There is mounting evidence that cyanobacterial lipopeptides can kill mammalian cells, presenting a hazard to human health. Unfortunately, their mechanism of toxicity is poorly understood. We have ...isolated new cyclic undeca-lipopeptides muscotoxin A and B containing unique lipophilic residue 3-amino-2,5-dihydroxydecanoic acid (5-OH Ahdoa). Muscotoxin B was not used for biological studies due to its poor yield. Muscotoxin A was cytotoxic to YAC-1, Sp/2, and HeLa cancer cell lines (LC50 ranged from 9.9 to 13.2 μM after 24 h of exposure), causing membrane damage and influx of calcium ions. Subsequently, we studied this lytic mechanism using synthetic liposomes with encapsulated fluorescent probes. Muscotoxin A permeabilized liposomes composed exclusively of phospholipids, demonstrating that no proteins or carbohydrates present in biomembranes are essential for its activity. Paradoxically, the permeabilization activity of muscotoxin A was mediated by a significant reduction in membrane surface fluidity (stiffening), the opposite of that caused by synthetic detergents and cytolytic lipopeptide puwainaphycin F. At 25 °C, muscotoxin A disrupted liposomes with and without cholesterol/sphingomyelin; however, at 37 °C, it was selective against liposomes with cholesterol/sphingomyelin. It appears that both membrane fluidity and organization can affect the lytic activity of muscotoxin A. Our findings strengthen the evidence that cyanobacterial lipopeptides specifically disrupt mammalian cell membranes and bring new insights into the mechanism of this effect.
Introduction: Collection of valid data in patients with hematologic malignancies remains a challenge. Especially low grade malignancies require long term follow-up and valid high quality data. The ...RMG registry was established in 2007 and has become one of the flagship projects of the Czech Myeloma group. To date, four parts of the registry are active - module for multiple myeloma (MM), monoclonal gammopathies of undetermined significance (MGUS), AL amyloidosis (ALA) and Waldeströms macroglobulinemia. The later two has been started in 2014.
Aim: To analyze current status of the registry in terms of amount of contained data.
Methods: All patients must sign a written consent before entering their data into the registry. Data concerning diagnosis, demography, treatment and survival are regularly collected and updated into the registry via online system at https://trials.cba.muni.cz/trialdb2/interface_forms/login_rmg.asp. The data from MGUS patients are retrospective and prospective, data from MM patients are only prospective (since 2007). Registry is regularly monitored and data are validated by an external monitor.
Results: There are 22 participating centers as of July 2015 (18 from the Czech Republic and 4 from Slovakia). Data from 4549 patients with MM, 2168 with MGUS, 121 patients with WM and 22 with ALA have been collected. Together 6860 patients have been included in the registry as of July 2015. Median follow-up of MGUS patients is 4 years (0-35 years) and median follow-up for MM patients is 2 years (0-32 years). The huge amount of data allowed publication of treatment results of MM patients treated with bortezomid and thalidomide in the Czech Republic and regular analysis of patients treated with lenalidomide. Novel prognostic models for MGUS progression and asymptomatic myeloma have been created based on registry data (manuscripts submitted).
Conclusion: The RMG is one of the largest registries in Europe. Its biggest advantage is collection of validated updated data which can be used to create rapid analyses in order to react to changing myeloma field. It helps us to create new guidelines and serves as a potent research tool. It can be also used to negotiate reimbursement with healthcare insurance companies and government regulatory authorities for novel drugs implementation into treatment standards.
Supported by The Ministry of Education, Youth and Sports (Specific university research of the Faculty of Medicine, University of Ostrava) project no. SGS01/LF/2014-2015, by the Moravian-Silesian Region - grant no. MSK 02692/2014/RRC, by the Institutional Development Plan of University of Ostrava in 2015, financial resources are allocated by The Ministry of Education, Youth and Sports. Supported by grant NT14575.
Hajek:Amgen: Honoraria; Celgene: Consultancy; Janssen: Consultancy.
Leachates from two Czech municipal solid waste (MSW) landfills (closed site and active site) were size-fractionated using the cascade frontal filtration/ultrafiltration procedure with filter cut-offs ...of 3
μm, 0.8
μm, 0.45
μm, 0.1
μm, 10
kDa and 1
kDa. To evaluate the binding of trace elements to colloidal particles, the filtrates were analyzed for major compounds (FAAS, ICP-OES and HPLC) and trace elements (ICP-MS) and the obtained elemental patterns were statistically evaluated. Transmission electron microscopy (TEM) indicated that the colloids were mostly inorganic, mainly composed of carbonates and clays. Characteristic features of the behaviour of trace elements and the main compounds were more pronounced at the active landfill site. Amongst the main compounds, only Fe and Ca decrease significantly and have similar patterns to numerous trace elements, indicating their capture by colloidal particles (at least 25%). Arsenic, Se and Rb exhibit zero or negligible decrease in concentration in the leachate during the filtration procedure. This fact indicates their particularly high mobility, which should be considered in preventing the flux of harmful compounds from landfill systems.
