De Novo Engineering of Pd-Metalloproteins and Their Use as Intracellular Catalysts.

The development of transition metal-based catalytic platforms that promote bioorthogonal reactions inside living cells remains a major challenge in chemical biology. This is particularly true for palladium-based catalysts, which are very powerful in organic synthesis but perform poorly in the cellular environment, mainly due to their rapid deactivation. We now demonstrate that grafting Pd(II) complexes into engineered ß-sheets of a model WW domain results in cell-compatible palladominiproteins that effectively catalyze depropargylation reactions inside HeLa cells. The concave shape of the WW domain ß-sheet proved particularly suitable for accommodating the metal center and protecting it from rapid deactivation in the cellular environment. A thorough NMR and computational study confirmed the formation of the metal-stapled peptides and allowed us to propose a three-dimensional structure for this novel metalloprotein motif.

Targeting cancer stem cell OXPHOS with tailored ruthenium complexes as a new anti-cancer strategy.

BACKGROUND: Previous studies by our group have shown that oxidative phosphorylation (OXPHOS) is the main pathway by which pancreatic cancer stem cells (CSCs) meet their energetic requirements; therefore, OXPHOS represents an Achille's heel of these highly tumorigenic cells. Unfortunately, therapies that target OXPHOS in CSCs are lacking. METHODS: The safety and anti-CSC activity of a ruthenium complex featuring bipyridine and terpyridine ligands and one coordination labile position (Ru1) were evaluated across primary pancreatic cancer cultures and in vivo, using 8 patient-derived xenografts (PDXs). RNAseq analysis followed by mitochondria-specific molecular assays were used to determine the mechanism of action. RESULTS: We show that Ru1 is capable of inhibiting CSC OXPHOS function in vitro, and more importantly, it presents excellent anti-cancer activity, with low toxicity, across a large panel of human pancreatic PDXs, as well as in colorectal cancer and osteosarcoma PDXs. Mechanistic studies suggest that this activity stems from Ru1 binding to the D-loop region of the mitochondrial DNA of CSCs, inhibiting OXPHOS complex-associated transcription, leading to reduced mitochondrial oxygen consumption, membrane potential, and ATP production, all of which are necessary for CSCs, which heavily depend on mitochondrial respiration. CONCLUSIONS: Overall, the coordination complex Ru1 represents not only an exciting new anti-cancer agent, but also a molecular tool to dissect the role of OXPHOS in CSCs. Results indicating that the compound is safe, non-toxic and highly effective in vivo are extremely exciting, and have allowed us to uncover unprecedented mechanistic possibilities to fight different cancer types based on targeting CSC OXPHOS.

Nirsevimab for the prevention of respiratory syncytial virus disease in children. Statement of the Spanish Society of Paediatric Infectious Disease (SEIP).

INTRODUCTION: Nirsevimab, a monoclonal antibody for the prevention of disease caused by respiratory syncytial virus (RSV), has recently been approved for use in Europe and Spain. OBJECTIVES: To provide recommendations for the administration of nirsevimab for prevention of RSV disease. METHODS: The approach chosen to develop these recommendations involved a critical review of the literature and the use of the Delphi and GRADE methods. An expert group was formed. The group engaged in three rounds to define the questions, express support or opposition, grade recommendations and establish the agreement or disagreement with the conclusions. RESULTS: In the general neonatal population, routine administration of nirsevimab is recommended to reduce the frequency of illness and hospitalisation for bronchiolitis and RSV lower respiratory tract infection. Nirsevimab is recommended for all infants born in high-incidence RSV season and infants aged less than 6 months at the season onset. In infants born preterm between 29 and 35 weeks of gestation, with haemodynamically significant heart disease or with chronic lung disease, routine administration of nirsevimab is recommended to reduce the incidence of disease and hospitalisation due to bronchiolitis and RSV lower respiratory tract infection. In patients in whom palivizumab is currently indicated, its substitution by nirsevimab is recommended to reduce the burden of bronchiolitis. CONCLUSIONS: Routine administration of nirsevimab to all infants aged less than 6 months born during the RSV season or aged less than 6 months at the start of the winter season is recommended to reduce the burden of disease and the frequency of hospitalization due to bronchiolitis.

Pedicled palmar intermetacarpal perforator flap for skin-graftless syndactyly release: Anatomical study and clinical application.

