Dose-Dependent Effect of Renin-Angiotensin System Blockade Following Transcatheter Aortic Valve Replacement

BackgroundThere is growing body of evidence from retrospective studies that renin-angiotensin system (RAS) blockade is associated with improved outcome after transcatheter aortic valve replacement (TAVR). However, it remains unknown whether the effect of RAS blockade is dose dependent. The current study sought to assess the dose-dependent effect of RAS blockade on survival and left-ventricular (LV) remodelling after TAVR.MethodsPatients who were enrolled into our observational TAVR study at our institution were retrospectively assessed according to different doses of RAS blockade: group 1 (no RAS blockade), group 2 (25% of maximum daily dose), group 3 (50% of maximum daily dose), and group 4 (full daily dose).ResultsA total of 323 patients between January 2015 and September 2019 were included. Patients with higher doses of RAS blockade showed a trend toward higher overall survival at 3-year follow-up (56% with no RAS blockade vs 66% with the 25% dose vs 79% with the 50% dose vs 78% with the full dose; P = 0.063). After adjustment for baseline characteristics, the difference in survival was significant (P = 0.042). Besides New York Heart Association class and left-ventricular ejection fraction (LVEF), RAS blockade dose was identified as independent predictor for all-cause mortality (hazard ratio [HR] 0.72; 95% confidence interval [CI], 0.54-0.97; P = 0.03). With respect to LV remodelling, a significantly larger reduction of LV mass index was observed during the follow-up with higher doses of RAS blockade.ConclusionsThe current study showed that the impact of RAS blockade treatment on clinical outcome and LV remodelling after TAVR is dose dependent.     

Does in vitro colony formation and chemosensitivity relate to DNA ploidy and S-phase fractions?

Summary In vitro colony formation and chemosensitivity were analyzed in 65 human solid tumors and compared to proliferation parameters simultaneously obtained by DNA flow cytometry of the same tumor specimens.Colony growth in the human tumor colony assay was enhanced in aneuploid tumors (39/65) in comparison to diploid tumors (26/65, P<0.05). In addition, there was a relationship between % S-phase and colony growth. The existence of polyploid sublines (23/65) improved in vitro growth even in tumors with a diploid main G_0/1-peak or with a low % S-phase. Metastases exhibited a higher proportion of aneuploidy and showed slightly better growth in vitro than primary tumors.Sensitivity testing in 34 of the 65 tumors showed no convincing relation between DNA parameters and the inhibition of colony formation by five standard anticancer agents with different mechanisms of action. This indicates additional factors other than the proliferative activity of the tumor to be responsible for drug sensitivity or resistance.     

Retroviral infection and selection of culture-derived platelets allows study of the effect of transgenes on platelet physiology ex vivo and on thrombus formation in vivo

Background- We recently reported the development of culture-derived (CD) platelets with the aim to express any protein of interest in these platelets. We now report a specific protocol of retroviral infection into the progenitor cells and subsequent selection, which allows to generate large amounts of highly homogenous transgene-expressing CD platelets and to study transgene function rapidly and reliably at large-scale ex vivo and in vivo settings. METHODS AND RESULTS: After retroviral infection and selection, the activation-dependent expression profile of surface markers, aggregation, and granule release were investigated. The function of transgene-expressing CD platelets, the precursor cells of which had been retrovirally infected, compared well to noninfected CD platelets or freshly isolated platelets. Hence, the retroviral infection protocol did not alter platelet physiology. In contrast, adenoviral infection of precursors to CD platelets resulted in marked functional alterations that obviated their use in analytic experiments. Additionally, sufficient amounts of selected CD platelets were generated to warrant intravenous injections into living mice. This approach permitted study of their adhesive profile at endothelial lesions and their effect on thrombus formation in vivo by intravital videofluorescence microscopy. CONCLUSIONS: The novel selection method allowed us to produce recombinant transgene-expressing platelets in sufficient amounts to study genetically modified platelets in vitro and in vivo.     

