Effective Apixaban removal using hemoadsorption during emergent open-heart surgery: a case report and narrative literature review.

BACKGROUND: The management of hemostasis in patients medicated with apixaban (Eliquis) undergoing emergency cardiac surgery is exceedingly difficult. The body's natural elimination pathways for apixaban prove ineffective in emergency situations, and the impact of hemodialysis is limited. The application of Cytosorb® may attenuate the concentration of apixaban, thereby facilitating the stabilization of these patients. CASE PRESENTATION: An 84-year-old man treated with apixaban, underwent emergency ascending aorta replacement surgery due to an acute type A aortic dissection. To address the challenges induced by apixaban, we integrated Cytosorb® cartridge into the Cardiopulmonary bypass circuit. There was a 63.7% decrease in perioperative apixaban-specific anti-factor Xa activity. The patient's postoperative course was favourable. CONCLUSION: Hemoadsorption with Cytosorb® may offers a safe and feasible approach for reducing apixaban concentration in emergency cardiac surgery, thereby mitigating the risk of hemorrhagic complications.

Hemoperfusion in Cardiac Surgery and ECMO.

Extracorporeal circulation (ECC) such as cardiopulmonary bypass or extracorporeal membrane oxygenation (ECMO) may induce a complex activation of the immune system. To date, strategies to mitigate this activation have failed to translate into meaningful improvement of clinical outcomes. Hemoperfusion is a blood purification technique, which relies on mass separation by a solid agent (hemoadsorption). It can be performed by adding a cartridge filled with adsorptive sorbent in the extracorporeal circuit. These devices have the theoretical advantage to enable the removal of excess pro- and anti-inflammatory molecules. Several studies have demonstrated the feasibility and safety of hemoperfusion during cardiac surgery. They have suggested that the procedure could decrease cytokine levels in situations where they were elevated. However, further studies are required to determine the clinical indications, timing, and duration of hemoperfusion during cardiac surgery. Although a similar rationale can apply to hemoperfusion in ECMO, available data in this situation are even more limited and results are conflicting. In this chapter, we discuss the rationale for hemoperfusion with ECC, how to practically do it, and the current level of evidence supporting this therapy.

O que mudou entre os períodos de pico e de platô durante a primeira onda do SARS-CoV-2? Estudo multicêntrico português em unidades de cuidados intensivos / What changed between the peak and plateau periods of the first COVID-19 pandemic wave? A multicentric Portuguese cohort study in intensive care

RESUMO Objetivo: Analisar e comparar as características de pacientes críticos com a COVID-19, a abordagem clínica e os resultados entre os períodos de pico e de platô na primeira onda pandêmica em Portugal. Métodos: Este foi um estudo de coorte multicêntrico ambispectivo, que incluiu pacientes consecutivos com a forma grave da COVID-19 entre março e agosto de 2020 de 16 unidades de terapia intensiva portuguesas. Definiram-se as semanas 10 - 16 e 17 - 34 como os períodos de pico e platô. Resultados: Incluíram-se 541 pacientes adultos com mediana de idade de 65 [57 - 74] anos, a maioria do sexo masculino (71,2%). Não houve diferenças significativas na mediana de idade (p = 0,3), no Simplified Acute Physiology Score II (40 versus 39; p = 0,8), na pressão parcial de oxigênio/fração inspirada de oxigênio (139 versus 136; p = 0,6), na terapia com antibióticos na admissão (57% versus 64%; p = 0,2) ou na mortalidade aos 28 dias (24,4% versus 22,8%; p = 0,7) entre o período de pico e platô. Durante o período de pico, os pacientes tiveram menos comorbidades (1 [0 - 3] versus 2 [0 - 5]; p = 0,002); fizeram mais uso de vasopressores (47% versus 36%; p < 0,001) e ventilação mecânica invasiva na admissão (58,1% versus 49,2%; p < 0,001), e tiveram mais prescrição de hidroxicloroquina (59% versus 10%; p < 0,001), lopinavir/ritonavir (41% versus 10%; p < 0,001) e posição prona (45% versus 36%; p = 0,04). Entretanto, durante o platô, observou-se maior uso de cânulas nasais de alto fluxo (5% versus 16%; p < 0,001) na admissão, remdesivir (0,3% versus 15%; p < 0,001) e corticosteroides (29% versus 52%; p < 0,001), além de menor tempo de internação na unidade de terapia intensiva (12 versus 8 dias; p < 0,001). Conclusão: Houve mudanças significativas nas comorbidades dos pacientes, nos tratamentos da unidade de terapia intensiva e no tempo de internação entre os períodos de pico e platô na primeira onda da COVID-19.

