AB1450 CHARACTERISTICS, OUTCOME AND FACTORS ASSOCIATED WITH EVOLUTION TO MULTIPLE MYELOMA AND SURVIVAL IN PATIENTS WITH SOLITARY BONE PLASMACYTOMA

Background

Solitary bone plasmacytoma (SPB) is a rare malignancy whose main risk is progression to multiple myeloma (MM).

Objectives

To describe the characteristics and outcome of patients treated for SBP and to identify factors associated with progression to MM and death.

Methods

This retrospective study was conducted between 1992 and 2020. Patients were included if they met the International Myeloma Working Group (IMWG) criteria for the diagnosis of SBP (1). Treatment response was assessed according to the IMWG criteria (2) for patients with detectable monoclonal protein and according to radiological response only for non-secretory SBP. Hazard ratios (HR) and their 95% confidence intervals (CI) were estimated by Cox proportional hazards models, adjusted for potential confounders. When available, 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) were reviewed by two experienced nuclear physicians.

Results

A total of 77 patients diagnosed with SBP were included. The median age was 59 years [range: 27-89]. Median follow-up duration was 87.1 months [range: 1.6-306.8]. At the end of the follow-up, 45 (58.4%) patients had developed a MM and 13 (16.9%) deaths occurred, including 10 patients with progression to MM. Five-year myeloma-free survival and overall survival were 47.9% and 86.8% respectively. All patients received radiotherapy with a median dose of 45 Grays [range: 30-55]. Chemotherapy was prescribed in 32 (41.6%) patients, concomitant to radiotherapy in 8, because of high risk of local extension, or adjuvant in 24 because of persistent disease after radiotherapy. Chemotherapy included mainly immunomodulatory drugs (28/32 (87.5%)) and/or proteasome inhibitors (11/32 (34.4%)) based combinations. Adjuvant chemotherapy after radiotherapy was associated with a reduced risk of MM compared to patients treated by radiotherapy alone, in a multivariate model adjusted for potential confounding factors, including response after radiotherapy alone (adjuvant chemotherapy versus no chemotherapy, HR 0.30, 95%CI [0.14-0.64]). Response to the first line of treatment (radiotherapy +/- chemotherapy) was the main factor associated with progression to MM (complete response versus partial response or progressive disease, HR 0.25, 95%CI [0.11-0.59]) and death (HR 0.22, 95%CI [0.05-0.99]). A non-significant trend between bone marrow plasmacytosis ≥ 5% at diagnosis and higher risk of MM was observed (≥ 5% versus <5%, HR 2.40, 95%CI [1.00-5.74]). 18F-FDG PET/CT images were available for review in only 36/77 patients. A significant decrease of 18F-FDG uptake after treatment was observed whereas the lesion size was unchanged. No association was observed with the risk of MM but the limited available images may have resulted in underpowered analyses.

Conclusion

In this large study of patients with SBP, we observed that even though mostly prescribed for insufficient response to radiotherapy alone, treatment with adjuvant chemotherapy was associated with a decreased risk of evolution to MM, suggesting that this treatment might be systematically prescribed in addition to radiotherapy alone. These observations need to be confirmed and justify conduction of a prospective trial evaluating adjuvant chemotherapy in patients with SBP.

References

[1]Rajkumar SV, Dimopoulos MA, Palumbo A, Blade J, Merlini G, Mateos M-V, et al. International Myeloma Working Group updated criteria for the diagnosis of multiple myeloma. Lancet Oncol. nov 2014;15(12):e538-548.

[2]Kumar S, Paiva B, Anderson KC, Durie B, Landgren O, Moreau P, et al. International Myeloma Working Group consensus criteria for response and minimal residual disease assessment in multiple myeloma. Lancet Oncol. août 2016;17(8):e328‑46.

Acknowledgements

The authors are indebted to all participants for their continued participation.

Disclosure of Interests

None declared

AB1017 ANTI RANK LIGAND IN ACUTE CHARCOT NEURO-OSTEOATHROPATHY OF THE FOOT: A PROMISING TREATMENT

Background:

Acute Charcot neuroarthropathy (CN) of the foot is a rare and severe complication of peripheral neuropathy leading to joint destruction. Usual treatment rely on standard pressure offloading and no pharmacological treatment is available. Inflammation and increased osteoclastic activity via receptor activator of nuclear factor (RANK) ligand are major features of acute CN.

Objectives:

To assess clinical, metabolic and radiographic effect of denosumab, a fully human monoclonal antibody against RANK ligand, in acute CN.

Methods:

In this open study, we included all consecutive patients with acute CN treated with denosumab 60 mg in our mixed rheumatology/diabetes clinic dedicated to diabetic foot. Diagnosis of acute CN was based on clinical presentation and supported by biology, radiography, magnetic resonance imaging (MRI). Baseline and follow-up assessment included clinical examination and emission tomography–computed tomography (PET-CT).

Results:

Seven patients with acute CN were treated with denosumab between 2017 and 2019 (age from 43 to 70 years). Five were diabetic. All patients received denosumab, because of failure of standard pressure offloading, with evolving joint destruction of midfoot. CN evolves since a median of 6 months (2 to 20) at denosumab initiation. All patients clinically improved after denosumab injection (table). After a mean follow-up of 16 months, only 1/7 patients had a new flare. In the 4 patients with available follow-up X-ray, structural damage remained stable. In all 3 patients with available PET-CT evolution, the maximum standardized uptake lean value (SUL max) decreased.

