ABSTRACT
Postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) pose increased morbidity and mortality, especially to elderly patients. The effect of anesthesia is debatable. The databases of PubMed, EMBASE, Google Scholar, Cochrane Library and Web of Science were searched from inception until 24 February 2022 to identify randomized-controlled trials (RCTs) studying the effect of depth of anesthesia on POD and POCD primarily. Data on length of hospital stay and mortality were also extracted. Trial sequential analysis was also performed. Seventeen studies were eligible for systematic review and 15 studies of 5392 patients were eligible for meta-analysis. High bispectral index (BIS) favored a reduction in POD and POCD at three months. We found no significant difference between High BIS and Low BIS for mini-mental state exam (MMSE) score and POCD on day 7. However, this did not translate to a significant difference in length of stay and mortality. The data was also underpowered and heterogeneous. Future RCTs should focus on high-risk patients. A standardized methodology of reporting postoperative delirium and cognitive dysfunction is needed to improve comparisons across trials.
ABSTRACT
A flow cytometry-based immuno-titration titer assay was established to determine infectious unit (IU) and transducing unit (TU) of modified vaccinia Ankara (MVA) virus vectors. This titration method enumerates infected cells by measuring the expression of viral protein for IU and transgene protein for TU in individual cells after staining with fluorophore-conjugated antibodies. It presents many advantages over standard virus titration approaches, such as TCID(50) or plaque assay, for its convenience, rapidity and accuracy as illustrated by excellent assay linearity and reproducibility. Importantly, the IU and the TCID(50) assays generated similar batch-specific titer values when testing varied MVA-derived virus preparations. Assay development revealed that the post-infection time at which viral protein expression is evaluated, host cell type, and blocking the formation and release of progeny virion with nocodazole, an anti-microtubule agent or rifampin, a specific vaccinia virus assembly inhibitor, are critical parameters for the precision, robustness, and accuracy of IU titer determination. An added advantage of this assay is that it enables the concurrent determination of IU and transducing units (TU) by measuring the expression of a transgene product when testing recombinant viruses. The latter was demonstrated using a MVA vector carrying a human HER-2 gene fragment as model. Hence, this assay is very versatile in that it can be used to determine IU as well as multiple TU titers simultaneously. Furthermore, it can readily be adapted to other poxvirus vectors.
