Part II: A new perspective for modeling the bone remodeling process: Biology, mechanics, and pathologies.

In this paper, we explore the effects of biological (pathological) and mechanical damage on bone tissue within a benchmark model. Using the Finite Element Methodology, we analyze and numerically test the model's components, capabilities, and performance under physiologically and pathologically relevant conditions. Our findings demonstrate the model's effectiveness in simulating bone remodeling processes and self-repair mechanisms for micro-damage induced by biological internal conditions and mechanical external ones within bone tissue. This article is the second part of a series, where the first part presented the mathematical model and the biological and physical significance of the terms used in a simplified benchmark model. It explored the bone remodeling model's application, implementation, and results under physiological conditions.

Tumor growth for remodeling process: A 2D approach.

This paper aims to present a comprehensive framework for coupling tumor-bone remodeling processes in a 2-dimensional geometry. This is achieved by introducing a bio-inspired damage that represents the growing tumor, which subsequently affects the main populations involved in the remodeling process, namely, osteoclasts, osteoblasts, and bone tissue. The model is constructed using a set of differential equations based on the Komarova's and Ayati's models, modified to incorporate the bio-inspired damage that may result in tumor mass formation. Three distinct models were developed. The first two models are based on the Komarova's governing equations, with one demonstrating an osteolytic behavior and the second one an osteoblastic model. The third model is a variation of Ayati's model, where the bio-inspired damage is induced through the paracrine and autocrine parameters, exhibiting an osteolytic behavior. The obtained results are consistent with existing literature, leading us to believe that our in-silico experiments will serve as a cornerstone for paving the way towards targeted interventions and personalized treatment strategies, ultimately improving the quality of life for those affected by these conditions.

Analysis of the airflow features and ventilation efficiency of an Ultra-Clean-Air operating theatre by qDNS simulations and experimental validation.

Ultra-Clean-Air (UCA) operating theatres aim to minimise surgical instrument contamination and wound infection through high flow rates of ultra-clean air, reducing the presence of Microbe Carrying Particles (MCPs). This study investigates the airflow patterns and ventilation characteristics of a UCA operating theatre (OT) under standard ventilation system operating conditions, considering both empty and partially occupied scenarios. Utilising a precise computational model, quasi-Direct Numerical Simulations (qDNS) were conducted to delineate flow velocity profiles, energy spectra, distributions of turbulent kinetic energy, energy dissipation rate, local Kolmogorov scales, and pressure-based coherent structures. These results were also complemented by a tracer gas decay analysis following ASHRAE standard guidelines. Simulations showed that contrary to the intended laminar regime, the OT's geometry inherently fosters a predominantly turbulent airflow, sustained until evacuation through the exhaust vents, and facilitating recirculation zones irrespective of occupancy level. Notably, the occupied scenario demonstrated superior ventilation efficiency, a phenomenon attributed to enhanced kinetic energy induced by the additional obstructions. The findings underscore the critical role of UCA-OT design in mitigating MCP dissemination, highlighting the potential to augment the design to optimise airflow across a broader theatre spectrum, thereby diminishing recirculation zones and consequently reducing the propensity for Surgical Site Infections (SSIs). The study advocates for design refinements to harness the turbulent dynamics beneficially, steering towards a safer surgical environment.

Tandem mass spectrometry for the study of glyoxal-derived advanced glycation end-products (AGEs) in peptides.