INTRODUCTION: Dorsal hand skin flaps have been described in order to avoid digit skin grafting in syndactyly release. Although these skin-graftless techniques present a lower rate of long term complications, they result in unsightly dorsal scarring and worse patient satisfaction. We describe a novel technique using an intermetacarpal palmar flap by performing an anatomic study and clinical application. MATERIALS AND METHODS: Ten colored-latex-injected fresh upper limbs were used to study the palmar cutaneous perforators to second to fourth intermetacarpal space skin flaps designed elliptical, its width extending from the center of each involved ray and measuring 40%-50% the length of the palm. RESULTS: The anatomical study revealed a mean 2.77 (range 1 to 4) cutaneous perforators originating from either the common or proper digital vessels for every intermetacarpal space and measuring 0.4 mm (range 0.3 to 0.5 mm) in diameter. CLINICAL APPLICATION: This flap, measuring a mean of 21.5 mm (range 20 to 23 mm) in length and 9.5 mm (range 9 to 10 mm) in width, was used to release simple syndactylies in three patients of mean age 24 months (range = 18-30 months). After skin incision, cutaneous septa to the digital canal were released to permit flap advancement to the web space. Cutaneous perforators were not dissected. Intra-operative palmar-flap advancement provided commissure coverage in all children with no skin grafts needed. Over a mean follow-up of 15 months, no complications occurred, mean palm scar VSS was 2.4 (range 2 to 3) while it was 3 (range 3 to 3) for the commissure scars. CONCLUSIONS: Skin-graftless syndactyly release using a palmar intermetacarpal flap seems both reliable and easy-to-perform. LEVEL OF EVIDENCE: Therapeutic IV.

Rational design of large flat nitrogen-doped graphene oxide quantum dots with green-luminescence suitable for biomedical applications.

Rational synthesis and simple methodology for the purification of large (35-45 nm in lateral size) and flat (1.0-1.5 nm of height) nitrogen-doped graphene oxide quantum dots (GOQDs) are presented. The methodology allows robust metal-free and acid-free preparation of N-GOQDs with a yield of about 100% and includes hydrothermal treatment of graphene oxide with hydrogen peroxide and ammonia. It was demonstrated that macroscopic impurities can be separated from N-GOQD suspension by their coagulation with 0.9% NaCl solution. Redispersible in water and saline solutions, particles of N-GOQDs were characterized using tip-enhanced Raman spectroscopy (TERS), photoluminescent, XPS, and UV-VIS spectroscopies. The size and morphology of N-GOQDs were studied by dynamic light scattering, AFM, SEM, and TEM. The procedure proposed allows nitrogen-doped GOQDs to be obtained, having 60-51% of carbon, 34-45% of oxygen, and up to 7.2% of nitrogen. The N-GOQD particles obtained in two hours of synthesis contain only pyrrolic defects of the graphene core. The fraction of pyridine moieties grows with the time of synthesis, while the fraction of quaternary nitrogen declines. Application of TERS allows demonstration that the N-GOQDs consist of a graphene core with an average crystallite size of 9 nm and an average distance between nearest defects smaller than 3 nm. The cytotoxicity tests reveal high viability of the monkey epithelial kidney cells Vero in the presence of N-GOQDs in a concentration below 60 mg L-1. The N-GOQDs demonstrate green luminescence with an emission maximum at 505 nm and sedimentation stability in the cell culture medium.

Intravenous Foreign Body at the Hand: Case Report.

Intravenous foreign bodies following trauma to the hand are relatively uncommon with sparse reports of this condition being published in the literature. They have been reported to migrate as far as the thoracic cavity and the heart. In the following case report, we describe a case of an intravenous foreign body following hand trauma, and the treatment and potential complications are also discussed.

One-stage Distal Interphalangeal Joint Fusion With External Fixator for the Treatment of Septic Joint Arthritis.

Septic joint arthritis in the small joints of the hand can be caused by penetrating trauma, ruptured ganglion cysts, or open joint dislocations, among others. The use of external fixation for the treatment of this condition has been reported in the past as a means of temporary joint distraction, or for secondary fusion procedures. In the present article, the authors describe a surgical technique involving the use of a low-cost external fixator for the primary arthrodesis of infected distal interphalangeal joints of the hand. The external fixator is fabricated with simple materials, threaded Kirshner wires, bone cement, and an insulin syringe, which the authors have used to fuse the distal interphalangeal joint primarily when destroyed by septic arthritis.

Controlling oncogenic KRAS signaling pathways with a Palladium-responsive peptide.