Evolución de pacientes tratados con armazones coronarios bioabsorbibles liberadores de everolimus tras su disolución completa

Introduction and objectivesLong-term outcomes of unselected patients treated with bioresorbable vascular scaffold (BVS) implantation are lacking, especially for the period after complete dissolution of the BVS. This study sought to evaluate 5-year outcomes in patients treated with BVS in routine practice.MethodsConsecutive patients who underwent implantation of everolimus-eluting BVS during routine clinical practice at 2 high-volume centres in Germany were studied. The patients were followed-up for up to 5 years. The primary endpoints of interest were the composite of death, myocardial infarction and target lesion revascularization, as well as definite scaffold thrombosis.ResultsA total of 419 patients (mean age 66.6 ± 10.9 years; 31.5% had diabetes) were included, of whom 38.9% presented with an acute coronary syndrome. Of the 527 lesions treated, 49.0% were classified as complex and 13.1% were bifurcation lesions. At 5 years, the composite clinical endpoint occurred in 33.1% of patients and definite scaffold thrombosis occurred in 4.7%. Most definite scaffold thrombosis occurred within 2 years after BVS implantation.ConclusionsIn patients treated with BVS implantation in routine clinical practice the rates of adverse clinical events at 5 years were high, including a considerable incidence of scaffold thrombosis.     

Clinical outcomes of patients treated with Nobori biolimus-eluting stent: Meta-analysis of randomized trials

Backgrounds

The Nobori is a new-generation, biodegradable-polymer coated, biolimus-eluting stent (BES) that has recently been investigated in several randomized trials with inconsistent results. The aim of this study was to assess the efficacy and safety of Nobori BES versus other drug-eluting stents (DES) in patients treated with percutaneous coronary intervention (PCI).

Methods

We undertook a meta-analysis of randomized trials investigating Nobori BES versus other DES. Primary efficacy and safety outcomes were target lesion revascularization (TLR) and definite/probable stent thrombosis (ST), respectively. Secondary outcomes were the composite of cardiac death/myocardial infarction (MI)/target vessel revascularization (TVR), MI and death.

Results

A total of 9114 PCI-patients randomly received Nobori BES (n = 5080) or other DES (n = 4034). This latter group comprised patients receiving everolimus- (n = 2533), sirolimus- (n = 1376) or paclitaxel-eluting stents (n = 125). Median follow-up was 11 months [interquartile range 9–12]. The Nobori BES versus other DES showed comparable risk of TLR (odds ratio [95% confidence interval] = 0.91 [0.57–1.46], p = 0.71). There was significant heterogeneity across trials due to significant lower TLR risk with Nobori BES versus paclitaxel-eluting stent (0.32 [0.10–0.98], p = 0.046; p for interaction = 0.009). Nobori BES versus other DES showed comparable risk of definite/probable ST (1.40 [0.66–2.97], p = 0.39), cardiac death/MI/TVR (1.05 [0.88–1.25], p = 0.59), MI (1.13 [0.87–1.48], p = 0.37) and death (1.09 [0.81–1.48], p = 0.56).

Conclusions

Nobori BES has comparable efficacy with other limus-eluting stents at 1-year follow-up. There is no difference in terms of safety profile between these stent platforms.     

Pharmacokinetics of intravenous, single-dose tiotropium in subjects with different degrees of renal impairment

Tiotropium, a new potent anticholinergic bronchodilator, is excreted mainly by the kidney. To investigate the pharmacokinetics of tiotropium in renal impairment, the authors evaluated the pharmacokinetics and safety after administration of a single dose of intravenous tiotropium 4.8 microg, given as an infusion over 15 minutes in subjects with normal renal function and a wide range of renal impairment based on measured creatinine clearance (normal: > 80 mL/min, n = 6; mild impairment: > 50-80 mL/min, n = 5; moderate impairment: 30-50 mL/min, n = 7; severe impairment: < 30 mL/min, n =6). As expected for a drug excreted predominantly in unchanged form by the kidneys, tiotropium plasma concentrations increased as renal impairment worsened, with mean values of 55.5 (16.2 percent geometric coefficient of variation [%gCV]), 77.1 (20.1 %gCV), 101 (29.8 %gCV), and 108 (27.3 %gCV) pgh/mL for AUC(0-4h) in the normal renal function and the mild, moderate, and severe renal impairment groups, respectively. The percentage of tiotropium dose excreted unchanged in the urine decreased from 60.1% of dose (17.7 %gCV) to 59.3% (14.4 %gCV), 39.9% (34.5 %gCV), and 37.4% (10.2 %gCV) in the normal renal function and the mild, moderate, and severe renal impairment groups, respectively. Plasma protein binding of tiotropium did not significantly change in the renal-impaired subjects. Two subjects with normal renal function experienced headache 10 hours after the infusion, which was mild and transient. No adverse events occurred in subjects with renal impairment. There were no clinically relevant changes in blood pressure, pulse rate, 12-lead ECG, physical examination, hematology, or clinical chemistry, compared with baseline values, in any subject after intravenous administration of tiotropium. Tiotropium should only be used in patients with moderate to severe renal insufficiency if the potential benefit outweighs the potential risks.     

