Cation exchange versus multimodal cation exchange resins for antibody capture from CHO supernatants: identification of contaminating host cell proteins by mass spectrometry.

We compared classical and multimodal cation exchange resins for the capture of recombinant antibodies from Chinese hamster ovary (CHO) cell culture supernatant. Both Capto S and Capto MMC resins present anionic groups while the multimodal Capto MMC also features a hydrophobic moiety. First we screened optimal binding and elution conditions in microplates with a pure antibody. We validated the results on the lab-scale with columns with a pure antibody and a CHO cell culture supernatant. Both resins achieved good yield and purity for the capture step of an antibody. However, the multimodal resin appeared more efficient and selective. Then we identified proteins in the antibody fraction by mass spectrometry in order to highlight the behavior of host cell proteins (HCPs).

Side effects of spiramycin masquerading as local anesthetic toxicity during labor epidural analgesia.

Significant fetal bradycardia occurred when a parturient receiving labor epidural analgesia experienced generalized numbness and tingling, a metallic taste and hot flushes. An emergent cesarean delivery under general anesthesia was performed with favorable outcomes for the mother and baby. The most likely source of the maternal symptoms was spiramycin, which was being administered for treatment of toxoplasmosis.

First-trimester prenatal diagnosis performed on pregnant women with fetal ultrasound abnormalities: the reliability of interphase fluorescence in situ hybridization (FISH) on mesenchymal core for the main aneuploidies.

OBJECTIVES: To examine the reliability of interphase FISH analysis of the main aneuploidies performed on mesenchymal core when prenatal diagnosis was performed on pregnant women with first-trimester fetal abnormalities on ultrasound. STUDY DESIGN: 386 first-trimester prenatal examinations were investigated from chorionic villus samplings for increased nuchal translucencies or other fetal ultrasound abnormalities. Interphase fluorescence in situ hybridization (FISH) for the main aneuploidies (trisomies 13, 18, 21 and gonosomal aneuploidies) was performed on the mesenchymal core of villi. Molecular cytogenetic results were always complemented by conventional cytogenetic results on long-term cultured villi (LTC-villi). Short-term cultured villi (STC-villi) preparations were retrospectively performed only when a chromosomal abnormality was observed with interphase FISH and/or LTC-villi. RESULTS: 88 chromosomal abnormalities (88/386=22.8% of first-trimester diagnoses) which could discuss subsequent abortions were observed after LTC-villi preparations. All cases possibly detectable by interphase FISH were detected. Thus, 85 aneuploidies (85/386=22.0% of first-trimester diagnoses; 85/88=96.6% of chromosomal abnormalities) were detected by interphase FISH, allowing early abortion by curettage before week 14 amenorrhea. No discrepancy occurred between interphase FISH and LTC-villi results for the aneuploidies studied. Three false-negative results (3/386=0.77% of first-trimester diagnoses; 3/88=3.41% of chromosomal abnormalities) were observed with STC-villi. CONCLUSION: We observed a high rate of false-negative results on cytotrophoblast cells. Conversely, interphase FISH of the main aneuploidies on the mesenchymal core provided rapid and reliable results, and therefore should be preferred to STC-villi in first-trimester prenatal diagnosis performed on pregnant women with fetal abnormalities on ultrasound.