Inability to perform maximal stair climbing test before lung resection: a propensity score analysis on early outcome

Abstract Objective: The objective of the present study was to assess whether patients unable to perform a preoperative maximal stair climbing test had an increased incidence of morbidity and mortality after major lung resection compared to patients who were able to exercise. Methods: Three hundred and ninety one patients submitted to pulmonary lobectomy or pneumonectomy for lung cancer were analyzed. Forty-five of these patients were unable to perform a preoperative maximal stair climbing test for underlying comorbidities. Unadjusted and propensity score case matched comparisons were performed between patients who could and who could not perform a preoperative stair climbing test. Multivariable analyses were then performed to identify predictors of morbidity and mortality, and were validated by bootstrap bagging. Results: Patients who could not perform the stair climbing test had similar morbidity rates (31.1 vs. 35.6%, respectively, PZ0.7), but higher mortality rates (15.6 vs. 4.4%, respectively, PZ0.08) and deaths among complicated patients (50 vs. 12.5%, respectively, PZ0.025), compared to propensity score matched patients who could perform the stair climbing test. Logistic regression analyses showed that the inability to perform the stair climbing test was an independent and reliable predictor of mortality (PZ0.005) but not of morbidity (PZ0.2). Conclusions: Patients unable to perform a preoperative maximal exercise test had an increased risk of mortality after major lung resection. Half of these patients did not survive postoperative complications, due to their decreased aerobic reserve caused by physical inactivity which made them unable to cope with the increased oxygen demand.

Unique Footprint in the scl1.3 Locus Affects Adhesion and Biofilm Formation of the Invasive M3-Type Group A Streptococcus

The streptococcal collagen-like proteins 1 and 2 (Scl1 and Scl2) are major surface adhesins that are ubiquitous among group A Streptococcus (GAS). Invasive M3-type strains, however, have evolved two unique conserved features in the scl1 locus: (i) an IS1548 element insertion in the scl1 promoter region and (ii) a nonsense mutation within the scl1 coding sequence. The scl1 transcript is drastically reduced in M3-type GAS, contrasting with a high transcription level of scl1 allele in invasive M1-type GAS. This leads to a lack of Scl1 expression in M3 strains. In contrast, while scl2 transcription and Scl2 production are elevated in M3 strains, M1 GAS lack Scl2 surface expression. M3-type strains were shown to have reduced biofilm formation on inanimate surfaces coated with cellular fibronectin and laminin, and in human skin equivalents. Repair of the nonsense mutation and restoration of Scl1 expression on M3-GAS cells, restores biofilm formation on cellular fibronectin and laminin coatings. Inactivation of scl1 in biofilm-capable M28 and M41 strains results in larger skin lesions in a mouse model, indicating that lack of Scl1 adhesin promotes bacterial spread over localized infection. These studies suggest the uniquely evolved scl1 locus in the M3-type strains, which prevents surface expression of the major Scl1 adhesin, contributed to the emergence of the invasive M3-type strains. Furthermore these studies provide insight into the molecular mechanisms mediating colonization, biofilm formation, and pathogenesis of group A streptococci

Insights on peptide topology in the computational design of protein ligands: the example of lysozyme binding peptides

Herein, we compared the ability of linear and cyclic peptides generated in silico to target different protein sites: internal pockets and solvent-exposed sites. We selected human lysozyme (HuL) as a model target protein combined with the computational evolution of linear and cyclic peptides. The sequence evolution of these peptides was based on the PARCE algorithm. The generated peptides were screened based on their aqueous solubility and HuL binding affinity. The latter was evaluated by means of scoring functions and atomistic molecular dynamics (MD) trajectories in water, which allowed prediction of the structural features of the protein-peptide complexes. The computational results demonstrated that cyclic peptides constitute the optimal choice for solvent exposed sites, while both linear and cyclic peptides are capable of targeting the HuL pocket effectively. The most promising binders found in silico were investigated experimentally by surface plasmon resonance (SPR), nuclear magnetic resonance (NMR), and electrospray ionization mass spectrometry (ESI-MS) techniques. All tested peptides displayed dissociation constants in the micromolar range, as assessed by SPR; however, both NMR and ESI-MS suggested multiple binding modes, at least for the pocket binding peptides. A detailed NMR analysis confirmed that both linear and cyclic pocket peptides correctly target the binding site they were designed for

Prognostic factors of lung cancer in lymphoma survivors (the LuCiLyS study)

