The chemical composition, in vitro genotoxicity, and cytotoxicity of the mainstream aerosol from the Tobacco Heating System 2.2 (THS2.2) were compared with those of the mainstream smoke from the 3R4F reference cigarette. In contrast to the 3R4F, the tobacco plug in the THS2.2 is not burnt. The low operating temperature of THS2.2 caused distinct shifts in the aerosol composition compared with 3R4F. This resulted in a reduction of more than 90% for the majority of the analyzed harmful and potentially harmful constituents (HPHCs), while the mass median aerodynamic diameter of the aerosol remained similar. A reduction of about 90% was also observed when comparing the cytotoxicity determined by the neutral red uptake assay and the mutagenic potency in the mouse lymphoma assay. The THS2.2 aerosol was not mutagenic in the Ames assay. The chemical composition of the THS2.2 aerosol was also evaluated under extreme climatic and puffing conditions. When generating the THS2.2 aerosol under "desert" or "tropical" conditions, the generation of HPHCs was not significantly modified. When using puffing regimens that were more intense than the standard Health Canada Intense (HCI) machine-smoking conditions, the HPHC yields remained lower than when smoking the 3R4F reference cigarette with the HCI regimen.

Amatoxins are the main poison of the green death cap (Amanita phalloides) and among the most dangerous natural toxins causing hepatic failure. A possible therapeutic approach is the inhibition of the transporting systems mediating the uptake of amatoxins into human hepatocytes, which, however, have yet to be identified. In the current study we tested whether members of the organic anion-transporting polypeptide (OATP) family, localized in the sinusoidal membranes of human hepatocytes, are involved in amatoxin uptake. For this, Madin Darby canine kidney strain II (MDCKII) cells stably expressing human OATP1B3, OATP2B1, or OATP1B1, were assayed for the uptake of 3H-labeled O-methyl-dehydroxymethyl-alpha-amanitin. Under our conditions, only OATP1B3 was able to transport amanitin with a K(m) value of 3.7 microM +/- 0.6 microM. Accordingly, toxin uptake was inhibited by OATP1B3 substrates and inhibitors (cyclosporin A, rifampicin, the quinoline derivatives MK571 ([(3-(3-(2-(7-chloro-2-quinolinyl)ethenyl)phenyl)((3-dimethylamino-3-oxopropyl)thio)methyl)thiopropanoic acid]) and montelukast, the cholecystokinin octapeptide (CCK-8), paclitaxel, and bromosulfophthalein), as well as by some antidotes used in the past for the treatment of human amatoxin poisoning (silibinin dihemisuccinate, penicillin G, prednisolone phosphate, and antamanide). These transport studies are in line with viability assays monitoring the toxic effect of amanitin on the transfected MDCKII cells. Further support for amatoxin transport was found in primary human hepatocytes, expressing OATP1B3, OATP2B1, and OATP1B1, where CCK-8, a substrate specific for OATP1B3, prevented the fragmentation of nucleoli, a lesion typical for amanitin action. In conclusion, we have identified OATP1B3 as the human hepatic uptake transporter for amatoxins; moreover, substrates and inhibitors of OATP1B3, among others rifampicin, may be useful for the treatment of human amatoxin poisoning.

Telaprevir (TVR) was approved by the FDA in May 2011 for the treatment of hepatitis C. This protease inhibitor converts into two diastereomers with significant difference in antiviral activity. Clinical efficacy has been correlated with serum concentrations. Therefore, a sensitive and selective high-performance liquid chromatographic method for the simultaneous determination of both clinically relevant diastereomers of TVR was developed. Linearity ranged from 20 to 10,000 ng/mL. The coefficients of variation were <7.3%, and accuracy was between −4.0 and 5.4%. In 105 clinical samples, both diastereomers of TVR had a high degree of correlation to each other, but concentrations showed a broad range and an increase during therapy.

WNT1mutations in humans are associated with a new form of osteogenesis imperfecta and with early-onset osteoporosis, suggesting a key role of WNT1 in bone mass regulation. However, the general mode of action and the therapeutic potential of Wnt1 in clinically relevant situations such as aging remain to be established. Here, we report the high prevalence of heterozygousWNT1mutations in patients with early-onset osteoporosis. We show that inactivation of Wnt1 in osteoblasts causes severe osteoporosis and spontaneous bone fractures in mice. In contrast, conditional Wnt1 expression in osteoblasts promoted rapid bone mass increase in developing young, adult, and aged mice by rapidly increasing osteoblast numbers and function. Contrary to current mechanistic models, loss of Lrp5, the co-receptor thought to transmit extracellular WNT signals during bone mass regulation, did not reduce the bone-anabolic effect of Wnt1, providing direct evidence that Wnt1 function does not require the LRP5 co-receptor. The identification of Wnt1 as a regulator of bone formation and remodeling provides the basis for development of Wnt1-targeting drugs for the treatment of osteoporosis.