Application of Raman spectroscopy in monoclonal antibody producing continuous systems for downstream process intensification.

Monoclonal antibodies (mAbs) are biopharmaceuticals produced by mammalian cell lines in bioreactors at a variety of scales. Cell engineering, media optimization, process monitoring, and control strategies for in vitro production have become crucial subjects to meet increasing demand for these high value pharmaceuticals. Raman Spectroscopy has gained great attention in the pharmaceutical industry for process monitoring and control to maintain quality assurance. For the first time, this article demonstrated the possibility of subclass independent quantitative mAb prediction by Raman spectroscopy in real time. The developed model estimated the concentrations of different mAb isotypes with average prediction errors of 0.2 (g/L) over the course of cell culture. In situ Raman spectroscopy combined with chemometric methods showed to be a useful predictive tool for monitoring of real time mAb concentrations in a permeate stream without sample removal. Raman spectroscopy can, therefore, be considered as a reliable process analytical technology tool for process monitor, control, and intensification of downstream continuous manufacturing. The presented results provide useful information for pharmaceutical industries to choose the most appropriate spectroscopic technology for their continuous processes.

The prevalence of "pigeon breeder's disease" in a Turkish city and review of the literature.

Hypersensitivity pneumonitis (HP) is a rarely encountered inflammatory interstitial lung disease caused by various antigens. Studies in the literature report contradictory rates about its prevalence. The aim of the present study was to determine the prevalence of "pigeon breeder's disease" (PBD) among pigeon breeders in Samsun province. The present study was performed in two phases. In the first phase, we contacted the Samsun Serinofil Association (Samsun Serinofil Dernegi) and a detailed questionnaire was given to the pigeon breeders to fill out. In the second phase, advanced diagnostic tests such as chest X-ray, high-resolution chest computed tomography, pulmonary function tests, natural provocation, bronchoalveolar lavage (BAL), and transbronchial lung biopsy (TBLB) were used to verify the diagnosis in those suspected with PBL. The questionnaire was administered to 185 male volunteers, of whom 11 had suspicious findings. Of eight subjects in whom the natural provocation was performed, one had a positive (acute PBL) response. After discontinuation of exposure, clinical improvement was observed in the second subject (subacute HP), of whom the radiological findings, BAL, and TBLB results were consistent with PBL. The third subject, who had dyspnea for 28 years, was diagnosed with chronic PBL. Consequently, the prevalence of PBL and the positivity of the natural provocation were 1.6 and 12.5%, respectively. In the present study, in which the prevalence of PBL was determined using natural provocation for the first time, the prevalence of HP (1.6%) was quite low compared with previous studies. The present study has demonstrated that a study solely based on a questionnaire is not adequate in determining the prevalence of HP.