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This article describes two types of flow-through cell retention devices based on the concept of layered piezoelectric resonators. A single-chamber device is compared to a novel optimized steam-sterilizable prototype ultrasonic cell separator with improved acoustic design and an integrated cooling circuit, eliminating the problem of local temperature increase caused by the high amplitudes necessary to achieve the separation of animal cells with low acoustic contrast. This setup yields highly reproducible results and is ideal for studying the long-term effects of ultrasonic sound fields and separation efficiency. The novel two-chamber system has the potential for scaleability due to the reduction in thermal and acoustic flow, increased field stability, and separation efficiency. Finally, the effect of power input on separation and cell viability is reported. Such flow-through cell retention systems could be used as systems to retain biomass within the fermentor or as a substitute for centrifugation, with the major advantage of eliminating high-speed rotational motion.

Pyrrolidine dithiocarbamate (PDTC) was examined for its potential in the intranasal treatment of human rhinovirus infections. Prior to clinical testing, a comprehensive non-clinical programme was performed to evaluate the general toxicity of PDTC. The animal experiments included investigations in rodents with study durations ranging from single dose to repeated dosing over a period of 28 days. The routes of administration were intranasal, inhalative, oral and intravenous for single-dose toxicity and pharmacokinetic studies, and intranasal for repeated dose studies. Blood and tissue samples were obtained from PDTC-treated rats to analyse pharmacokinetics and tissue distribution. Accumulation of selected metals due to PDTC treatment was examined in liver, brain, nerves and fat tissues.Pyrrolidine dithiocarbamate (PDTC) applied intranasally (up to 121 mg ⁄ kg) or via single inhalation (1.64% PDTC applied for 4 hr) or repeated intranasal dosing up to 28 days (up to 102 mg ⁄ kg ⁄ day) did not result in major systemic toxicities or local intolerance. Pharmacokinetic evaluations indicate a very rapid absorption of PDTC after intranasal application. A high single intravenous or oral dose of PDTC induced neurotoxicity. The neurotoxic effects are in accordance with the toxicity profile described for dithiocarbamates (DTCs) with effects on the autonomous and nervous system. The intravenous LD 50 was defined at 282 mg ⁄ kg in mice and at 306 mg ⁄ kg in rats. The oral LD 50 was calculated at above 1500 mg ⁄ kg for mice and rats. The results from in vitro and in vivo genotoxicity studies do not elucidate a genotoxic potential for PDTC.Concluding from the toxicology data set, PDTC qualifies as a valuable drug candidate for intranasal or inhalative administration.Pyrrolidine dithiocarbamate, a very effective NF-jB inhibitor [1], known to inhibit inflammatory processes [2], is suggested as a key factor in the treatment of human rhinovirus (HRV) infections. Unpublished in vitro data strongly support this hypothesis. Thus, the aim of this project was to describe the toxicity profile of PDTC allowing for clinical use of the potential HRV drug candidate. Pyrrolidine dithiocarbamate is a compound of the class of DTCs. Dithiocarbamates and their disulphides have been used in medicine, industry and agriculture for more than 20 years. The compounds class reported biological effects include ability to influence oxidative stress, apoptosis, enzyme inhibition or modulation of transcription as well as inhibition of inflammatory processes via NF-jB inhibition [1,[3][4][5][6][7][8].Two DTCs, diethyldithiocarbamate and its disulphide disulphiram (Antabuse) are marketed drugs: Diethyldithiocarbamate is used in the treatment of nickel intoxication, Antabuse is marketed for alcohol aversion therapy. The potential clinical use of closely related compounds is currently being explored for various indications including the treatment of ocular inflammations [9,10], infection caused by rhinovirus [11] and coxsackievirus [12], methicillin-resi...

Based on the method of direct cloning into the baculovirus genome by linearizing and re-ligation in presence of the target insert, we designed viral constructs that express foreign genes on the surface of baculovirus particles. We chose the glycosylated envelope protein gp41 of human immunodeficiency virus type 1 (HIV-1) as a model for displaying recombinant proteins on budded virus. The ectodomain of the envelope protein gp41 of HIV-1 was being fused to the entire baculovirus major coat protein gp64 (Ac-cops41) and to the membrane anchor sequence of gp64 (Acmars41). Two different promoters, the "very late" polyhedrin promoter (Ac-mars41) and the "early and late" gp64 promoter (Ac-promars41) were compared. The expression of gp41 in infected cells and its presence on viral particles was confirmed by enzyme-linked immunosorbent assay (ELISA), Western blot and electron microscopy.

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