ABSTRACT Objective: To analyze and compare COVID-19 patient characteristics, clinical management and outcomes between the peak and plateau periods of the first pandemic wave in Portugal. Methods: This was a multicentric ambispective cohort study including consecutive severe COVID-19 patients between March and August 2020 from 16 Portuguese intensive care units. The peak and plateau periods, respectively, weeks 10 - 16 and 17 - 34, were defined. Results: Five hundred forty-one adult patients with a median age of 65 [57 - 74] years, mostly male (71.2%), were included. There were no significant differences in median age (p = 0.3), Simplified Acute Physiology Score II (40 versus 39; p = 0.8), partial arterial oxygen pressure/fraction of inspired oxygen ratio (139 versus 136; p = 0.6), antibiotic therapy (57% versus 64%; p = 0.2) at admission, or 28-day mortality (24.4% versus 22.8%; p = 0.7) between the peak and plateau periods. During the peak period, patients had fewer comorbidities (1 [0 - 3] versus 2 [0 - 5]; p = 0.002) and presented a higher use of vasopressors (47% versus 36%; p < 0.001) and invasive mechanical ventilation (58.1 versus 49.2%; p < 0.001) at admission, prone positioning (45% versus 36%; p = 0.04), and hydroxychloroquine (59% versus 10%; p < 0.001) and lopinavir/ritonavir (41% versus 10%; p < 0.001) prescriptions. However, a greater use of high-flow nasal cannulas (5% versus 16%, p < 0.001) on admission, remdesivir (0.3% versus 15%; p < 0.001) and corticosteroid (29% versus 52%, p < 0.001) therapy, and a shorter ICU length of stay (12 days versus 8, p < 0.001) were observed during the plateau. Conclusion: There were significant changes in patient comorbidities, intensive care unit therapies and length of stay between the peak and plateau periods of the first COVID-19 wave.

Temporary Right Ventricular Assist Device After Redo Aortic Valve Replacement And Heartmate 3tm Implantation - A Case Report.

The implantation of the left ventricular assist device Abbott HeartMate 3TM is being increasingly performed for management of end-stage heart failure. LVAD implantation might be associated with early or late right ventricular dysfunction. When severe, a temporary right ventricular support device may need to be implanted. However, these situations are associated with higher mortality. We report a successful case of temporary right ventricular support following HeartMate 3 implantation.

Structural Characterization of Mycobacterium abscessus Phosphopantetheine Adenylyl Transferase Ligand Interactions: Implications for Fragment-Based Drug Design.