RATIONALE: The post-translational modification known as glycation affects the physiological properties of peptides and proteins. Glycation is particularly important during hyperglycaemia where α-dicarbonyl compounds are generated. These compounds react with proteins to generate α-dicarbonyl-derived glycation products, which are correlated with diabetic complications such as nephropathy, retinopathy, and neuropathy, among others. One of these α-dicarbonyl compounds is ethanedial, also known as glyoxal. Thereby, glyoxal binding to protein/peptides is studied by electron capture dissociation (ECD) and collisionally activated dissociation (CAD). METHODS: Acetylated and non-acetylated undecapeptides containing one lysine and one arginine susceptible of glycation were reacted with glyoxal under pseudo-physiological and MeOH/H2O (50:50) conditions. Two types of glyoxal-derived AGEs were fragmented by ECD and CAD using 12 Tesla Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS). RESULTS: Reaction with glyoxal under different reaction conditions showed the addition of C2O and C2H2O2, which corresponded to a net increase on the peptide mass of 39.9949 Da and 58.0055 Da, respectively. The binding site was assigned within an error <1 ppm, using ECD and CAD. The results indicated that both types of glyoxal-derived AGEs are formed at the side chain of arginine located in position 3. CONCLUSIONS: Types and binding sites of glyoxal-derived AGEs were investigated in peptides containing one arginine-one lysine using FTICRMS. Two net mass additions to the mass of the peptide were assigned as C2O and C2H2O2, which were located at the arginine side chain. In addition, these mass additions (C2O and C2H2O2) observed in the peptides were unaffected by different reaction conditions.

Clay exfoliation method as a route to obtain mesoporous catalysts for CO2 methanation.

A unique method for obtaining a mesoporous catalytic support through the exfoliation of a montmorillonite is reported. This method consisted of the intercalation of Na-clay with Al-Keggin species and polyvinyl alcohol followed by microwave irradiation. The mesoporous support was employed to prepare Ni-catalysts which were used in the natural gas synthesis through CO2 methanation. The synthesis method was validated confirming the clay exfoliation and the main formation of mesopores. Also, the Ni-catalysts have mainly weak basic surface properties lower than 38 µmol.g-1, and containing Ni0 nanoparticles with sizes between 9 and 12 nm which were thermally stable after reduction and methanation reaction. The catalyst with 5% Ni wt. gave conversions between 50 and 80% with temperatures ranging from 200 to 300 °C and selectivities of 100% towards the formation of CH4 without coke formation. The (3 and 5% Ni) Ni-catalysts are stable up to 8 h at 400 °C in the methanation reaction maintaining 100% of selectivity.•Mesoporous catalytic supports are obtained through a unique clay exfoliation method (Al-keggin, PVA, and microwaves).•(3% and 5% wt.) Ni-mesoporous catalysts are thermally stable and Ni0 nanoparticles between 9 and 12 nm are achieved.•5%wt. Ni-catalyst have no deactivation up to 8 h at 400 °C and displays unprecedented performance at low temperatures in CO2-methanation with 100% of selectivity.

Reconstruction of a Distal Humeral Fracture with Articular Bone Loss Using Osteochondral Allograft: A Case Report.

CASE: A 31-year-old right-hand-dominant man sustained an open left distal humerus fracture resulting in a complete loss of the lateral column involving 30% of the articular surface and the lateral collateral ligament complex. Reconstructive surgery was conducted in 2 stages, beginning with articulated external elbow fixation followed by reconstruction with a fresh osteochondral allograft. Outcomes were satisfactory with no elbow pain or instability, and osseointegration was demonstrated in radiographs. CONCLUSION: The technique described in this report can be a viable option for treating young patients with a severe distal humerus fracture complicated and can provide favorable clinical and radiological outcomes.

A unified framework of cell population dynamics and mechanical stimulus using a discrete approach in bone remodelling.

