFIA experienced a problem of matrix interference, which was probably caused by some unknown chelating components in the samples as a result of the fact that the fluorescence of the BCTOT-Eu chelate was prone to quenching or enhancement by some chelating reagents. To remove this problem, an indirect serum T4 TRFIA was proposed with the use of BCTOT-Eu-labeled streptavidin (SA) as signal generation reagent. The concentrations of T4 in 27 human serums were determined by indirect T4 TRFIA, and the assay results correlated well with those obtained by commercial Coming-CLIA (r = 0.955) and Wallac-DELFIA (r 0.965).

Time-resolved immunofluorometry of serum hTSH with enhanced sensitivity.

Sensitive TSH immunoassays offer a clear advance in discriminating the TSH concentrations in serum between hyperthyroid and euthyroid individuals; they have been proposed as the best single screening test for thyroid disorders. We have developed a highly sensitive serum TSH TRFIA based on DELFIA technology. Three monoclonal antibodies (McAbs) directed against different epitopes of the TSH molecule were involved in this assay, of which, one McAb was used to coat clear microwells, and the other two were biotinylated' for signal generation after being bound by the europium labeled streptavidin. The europium label captured on the well surface was quantified by a routine dissociation-enhancement procedure. The fluorescence intensity was directly proportional to the serum hTSH concentration. The assay required two steps and could be completed within 5 h. The analytical sensitivity reached 0.002 mIU/L with a sample volume of 100 microL, the function sensitivity was 0.017 mIU/L. Measurements by the present method correlated well with that obtained by the ACS-180 chemi-luminescence immunoassay (CLIA). The discrimination of hyperthyroid patients from clinically euthyroid patients by the present method was much better than that by the routine IRMA.