Table 1.

Baseline characteristics and follow up treatment

Three patients were retreated, with a mean interval of 6 months: One patients because of persistent clinical and biological inflammation (CRP 17 mg/L), one because of relapse due to intensive walking, and one due to an associated osteoporosis.

No adverse event and hypocalcemia was observed.

Conclusion:

One to three injection of denosumab 60 mg was efficient in preventing flare and further bone destruction in a 16 months medium follow up. These results justify the conduction of a randomized control study to assess the efficacy of denosumab as the first-line pharmacological therapy in acute CN.

References:

[1]Molines L and al. Charcot’s foot: Newest findings on its pathophysiology, diagnosis and treatment. Diabetes Metab. Sept 2010;36(4):251-5.

[2]Mabilleau G, and al. Increased osteoclastic activity in acute Charcot’s osteoarthropathy: the role of receptor activator of nuclear factor-kappaB ligand. Diabetologia. juin 2008;51(6):1035-40.

Disclosure of Interests:

None declared

Disclosure of Interests:

Sandrine Carvès: None declared, Julien Henry: None declared, Murielle BOURGEON GHITTORI: None declared, Rakiba Belkhir: None declared, Gaetane Nocturne: None declared, Florent Besson: None declared, Guillaume Cluzel: None declared, Maud Creze: None declared, Raphaèle Seror Consultant of: BMS UCB Pfizer Roche, Xavier Mariette Consultant of: BMS, Gilead, Medimmune, Novartis, Pfizer, Servier, UCB

The VIADUC project: innovation in climate adaptation through service design

Abstract. From the French National Adaptation to Climate Change Plan, the "Drias, les futurs du climat" service has been developed to provide easy access to French regional climate projections. This is a major step for the implementation of French Climate Services. The usefulness of this service for the end-users and decision makers involved with adaptation planning at a local scale is investigated. As such, the VIADUC project is: to evaluate and enhance Drias, as well as to imagine future development in support of adaptation. Climate scientists work together with end-users and a service designer. The designer's role is to propose an innovative approach based on the interaction between scientists and citizens. The chosen end-users are three Natural Regional Parks located in the South West of France. The latter parks are administrative entities which gather municipalities having a common natural and cultural heritage. They are also rural areas in which specific economic activities take place, and therefore are concerned and involved in both protecting their environment and setting-up sustainable economic development. The first year of the project has been dedicated to investigation including the questioning of relevant representatives. Three key local economic sectors have been selected: i.e. forestry, pastoral farming and building activities. Working groups were composed of technicians, administrative and maintenance staff, policy makers and climate researchers. The sectors' needs for climate information have been assessed. The lessons learned led to actions which are presented hereinafter.

Diurnal temperature cycle deduced from extreme daily temperatures and impact over a surface reanalysis system

Abstract. Due to the evolution of the observation network, hourly 2 m temperature analysis performed by reanalysis systems shows temporal inhomogeneities. The observation network gap is less present for extreme daily temperature observations. In order to reduce inhomogeneities and enable a climatological use of temperature analysis, information from extreme temperatures could be useful. In this study, the diurnal temperature cycle has been reconstructed for stations which only record extreme temperatures. These new "pseudo" hourly temperature observations are then provided to the analysis system. Two methods have been used to deduce hourly temperatures from extremes and compared to real observations. The results have shown that using those new pseudo-observations as an input for two different reanalysis systems enables reducing the bias in temperature analysis.

Second harmonic generation from tryptophan-rich short peptides: W(n)K(m) and gramicidin A

We report the first hyperpolarizability of a series of tryptophan-rich short peptides with the respective sequence KWK, KWWK, KWWWK, KWWKWWK, where W and K stand for tryptophan and lysine. The measurements were performed with the technique of hyper-Rayleigh scattering in the bulk of an aqueous Tris buffer solution at a pH of 8.5 and a salt concentration of 150 mM at the non-resonant fundamental wavelength of 784 nm. The first hyperpolarizability of the different peptides follows a simple additive model scaling with the number of tryptophan residues contained in the peptide. However, it appears that the first hyperpolarizability response of a single tryptophan residue in the peptide strongly differs from that of an isolated tryptophan. Hence, it is therefore demonstrated that the local environment of the tryptophan residues within the peptide strongly influences its nonlinear optical response. A comparison with the first hyperpolarizability of the natural peptide gramicidin A measured in trifluoroethanol (TFE) further confirms the key role of the local environment on the first hyperpolarizability of tryptophan residues in peptides.

First hyperpolarizability of the natural aromatic amino acids tryptophan, tyrosine, and phenylalanine and the tripeptide lysine-tryptophan-lysine determined by hyper-Rayleigh scattering

We report the first hyperpolarizability of tryptophan (Trp) and tyrosine (Tyr) and an upper limit for that of phenylalanine (Phe), three natural aromatic amino acids. The measurements were performed with hyper-Rayleigh scattering in an aqueous Tris buffer solution at a pH of 8.5 and 150 mM salt concentration with a fundamental wavelength of 780 nm. A value of (4.7 ± 0.7) × 10(-30) esu is found for Trp and (4.1 ± 0.7) × 10(-30) esu for Tyr whereas the upper limit of 1.4 × 10(-30) esu is found for that of Phe due to its limited solubility. The influence of the presence of lysine (Lys) in close vicinity of Trp is investigated with a measurement of the first hyperpolarizabilty of Trp in an excess of Lys and compared to the first hyperpolarizability obtained for the tripeptide Lys-Trp-Lys. The clear decrease of the values measured in these two cases indicates that the first hyperpolarizabilty of Trp is very sensitive to its local environment.

