Ab initio quasi-harmonic thermoelasticity of molybdenum at high temperature and pressure.

We present the ab initio thermoelastic properties of body-centered cubic molybdenum under extreme conditions obtained within the quasi-harmonic approximation including both the vibrational and electronic thermal excitation contributions to the free energy. The quasi-harmonic temperature-dependent elastic constants are calculated and compared with existing experiments and with the quasi-static approximation. We find that the quasi-harmonic approximation allows for a much better interpretation of the experimental data, confirming the trend found previously in other metals. Using the Voigt-Reuss-Hill average, we predict the compressional and shear sound velocities of polycrystalline molybdenum as a function of pressure for several temperatures, which might be accessible in experiments.

[Evolution of the performance of Latin America Reference Laboratories in the detection of mechanisms of antimicrobial resistanceEvolução do desempenho dos Laboratórios de Referência na América Latina na detecção de mecanismos de resistência antimicrobiana]. / Evolución del desempeño de Laboratorios de Referencia de América Latina en la detección de mecanismos de resistencia a los antimicrobianos.

OBJECTIVE: The objective is to present the results of the Latin American Program for Quality Assurance in Bacteriology and Antimicrobial Resistance (LA-EQAS) between 2000 and 2018 and the evolution of the detection of resistance mechanisms with clinical impact. METHODS: The participating National Reference Laboratories (NRLs) received 25 surveys with 10 strains in each one, representing a total of 86 bacterial species and 40 resistance mechanisms. To evaluate the performance of the NRLs, five indicators were analyzed: bacterial identification, interpretation of susceptibility testing, acceptable ranges for zones of inhibition, inferred resistance mechanism, and delay time for the response. RESULTS: The average concordance was 82.6% (range: 74-95%) for bacterial identification, 93.3% (85-98%) for the interpretation of susceptibility testing, 84.6% (70-94%) for the zones of inhibition, and 82.5% (73-96%) for the inferred resistance mechanisms. The average delay time for the response was 34 days. Improvements in the detection of mechanisms of clinical importance, such as resistance to methicillin, macrolides and glycopeptides in Gram-positive cocci, and extended-spectrum, AmpC plasmid and carbapenemase beta-lactamases in Gram-negative bacilli, were observed. CONCLUSIONS: The LA-EQAS is an excellent tool for continuous quality improvement in the diagnosis of infections due to multiresistant microorganisms in NRLs in Latin America.

OBJETIVO: O objetivo deste trabalho é apresentar os resultados do Programa Latino-Americano de Garantia da Qualidade em Bacteriologia e Resistência Antimicrobiana (LA-EQAS, na sigla em inglês) entre 2000 e 2018 e a evolução na detecção de mecanismos de resistência com impacto clínico. MÉTODOS: Os Laboratórios Nacionais de Referência (LNRs) participantes receberam 25 inquéritos com 10 cepas bacterianas cada, representando um total de 86 espécies bacterianas e 40 mecanismos de resistência. Para avaliar o desempenho dos LNRs, foram analisados cinco indicadores: identificação bacteriana, interpretação dos testes de sensibilidade, faixas das zonas de inibição aceitáveis, mecanismo de resistência inferido e tempo de demora na resposta. RESULTADOS: A concordância média foi de 82,6% (intervalo: 74-95%) na identificação bacteriana, 93,3% (85-98%) na interpretação dos testes de sensibilidade, 84,6% (70-94%) nas zonas de inibição, 82,5% (73-96%) no mecanismo de resistência inferido e 34 dias na demora na resposta. Observou-se uma melhoria na detecção de mecanismos clinicamente relevantes, como a resistência a meticilina, macrolídeos e glicopeptídeos em cocos Gram-positivos, beta-lactamases de espectro ampliado, AmpC plasmídica e carbapenemases em bacilos Gram-negativos. CONCLUSÕES: O LA-EQAS é uma excelente ferramenta para a melhoria contínua da qualidade no diagnóstico de infecções por microrganismos multirresistentes nos LNRs da América Latina.

The possible role of burden of therapy on the risk of myeloma extramedullary spread.