Introduction: Revised prognostic scoring system R-ISS (standard ISS plus cytogenetic changes) has been introduced as a possible tool for evaluation of patients with multiple myeloma. This system is ...based on pooled data from various clinical trials but has not been validated in patients´ population outside the clinical trial setting.
Aim: To evaluate clinical relevance of R-ISS in real life population of multiple myeloma patients.
Methods: Registry of monoclonal gammopathies (RMG) was established in 2007 and has become one of the flagship projects of the Czech Myeloma Group. The registry collects prospective data from patients with myeloma and other gammopathies (https://trials.cba.muni.cz/trialdb2/interface_forms/login_rmg.asp). Registry is regularly monitored and data are validated by an external monitor. Data from registry were retrieved to identify patients in whom all above mentioned parameters were available. These patients were then stratified according to R-ISS and TTP and OS were calculated as primary endpoints.
Results: 555 patients (260 females, 295 males, median age 66 years) with multiple myeloma who had full set of necessary data available were identified. Median follow-up of this cohort was 22.2 months. 97 17.5% (97/555) patients were R-ISS stage I, 55.7% 309/555 were R-ISS stage II and 26.8% (149/555) patients were R-ISS III. Median overall survival was not reached for stage I, 3.9 years for stage II and 2.5 years for stage III. The differences were statistically significant (p<0.001, log-rank test). Median time to progression was 3.3 years for stage I, 1.9 years for stage II and 1.3 years for stage III. The differences were statistically significant (p<0.001, log-rank test). Stage I versus II showed HR (95% CI): 2.84 (1.66-4.87), p<0.001 and stage I versus III HR (95% CI): 5.20 (2.99-9.03), p<0.001 for overall survival and HR (95% CI): 2.02 (1.37-2.96), p<0.001 and (95% CI): 2.49 (1.64-3.77), p< 0.001 for time to progression. Similar survival pattern can be seen in a subgroup of patients treated with autologous stem cell transplantation, without autologous stem cell transplantation and the system provides valuable information even in a subgroup of patients who were never treated with novel agents. Figure 1 shows overall survival and figure 2 time to progression of the cohort.
Conclusion: Revised ISS provides valuable information about the long term prognosis in a mixed cohort of real life multiple myeloma patients. This system enables to estimate the prognostic category of each specific patient in a horizon of several years ahead.
Supported by PRVOUK P37.
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Spicka:BMS: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding; Janssen Cilag: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees; Amgen: Consultancy, Honoraria; Millenium: Honoraria. Hájek:Janssen: Honoraria; Celgene: Consultancy, Research Funding; BMS: Honoraria; Amgen: Consultancy, Honoraria, Research Funding; Takeda: Consultancy.
Carbosilane metallodendrimers with variable length of carbon spacer between titanocene dichloride end units and the outermost silicon atoms were prepared. Computer models of metallodendrimers were ...simulated in THF solvent using molecular dynamics. The largest dendrimers were used to catalyze allylic coupling reactions of allylic bromides.
•Carbosilane metallodendrimers with titanocene dichloride endgroups were prepared.•Molecular dynamics simulations have shown that Ti centers are easily accessible.•Metallodendrimers catalyze after reduction by Mn allylic coupling reactions.•One of the first non-polymerization uses of titanium metallodendrimers is described.
Carbosilane metallodendrimers of the first generation Si{CH2CH2CH2SiMe2CH2CH2SiMe2(CH2)nC5H4TiCl2C5H5}4 and Si{CH2CH2CH2SiMeCH2CH2SiMe2(CH2)nC5H4TiCl2C5H52}4 (n=1, 5) and of the second generation Si{CH2CH2CH2SiMeCH2CH2CH2SiMe2CH2CH2SiMe2(CH2)nC5H4TiCl2C5H52}4 (n=1, 5) and Si{CH2CH2CH2SiMeCH2CH2CH2SiMe(CH2CH2SiMe2(CH2)nC5H4TiCl2C5H5)22}4 (n=5) were prepared, purified using GPC-NMR and GPC, and characterized by multinuclear NMR, IR and ESI-TOF mass spectrometry.
Computer atomistic models of the second generation metallodendrimers with the length of carbon spacer n=1, 3, and 5 carbon atoms were created, parametrized, and consequently simulated in THF solvent using molecular dynamics. The equilibrated dendrimer model structures were analyzed to provide inter alia density distribution of selected molecular components. It was shown that (i) average distance between the closest pairs of Ti atoms (around 11Å), (ii) permanent accessibility of Ti atoms from many sites even if they were in close contact with another Ti atom, and (iii) high dynamics of titanocene groups were favorable conditions to fully use all Ti atoms for the catalytic reaction in case of the longest five carbon spacer.
Dendrimers of the second generation with 8 and 16 end groups and the five carbon spacer were used in the catalytic system with manganese metal to catalyze allylic coupling reactions of cinnamyl and geranyl bromides with low catalyst loadings.