Ca(2+)-induced changes of surfactin conformation: a FTIR and circular dichroism study

Previous NMR studies on surfactin proposed two gamma or beta-turn-containing conformers while recent CD studies described beta-sheets and alpha-helices in surfactin. Since these data were not obtained in the same conditions, the conformation of surfactin was reinvestigated by FTIR spectroscopy, a diagnostic method for beta-sheets. In trifluoroethanol, the FTIR spectra of surfactin and its diester are compatible with gamma and/or beta-turn(s) and the differences in their CD spectra show the importance of the Glu(1) and Asp(5) COOH groups in stabilizing the lipopeptide conformation. The calcium-induced spectral changes of both lipopeptides suggest a first binding of the divalent ions to the surfactin COOH groups (until calcium-lipopeptide mole ratio reached 1) followed by bulk conformational changes (at higher mole ratios). In Tris buffer at pH 8.5, the FTIR amide I band shape, without the typical 1610-1628 and 1675-1695 cm(-1) bands, ascertains the absence of beta-sheets.

NMR structure of antibiotics plipastatins A and B from Bacillus subtilis inhibitors of phospholipase A(2)

Plipastatins A and B are antifungal antibiotics belonging to a family of lipopeptides capable of inhibiting phospholipase A(2) (PLA(2)) and are biosynthesised under certain circumstances by Bacillus subtilis. U-(15)N plipastatins A and B were obtained from cultures of the strain NCIB 8872 on a Landy medium modified for stable-isotope labelling by the substitution of the L-glutamic acid used as the sole nitrogen source, by (15)NH(4)Cl. These two lipo-decapeptides, lactonised by esterification of the Ile10 C-terminus with the phenolic hydroxyl of Tyr3, differ only by a D-Ala (plipastatin A)/D-Val (plipastatin B) substitution at the position 6. The (1)H- and (15)N-nuclear magnetic resonance (NMR) signals of a 4:6 mixture of plipastatins A and B were unambiguously assigned and their structures in dimethylsulfoxide solution were calculated on the basis of a set of NMR-derived restraints. Plipastatins A and B are well-defined structures in solution stabilised by a type 1 beta-turn comprising residues 6-9 and several other specific hydrogen bonds. The structures afford a first molecular basis for the future studies of their biological activities both in lipidic layers or on PLA(2).

Role of metal ions on the secondary and quaternary structure of alkaline phosphatase from bovine intestinal mucosa

Alkaline phosphatase (EC 3.1.3.1) from bovine intestinal mucosa (BIAP) is an homodimeric metalloenzyme, containing one Mg2+ and two Zn2+ ions in each active site. ApoBIAP, prepared using ion-chelating agents, exhibited a dramatic decrease of its hydrolase activity, concomittant to conformational changes in its quaternary structure. By rate-zonal centrifugation and electrophoresis, we demonstrated, for the first time, that the loss of divalent ions leads to some monomerization process for a metal-depleted alkaline phosphatase. Divalent ions are also involved in the secondary and tertiary structures. Metal-depletion induced more exposure of some Trp residues and hydrophobic regions to the solvent (as proved by intrinsic and ANS fluorescences). These changes might correspond to the disappearance of alpha-helices and/or turns with a concomittant appearance of unordered structures and beta-sheets (as probed by FTIR spectroscopy). For BIAP, three steps of temperature-induced changes were exhibited, while for apoBIAP, only one step was exhibited at 55 degrees C. Our work on BIAP showed two main differences with alkaline phosphatase from Escherichia coli. The loss of the divalent ions induces protein monomerization and the total recovery of enzyme activity by divalent ion addition to apoBIAP was not obtained.

A FTIR spectroscopy evidence of the interactions between wheat germ agglutinin and N-acetylglucosamine residues

Wheat germ agglutinin (WGA), a lectin binding a N-acetyl-D-neuraminic acid (NeuNAc) and/or N-acetyl-D-glucosamine (GlcNAc) group, was studied by Fourier transform infrared (FTIR) spectroscopy. Deconvolution of the FTIR spectrum of WGA alone indicated the presence of few alpha-helices and beta-sheets, in contrast to many other lectins. These results agree with previous WGA crystal data. The WGA conformational changes, induced by GlcNAc-bearing liposomes or GlcNAc oligomers, were studied by infrared differential spectroscopy. The GlcNAc binding to WGA resulted in a decrease of turns and alpha-helices and a concomitant appearance of beta-sheets, inducing more or less peptidic N-H deuteration.