Multiphysics models have become a key tool in understanding the way different phenomenon are related in bone remodeling and various approaches have been proposed, yet, to the best of the author's knowledge there is no model able to link a cell population model with a mechanical stimulus model using a discrete approach, which allows for an easy implementation. This article couples two classical models, the cell population model from Komarova and the Nackenhorst model in a 2D domain, where correlations between the mechanical loading and the cell population dynamics can be established, furthermore the effect of different paracrine and autocrine regulators is seen on the overall density of a portion of trabecular bone. A discretization is performed using frame 1D finite elements, representing the trabecular structure. The Nackenhorst model is implemented by using the finite element method to calculate the strain energy as the main mechanical stimulus that determines the bone mass density evolution in time. This density is normalized to be added to the bone mass percentage proposed by the Komarova model, where coupling terms have been added as well that guarantee a stable response. In the simulations, the equations were solved employing the finite element method with a user subroutine implemented in ABAQUS (2017) and by applying a direct formulation. The methodology presented can model the cell dynamics occurring in bone remodelling in accordance with the asynchronous nature of this process, yet allowing to differentiate zones with higher density, the main trabecular groups are obtained for the proximal femur. Finally, the model is tested in pathological cases, such as osteoporosis and osteopetrosis, yielding results similar to the pathology behavior. Furthermore, the discrete modelling technique is shown to be of use in this particular application.

Brighter-colored paper wasps (Polistes dominula) have larger poison glands.

INTRODUCTION: Aposematism is a defense system against predators consisting of the toxicity warning using conspicuous coloration. If the toxin production and aposematic coloration is costly, only individuals in good physical condition could simultaneously produce abundant poison and striking coloration. In such cases, the aposematic coloration not only indicates that the animal is toxic, but also the toxicity level of individuals. The costs associated with the production of aposematic coloration would ensure that individuals honestly indicate their toxicity levels. In the present study, we examine the hypothesis that a positive correlation exists between the brightness of warning coloration and toxicity level using as a model the paper wasp (Polistes dominula). RESULTS: We collected wasps from 30 different nests and photographed them to measure the brightness of warning coloration in the abdomen. We also measured the volume of the poison gland, as well as the length, and the width of the abdomen. The results show a positive relationship between brightness and poison-gland size, which remained positive even after controlling for the body size and abdomen width. CONCLUSION: The results suggest that the coloration pattern of these wasps is a true sign of toxicity level: wasps with brighter colors are more poisonous (they have larger poison glands).

Yellow fever surveillance suggests zoonotic and anthroponotic emergent potential.

Yellow fever is transmitted by mosquitoes among human and non-human primates. In the last decades, infections are occurring in areas that had been free from yellow fever for decades, probably as a consequence of the rapid spread of mosquito vectors, and of the virus evolutionary dynamic in which non-human primates are involved. This research is a pathogeographic assessment of where enzootic cycles, based on primate assemblages, could be amplifying the risk of yellow fever infections, in the context of spatial changes shown by the disease since the late 20th century. In South America, the most relevant spread of disease cases affects parts of the Amazon basin and a wide area of southern Brazil, where forest fragmentation could be activating enzootic cycles next to urban areas. In Africa, yellow fever transmission is apparently spreading from the west of the continent, and primates could be contributing to this in savannas around rainforests. Our results are useful for identifying new areas that should be prioritised for vaccination, and suggest the need of deep yellow fever surveillance in primates of South America and Africa.

A simple and effective 1D-element discrete-based method for computational bone remodeling.

In-silico models applied to bone remodeling are widely used to investigate bone mechanics, bone diseases, bone-implant interactions, and also the effect of treatments of bone pathologies. This article proposes a new methodology to solve the bone remodeling problem using one-dimensional (1D) elements to discretize trabecular structures more efficiently for 2D and 3D domains. An Euler integration scheme is coupled with the momentum equations to obtain the evolution of material density at each step. For the simulations, the equations were solved by using the finite element method, and two benchmark tests were solved varying mesh parameters. Proximal femur and calcaneus bone were selected as study cases given the vast research available on the topology of these bones, and compared with the anatomical features of trabecular bone reported in the literature. The presented methodology has proven to be efficient in optimizing topologies of lattice structures; It can predict the trend of formation patterns of the main trabecular groups from two different cancellous bones (femur and calcaneus) using domains set up by discrete elements as a starting point. Preliminary results confirm that the proposed approach is suitable and useful in bone remodeling problems leading to a considerable computational cost reduction. Characteristics similar to those encountered in topological optimization algorithms were identified in the benchmark tests as well, showing the viability of the proposed approach in other applications such as bio-inspired design.

