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We investigated the effects of different lipids on the activity of the angiotensin II type 1 receptor (AT1R). As calcium plays a key role in the signaling of the AT1R, we used the calcium-sensitive fluorescence indicators fura-2 to detect intracellular calcium release upon stimulation with the agonist angiotensin II. At first sight, cells preincubated with Very low-density lipoprotein (VLDL) showed a reduced calcium release triggered by angiontensin II compared to untreated control. However, on closer examination, this result seemed to be an artifact. Incubation with VLDL reduced also the amount of intracellular fura-2, as measured by fluorescence in the isosbestic point. Additionally, the maximal obtainable ratio, obtained after complete saturation with calcium ions, was reduced in cells preincubated with VLDL. These findings rendered our initial results questionable. We report the results of our work and our suggestions regarding the experimental setup to contribute to the understanding of the interpretation of fura-2 measurements and to avoid erroneous conclusions.

Based on an early suggestion by Winkler et al. 2003 and a subsequent successful study by Wang et al. 2006 using lipid apheresis (LA) in 9 patients with preeclampsia to prolong pregnancies, the use of apheresis as therapeutic option in severe early onset preeclampsia has received increasing attention. Further studies using different LA systems also prolonged pregnancy and have been published in the last few years. Albeit using different LA systems and relying on different working hypothesis, all studies demonstrated a promising stabilisation against the disease's progression. Overall time from hospitalisation to the need for mandatory delivery was longer for those patients receiving apheresis compared to historical or matched control patients not receiving apheresis. These data will be reviewed and different hypotheses about the beneficial mechanism of action of apheresis will be discussed. Since up to now there is no curative treatment for preeclampsia other than observation and delivery, future work shall be encouraged.

Background Nanoscale drug delivery systems accumulate in solid tumors preferentially by the enhanced permeation and retention effect (EPR-effect). Nevertheless, only a miniscule fraction of a given dosage reaches the tumor, while >90% of the given drug ends up in otherwise healthy tissues, leading to the severe toxic reactions observed during chemotherapy. Once accumulation in the tumor has reached its maximum, extracorporeal elimination of circulating nanoparticles by plasmapheresis can diminish toxicities. Objective In this study, we investigated the effect of dosing and plasmapheresis timing on adverse events and antitumor efficacy in a syngeneic rat tumor model. Methods MAT-B-III cells transfected with a luciferase reporter plasmid were inoculated into female Fisher rats, and pegylated liposomal doxorubicin (PLD) was used for treatment. Plasmapheresis was performed in a discontinuous manner via centrifugation and subsequent filtration of isolated plasma. Results Bioluminescence measurements of tumor growth could not substitute caliper measurements of tumor size. In the control group, raising the dosage above 9 mg PLD/kg body weight did not increase therapeutic efficacy in our fully immunocompetent animal model. Plasmapheresis was best done 36 h after injecting PLD, leading to similar antitumor efficacy with significantly less toxicity. Plasmapheresis 24 h after injection interfered with therapeutic efficacy, while plasmapheresis after 48 h led to fewer side effects but also to increased weight loss. Conclusion Long-circulating nanoparticles offer the unique possibility to eliminate the excess of circulating particles after successful accumulation in tumors by EPR, thereby reducing toxicities and likely toxicity-related therapeutic limitations.