Background Second cancer is the leading cause of death in lymphoma survivors, with lung cancer representing the most common solid tumor. Limited information exists about the treatment and prognosis of second lung cancer following lymphoma. Herein, we evaluated the outcome and prognostic factors of Lung Cancer in Lymphoma Survivors (the LuCiLyS study) to improve the patient selection for lung cancer treatment. Methods This is a retrospective multicentre study including consecutive patients treated for lymphoma disease that subsequently developed non-small cell lung cancer (NSCLC). Data regarding lymphoma including age, symptoms, histology, disease stage, treatment received and lymphoma status at the time of lung cancer diagnosis, and data on lung carcinoma as age, smoking history, latency from lymphoma, symptoms, histology, disease stage, treatment received, and survival were evaluated to identify the significant prognostic factors for overall survival. Results Our study population included 164 patients, 145 of which underwent lung cancer resection. The median overall survival was 63 (range, 58–85) months, and the 5-year survival rate 54%. At univariable analysis no-active lymphoma (HR: 2.19; P=0.0152); early lymphoma stage (HR: 1.95; P=0.01); adenocarcinoma histology (HR: 0.59; P=0.0421); early lung cancer stage (HR: 3.18; P<0.0001); incidental diagnosis of lung cancer (HR: 1.71; P<0.0001); and lung cancer resection (HR: 2.79; P<0.0001) were favorable prognostic factors. At multivariable analysis, no-active lymphoma (HR: 2.68; P=0.004); early lung cancer stage (HR: 2.37; P<0.0001); incidental diagnosis of lung cancer (HR: 2.00; P<0.0001); and lung cancer resection (HR: 2.07; P<0.0001) remained favorable prognostic factors. Patients with non-active lymphoma (n=146) versus those with active lymphoma (n=18) at lung cancer diagnosis presented better median survival (64 vs. 37 months; HR: 2.4; P=0.02), but median lung cancer specific survival showed no significant difference (27 vs. 19 months; HR: 0.3; P=0.17). Conclusions The presence and/or a history of lymphoma should not be a contraindication to resection of lung cancer. Inclusion of lymphoma survivors in a lung cancer-screening program may lead to early detection of lung cancer, and improve the survival

Neutralizing antibodies to Omicron after the fourth SARS-CoV-2 mRNA vaccine dose in immunocompromised patients highlight the need of additional boosters

IntroductionImmunocompromised patients have been shown to have an impaired immune response to COVID-19 vaccines.MethodsHere we compared the B-cell, T-cell and neutralizing antibody response to WT and Omicron BA.2 SARS-CoV-2 virus after the fourth dose of mRNA COVID-19 vaccines in patients with hematological malignancies (HM, n=71), solid tumors (ST, n=39) and immune-rheumatological (IR, n=25) diseases. The humoral and T-cell responses to SARS-CoV-2 vaccination were analyzed by quantifying the anti-RBD antibodies, their neutralization activity and the IFN-γ released after spike specific stimulation.ResultsWe show that the T-cell response is similarly boosted by the fourth dose across the different subgroups, while the antibody response is improved only in patients not receiving B-cell targeted therapies, independent on the pathology. However, 9% of patients with anti-RBD antibodies did not have neutralizing antibodies to either virus variants, while an additional 5.7% did not have neutralizing antibodies to Omicron BA.2, making these patients particularly vulnerable to SARS-CoV-2 infection. The increment of neutralizing antibodies was very similar towards Omicron BA.2 and WT virus after the third or fourth dose of vaccine, suggesting that there is no preferential skewing towards either virus variant with the booster dose. The only limited step is the amount of antibodies that are elicited after vaccination, thus increasing the probability of developing neutralizing antibodies to both variants of virus.DiscussionThese data support the recommendation of additional booster doses in frail patients to enhance the development of a B-cell response directed against Omicron and/or to enhance the T-cell response in patients treated with anti-CD20

Spontaneous Pneumomediastinum Following Electronic Cigarette Use

Spontaneous pneumomediastinum (SPM) is an uncommon condition typically occurring in young males presenting with pleuritic pain, dyspnea and subcutaneous emphysema. We reported an exceptional case of spontaneous pneumomediastinum following electronic cigarette use in an otherwise healthy young man

Streptococcal Collagen-like Protein 1 Binds Wound Fibronectin: Implications in Pathogen Targeting