RAS oncoproteins are molecular switches associated with critical signaling pathways that regulate cell proliferation and differentiation. Mutations in the RAS family, mainly in the KRAS isoform, are responsible for some of the deadliest cancers, which has made this protein a major target in biomedical research. Here we demonstrate that a designed bis-histidine peptide derived from the αH helix of the cofactor SOS1 binds to KRAS with high affinity upon coordination to Pd(II). NMR spectroscopy and MD studies demonstrate that Pd(II) has a nucleating effect that facilitates the access to the bioactive α-helical conformation. The binding can be suppressed by an external metal chelator and recovered again by the addition of more Pd(II), making this system the first switchable KRAS binder, and demonstrates that folding-upon-binding mechanisms can operate in metal-nucleated peptides. In vitro experiments show that the metallopeptide can efficiently internalize into living cells and inhibit the MAPK kinase cascade.

COVID-19 diagnosis by RT-qPCR in alternative specimens.

BACKGROUND: The high demand for adequate material for the gold standard reverse transcription real-time polymerase chain reaction (RT-qPCR)-based diagnosis imposed by the Coronavirus disease 2019 (COVID-19) pandemic, combined with the inherent contamination risks for healthcare workers during nasopharyngeal swab (NP) sample collection and the discomfort it causes patients, brought the need to identify alternative specimens suitable for the diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). OBJECTIVES: The aim of this work was to compare saliva and gingival fluid swabs to NP swabs as specimens for RT-qPCR-based SARS-CoV-2 diagnosis. METHODS: We compared gingival fluid swabs (n = 158) and saliva (n = 207) to the rayon-tipped NP swabs obtained from mild-symptomatic and asymptomatic subjects as specimens for RT-qPCR for SARS-CoV-2 detection. FINDINGS: When compared to NP swabs, gingival fluid swabs had a concordance rate of 15.4% among positive samples, zero among inconclusive, and 100% among negative ones. For saliva samples, the concordance rate was 67.6% among positive samples, 42.9% among inconclusive, and 96.8% among negative ones. However, the concordance rate between saliva and NP swabs was higher (96.9%) within samples with lower cycle threshold (Ct) values (Ct > 10 ≤ 25). MAIN CONCLUSIONS: Our data suggests that whereas gingival fluid swabs are not substitutes for NP swabs, saliva might be considered whenever NP swabs are not available or recommended.

Inactivation of avian influenza viruses by hydrostatic pressure as a potential vaccine development approach.

Vaccines are a recommended strategy for controlling influenza A infections in humans and animals. Here, we describe the effects of hydrostatic pressure on the structure, morphology and functional characteristics of avian influenza A H3N8 virus. The effect of hydrostatic pressure for 3 h on H3N8 virus revealed that the particles were resistant to this condition, and the virus displayed only a discrete conformational change. We found that pressure of 3 kbar applied for 6 h was able to inhibit haemagglutination and infectivity while virus replication was no longer observed, suggesting that full virus inactivation occurred at this point. However, the neuraminidase activity was not affected at this approach suggesting the maintenance of neutralizing antibody epitopes in this key antigen. Our data bring important information for the area of structural virology of enveloped particles and support the idea of applying pressure-induced inactivation as a tool for vaccine production.

Bioorthogonal Azide-Thioalkyne Cycloaddition Catalyzed by Photoactivatable Ruthenium(II) Complexes.

Tailored ruthenium sandwich complexes bearing photoresponsive arene ligands can efficiently promote azide-thioalkyne cycloaddition (RuAtAC) when irradiated with UV light. The reactions can be performed in a bioorthogonal manner in aqueous mixtures containing biological components. The strategy can also be applied for the selective modification of biopolymers, such as DNA or peptides. Importantly, this ruthenium-based technology and the standard copper-catalyzed azide-alkyne cycloaddition (CuAAC) proved to be compatible and mutually orthogonal.

Mortality in Perinatally HIV-infected Adolescents After Transition to Adult Care in Spain.