Objective Soluble Fms-like tyrosine kinase-1 (sFlt-1) is thought to be causative in the pathogenesis of preeclampsia (PE) and specific removal of sFlt-1 via dextran sulfate cellulose (DSC)-apheresis was suggested as a cure to allow for prolongation of pregnancy in preterm PE. However, in addition a deranged lipoprotein metabolism may impact endothelial and placental function in PE. Lipoprotein-apheresis by heparin-mediated extracorporeal LDL-precipitation (H.E.L.P.) was previously applied and has been shown to alleviate symptoms in PE. This clinical trial reevaluates the clinical efficacy of H.E.L.P.-apheresis in PE considering sFlt-1. Methods Open pilot study assessing the prolongation by H.E.L.P.-apheresis in 6 women (30–41 years) with very preterm PE (24 + 4 to 27 + 0 gestational weeks (GW)) (NCT01967355) compared to a historic control-group matched for GW at admission. Clinical outcome of mothers and babies, and pre- and post H.E.L.P.-apheresis levels of sFlt-1and PlGF were monitored. Results In apheresis patients (2–6 treatments), average time from admission to birth was 15.0 days (6.3 days in controls; p = 0.027). Lung maturation was induced in all treated cases, and all children were released in healthy condition. Apheresis reduced triglycerides and LDL-cholesterol by more than 40%. Although H.E.L.P.-apheresis induced a transient peak, baseline levels did not change and rather stabilized sFlt-1 levels at pre-apheresis levels Discussion Lipoprotein-apheresis proved again to be safe and prolongs pregnancies in PE. However, without changing sFlt-1 levels below baseline lowering lipids or other yet undefined factors appear to be of more relevance than reducing sFlt-1.

Introduction Preeclampsia is a potentially life threatening disease occurring in pregnancy. The only causative cure consists in delivery with all the risks for a premature fetus. In preeclampsia, the lipid metabolism is substantially altered and lipid apheresis is being explored as a possible therapeutic approach to prolong preeclamptic pregnancies and allow further maturation of the fetus. In the Freiburg H.E.L.P.-Apheresis Study, 6 early onset preeclamptic patients were treated with H.E.L.P. apheresis. Objective/hypothesis Detailed analysis of apheresis-induced dynamics in serum lipid parameters. Methods 6 early onset preeclamptic patients underwent repeated apheresis treatments (n = 23). We evaluated parameters of the lipoprotein metabolism in 6 preeclamptic patients in detail. Results Reduction of lipoproteins by apheresis was lower than theoretically expected. Lipids reached previous pre-apheresis levels before the next apheresis even though apheresis was repeated within 2.9 ± 1.2 days. Fractional catabolic rates and synthetic rates were found to be substantially elevated, with fractional catabolic rates for ApoB/ LDL-cholesterol being 0.7 ± 0.3/ 0.4 ± 0.2 [day−1] and synthetic rates being 26 ± 8/ 17 ± 8 [mg*kg−1*day−1]. The distribution of LDL-subclasses after apheresis shifted to larger buoyant LDL, while IDL levels remained unaffected. Discussion Apheresis induced changes in lipoprotein profiles point to an underlying remnant removal disease like imbalance in plasma lipid conversion during preeclamptic conditions.

Objectives Preeclampsia (PE) and IUGR share common pathomechanisms. Recently, we reported on serum lipid concentrations in both conditions in the early-onset form of PE before 34 weeks of gestation (Pecks et al., 2012). Subtle changes of triglyceride concentrations were noticed in PE while a significant decrease in LDL levels was found in IUGR subjects when compared to a control group (CTRL). We now aimed to extend our lipid analysis within our cohort to gain a deeper understanding of lipid metabolism and its role in the pathogenesis of both diseases. Methods Serum of (i) PE, (ii) PE with IUGR, and (iii) normotensive IUGR each n = 10 was matched to a CTRL group (iv, n = 30). HDL, IDL, LDL, VLDL were isolated by sequential preparative ultracentrifugation. Esterified and non-esterified cholesterol, phospholipid, and triglyceride concentrations were determined in each fraction. Statistical analysis was done using 2-way ANOVA. Results No significant difference between the case groups and CTRL could be observed in the HDL fraction. In the IDL fraction triglyceride levels were higher in PE as compared to CTRL. Within the LDL fraction esterified and non-esterified cholesterol and phospholipid levels were lower in IUGR and IUGR + PE. Within the VLDL fraction triglycerides were higher in all three case groups as compared to CTRL (table). Conclusions Our results suggest a disturbed conversion of VLDL to LDL is involved in both IUGR and preeclampsia. Triglyceride metabolism appears to be most affected in preeclampsia whereas cholesterol metabolism is disturbed in IUGR irrespectively of additional preeclampsia. One has to carefully separate all three entities to avoid misinterpretation. Disclosures U. Pecks: None. B. Winkler: None. T. Goecke: None. N. Maass: None. C. Contini: None. K. Winkler: None.