Group A Streptococcus (GAS) infections are responsible for significant morbidity and mortality worldwide. The outlook for an effective global vaccine is reduced because of significant antigenic variation among GAS strains worldwide. Other challenges in GAS therapy include the lack of common access to antibiotics in developing countries, as well as allergy to and treatment failures with penicillin and increasing erythromycin resistance in the industrialized world. At the portal of entry, GAS binds to newly deposited extracellular matrix, which is rich in cellular fibronectin isoforms with extra domain A (EDA, also termed EIIIA) via the surface adhesin, the streptococcal collagen-like protein 1 (Scl1). Recombinant Scl1 constructs, derived from diverse GAS strains, bind the EDA loop segment situated between the C and C' β-strands. Despite the sequence diversity in Scl1 proteins, multiple sequence alignments and secondary structure predictions of Scl1 variants, as well as crystallography and homology modeling studies, point to a conserved mechanism of Scl1-EDA binding. We propose that targeting this interaction may prevent the progression of infection. A synthetic cyclic peptide, derived from the EDA C-C' loop, binds to recombinant Scl1 with a micromolar dissociation constant. This review highlights the current concept of EDA binding to Scl1 and provides incentives to exploit this binding to treat GAS infections and wound colonization

In Silico Generation of Peptides by Replica Exchange Monte Carlo: Docking-Based Optimization of Maltose-Binding-Protein Ligands.

Short peptides can be designed in silico and synthesized through automated techniques, making them advantageous and versatile protein binders. A number of docking-based algorithms allow for a computational screening of peptides as binders. Here we developed ex-novo peptides targeting the maltose site of the Maltose Binding Protein, the prototypical system for the study of protein ligand recognition. We used a Monte Carlo based protocol, to computationally evolve a set of octapeptides starting from a polialanine sequence. We screened in silico the candidate peptides and characterized their binding abilities by surface plasmon resonance, fluorescence and electrospray ionization mass spectrometry assays. These experiments showed the designed binders to recognize their target with micromolar affinity. We finally discuss the obtained results in the light of further improvement in the ex-novo optimization of peptide based binders

Klebsiella phage KP34gp57 capsular depolymerase structure and function: from a serendipitous finding to the design of active mini-enzymes against K. pneumoniae

ABSTRACT Virion-associated depolymerases are large trimeric and multi-domain proteins that constitute the phage arsenal to degrade the polysaccharide layers in their bacterial host. Thus, as recombinant proteins, they are endowed with huge potential in biotechnology and medicine. In this study, we elucidated the structural and functional features of the capsular depolymerase KP34gp57 from the Klebsiella phage KP34. Based on the crystal structure and site-directed mutagenesis, we localized the key catalytic residues in an intra-subunit deep groove. Moreover, we engineered several N- and C-terminally truncated versions of KP34gp57 to dissect the role of each domain in the enzyme’s stability and catalytic activity. Serendipitously, our studies revealed C-terminally trimmed KP34gp57 variants that did not trimerize and were sufficiently stable to preserve full catalytic activity as monomers. The elaboration of trimmed monomeric and fully active phage depolymerases is innovative in the field, as no previous example exists apart from bacterial enzymes. Mini phage depolymerases can be optionally combined within chimeric enzymes to extend their activity range, facilitating their use in stand-alone treatments. Moreover, the intra-subunit and inter-subunit locations of the catalytic pocket in phage depolymerases might suggest differences in their evolutionary origin. IMPORTANCE In this work, we determined the structure of Klebsiella phage KP34p57 capsular depolymerase and dissected the role of individual domains in trimerization and functional activity. The crystal structure serendipitously revealed that the enzyme can exist in a monomeric state once deprived of its C-terminal domain. Based on the crystal structure and site-directed mutagenesis, we localized the key catalytic residues in an intra-subunit deep groove. Consistently, we show that C-terminally trimmed KP34p57 variants are monomeric, stable, and fully active. The elaboration of monomeric, fully active phage depolymerases is innovative in the field, as no previous example exists. Indeed, mini phage depolymerases can be combined in chimeric enzymes to extend their activity ranges, allowing their use against multiple serotypes

(a-b) Overlap of the 10 peptides final configurations obtained by redocking 10 times MBP-9 with the Vina+MC code for 100 steps at kBT = 0.6 on the Met330 site of the MBP (yellow) in open conformation (a) and in its maltotriose (red) containing closed conformation (b). (c) The MC+Vina calculated BE where the errorbars are the sums of the standard errors of the means calculated over the last 10 configurations of 10 runs of the docking protocols.

<p>(a-b) Overlap of the 10 peptides final configurations obtained by redocking 10 times MBP-9 with the Vina+MC code for 100 steps at kBT = 0.6 on the Met330 site of the MBP (yellow) in open conformation (a) and in its maltotriose (red) containing closed conformation (b). (c) The MC+Vina calculated BE where the errorbars are the sums of the standard errors of the means calculated over the last 10 configurations of 10 runs of the docking protocols.</p