This study used data from the Czech Myeloma Group Registry of Monoclonal Gammopathies to validate the International Myeloma Working Group (IMWG) and revised International Staging System (R‐ISS) ...indices for risk stratification in patients with multiple myeloma (MM) in clinical practice. Patients were included if they had symptomatic MM, complete data allowing R‐ISS and IMWG staging (including cytogenetic information regarding t(4;14), t(14;16), and del(17p)), and key parameters for treatment evaluation. Median overall survival (OS) in included patients (n = 550) was 47.7 (95% CI: 39.5‐55.9) and 46.2 (95% CI: 38.9‐53.5) months from diagnosis and initiation of first‐line therapy, respectively. Patients categorized as higher vs lower risk had reduced survival; median OS from diagnosis was 35.4 (95% CI: 30.5‐40.3) vs 58.3 (95% CI: 53.8‐62.9) months in high‐risk vs other patients (IMWG; P = .001) and 34.1 (95% CI: 30.2‐38.0) vs 47.2 (95% CI: 43.4‐51.0) months in Stage III vs Stage II patients (R‐ISS; P < .001). In conclusion, IMWG and R‐ISS risk stratification indices are applicable to patients with MM in a real‐world setting.
We have successfully validated R‐ISS myeloma prognostic score on real‐life unselected population. The system can be broadly applicable outside clinical trials.
Background:Subcutaneous (SC) application of bortezomib has been recently introduced as a new application route in multiple myeloma (MM) patients. The results of an international randomized phase III ...trial confirmed that SC application of bortezomib is not inferior to intravenous (IV) route, with similar response rates and improved toxicity profile.
Our aim was to confirm the results on a larger cohort of patients treated with IV or SC bortezomib in 2-year period within the Czech Myeloma Group.
Patients and methods: We performed a retrospective analysis of 262 patients with MM treated with bortezomib based regimens during 2012-2013 in the Czech Republic. In total, there were 177 patients in the IV arm and 85 patients in the SC arm. Patients undergoing high-dosed chemotherapy followed by autologous stem cell transplantation (ASCT) were assessed separately (N = 99). There were 164 patients treated in the first line setting and 98 patients in relapse/progression of MM. The patients received up to eight 28-day cycles of bortezomib-based regimen with bortezomib dose 1.3mg/m2. The regimens used were following: CVD (cyclophosphamide, bortezomib, dexamethasone) in 58.2%/60.0%, VD (bortezomib, dexamethasone) in 10.7%/9.4%, BDD (bortezomib, doxorubicin, dexamethasone) in 9.6%/14.2%, VMP (bortezomib, melphalan, prednisone) in 6.0%/9.0%, bortezomib monotherapy in 1.1%/1.2%, BBD (bortezomib, bendamustine, dexamethasone) in 1.1%/2.4%, BP (bortezomib, prednisone) in 0%/1.6%, and other in 13.6%/2.4%. In order to reduce neurological toxicities, most of the patients received bortezomib once weekly. In both IV and SC arms we assessed the demographics and baseline characteristics, response rates and toxicities.
For statistical estimation we used Mann-Whitney U test and Chi-square test at p < 0.05.
Results:There were mild differences in the age and gender between IV and SC arms (median age 71.3 vs 67.9 years, p = 0.024; M/F ratio 1.4:1 vs 0.6:1, p = 0.007), other variables were without significant difference, including laboratory parameters (M-protein, hemoglobin, thrombocyte count, serum calcium level, albumin, creatinine, beta-2-microglobulin, lactate dehydrogenase, CRP), line of chemotherapy (first line, second line, third line and fourth and higher line) and therapeutic regimen used. Patients received median of 6 cycles in the IV group and 5 cycles in the SC group. The rates of response were similar in both, IV and SC arms with overall response rate (ORR) 71.7% vs 70.7%, complete remissions (CR) including stringent complete remissions (sCR) in 13.9% vs 8.6%, very good partial remissions (VGPR) in 30.8% vs 34.5% and partial remissions (PR) in 27% vs 27.6%. Toxicities were present in most patients (up to 99%), prevailing grade 1-2 toxicities, the most frequent grade ≥3 toxicities were anemia, thrombocytopenia and neutropenia, with no significant differences between IV and SC group. There were no significant differences in the rate of peripheral neuropathy (PN). PN of any grade was present in 48% patients in the IV arm and in 41% in the SC arm. PN grade ≥2 was present in 20% vs 18% and PN grade ≥3 was present in 6% vs 4% (p = 0.782).
Conclusions:Subcutaneous application of bortezomib has similar therapeutic outcomes and toxicity profile as intravenous route of application. In our cohort there was no difference in the incidence of PN, suggesting that PN is dose dependent and might be reduced by lower intensity schemes rather than by the route of administration.
Supported by the grants IGA MZ CR NT 14393, NT 12215-4/2011, NT 14400, NT12451-5, NT 12215-4, and the grant MSM0021622434.
No relevant conflicts of interest to declare.
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