NMR structure of active and inactive forms of the sterol-dependent antifungal antibiotic bacillomycin L

The antifungal antibiotic lipopeptide bacillomycin L [cyclo-(L-Asp1-D-Tyr2-D-Asn3-L-Ser4-L-Gln5-D-Ser6++ +-L-Thr7-beta-amino fatty acid)] from Bacillus subtilis belongs to the iturinic family of antifungal agents and acts with a strict sterol-phospholipid dependence on biomembranes. This antibiotic has been analysed using solution NMR spectroscopy in its native active form and its inactive (L-Asp1, D-Tyr2) di-O-methylated form. The structures were calculated under NMR-derived restraints using molecular-dynamic simulated-annealing protocols starting from a random array of atoms. The structure of the native antibiotic is spread over different conformers in which two families are recognized. It was found that most structures have dihedral phi and psi angles defining a type-II' beta-turn including amino acids 5-8, in certain cases stabilized by a 8HN-5CO hydrogen bond, whereas a minority of structures adopt an inverse gamma-turn including amino acids 6-8, stabilized in all cases by an 8HN-6CO hydrogen bond. The di-O-methylation of L-Asp1 and D-Tyr2, an amino acid strictly conserved within the iturinic group of antibiotics, does not induce major differences in the NMR spectra and in the NMR structures. The results are discussed in relation to the specific loss of interaction with sterols when the native antifungal bacillomycin L is methylated on the conserved D-Tyr2 position.

Conformational changes of arginine kinase induced by photochemical release of nucleotides from caged nucleotides--an infrared difference-spectroscopy investigation

The conformations of arginine kinase (AK) in AK x Mg x ADP, AK x Mg x ATP, AK x Mg x ADP x NO3-, AK x Mg x ADP x Arg and AK x Mg x ADP x NO3- x Arg complexes were investigated by measuring their reaction-induced infrared difference spectra (RIDS). The photochemical release of ATP from ATP[Et(PhNO2)] and of ADP from ADP[Et(PhNO2)] produced distinct RIDS of AK complexes, suggesting that binding of ADP and ATP promoted different structural alterations of the enzyme active-site. Small infrared changes in the amide-I region were observed, indicating that about 5-10 amino acid residues were involved in the nucleotide-binding site. These infrared changes were due to the structural alteration of the peptide backbone caused by the nucleotide-binding and to the coupling effects between the nucleotide-binding site and the other substrate (Arg or NO3-)-binding site. ATP binding to AK (as well as ADP-binding to AK in the presence of NO3-) induced protonation of a carboxylate group of Asp or Glu, as evidenced by the appearance of the 1733-cm(-1) band, which was not observed with the AK x Mg x ADP, AK x Mg x ADP x Arg and AK x Mg x ADP x NO3- x Arg complexes. The RIDS of the AK x Mg x ADP x NO3- x Arg complex showed new infrared bands at 1622 cm(-1) (negative) and at 1613 cm(-1) (positive), which were not seen in the RIDS of other complexes (without NO3- or/and Arg). In the transition-state-analog complex of AK, no protonation of the carboxylate residue (Asp or Glu) was observed, and the binding site of NO3- or the gamma-phosphate group of nucleotide was altered.

[Results of a randomized study comparing combination of navelbine-cisplatin to combination of vindesine-cisplatin and to navelbine alone in 612 patients with inoperable non-small cell lung cancer]

The combination of vindesine and cisplatin is considered a reference regimen in advanced NSCLC which has yielded a significant improvement in the duration of survival. A phase II study of a new semi-synthetic vinca alkaloid, Navelbine, reported an unusually high 29% response rate in stage III-IV NSCLC and a phase I-II study established the feasibility of the combination of Navelbine and cisplatin. We, therefore, designed a prospective randomized trial to compare Navelbine and cisplatin (NVB-P) to vindesine and cisplatin (VDS-P) and to evaluate whether the best of these regimens affords a survival benefit compared to Navelbine alone (NVB), an outpatient regimen. Forty-five centers included 612 patients in this study: 206 in NVB-P, 200 in VDS-P and 206 in NVB. Navelbine was given at a dose of 30 mg/m2 weekly, cisplatin at 120 mg/m2 on day 1, day 29 and then every 6 weeks and vindesine at 3 mg/m2 weekly for 6 weeks and then every other week. Treatment was continued until progression or toxicity. Patients' characteristics were similar in the three groups with 59% of patients presenting with metastatic disease. An objective response rate was observed in 30% of patients in NVB-P versus 19% in VDS-P (P = .02) and 14% in NVB (P < .001). The median duration of survival was 40 weeks in NVB-P compared to 32 weeks in VDS-P and 31 weeks in NVB. The comparison of survival between the three groups demonstrated an advantage for NVB-P compared to VDS-P (P = .04) and NVB (P = .02). Neutropenia was significantly higher in the NVB-P group (P < .001) and neurotoxicity more frequent with VDS-P (P < .004). Since our results have demonstrated that NVB-P yields a longer survival duration and a higher response rate than VDS-P or NVB alone, with acceptable toxicity, this combination should be considered a reference regimen in advanced NSCLC.

Inhibition of gap junction intercellular communications of cultured rat hepatocytes by ethanol: role of ethanol metabolism

BACKGROUND/AIMS

In a previous study, we reported that in cultured rat hepatocytes, ethanol inhibits intercellular communication which is known to play a central role in the regulation of cell growth and differentiation. This work was designed to find out if ethanol exerts a direct action on cell membranes, comparable to other long-chain (C6-C9) alcohols, or an indirect action.