INTRODUCTION: After the introduction of combination antiretroviral treatment, (ART) mortality in HIV-infected patients has dramatically decreased. However, it is still high in patients at risk, as adolescents transitioning to adult care (AC) without virologic control. The aim of this study was to characterize mortality and comorbidities of perinatally infected HIV (PHIV) patients after transition to AC. METHODS: A multicenter retrospective study from patients included in the CoRISpe-FARO Spanish cohort was conducted. PHIV patients who died after transition to AC between 2009 and 2019 were included. Clinical, immunovirologic characteristics, treatments received, comorbidities and causes of death were described. RESULTS: Among 401 PHIV patients, 14 died (3.5%). All were Spanish, 11/14 (78.6%) women. The median age at diagnosis was 1.5 years (interquartile range [IQR] 0.5-3.9), at transfer to AC was 18 years [16.1-19.9] and at death was 25.8 years [23.6-27.1]. In pediatric units [pediatric care (PC)], CD4+ nadir was 85 cells/µL [IQR 9.7-248.5] and 6/14 patients were classified as C-clinical stage. During AC, all patients were on C-clinical stage and CD4+ nadir dropped to 11.5 cells/µL [4.5-43.3]. cART adherence was extremely poor: in PC, 8/14 patients registered voluntary treatment interruptions; only one had undetectable VL at transition. In AC, 12/14 patients stopped treatment 2 or more periods of time. All deaths were related to advanced HIV disease. Mental health disorders were observed in 7/14 (50%). Main complications described: recurrent bacterial infections (57.1%), wasting syndrome (42.9%), esophageal candidiasis (28.6%) and Pneumocystis jirovecii pneumonia (28.6%). Four women had 11 pregnancies; 5 children were born (none infected). CONCLUSIONS: Young adults PHIV infected who transition to AC without virologic suppression or proven ability to adhere to ART are at high risk of mortality. Mortality was noted as a consequence of advanced HIV disease, frequent mental health problems and poor adherence to ART.

COVID-19 diagnosis by RT-qPCR in alternative specimens

BACKGROUND The high demand for adequate material for the gold standard reverse transcription real-time polymerase chain reaction (RT-qPCR)-based diagnosis imposed by the Coronavirus disease 2019 (COVID-19) pandemic, combined with the inherent contamination risks for healthcare workers during nasopharyngeal swab (NP) sample collection and the discomfort it causes patients, brought the need to identify alternative specimens suitable for the diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). OBJECTIVES The aim of this work was to compare saliva and gingival fluid swabs to NP swabs as specimens for RT-qPCR-based SARS-CoV-2 diagnosis. METHODS We compared gingival fluid swabs (n = 158) and saliva (n = 207) to the rayon-tipped NP swabs obtained from mild-symptomatic and asymptomatic subjects as specimens for RT-qPCR for SARS-CoV-2 detection. FINDINGS When compared to NP swabs, gingival fluid swabs had a concordance rate of 15.4% among positive samples, zero among inconclusive, and 100% among negative ones. For saliva samples, the concordance rate was 67.6% among positive samples, 42.9% among inconclusive, and 96.8% among negative ones. However, the concordance rate between saliva and NP swabs was higher (96.9%) within samples with lower cycle threshold (Ct) values (Ct > 10 ≤ 25). MAIN CONCLUSIONS Our data suggests that whereas gingival fluid swabs are not substitutes for NP swabs, saliva might be considered whenever NP swabs are not available or recommended.

Remote Activation of Hollow Nanoreactors for Heterogeneous Photocatalysis in Biorelevant Media.

Major current challenges in nano-biotechnology and nano-biomedicine include the implementation of predesigned chemical reactions in biological environments. In this context, heterogeneous catalysis is emerging as a promising approach to extend the richness of organic chemistry onto the complex environments inherent to living systems. Herein we report the design and synthesis of hybrid heterogeneous catalysts capable of being remotely activated by near-infrared (NIR) light for the performance of selective photocatalytic chemical transformations in biological media. This strategy is based on the synergistic integration of Au and TiO2 nanoparticles within mesoporous hollow silica capsules, thus permitting an efficient hot-electron injection from the metal to the semiconductor within the interior of the capsule that leads to a confined production of reactive oxygen species. These hybrid materials can also work as smart NIR-responsive nanoreactors inside living mammalian cells, a cutting-edge advance toward the development of photoresponsive theranostic platforms.

A Randomized Clinical Trial on the Use of Antiseptic Solutions for the Pin-Site Care of External Fixators: Chlorhexidine-Alcohol Versus Povidone-Iodine.

Pin-site infections remain a common clinical complication in patients with external fixators. Pin-site care is commonly performed with either chlorhexidine-alcohol solution or povidone-iodine solution. This study aimed to investigate the superiority of chlorhexidine-alcohol solution versus povidone-iodine solution for external fixator pin-site care in pin-site infection. This prospective randomized clinical trial using an open, parallel-group design was conducted in a single Spanish hospital. Eligible consenting patients from November 2018 to May 2019 who underwent placement of an external fixator were included. Patients were randomly assigned to receive pin-site care using either a 2% chlorhexidine-alcohol solution or a 10% povidone-iodine solution. The primary endpoint was the development of a pin-site infection. In total, 568 pins were analyzed (128 patients, with a mean of 4.3 pins per patient). No significant differences were found between groups. However, statistically significant differences were found regarding time and infection variables. The longer the person had the fixator, the higher the risk of infection, t(x) = 5.49, p = .002. Both chlorhexidine-alcohol and povidone-iodine solutions are equally effective antiseptic agents for the prevention of infections in external fixators.