Extramedullary relapse (EMR) represents a poor prognostic marker in the course of multiple myeloma (MM). We reviewed data from 329 patients, diagnosed between 2000 and 2010, without extramedullary disease at onset to explore possible risk factors for EMR. The median overall survival of our study cohort was 6.4 years. The risk of EMR was 28 % with a median time from diagnosis to first EMR of 2.2 years (0.2-9.1 years). Patients with soft tissue masses located in extra-osseous organs (EMR-S) showed the worst outcome, compared to those with tumor masses arising from adjacent bone (EMR-B) (median OS 1.6 vs 2.4 years, p = 0.006). In addition, patients with EMR-S showed a significant trend for further development of extramedullary masses in a very short time (3.7 vs 5.7 months for EMR-B, p = 0.043). Multivariate analysis failed to identify any clinically presenting features predictive for EMR. The occurrence of EMR was higher in patients with more complex treatment history, defined on the basis of longer treatment duration (≥6 vs <6 months) and on elevated number of treatment lines administered (>2 vs ≤2 lines) (HR = 4.5, p < 0.001 and HR = 9.0, p < 0.001, respectively, when one or both factors are present).In conclusion, increasing burden of treatment might be a possible risk factor for EMR. MM patients with multiple relapses should be comprehensively investigated including, when possible, a whole-body-targeted radiologic technique to accurately detect EMR. Treatment choice should take into account the very poor outcome for patients with soft tissue involvement.

Modeling Meropenem Treatment, Alone and in Combination with Daptomycin, for KPC-Producing Klebsiella pneumoniae Strains with Unusually Low Carbapenem MICs.

Klebsiella pneumoniae strains producing K. pneumoniae carbapenemase (KPC) cause serious infections in debilitated and immunocompromised patients and are associated with prolonged hospital stays and increased mortality rates. Daptomycin is a lipopeptide used against Staphylococcus aureus infection and considered inactive against Gram-negative bacteria. We investigated the effectiveness of a daptomycin-meropenem combination by synergy kill curve and a pharmacokinetic/pharmacodynamic model. The combination may represent a novel therapeutic strategy against infections caused by KPC-producing K. pneumoniae strains.

Chaperone patterns in vernal keratoconjunctivitis are distinctive of cell and Hsp type and are modified by inflammatory stimuli.

BACKGROUND: Vernal keratoconjunctivitis (VKC) is a severe ocular allergy with pathogenic mechanism poorly understood and no efficacious treatment. The aims of the study were to determine quantities and distribution of Hsp chaperones in the conjunctiva of VKC patients and assess their levels in conjunctival epithelial and fibroblast cultures exposed to inflammatory stimuli. METHODS: Hsp10, Hsp27, Hsp40, Hsp60, Hsp70, Hsp90, Hsp105, and Hsp110 were determined in conjunctiva biopsies from nine patients and nine healthy age-matched normal subjects, using immunomorphology and qPCR. Conjunctival epithelial cells and fibroblasts were cultured and stimulated with IL-1ß, histamine, IL-4, TNF-α, or UV-B irradiation, and changes in Hsp levels were determined by Western blotting. RESULTS: Hsp27, Hsp40, Hsp70, and Hsp90 levels increased in the patients' conjunctiva, whereas Hsp10, Hsp60, Hsp100, and Hsp105 did not. Double immunofluorescence demonstrated colocalization of Hsp27, Hsp40, Hsp70, and Hsp90 with CD68 and tryptase. Testing of cultured conjunctival cells revealed an increase in the levels of Hsp27 in fibroblasts stimulated with IL-4; Hsp40 in epithelial cells stimulated with IL-4 and TNF-α and in fibroblasts stimulated with IL-4, TNF-α, and IL-1ß; Hsp70 in epithelial cells stimulated with histamine and IL-4; and Hsp90 in fibroblasts stimulated with IL-1ß, TNF-α, and IL-4. UV-B did not induce changes. CONCLUSIONS: VKC conjunctiva displays distinctive quantitative patterns of Hsps as compared with healthy controls. Cultured conjunctival cells respond to cytokines and inflammatory stimuli with changes in the Hsps quantitative patterns. The data suggest that interaction between the chaperoning and the immune systems drives disease progression.