METHODS

Intercellular communication was measured on short-term cultured rat hepatocytes by the fluorescent Lucifer-Yellow CH transfer method. Intracellular pH was measured by spectrofluorimetry and membrane expression of connexin 32 by indirect immunofluorescence.

RESULTS

Under our conditions, ethanol (20 mM) inhibited intercellular communication of hepatocytes to the same extent as did octanol and 1 mM. Immunofluorescence semi-quantitative studies of connexin 32 suggested that the observed inhibition was not related to a decrease in the number of gap junction plaques. In contrast with those of octanol, the inhibitory effects of ethanol appeared to be indirect because the inhibition of ethanol metabolism by 4-methyl pyrazole abolished its effects on intercellular communication, while 4-methyl pyrazole did not influence the effects of octanol. Acetaldehyde, the main metabolite of ethanol was without effect on gap junctions.

CONCLUSIONS

This suggests that the inhibition of intercellular communication induced by ethanol may be included among the consequences of intermediary cell metabolism disturbances indirectly due to ethanol oxidation. This may be one of the mechanisms by which ethanol metabolism exerts a hepatotoxic possibly carcinogenic action.

Characterization of iturin synthetase in the wild-type Bacillus subtilis strain producing iturin and in an iturin deficient mutant

The multi-enzyme system responsible for the biosynthesis of iturin, an antifungal lipopeptide of Bacillus subtilis, was partially purified by chromatography on different affigels. In the wild-type strain, two subunits of the iturin synthetase (ITs and ITagp) were characterized: ITs activated only L-Ser, one of the iturin amino acid components, and ITagp activated L-Asn, D-Asn, L-Gln and L-Pro, amino acids corresponding to a partial sequence of iturin. In an iturin deficient mutant, the activity of the ITagp subunit was modified.

Studies on lipopeptide biosynthesis by Bacillus subtilis: isolation and characterization of iturin-, surfactin+ mutants

Two mutant strains, M35 and M89, were obtained by UV irradiation from a wild-type Bacillus subtilis producing iturin and surfactin. Sporulation and surfactin production were similar in both mutants and in the parent strain, while the iturin production of M35 was 300-fold less than that of the wild-type strain; M89 did not produce any iturin. The analysis of the incorporation of sodium [1-14C]acetate into cellular lipids and lipopeptides showed that M89 still synthesized beta-amino fatty acids, the lipid moiety of iturin.

A three-arm trial of vinorelbine (Navelbine) plus cisplatin, vindesine plus cisplatin, and single-agent vinorelbine in the treatment of non-small cell lung cancer: an expanded analysis

Phase II studies have demonstrated that vinorelbine (Navelbine; Burroughs Wellcome Co, Research Triangle Park, NC; Pierre Fabre Médicament, Paris, France) alone or in combination with cisplatin has promising activity against non-small cell lung cancer (NSCLC). On the basis of these preliminary trials, a phase III study was designed to compare intravenous vinorelbine (30 mg/m2 weekly) plus cisplatin (120 mg/m2 on day 1 and day 29 and then every 6 weeks) with vindesine (3 mg/m2 weekly for 6 weeks and then every 2 weeks) plus cisplatin, and to evaluate whether the best of these regimens afforded a survival benefit compared with intravenous vinorelbine alone, an outpatient regimen. This report presents an expanded analysis of data from this previously published study. Six hundred twelve patients were enrolled in this trial: 206 in the vinorelbine plus cisplatin arm, 200 in the vindesine plus cisplatin group, and 206 in the single-agent vinorelbine arm. The vinorelbine plus cisplatin regimen was superior to the other two arms of the study in objective response rate (30% v 19% for vindesine plus cisplatin [P = .02] and 14% for vinorelbine alone [P = .001]), median survival duration (40 weeks v 32 weeks for vindesine plus cisplatin and 31 weeks for vinorelbine alone), and 1-year survival rate (35% v 27% for vindesine plus cisplatin and 30% for vinorelbine alone). An adjusted log-rank test provided a significant advantage for vinorelbine plus cisplatin when compared with vindesine plus cisplatin (P = .04) and with vinorelbine alone (P = .02). The major difference in survival between the two cisplatin-containing regimens occurred in patients with metastatic (stage IV) NSCLC. The incidence of granulocytopenia was significantly higher in the vinorelbine plus cisplatin arm compared with the other two treatment groups, but neurotoxicity was significantly more frequent in the vindesine plus cisplatin group. The results of this study indicate that the combination of vinorelbine plus cisplatin is a viable treatment option for patients with NSCLC and may provide advantages compared with other commonly used regimens.

Studies on bacillomycin D biosynthesis by Bacillus subtilis

The biosynthesis of bacillomycin D, an antibiotic containing a beta-amino fatty acid and a peptide moiety with asparagine, glutamic acid, serine, proline, threonine, and tyrosine, was studied by incubating the Bacillus subtilis producer with various 14C-labelled precursors. Sodium acetate was incorporated into beta-amino fatty acids of bacillomycin D, and asparagine was the best precursor of the peptidic moiety. The kinetics of the incorporation of radioactive substrates into bacillomycin D and into beta-amino fatty acids show that the lipid and the peptide moieties of the antibiotic were synthesized at the same stage of growth of the bacteria. Comparing the effects of different inhibitors on the incorporation of radioactive precursors, the bacillomycin D and beta-amino fatty acids biosyntheses are discussed in relation to the biosyntheses of proteins, lipids and with sporulation.