Factors Associated With Hospitalization or Intensive Care Admission in Children With COVID-19 in Latin America.

Background: Limited data is available from low-middle and upper-middle income countries of the factors associated with hospitalization or admission to pediatric intensive care unit (PICU) for children with COVID-19. Objective: To describe the factors associated with hospitalization or PICU admission of children with COVID-19 in Latin America. Method: Multicenter, analytical, retrospective study of children reported from 10 different Latin American countries to the Latin-American Society of Pediatric Infectious Diseases (SLIPE-COVID) research network from June 1, 2020, and February 28, 2021. Outpatient or hospitalized children <18 years of age with COVID-19 confirmed by polymerase chain reaction or antigen detection from the nasopharynx were included. Children with multisystem inflammatory syndrome in children (MIS-C) were excluded. Associations were assessed using univariate and multivariable logistic regression models. Results: A total of 1063 children with COVID-19 were included; 500 (47%) hospitalized, with 419 (84%) to the pediatric wards and 81 (16%) to the ICU. In multivariable analyses, age <1 year (Odds Ratio [OR] 1.78; 95% CI 1.08-2.94), native race (OR 5.40; 95% CI 2.13-13.69) and having a co-morbid condition (OR 5.3; 95% CI 3.10-9.15), were associated with hospitalization. Children with metabolic or endocrine disorders (OR 4.22; 95% CI 1.76-10.11), immune deficiency (1.91; 95% CI 1.05-3.49), preterm birth (OR 2.52; 95% CI 1.41-4.49), anemia at presentation (OR 2.34; 95% CI 1.28-4.27), radiological peribronchial wall thickening (OR 2.59; 95% CI 1.15-5.84) and hypoxia, altered mental status, seizures, or shock were more likely to require PICU admission. The presence of pharyngitis (OR 0.34; 95% CI 0.25-0.48); myalgia (OR 0.47; 95% CI 0.28-0.79) or diarrhea (OR 0.38; 95% CI 0.21-0.67) were inversely associated with hospital admission. Conclusions: In this data analysis reported to the SLIPE research network in Latin America, infants, social inequalities, comorbidities, anemia, bronchial wall thickening and specific clinical findings on presentation were associated with higher rates of hospitalization or PICU admission. This evidence provides data for prioritization prevention and treatment strategies for children suffering from COVID-19.

Epidemiological Indicators of SARS-CoV-2 (COVID-19) and Vaccination Effectiveness on the Report of Positive Cases in the Colombian Army.

The description of the epidemiological indicators of SARS-CoV-2 (COVID-19), such as the mortality rate (MR), the case fatality rate (CFR), and the attack rate (AR), as well as the geographical distribution and daily case reports, are used to evaluate the impact that this virus has had within the Colombian Army and its health system. As military forces around the world represent the force that defends sovereignty, independence, the integrity of the national territory, and the constitutional order, while maintaining migration controls in blocked border areas during this critical pandemic times, they must carry out strict epidemiological surveillance to control the situation among the servicemen. Up to date, the Colombian Army has faced a very high attack rate (AR = 8.55%) due, among others, to living conditions where active military personnel share bedrooms, bathrooms, and dining facilities, which facilitate the spread of the virus. However, being a mainly young and healthy population, the MR was 1.82 deaths/1,000 ha, while the CFR = 2.13% indexes consistently low if compared with those values reported for the national population. In addition, the effectiveness of vaccination is shown in daily cases of COVID-19, where, for the third peak, the active military population presented a decrease of positive patients compared to the dynamics of national transmission and the total population of the military forces (active, retired, and beneficiaries).

[Multicenter retrospective study about the epidemiological, clinical and therapeutic aspects of Kawasaki disease in children from Panama]. / Estudio multicéntrico retrospectivo de los aspectos epidemiológicos, clínicos y terapéuticos de la enfermedad de Kawasaki en niños de Panamá.