Neutrophil to lymphocyte ratio (NLR) improves the risk assessment of ISS staging in newly diagnosed MM patients treated upfront with novel agents.

Recent reports identify the ratio between absolute neutrophil count (ANC) and absolute lymphocyte count (ALC), called neutrophil to lymphocyte ratio (NLR), as a predictor of progression-free survival (PFS) and overall survival (OS) in various malignancies. We retrospectively examined the NLR in a cohort of 309 newly diagnosed multiple myeloma (MM) patients treated upfront with novel agents. NLR was calculated using data obtained from the complete blood count (CBC) at diagnosis and subsequently correlated with PFS and OS. The median NLR was 1.9 (range 0.4-15.9). Higher NLR was independent of international staging system (ISS) stage, plasma cell infiltration or cytogenetics. The 5-year PFS and OS estimates were, respectively, 18.2 and 36.4 % for patients with NLR ≥ 2 versus 25.5 and 66.6 % in patients with NLR < 2. Among younger patients (age <65 years, N = 179), NLR ≥ 2 had a negative prognostic impact on both PFS and OS, in all ISS stages. By combining ISS stage and NLR in a model limited to young patients, we found that 19 % of the patients were classified as very low risk, 70 % standard risk and 11 % very high risk. The 5-year estimates were 39.3, 19.4 and 10.9 % for PFS and 95.8, 50.9 and 23.6 % for OS for very low, standard-risk and very high-risk groups. We found NLR to be a predictor of PFS and OS in MM patients treated upfront with novel agents. NLR can be combined with ISS staging system to identify patients with dismal outcome. However, larger cohorts and prospective studies are needed to use NLR as additional parameter to personalise MM therapy in the era of novel agents.

Inter-observer agreement for the evaluation of bone involvement on Whole Body Low Dose Computed Tomography (WBLDCT) in Multiple Myeloma (MM).

OBJECTIVE: We aimed to assess inter-observer agreement in bone involvement evaluation and define accuracy and reproducibility of MDCT images analysis in Multiple Myeloma (MM), by comparing two acquisition protocols at two different institutions. METHODS: A total of 100 MM patients underwent whole body low-dose computed tomography (WB-LDCT), with two protocols: Group I (50 patients), 80 kV and 200-230 mAs; Group II, 120 kV-40 mAs. Four readers (two experts) retrospectively reviewed 22 anatomical districts, reporting the following for each patient: 1) osteolytic lesions; 2) cortical bone integrity; 3) fractures; 4) risk of vertebral collapse; 5) hyperattenuating bone lesions; and 6) extraosseous extension. Inter-observer agreement (by all readers, expert and young observers and comparison of the two protocols) was then statistically analyzed. RESULTS: According to Cohen's criteria, inter-observer agreement among the four readers and between experts and residents was good for the detection of bone lesions and extra-medullary extension, and for the evaluation of risk of collapse and cortical integrity. There was good agreement when comparing the two protocols. A greater variability was found for the evaluation of hyperattenuating lesions and the presence of fractures. CONCLUSIONS: WB-LDCT represents a reproducible and reliable technique that is helpful for defining bone disease in MM patients, with partial influence of readers' experience. KEY POINTS: • MDCT represents a reproducible technique for defining bone disease in MM. • Overall inter-observer agreement is good, even when comparing two different protocols. • Influence of readers' experience on image analysis is partial.

Analysis of buried interfaces in multilayer mirrors using grazing incidence extreme ultraviolet reflectometry near resonance edges.

Accurate measurements of optical properties of multilayer (ML) mirrors and chemical compositions of interdiffusion layers are particularly challenging to date. In this work, an innovative and nondestructive experimental characterization method for multilayers is discussed. The method is based on extreme ultraviolet (EUV) reflectivity measurements performed on a wide grazing incidence angular range at an energy near the absorption resonance edge of low-Z elements in the ML components. This experimental method combined with the underlying physical phenomenon of abrupt changes of optical constants near EUV resonance edges enables us to characterize optical and structural properties of multilayers with high sensitivity. A major advantage of the method is to perform detailed quantitative analysis of buried interfaces of multilayer structures in a nondestructive and nonimaging setup. Coatings of Si/Mo multilayers on a Si substrate with period d=16.4 nm, number of bilayers N=25, and different capping structures are investigated. Stoichiometric compositions of Si-on-Mo and Mo-on-Si interface diffusion layers are derived. Effects of surface oxidation reactions and carbon contaminations on the optical constants of capping layers and the impact of neighboring atoms' interactions on optical responses of Si and Mo layers are discussed.