Biosynthesis of bacillomycin D by Bacillus subtilis. Evidence for amino acid-activating enzymes by the use of affinity chromatography

Bacillomycin D is an antifungal lipopeptide produced by B. subtilis. The formation of the peptidyl bonds of bacillomycin D occurs non-ribosomally, as demonstrated by the use of chloramphenicol, an inhibitor of protein biosynthesis. Amino acid-activating enzymes were found in B. subtilis cell lysates purified by affinity chromatography on a gel containing L-Pro, an amino acid of bacillomycin D. Presence of ATP during this purification increases the binding of enzymatic proteins and their activity. An enzyme, with an apparent molecular weight of 230 kDa, catalyzed ATP-PPi exchange reactions, which were mediated by specific amino acids, corresponding to a partial sequence of bacillomycin D.

Synthesis of beta-hydroxy fatty acids and beta-amino fatty acids by the strains of Bacillus subtilis producing iturinic antibiotics

The iturinic antibiotics, which contain long chain beta-amino acids, are produced by Bacillus subtilis. Screening these strains for the presence of a possible precursor of the iturinic antibiotics, we isolated a lipopeptide containing beta-hydroxy fatty acids. The structure of this compound was studied and it appears to be identical or structurally very similar to surfactin. The carbon chain of its beta-hydroxy fatty acids was n C16, iso C16, iso C15 or anteiso C15. The percentages of each beta-hydroxy fatty acids varied according to the strain producing iturinic antibiotics and were influenced by addition of branched-chain alpha-amino acids to the culture medium. These results demonstrate for the first time that iso C14 beta-hydroxy fatty acid is a constituent present in such a surfactin like lipopeptide. Besides, the presence of radioactive beta-hydroxy fatty acids in the phospholipids when the strains were grown in the presence of sodium [14C]acetate seems also characterize the different strains producing iturinic antibiotics.

Phase I-II study of vinorelbine (Navelbine) plus cisplatin in advanced non-small cell lung cancer

32 patients with advanced non-small cell lung cancer previously untreated by chemotherapy were included in a phase I-II study in order to determine the feasibility of the combination of vinorelbine and cisplatin, each administered at its optimal dose, i.e. 30 mg/m2 weekly and 120 mg/m2 every 4-6 weeks, respectively. There were 27 males and 5 females with a mean age of 55 years and a median performance status of 80%. 13 had locally advanced disease and 19 had distant metastases at the time of inclusion. Our study demonstrated the feasibility of this protocol. Dose intensities could be maximised by adapting vinorelbine doses rather than by postponing treatment in the event of neutropenia. Both response rate (33%) and overall survival of the population (median 11 months) justify further studies.

Studies on the biosynthesis of iturin, an antibiotic of Bacillus subtilis, and a lipopeptide containing beta-hydroxy fatty acids

The biosynthesis of iturin, an antibiotic containing a beta-amino fatty acid, was studied by incubating Bacillus subtilis in the presence of various 14C-labelled precursors. Sodium acetate or palmitic acid were incorporated into the beta-amino acids of iturin. Among the alpha-amino acids (asparagine, glutamine, serine, proline and tyrosine) in the peptidic part of iturin, asparagine appears to be the best precursor. In the presence of sodium [14C]acetate or [14C]asparagine, there was a synthesis of radioactive compound (compound X) before the synthesis of radioactive iturin. Compound X contained asparagine and/or aspartic acid, glutamine and/or glutamic acid and beta-hydroxy fatty acids.

Specific inhibition of iturin biosynthesis by cerulenin

Cerulenin, an inhibitor of fatty acid synthesis, inhibits the biosynthesis of iturin by Bacillus subtilis. With a cerulenin concentration of 2 micrograms/mL, 50% inhibition was achieved. At this concentration, cerulenin does not affect growth or total protein synthesis but does inhibit the incorporation of sodium [14C]acetate, [14C]myristic acid, and [14C]asparagine into iturin. Since cerulenin is known to block the condensation of malonyl-CoA subunits in the formation of fatty acids, the inhibition of iturin and beta-amino acid syntheses by cerulenin is discussed in relation with lipid synthesis.

Fatty acid and beta-amino acid syntheses in strains of Bacillus subtilis producing iturinic antibiotics

Iturinic antibiotics, produced by different strains of Bacillus subtilis, contain long-chain beta-amino acids (beta-AA). The regulation of the synthesis of fatty acids (FA) and beta-AA was studied by modifying the culture medium. Addition of possible precursors, branched-chain alpha-amino acids, to the medium affected the FA and beta-AA compositions. According to this, the B. subtilis strains can be divided into two groups. The first contains the producers of mycosubtilin and bacillomycin F which synthesize a high level of iso C16 chains; the second contains the producers of bacillomycin D, bacillomycin L and iturin which synthesize a high level of n carbon chains. The incorporation of radioactive sodium acetate into FA and beta-AA showed rapid FA synthesis followed by a second synthetic step. Although the detailed mechanism has not yet been elucidated, this second step, corresponding to the beta-AA synthesis, seemed to be a key step in determining the alkyl chain of beta-AA.