BACKGROUND: Kawasaki disease (KD) is the leading cause of pediatric acquired heart disease in many countries, however, there are few published studies from Latin America (LA). AIM: To describe the epidemiology, clinical aspects, and treatment of KD in children from Panama as part of the REKAMLATINA-2 in LA. METHODS: Retrospective descriptive review of hospitalized patients diagnosed with KD, attended at three main pediatric hospitals of Panama from January-1-2009 to December-31-2013. RESULTS: 111 patients were analyzed, 61(54.9 %) were male. All children were hospitalized, and had a mean length of hospitalization of 5.8 (4-7) days. Median age at admission was 28.9 (12-38) months. Prior to KD final diagnosis, 63.9% patients received antibiotics for other presumed diagnoses. 105 (94.6%) patients received IGIV, 10 (9.5%) were resistant. On initial echocardiogram, 11.7% of cardiovascular complications were reported, of which coronary artery lesions (CALs) were detected in 3 (2.9 %) patients. CONCLUSION: The data suggest that KD in Panama has an incidence of about 2.05 x 100,000 in children under 15 years of age, and with a frequency 2.6 times higher in children under 3 years. A high rate of antibiotic misuse on outpatient prior to diagnostic confirmation was observed, suggesting KD unawareness and late recognition in Panamá.

Asociación Linfoma-Tuberculosis ganglionar: Un reto diagnóstico y terapéutico

La tuberculosis, una enfermedad infectocontagiosa, de amplia distribución mundial constituye en una de las causas de morbi-mortalidad más frecuentes en países subdesarrollados. Por otra parte, el linfoma de Hodgkin, una neoplasia linfoide maligna, poco frecuente, tiende a tener un diagnóstico diferencial amplio, incluyendo la tuberculosis extrapulmonar. Se presenta el caso de un paciente masculino de 10 años, procedente de un área endémica para tuberculosis, con cuadro de un mes de evolución de aumento de volumen abdominal, asociado a fiebre vespertina y pérdida de peso, tratado inicialmente como cuadro gastroentérico, sin embargo, con múltiples estudios se logró documentar Tuberculosis ganglionar y Linfoma de Hodgkin clásico en su variante esclerosis nodular en estadio IV b, constituyéndose en un reto diagnóstico y terapéutico.   (provisto por Infomedic International)

Tuberculosis, an infectious disease with a wide global distribution, constitutes one of the most frequent causes of morbidity and mortality in underdeveloped countries. On the other hand, Hodgkin lymphoma, a rare lymphoid malignancy, tends to have a wide differential diagnosis, including extrapulmonary tuberculosis. We present the case of a 10-year-old male patient, from an endemic area for tuberculosis, with a one-month history of increased abdominal volume, associated with evening fever and weight loss, initially treated as gastroenteric symptoms, however , with multiple studies it was possible to document lymph node tuberculosis and classical Hodgkin lymphoma in its variant nodular sclerosis in stage IV b, constituting a diagnostic and therapeutic challenge. (provided by Infomedic International)

Clinical and Parasitological Features of Patients with American Cutaneous Leishmaniasis that Did Not Respond to Treatment with Meglumine Antimoniate.