Aldehyde reductase activity in the antennae of Helicoverpa armigera.

In the present study, we identified two aldehyde reductase activities in the antennae of Helicoverpa species, NADH and NADPH-dependent activity. We expressed one of these proteins of H. armigera, aldo-keto reductase (AKR), which bears 56% identity to bovine aldose reductase, displays a NADPH-dependent activity and is mainly expressed in the antennae of adults. Whole-mount immunostaining showed that the enzyme is concentrated in the cells at the base of chemosensilla and in the nerves. The enzyme activity of H. armigera AKR is markedly different from those of mammalian enzymes. The best substrates are linear aliphatic aldehydes of 8-10 carbon atoms, but not hydroxyaldehydes. Both pheromone components of H. armigera, which are unsaturated aldehydes of 16 carbons, are very poor substrates. Unlike mammalian AKRs, the H. armigera enzyme is weakly affected by common inhibitors and exhibits a different behaviour from the action of thiols. A model of the enzyme suggests that the four cysteines are in their reduced form, as are the seven cysteines of mammalian enzymes. The occurrence of orthologous proteins in other insect species, that do not use aldehydes as pheromones, excludes the possibility of classifying this enzyme among the pheromone-degrading enzymes, as has been previously described in other insect species.

Synthesis and biological evaluation of dual action cyclo-RGD/SMAC mimetic conjugates targeting α(v)ß(3)/α(v)ß(5) integrins and IAP proteins.

The rational design, synthesis and in vitro biological evaluation of dual action conjugates 11-13, containing a tumour targeting, integrin αvß3/αvß5 ligand portion and a pro-apoptotic SMAC mimetic portion (cyclo-RGD/SMAC mimetic conjugates) are reported. The binding strength of the two separate units is generally maintained by these dual action conjugates. In particular, the connection between the separate units (anchor points on each unit; nature, length and stability of the linker) influences the activity of each portion against its molecular targets (integrins αvß3/αvß5 for cyclo-RGD, IAP proteins for SMAC mimetics). Each conjugate portion tolerates different substitutions while preserving the binding affinity for each target.

Risk of second cancers in Waldenström macroglobulinemia.

BACKGROUND: An increased incidence of second cancers has been reported in lymphoproliferative disorders. PATIENTS AND METHODS: We assessed the frequency, characteristics and predictive factors of second cancers in 230 patients with Waldenström macroglobulinemia (WM) and compared the incidence of second cancers in WM with that of an age- and sex-matched control population. RESULTS: Twenty-two patients (10%) developed solid cancers and 10 (4%) second hematologic malignancies. In a competing risk model, the cumulative incidence of solid cancers was 12% at 10 years and 17% at 15 years while the incidence of hematologic malignancies was 6% and 8%, respectively. The overall risk of second cancer in WM was 1.69 times higher than expected (P = 0.002). WM patients were at increased risk for diffuse large B-cell lymphoma [standardized incidence ratio (SIR) 9.24, P < 0.0001], myelodisplastic syndrome/acute myeloid leukemia (SIR 8.4, P < 0.0001), brain cancer (SIR 8.05, P = 0.0004). The risk of a second hematologic malignancy was fourfold higher in patients previously treated, though not reaching statistical significance (P = 0.19). CONCLUSIONS: WM patients are at higher risk of second cancers as compared with the general population. The sample size does not allow firm conclusions about the effect of therapy on the development of second cancers.

Incidence, presenting features and outcome of extramedullary disease in multiple myeloma: a longitudinal study on 1003 consecutive patients.