Relationship between the 4 mmol running velocity, the time-distance relationship and the Léger-Boucher's test

The relationship between distance and best time is roughly linear for distances between 1500 and 5000 m. The slope of this relationship has the dimension of a velocity (Vlim) which can be sustained during a long time. The individual time-distance relationships and the resulting Vlim have been studied in 32 subjects practicing different athletic activities by measuring exhaustion time for 2 to 4 constant-velocity running exercises performed to exhaustion. The velocity corresponding to 4 mmol.l-1 of blood lactate (V4 mmol) has been compared with Vlim. As maximal oxygen uptake is a major factor determining V4 mmol, Vlim and V4 mmol have also been correlated with the result of a field test which is assumed to measure maximal aerobic power (Léger-Boucher's test). This test consists in running until exhaustion at a velocity which increases every two minutes. The higher the velocity at exhaustion (Vléger) is, the higher the maximal oxygen uptake is assumed. Both Vlim and Vléger were very well correlated with V4 mmol (r greater than 0.90) and the average value of Vlim was almost equal to the average value of V4 mmol (13.89 vs 13.71 km.h-1). However, it was not possible to estimate V4 mmol accurately from the values of Vlim or Vléger because the standard errors of estimates were too large.

[Morphology of renal structures in the dog after prolonged administration of Plasmacair]

Infusion of 10% Dextran 40,000 (Dextran 40) solute was reported to induce acute renal failure with oligoanuria in some patients and in animals during experimental pharmacological studies. Dogs were infused daily with 40 ml.kg-1 a large volume (twice the dose intended in human clinical practice) of a 3,5% dextran 40 solute, associated with electrolytes Plasmacair After 30 days of administration, no differences in creatinine clearance and renal structures were noted between control and treated animals.

Bacillomycins Fb and Fc: isolation and characterization

Bacillomycins Fb and Fc, new antifungal antibiotics, were isolated from a strain of Bacillus subtilis producing bacillomycin F. Because of the presence of beta-amino acids, these compounds belong to the iturin group. The acid hydrolysates contained alpha-amino acids Asp3, Glu1, Pro1, Thr1, Tyr1 and a mixture of iso-C15, anteiso-C15, iso-C16, iso-C17 and anteiso-C17 beta-amino acids. The ratios of the different beta-amino acids depend on the nature of the culture medium. Bacillomycins Fb and Fc differ from bacillomycin F by the presence of free carboxyl groups.

Studies on the biosynthesis of beta-amino acids, the lipid moiety of iturins A, in Bacillus subtilis

The biosynthesis of the beta-amino acid components of iturins A was studied in comparison to the biosynthesis of fatty acids. Palmitic acid was incorporated into the lipid moiety of iturins A when it was added to the culture medium of the iturin producer Bacillus subtilis. Addition of unlabeled palmitic acid enhanced the formation of straight-chain beta-amino acids and addition of valine or leucine increased the production of branched beta-amino acids. These modifications correlated with modifications in the corresponding biosynthesized fatty acids.

Isolation and characterization of new iturins: iturin D and iturin E

Two new antibiotics, iturin D and iturin E, were isolated from a strain of Bacillus subtilis producing iturin A. These compounds belong to the iturin group, the acid hydrolysates contained alpha-amino acids Asp3, Glu1, Pro1, Ser1, Tyr1, and a mixture of n-C14, iso-C15, anteiso-C15, iso-C16 and n-C16 beta-amino acids. They differ from iturin A by the presence of a free carboxyl group in iturin D and a carboxymethyl group in iturin E.

Influence of the culture medium on the production of iturin A by Bacillus subtilis

The production of iturin A by Bacillus subtilis was studied with respect to the composition of the culture medium. Increasing phosphate concentrations did not modify the antibiotic yield. Fructose, sucrose and mannitol were better carbon sources than glucose for antibiotic production. The nature of the nitrogen source was an important factor in the production of antibiotic. Among the amino acids which are components of iturin A, L-asparagine was the best substrate for the biosynthesis of iturin A; L-glutamine and L-serine were rather poor substrates while L-proline and D-tyrosine gave no antibiotic. Ammonium salts permitted good synthesis of antibiotic but the addition of calcium ions to the culture medium inhibited the excretion of antibiotic from the cells.

Effect of various growth conditions on spore formation and bacillomycin L production in Bacillus subtilis

Bacillomycin L is produced by Bacillus subtilis NCIB 8872 in the stationary phase; it is excreted into the culture medium, without prior accumulation in the bacterial cells. The production of bacillomycin L is largely dependent on the composition of the culture medium. The action of specific inhibitors of sporulation, netropsin and diethyl malonate, on antibiotic synthesis is dependent on the composition of the culture medium. Although they occurred at the same time, there appears to be no direct correlation between sporulation and antibiotic synthesis.

Induction of specific base-pair substitutions in E. coli trpA mutants by chloroethylene oxide, a carcinogenic vinyl chloride metabolite

Chloroethylene oxide (CEO), an ultimate carcinogenic metabolite of vinyl chloride, induces base-pair substitution mutations but not frameshift mutations in bacteria. The mutational specificity of CEO was investigated in Escherichia coli, using the trpA mutants developed by Yanofsky. Reversion frequencies to tryptophan prototrophy were analysed, and CEO was found to induce more GC----AT transitions than AT----TA transversions, in addition to a low frequency of other types of substitution. This specificity indicates that CEO is mutagenic through a miscoding DNA adduct. The results are discussed in relation to the various CEO-DNA adducts formed and to their reported or expected mispairing properties.