BACKGROUND: American cutaneous leishmaniasis (ACL) is a complicated disease producing about 67.000 new cases per year. The severity of the disease depends on the parasite species; however in the vast majority of cases species confirmation is not feasible. WHO suggestion for ACL produced by Leishmania braziliensis, as first line treatment, are pentavalent antimonial derivatives (Glucantime or Sodium Stibogluconate) under systemic administration. According to different authors, pentavalent antimonial derivatives as treatment for ACL show a healing rate of about 75% and reasons for treatment failure are not well known. METHODS: In order to characterise the clinical and parasitological features of patients with ACL that did not respond to Glucantime, a cross-sectional observational study was carried out in a cohort of 43 patients recruited in three of the Colombian Army National reference centers for complicated ACL. Clinical and paraclinical examination, and epidemiological and geographic information were recorded for each patient. Parasitological, histopathological and PCR infection confirmation were performed. Glucantime IC50 and in vitro infectivity for the isolated parasites were estimated. RESULTS: Predominant infecting Leishmania species corresponds to L. braziliensis (95.4%) and 35% of the parasites isolated showed a significant decrease in in vitro Glucanatime susceptibility associated with previous administration of the medicament. Lesion size and in vitro infectivity of the parasite are negatively correlated with decline in Glucantime susceptibility (Spearman: r = (-)0,548 and r = (-)0,726; respectively). CONCLUSION: A negative correlation between lesion size and parasite resistance is documented. L. braziliensis was found as the main parasite species associated to lesion of patients that underwent treatment failure or relapse. The indication of a second round of treatment in therapeutic failure of ACL, produced by L. braziliensis, with pentavalent antimonial derivatives is discussable.

Estudio multicéntrico retrospectivo de los aspectos epidemiológicos, clínicos y terapéuticos de la enfermedad de Kawasaki en niños de Panamá

Resumen Antecedentes: La enfermedad de Kawasaki (EK) representa la principal causa de cardiopatía pediátrica adquirida en muchos países; sin embargo, hay pocos estudios publicados en Latinoamérica. Objetivo: Describir la epidemiología, los aspectos clínicos y el tratamiento de EK en niños en Panamá como parte del estudio de vigilancia de REKAMLATINA-2 en Latinoamérica. Pacientes y Métodos: Estudio retrospectivo, descriptivo, de pacientes internados con diagnóstico de EK, atendidos en tres hospitales pediátricos de Panamá del 1-enero-2009 al 31-diciembre-2013. Resultados: Se analizaron 111 pacientes, 61(54,9%) eran hombres. Todos fueron hospitalizados, siendo la media de hospitalización de 5,8 (4-7) días. La mediana de edad al ingreso fue de 28,9 (12-38) meses. Un 63,9% recibió antimicrobianos recientemente por otros posibles diagnósticos. Recibieron inmunoglobulina intravenosa (IGIV) 105 (94,6%) pacientes; de éstos, 10 (9,5%) fueron resistentes. Un 11,7% tuvo alteraciones cardiovasculares en el ECO inicial, de las cuales las lesiones coronarias se detectaron en 3 (2,9%) pacientes. Conclusiones: Los datos sugieren que EK en Panamá tiene una incidencia cercana a 2,05 x 100,000 bajo 15 años de edad y una frecuencia 2,6 veces mayor bajo 3 años de edad. Se observó un alto porcentaje de uso de antimicrobianos ambulatoriamente antes de la confirmación diagnóstica, lo cual sugiere reconocimiento tardío de EK en Panamá.

Abstract Background: Kawasaki disease (KD) is the leading cause of pediatric acquired heart disease in many countries, however, there are few published studies from Latin America (LA). Aim: To describe the epidemiology, clinical aspects, and treatment of KD in children from Panama as part of the REKAMLATINA-2 in LA. Methods: Retrospective descriptive review of hospitalized patients diagnosed with KD, attended at three main pediatric hospitals of Panama from January-1-2009 to December-31-2013. Results: 111 patients were analyzed, 61(54.9 %) were male. All children were hospitalized, and had a mean length of hospitalization of 5.8 (4-7) days. Median age at admission was 28.9 (12-38) months. Prior to KD final diagnosis, 63.9% patients received antibiotics for other presumed diagnoses. 105 (94.6%) patients received IGIV, 10 (9.5%) were resistant. On initial echocardiogram, 11.7% of cardiovascular complications were reported, of which coronary artery lesions (CALs) were detected in 3 (2.9 %) patients. Conclusion: The data suggest that KD in Panama has an incidence of about 2.05 x 100,000 in children under 15 years of age, and with a frequency 2.6 times higher in children under 3 years. A high rate of antibiotic misuse on outpatient prior to diagnostic confirmation was observed, suggesting KD unawareness and late recognition in Panamá.