BACKGROUND: There are few data on the incidence and prognosis of extramedullary (EM) multiple myeloma (MM). There are concerns about a possible increase of EM relapses with the expanding use of high-dose therapy (HDT) and biological agents. PATIENTS AND METHODS: The incidence of EM disease, its relationship with prior exposure to HDT or novel agents, and its prognostic impact were analyzed in 1003 MM patients. Based on the different therapies available, three periods were considered: 1971-1993, conventional-dose chemotherapy; 1994-1999, HDT for younger patients; and 2000-2007, introduction of novel agents. RESULTS: Overall, 13% of patients had EM disease, 7% at diagnosis and 6% later. In the 2000-2007 period, there was a significant increase of EM involvement, at diagnosis (P = 0.02) and during follow-up (P = 0.03). The risk of EM spread was not significantly increased after HDT [hazard ratio (HR 0.6)], bortezomib (HR 1.62), or thalidomide/lenalidomide (HR 1.07). EM disease was associated with shorter overall (HR 3.26, P < 0.0001) and progression-free (HR 1.46, P = 0.04) survival. CONCLUSIONS: The incidence of EM disease has increased, probably due to the availability of more sensitive imaging techniques and the prolongation of patients' survival. HDT or novel agents seem not to increase the risk of EM disease. EM involvement confers a poor prognosis.

Fluoroquinolone-resistant Streptococcus agalactiae isolates from Argentina.

Fluoroquinolone resistance is a growing problem that has only recently emerged in S. agalactiae. Between 2005-2007, WHONET--Argentina network evaluated levofloxacin susceptibility in 1128 clinical S. agalactiae isolates, 10 (0.9%) of which proved to be resistant. Nine of them had come from 5 hospitals (in Buenos Aires City and 4 Argentinean provinces) and recovered from urine (n=7) and vaginal screening cultures (n=2). Three strains were also resistant to macrolides, lincosamides and B streptogramins due to the ermA gene. All nine fluoroquinolone-resistant isolates bore the same two mutations, Ser79Phe in ParC and Ser81Leu in GyrA proteins. Genetic relationships were analyzed by Apal-PFGE and two clones were determined, A (n=6) and B (n=3). To our knowledge, these are the first fluoroquinolone-resistant S. agalactiae isolates detected in Latin America.

String tension and stability of magic tip-suspended nanowires.

Multishell helical gold nanowires were recently imaged by electron microscopy. We show theoretically that the contact with the gold tips at either end of the wire plays a crucial role and that local minima in the string tension rather than the total wire free energy determine the nanowire stability. Density functional electronic structure calculations of the simplest and thinnest coaxial gold and silver wires of variable radius and chirality were carried out. We found a string tension minimum for a single-tube gold nanowire that is chiral and consists of seven strands, in striking agreement with observation. In contrast, no such minimum was found for silver, where the s-d competition leading to surface reconstruction is lacking.

Prevalence of mef and ermB genes in invasive pediatric erythromycin-resistant Streptococcus pneumoniae isolates from Argentina.

During the period 1993-2001, a total of 1,499 pneumococci isolates were recovered through the Argentinean surveillance of Streptococcus pneumoniae causing invasive disease in children under 6 years of age, 3.5% of which were erythromycin resistant. Among the 50 erythromycin-resistant strains available, 58% (n=29) harbored mefA/E genes (15 mefA, 30%; and 14 mefE, 28%), 34% (n=17) ermB, and 6% (n=3) both mefA/E plus ermB genes, while one isolate was negative for all the acquired genes studied. The England14-9 (42%), Poland6B-20 (20%) and Spain9V-3 (16%) clones were responsible for the emergence of pneumococcal macrolide resistance in pediatric population from Argentina.

Correction: Isolation of five Enterobacteriaceae species harbouring blaNDM-1 and mcr-1 plasmids from a single paediatric patient.

[This corrects the article DOI: 10.1371/journal.pone.0221960.].

Isolation of five Enterobacteriaceae species harbouring blaNDM-1 and mcr-1 plasmids from a single paediatric patient.