Structures of bacillomycin D and bacillomycin L peptidolipid antibiotics from Bacillus subtilis

The complete structures of bacillomycin D and bacillomycin L were revised by FAB mass spectrometry and by Edman degradation of the derivatives resulting from the N-bromosuccinimide reaction. The homologous components of both series of antibiotics were separated by HPLC and the beta-amino acids were identified by capillary gas chromatography.

Action of the antibiotics of the iturin group on artificial membranes

The action of iturin A and bacillomycin L on vesicles of dipalmitoylphosphatidylcholine (DPPC) and DPPC-cholesterol was studied. Iturin A destroyed the vesicles, bacillomycin L bound with DPPC vesicles and destroyed vesicles containing DPPC and cholesterol. These results are discussed in comparison with the action of antibiotics of the iturin group on cytoplasmic membranes.

Action of antifungal peptidolipids from Bacillus subtilis on the cell membrane of Saccharomyces cerevisiae

Iturin A and bacillomycin L, antibiotics of the iturin group inhibit the growth of Saccharomyces cerevisiae and the lethal doses were respectively 10 and 60 micrograms/ml. Both antibiotics had an effect on the incorporation of radioactive precursors into macromolecules which decreased with increasing concentrations of antibiotics. However, no specificity was observed on the various macromolecules, proteins, ribonucleic acids and polysaccharides. The site of action on yeast cells was demonstrated to be the cytoplasmic membrane: both antibiotics of iturin group lysed spheroplasts of S. cerevisiae. Moreover, a rapid leakage of potassium ions occurred in the presence of the antibiotics; this leakage was directly associated to the killing effect. These results are consistent with a disruption of the structural integrity of the cytoplasmic membrane correlated to the loss of viability of the yeast cells.

Action of peptidolipidic antibiotics of the iturin group on erythrocytes. Effect of some lipids on hemolysis

Iturin A, bacillomycin L and bacillomycin L dimethyl ester have a strong lytic activity upon human erythrocytes while iturin C is totally inactive. The hemolytic action of the antibiotics is inhibited by free cholesterol as well as by cholesterol included in mixed liposomes of phosphatidylcholine-cholesterol and to a lesser extent by phosphatidylcholine liposomes. This inhibition is the result of an interaction between the antibiotic and added lipids which diminishes the concentration of free antibiotic available to lyse erythrocytes. The inhibitory effect of liposomes on hemolysis demonstrated the affinity of the antibiotic for artificial membrane, especially those containing cholesterol.

Structure of bacillomycin D, a new antibiotic of the iturin group

Bacillomycin D is an antifungal agent extracted from the culture medium of a strain of Bacillus subtilis. It is a mixture of two homologous lipopeptides: the lipid moiety consists of 3-amino-12-methyltridecanoic acid or 3-amino-12-methyltetradecanoic acid; the peptide moiety contains one residue of each of the following seven amino acid: D-asparagine, L-aspartate, L-glutamate, L-proline, D-serine, L-threonine and D- tyrosine. The peptide sequence and the cyclic structure were determined by structural analysis of the peptides obtained by mild acid hydrolysis and by cleavage of the molecule with N-bromosuccinimide.

Characterization of a new antibiotic of iturin group: bacillomycin D

The characterization of an antibiotic isolated from a strain of Bacillus subtilis revealed that this compound is a new antifungal antibiotic of the iturin group. It contains a lipid moiety which is a mixture of 3-amino 12-methyl tridecanoic acid (40%) and 3-amino 12-methyl tetradecanoic acid (60%) and a peptide moiety: L-Asp1, D-Asp1, L-Glu1, L-Pro1, D-Ser1, L-Thr1 and D-Tyr1. These two moieties are joined by a threonyl-beta-aminoacid linkage.

Antifungal activity upon Saccharomyces cerevisiae of iturin A, mycosubtilin, bacillomycin L and of their derivatives; inhibition of this antifungal activity by lipid antagonists

The antifungal activity of three antibiotics of the iturin group: iturin A, mycosubtilin, bacillomycin L and of eleven methylated and acetylated derivatives of these antibiotics was tested upon Saccharomyces cerevisiae. The lowest MIC values were found for natural antibiotics. The substitution of polar groups diminished the antifungal activity. Various lipids, sterols, fatty acids, fatty acid methyl esters and phospholipids were tested as inhibitors of the antifungal activity of iturin A, mycosubtilin and bacillomycin L. Cholesterol was the strongest inhibitor upon the three antibiotics; ergosterol, oleic acid and cis-vaccenic acid were less potent inhibitors. Among phospholipids, phosphatidyl choline inhibited bacillomycin L and iturin A while diphosphatidyl glycerol inhibited bacillomycin L and mycosubtilin. The inhibitory effect appeared to be dependent on the nature of both the hydrophilic group and the fatty acid part of phospholipids.

[Home assisted ventilation for patients suffering from silicosis (author's transl)]

One hundred and seventy-five patients suffering from silicosis benefitted from home assisted ventilation at the rate of 5 minutes per hour every hour. This treatment led to a decrease in hospitalizations and increased the comfort of the patients.