A single-step high-throughput bioassay for quantifying Fc-containing recombinant proteins based on non-classical calculation of fluorescence polarization.

The titer of recombinant proteins is one of the key parameters in biopharmaceutical manufacturing processes. The fluorescence polarization (FP)-based assay, a homogeneous, high-throughput and real-time analytical method, had emerged as a powerful tool for biochemical analysis and environmental monitoring. In this study, an FP-based bioassay was utilized to quantify antibody fragment crystallizable (Fc)-containing proteins, such as recombinant monoclonal antibodies (mAbs) and mAb derivatives, in the cell culture supernatant, and the impacts of tracer molecular weight and FITC-coupling conditions on fluorescence polarization were methodically examined. Distinct from the fluorescence polarization potency calculated by classical formula, we for the first time proposed a new concept and calculation of fluorescence polarization intensity, based on which an analytical method with broader detection range and analysis window was established for quantifying Fc-containing proteins. This provided new ideas for the practical application of fluorescence polarization theory. The established method could detect 96 samples within 30 minutes, with dynamic titer range of 2.5-400 mg L-1, and a linear fitting R2 between the measured and actual concentration reaching 0.99. The method had great application prospects in determining the titer of recombinant proteins with Fc fragments, especially when applied to large-scale screening of high-yield and stable expression CHO cell lines commonly used in biopharmaceutical industry.

A review of vaginal hysterectomies in the gynaecology department of a tertiary care hospital.

This retrospective cohort study analysed the trends and complications of vaginal hysterectomy conducted at Services Hospital, Lahore, from January 1, 2015 to December 31, 2020. Demographics, indications, surgery duration, complications (haemorrhage, urological or rectal problems, infection), and hospital stay were recorded. Out of 819 hysterectomies performed for benign gynaecological conditions, 112 (13.68%) were vaginal hysterectomies. Non-descent vaginal hysterectomy (NDVH) accounted for 33(29.46%) and uterine prolapse for 79(70.53%) of the cases. Mean age was 52.35±8.74 years, parity was 5.01±1.32, intraoperative haemorrhage was 796.87±450.1 ml, surgery duration was 48.61±12.28 minutes, and hospital stay was 2.58±0.41 days. Complications occurred in 19(16.97%) of the cases, while 93(83.03%) cases had no complications. Outcomes were comparable between NDVH and vaginal hysterectomy for prolapse (p=0.552). This indicates that vaginal hysterectomy is a safe procedure with minimal complications and quick recovery for uterine prolapse and non-descent uterus. However, a declining trend was observed over the study period.