Chromosomal alterations in osteosarcoma cell lines revealed by comparative genomic hybridization and multicolor karyotyping

We characterized the chromosomal alterations in eight osteosarcoma cell lines (OST, HOS, U-2 OS, ZK-58, MG-63, SJSA-1, Saos-2, and MNNG) by comparative genomic hybridization (CGH); gains and losses of DNA sequences were defined as chromosomal regions with a fluorescence ratio, wherein all of the 95% confidence interval was above 1.25 and below 0.75, respectively. In four of 8 cell lines, multicolor karyotyping (MK) was added. CGH revealed the average number of aberrations per cell line was 20.8 (range: 10–31); the average numbers of gains and losses were 11.1 and 9.6, respectively. The frequent gains were identified on 1p21q24, 1q25q31, 7p21, 7q31, 8q23q24, and 14q21; frequent losses were at 18q21q22, 18q12, 19p, and 3p12p14. High-level gains were observed on 8q23q24, 5p, and 1p21p22. MK revealed the most common translocations in the four cell lines were t(8;9), t(1;3), t(3;5), t(1;13), t(2;6), t(3;17), t(1;15), t(10;20), and t(6;20). Chromosomes 1, 3, 8, 9, and 20 were most frequently involved in translocation events. The concordance rate of aberrations in CGH and translocations in MK was 76%. MK was useful to identify the chromosomal alterations and as a supplement to the CGH results in three of four chromosomes.     

Selective and nonselective toxicity of TRAIL/Apo2L combined with chemotherapy in human bone tumour cells vs. normal human cells

Although TRAIL/Apo2L preferably induces apoptosis in tumour cells without toxicity in normal cells, many tumour cell types display TRAIL/Apo2L resistance. Whether TRAIL/Apo2L in combination with chemotherapy may overcome TRAIL/Apo2L resistance while maintaining tumour selectivity remains to be determined. Here, we report that while ActD, DOX and CDDP sensitised both OS and Ewing's tumour cell lines and normal cells (hOBs, synovial cells, fibroblasts) to TRAIL/Apo2L-induced apoptosis, the combination of etoposide (VP16) and TRAIL/Apo2L was selectively active on tumour cells without affecting normal cells. Sensitisation of OS cells and hOBs to TRAIL/Apo2L did not correlate with a compatible change in the gene expression profile of the receptors for TRAIL/Apo2L determined by quantitative real-time RT-PCR. Also, sensitisation of the TRAIL/Apo2L death pathway did not rely entirely on the chemotherapy-induced, caspase-dependent cytotoxicity. Further, chemotherapy did not cause a compatible change in expression levels of proteins such as Bcl-2, Bcl-x(L), Bax, cIAP2, XIAP and survivin. However, ActD, DOX and CDDP downregulated expression of cFLIP in OS cells as well as expression of p21 in normal hOBs. Interestingly, while VP16 also extinguished cFLIP in OS cells, which were sensitised for TRAIL/Apo2L by VP16, VP16 induced cFLIP and enhanced p21 levels in normal hOBs, which remained refractory to VP16 plus TRAIL/Apo2L. Together, our data reveal that TRAIL/Apo2L combined with certain chemotherapeutic drugs is toxic to bone tumour and normal human cells and suggest that cotreatment with TRAIL/Apo2L and VP16 provides an attractive approach for selective killing of tumour cells while leaving unaffected normal cells.