Advances in hollow fiber membrane technology for high density perfusion cell culture

Continuous manufacturing, a trend for the production of biopharmaceuticals, holds significant promise for achieving higher productivity and lower cost. Next generation cell culture perfusion processes are among the most sought after to deliver on this promise. While the concept of continuous cell culture is not new, hurdles in the robustness and consistency of cell retention devices slow current adoption. The inherent lot-to-lot variability in commercially available hollow-fiber membrane (HFMs) often requires operators to adjust process parameters during the course of the perfusion process. Reproducible process intensification using HFM devices for cell retention requires membranes with consistent flux (LMH), bubble point (BP), and effective filtration area (EFA) optimized for each cell culture process. The selection of suitable membranes must depend on our knowledge of flux and BP, rather than on arbitrary membrane porosity designations. We found that the lot-to-lot distribution range of flux/BP in HFM devices is essential and must be within narrow limits to ensure consistent process performance. We present data on a novel well-characterized HFM device, SepraPor™, which is ideally suited to achieve reproducible results with constant process parameters

Nestorone® as a Novel Progestin for Nonoral Contraception:Structure-Activity Relationships and Brain Metabolism Studies

Nestorone® (NES) is a highly potent non-androgenic progestin being developed for contraception. NES is a synthetic progestin that may possess neuroprotective and myelin regenerative potential as an added health benefits. In receptor transactivation experiments, NES displayed greater potency than progesterone to transactivate the human progesterone receptor (hPR). This was confirmed by docking experiments which revealed that NES adopts the same docking position within the PR ligand-binding domain (LBD) as progesterone and forms additional stabilizing contacts between 17α-acetoxy and 16-methylene groups and PR LBD supporting its higher potency than progesterone. The analogue 13-ethyl NES also establishes similar contacts as NES with Met909, leading to comparable potency as NES. In contrast, NES is not stabilized within the human androgen receptor (hAR)-LBD leading to negligible AR transactivation. Since progesterone acts in the brain by both PR-binding and indirectly via the metabolite allopregnanolone binding to GABA_A receptor (GABA_A_R), we investigated if NES is metabolized to 3α, 5α-tetrahydronestorone (3α, 5α-THNES) in the brain and if this metabolite could interact with GABA_A_R. In female mice, low concentrations of reduced NES metabolites were identified by Gas Chromatography-Mass Spectrometry in both plasma and brain. However, electrophysiological studies showed that 3α, 5α-THNES exhibited only limited activity to enhance GABAAR-evoked responses with WSS-1 cells and did not modulate synaptic GABA_A_Rs of mouse cortical neurons. Thus the inability of reduced metabolite of NES (3α, 5α-THNES) to activate GABA_A_R suggests that the neuroprotective and myelin regenerative effects of NES are mediated via PR binding and not via its interaction with the GABA_A_R

Molecular analysis of the vaginal response to estrogens in the ovariectomized rat and postmenopausal woman

<p>Abstract</p> <p>Background</p> <p>Vaginal atrophy (VA) is the thinning of the vaginal epithelial lining, typically the result of lowered estrogen levels during menopause. Some of the consequences of VA include increased susceptibility to bacterial infection, pain during sexual intercourse, and vaginal burning or itching. Although estrogen treatment is highly effective, alternative therapies are also desired for women who are not candidates for post-menopausal hormone therapy (HT). The ovariectomized (OVX) rat is widely accepted as an appropriate animal model for many estrogen-dependent responses in humans; however, since reproductive biology can vary significantly between mammalian systems, this study examined how well the OVX rat recapitulates human biology.</p> <p>Methods</p> <p>We analyzed 19 vaginal biopsies from human subjects pre and post 3-month 17β-estradiol treated by expression profiling. Data were compared to transcriptional profiling generated from vaginal samples obtained from ovariectomized rats treated with 17β-estradiol for 6 hrs, 3 days or 5 days. The level of differential expression between pre- vs. post- estrogen treatment was calculated for each of the human and OVX rat datasets. Probe sets corresponding to orthologous rat and human genes were mapped to each other using NCBI Homologene.</p> <p>Results</p> <p>A positive correlation was observed between the rat and human responses to estrogen. Genes belonging to several biological pathways and GO categories were similarly differentially expressed in rat and human. A large number of the coordinately regulated biological processes are already known to be involved in human VA, such as inflammation, epithelial development, and EGF pathway activation.</p> <p>Conclusion</p> <p>At the transcriptional level, there is evidence of significant overlap of the effects of estrogen treatment between the OVX rat and human VA samples.</p

It\u27s Time to Blow the Whistle on Performance Enhancing Drugs

Performance enhancing drug (“PED”) use is nothing new to the four major sports leagues in the United States. Nonetheless, these sports leagues struggle to manage PED use because it is a topic that must be negotiated and finalized in a collective bargaining agreement (“CBA”), by the players and the league. Players have consistently resisted the inclusion of stringent drug testing in CBAs for fear of the stigma attached to a positive drug test and the potential impact it could have on a player’s career. The time has come, however, to “clean up” PED use within the leagues once and for all. This Article proposes that the best way to diminish PED use within the major sports leagues is to address the issue directly from the inside—leagues should implement whistleblower policies through their respective CBAs. By providing insiders protection to “blow the whistle,” players can report PED use without the fear of being labeled a “rat” or being shunned by teammates. At the same time, a whistleblower policy allows the leagues to effectively “clean up” themselves. With a comprehensive whistleblower policy that this Article suggests, players would likely be inclined to break their silence regarding PED use and anonymously help regulate an issue that has plagued American sports leagues for decades