Nosocomial bacteremia and urinary tract infections caused by extended-spectrum beta -lactamase-producing Klebsiella pneumoniae with plasmids carrying both SHV-5 and TLA-1 genes.

We describe the prevalence and molecular characteristics of extended-spectrum beta -lactamase (ESBL)-producing Klebsiella pneumoniae causing nosocomial bacteremia and urinary tract infections in a Mexican general hospital. We analyzed 82 episodes of bacteremia (approximately 60% of episodes) and urinary tract infection (approximately 40% of episodes) due to K. pneumoniae during a 23-month surveillance period. The neonatal intensive care unit accounted for 49% of all episodes. All strains were imipenem susceptible; 62.2% of the strains were resistant to ceftazidime, cefotaxime, and aztreonam; 69.5% were resistant to amikacin; 58.5% were resistant to gentamicin; and 7.3% were resistant to ciprofloxacin. All strains were associated with 28 pulsed-field gel electrophoresis patterns, and dissemination of 2 ceftazidime-resistant clones produced 44% of the cases. The ESBL phenotype in these clones was transferred by identical or highly related megaplasmids. The ESBL activity corresponded to SHV-5 and TLA-1. Cross-transmission of 2 ceftazidime-resistant clones and the horizontal spread of identical or highly related megaplasmids explain the high prevalence of ESBL phenotype in these infections.

Unexpected crosslinking and diglycation as advanced glycation end-products from glyoxal.

Glyoxal-derived advanced glycation end-products (AGEs) are formed in physiological systems affecting protein/peptide function and structure. These AGEs are generated during aging and chronic diseases such as diabetes and are considered arginine glycating agents. Thus, the study of glyoxal-derived AGEs in lysine residues and amino acid competition is addressed here using acetylated and non-acetylated undecapeptides, with one arginine and one lysine residue available for glycation. Tandem mass spectrometry results from a Fourier transform ion cyclotron resonance mass spectrometer showed glycated species at both the arginine and lysine residues. One species with the mass addition of 116.01096 Da is formed at the arginine residue. A possible structure is proposed to explain this finding (Nδ-[2-(dihydroxymethyl)-2H,3aH,4H,6aH-[1,3]dioxolo[5,6-d]imidazolin-5-yl]-L-ornithine-derived AGE). The second species corresponded to intramolecular crosslink involving the lysine residue and its presence is checked with ion-mobility mass spectrometry.

Study of an unusual advanced glycation end-product (AGE) derived from glyoxal using mass spectrometry.

Glycation is a post-translational modification (PTM) that affects the physiological properties of peptides and proteins. In particular, during hyperglycaemia, glycation by α-dicarbonyl compounds generate α-dicarbonyl-derived glycation products also called α-dicarbonyl-derived advanced glycation end products. Glycation by the α-dicarbonyl compound known as glyoxal was studied in model peptides by MS/MS using a Fourier transform ion cyclotron resonance mass spectrometer. An unusual type of glyoxal-derived AGE with a mass addition of 21.98436 Da is reported in peptides containing combinations of two arginine-two lysine, and one arginine-three lysine amino acid residues. Electron capture dissociation and collisionally activated dissociation results supported that the unusual glyoxal-derived AGE is formed at the guanidino group of arginine, and a possible structure is proposed to illustrate the 21.9843 Da mass addition.

Decrease in Hospitalizations for Pneumonia in Children under Five Years of Age in an Indian Reservation in Panama after the Introduction of the Heptavalent Pneumococcal Conjugate Vaccine (PCV7).

This study quantifies the impact of Heptavalent-Pneumococcal Conjugate Vaccine (PCV7) in Panama on indigenous children younger than 5 years old, based on clinical pneumonia cases. This study demonstrates a significant 41.2% reduction in hospitalizations and 38.6% reduction in referrals for pneumonia following the introduction of PCV7. Burden of disease from pneumonia appears reduced in the ≤12-month- and 13-to-24-month-old groups.