Response to direct-acting antivirals for hepatitis C treatment in vertically HIV/HCV co-infected patients.

Direct-acting antivirals (DAAs) for HCV treatment have improved tolerance and efficacy among adults, but experience in vertical transmission is scarce. In our vertically HIV/HCV co-infected youth cohort of 58 patients, DAA achieved excellent rates of cure among naïve and pretreated individuals. Treating vertically infected seems important as 29.6% displayed advanced fibrosis at treatment initiation.

Low lineage diversity and increased virulence of group C Streptococcus dysgalactiae subsp. equisimilis.

Introduction. In some species, the population structure of pathogenic bacteria is clonal. However, the mechanisms that determine the predominance and persistence of specific bacterial lineages of group C Streptococcus remain poorly understood. In Brazil, a previous study revealed the predominance of two main lineages of Streptococcus dysgalactiae subsp. equisimilis (SDSE).Aim. The aim of this study was to assess the virulence and fitness advantages that might explain the predominance of these SDSE lineages for a long period of time.Methodology. emm typing was determined by DNA sequencing. Adhesion and invasion tests were performed using human bronchial epithelial cells (16HBE14o-). Biofilm formation was tested on glass surfaces and the presence of virulence genes was assessed by PCR. Additionally, virulence was studied using Caenorhabditis elegans models and competitive fitness was analysed in murine models.Results. The predominant lineages A and B were mostly typed as emm stC839 and stC6979, respectively. Notably, these lineages exhibited a superior ability to adhere and invade airway cells. Furthermore, the dominant lineages were more prone to induce aversive olfactory learning and more likely to kill C. elegans. In the competitive fitness assays, they also showed increased adaptability. Consistent with the increased virulence observed in the ex vivo and in vivo models, the predominant lineages A and B showed a higher number of virulence-associated genes and a superior ability to accumulate biofilm.Conclusion. These results suggest strongly that this predominance did not occur randomly but rather was due to adaptive mechanisms that culminated in increased colonization and other bacterial properties that might confer increased bacteria-host adaptability to cause disease.

Forearm Shortening Impact on Pronation and Supination.

Background: Shortening has been described to treat severely mangled extremities, replantations and nonunions. Outcomes after this procedure in the forearm are vaguely described. This study addresses how the forearm rotation is affected by: (1) location of the shortening; (2) the amount of the shortening at different locations. Methods: Nine fresh cadaveric forearms were dissected preserving intact proximal and distal radio ulnar joints and interosseous membrane. The widest point of the interosseous space and its location over the ulna were measured, defining the peak interosseous distance (PID) and the peak interosseous distance level (PIDL). Stabilization and fixation of the specimens were performed by using a platform and external fixators. Consecutive ostectomies were performed within one centimeter intervals at the distal, middle and proximal forearm thirds. A repeated measures mixed-effects (RMME) specific model was designed for the statistical analysis. Results: Before intervention, the average full forearm rotation was 157° (101-185), supination 80° (56-90)/pronation 77° (45-95). The average PID was 15.6 mm in supination and 12.5 mm in pronation. The PIDP were 52.2% and 58.3% of the ulna length in supination and pronation, respectively. The rotation lost were: middle third 5.31°/cm in supination and 6.12°/cm in pronation, distal third 1.62°/cm in supination and 2.20°/cm in pronation, the proximal third was not affected by up to 5 cm of shortening. Conclusions: These data suggest that shortening of the middle and distal third of the forearm might have more significant adverse effect on forearm rotation compared with the proximal third.

Hollow nanoreactors for Pd-catalyzed Suzuki-Miyaura coupling and O-propargyl cleavage reactions in bio-relevant aqueous media.

We describe the fabrication of hollow microspheres consisting of mesoporous silica nanoshells decorated with an inner layer of palladium nanoparticles and their use as Pd-nanoreactors in aqueous media. These palladium-equipped capsules can be used to promote the uncaging of propargyl-protected phenols, as well as Suzuki-Miyaura cross-coupling, in water and at physiologically compatible temperatures. Importantly, the depropargylation reaction can be accomplished in a bioorthogonal manner in the presence of relatively high concentrations of biomolecular components and even in the presence of mammalian cells.