In Argentina, NDM metallo-ß-lactamase was first reported in 2013. By now, it has disseminated throughout the country in diverse Gram negative bacteria. Here, we report the case of a paediatric patient that underwent a 1-year hospitalisation due to erythrodermic psoriasis in 2014 and received multiple antimicrobial treatments. During his stay, five isolates were obtained from rectal swabs (rs) or blood culture (bc) suspicious of carbapenemase production: a K. quasipneumoniae subsp. quasipneumoniae (rs), Citrobacter freundii (rs), Escherichia coli (bc), Enterobacter cloacae (rs), and a Serratia marcescens (bc). The isolates were studied with broth microdilution, biparental conjugation and plasmid and whole genome sequencing (Illumina). All isolates harboured an 138,998-bp type 1 IncC plasmid that carried blaNDM-1, bleMBL, blaCMY-6, rmtC, aac(6')-Ib, and sul1 resistance genes. Additionally, the blaNDM-plasmids contained ISKpn8 an insertion sequence previously described as associated only to blaKPC. One isolate, a colistin-resistant E. coli, also carried a mcr-1-containing an IncI2 plasmid, which did not harbour additional resistance. The whole genome of K. quasipneumoniae subsp. quasipneumoniae isolate was fully sequenced. This isolate harboured, additionally to blaNDM, three plasmid-mediated quinolone resistance genes: qnrB4, qnrB52 and aac(6')-Ib-cr1. The E. cloacae isolate also harboured qnrA1. These findings alert to the underestimated horizontal dissemination of multidrug-resistant plasmids limiting treatment options with last resort antimicrobials.

From a dull enzyme to something else: facts and perspectives regarding aldose reductase.

Aldose Reductase (ALR2) is defined as the first enzyme of the "polyol pathway". As such, ALR2 would convert glucose to sorbitol through an NADPH dependent reaction. Considered a promoter of osmotic imbalance under hyperglycemic conditions, the enzyme has been under intense investigation as a critical target to prevent and control diabetic complications through the inhibition of its activity. Further characterization of ALR2 suggests its participation in cell detoxification mechanisms through the reduction of toxic aldehydes. Moreover, intriguing is the apparent involvement of the enzyme in the signalling machinery of inflammatory cell response. Here, the structural and functional assessment of ALR2 as an aldose/aldehyde reducing enzyme, and its involvement in various aspects of cell function from sugar metabolism to redox homeostasis and cell signaling are presented.

Low efficacy of thalidomide in improving response after induction in multiple myeloma patients who are candidates for high-dose therapy.

Giving the impact of complete response (CR) on outcome of multiple myeloma patients addressed to high-dose melphalan, we explored the role of a pre-transplant intensification with 3 months thalidome plus dexamethasone therapy (Thal-Dex), after pulse-VAD induction. Seventy-four multiple myeloma patients (MM pts) uniformly treated, were retrospectively studied. The response rate after pulse-VAD were: CR 6%, VGPR 40%, PR 23%, MR 23%, and progression 8%. The response rate after Thal-Dex were similar: CR 11%, VGPR 39%, PR 17%, MR 9%, and progression 24%. Giving no advantage in terms of response rate with an additive toxicity, Thal-Dex does not seem useful for intensification before transplant.

A different schedule of zoledronic acid can reduce the risk of the osteonecrosis of the jaw in patients with multiple myeloma.

Osteonecrosis of the jaw (ONJ) is a reported complication of bisphosphonate use. The incidence ranges between 6 and 13% and seems to be higher in people treated with zoledronic acid (ZA) than with pamidronate. We retrospectively evaluated the incidences of ONJ and skeletal-related events (SRE) in 106 patients with multiple myeloma divided in two groups according to the schedule of administration of bisphosphonates: 51 received monthly administrations until tolerated (group A, standard schedule), 55 were treated monthly during the first year and then every 3 months (group B, reduced schedule). The incidence of SRE was similar (15.1 per 100 person years in group A and 17.7 in group B). ONJ occurred in seven patients, six in group A and one in group B (P=0.049). The risk of ONJ was eight-fold lower with the reduced schedule than with the standard schedule. The only significant risk factor for ONJ was the type of bisphosphonate (P=0.006). The incidence of ONJ was significantly higher with ZA than with pamidronate + ZA (9.1 vs 1.6 per 100 person-years). No ONJ was observed in patients treated only with pamidronate. A reduced schedule of ZA may be safer than the standard schedule while maintaining anti-resorptive efficacy.