Anti-microbial resistance is a rising global healthcare concern that needs urgent attention as growing number of infections become difficult to treat with the currently available antibiotics. This is particularly true for mycobacterial infections like tuberculosis and leprosy and those with emerging opportunistic pathogens such as Mycobacterium abscessus, where multi-drug resistance leads to increased healthcare cost and mortality. M. abscessus is a highly drug-resistant non-tuberculous mycobacterium which causes life-threatening infections in people with chronic lung conditions such as cystic fibrosis. In this study, we explore M. abscessus phosphopantetheine adenylyl transferase (PPAT), an enzyme involved in the biosynthesis of Coenzyme A, as a target for the development of new antibiotics. We provide structural insights into substrate and feedback inhibitor binding modes of M. abscessus PPAT, thereby setting the basis for further chemical exploration of the enzyme. We then utilize a multi-dimensional fragment screening approach involving biophysical and structural analysis, followed by evaluation of compounds from a previous fragment-based drug discovery campaign against M. tuberculosis PPAT ortholog. This allowed the identification of an early-stage lead molecule exhibiting low micro molar affinity against M. abscessus PPAT (Kd 3.2 ± 0.8 µM) and potential new ways to design inhibitors against this enzyme. The resulting crystal structures reveal striking conformational changes and closure of solvent channel of M. abscessus PPAT hexamer providing novel strategies of inhibition. The study thus validates the ligandability of M. abscessus PPAT as an antibiotic target and identifies crucial starting points for structure-guided drug discovery against this bacterium.

Development of Inhibitors of SAICAR Synthetase (PurC) from Mycobacterium abscessus Using a Fragment-Based Approach.

Mycobacterium abscessus (Mab) has emerged as a challenging threat to individuals with cystic fibrosis. Infections caused by this pathogen are often impossible to treat due to the intrinsic antibiotic resistance leading to lung malfunction and eventually death. Therefore, there is an urgent need to develop new drugs against novel targets in Mab to overcome drug resistance and subsequent treatment failure. In this study, SAICAR synthetase (PurC) from Mab was identified as a promising target for novel antibiotics. An in-house fragment library screen and a high-throughput X-ray crystallographic screen of diverse fragment libraries were explored to provide crucial starting points for fragment elaboration. A series of compounds developed from fragment growing and merging strategies, guided by crystallographic information and careful hit-to-lead optimization, have achieved potent nanomolar binding affinity against the enzyme. Some compounds also show a promising inhibitory effect against Mab and Mtb. This work utilizes a fragment-based design and demonstrates for the first time the potential to develop inhibitors against PurC from Mab.

Discovery of Novel Inhibitors of Uridine Diphosphate-N-Acetylenolpyruvylglucosamine Reductase (MurB) from Pseudomonas aeruginosa, an Opportunistic Infectious Agent Causing Death in Cystic Fibrosis Patients.

Pseudomonas aeruginosa is of major concern for cystic fibrosis patients where this infection can be fatal. With the emergence of drug-resistant strains, there is an urgent need to develop novel antibiotics against P. aeruginosa. MurB is a promising target for novel antibiotic development as it is involved in the cell wall biosynthesis. MurB has been shown to be essential in P. aeruginosa, and importantly, no MurB homologue exists in eukaryotic cells. A fragment-based drug discovery approach was used to target Pa MurB. This led to the identification of a number of fragments, which were shown to bind to MurB. One fragment, a phenylpyrazole scaffold, was shown by ITC to bind with an affinity of Kd = 2.88 mM (LE 0.23). Using a structure guided approach, different substitutions were synthesized and the initial fragment was optimized to obtain a small molecule with Kd = 3.57 µM (LE 0.35).

Targeting Mycobacterium tuberculosis CoaBC through Chemical Inhibition of 4'-Phosphopantothenoyl-l-cysteine Synthetase (CoaB) Activity.

Coenzyme A (CoA) is a ubiquitous cofactor present in all living cells and estimated to be required for up to 9% of intracellular enzymatic reactions. Mycobacterium tuberculosis (Mtb) relies on its own ability to biosynthesize CoA to meet the needs of the myriad enzymatic reactions that depend on this cofactor for activity. As such, the pathway to CoA biosynthesis is recognized as a potential source of novel tuberculosis drug targets. In prior work, we genetically validated CoaBC as a bactericidal drug target in Mtb in vitro and in vivo. Here, we describe the identification of compound 1f, a small molecule inhibitor of the 4'-phosphopantothenoyl-l-cysteine synthetase (PPCS; CoaB) domain of the bifunctional Mtb CoaBC, and show that this compound displays on-target activity in Mtb. Compound 1f was found to inhibit CoaBC uncompetitively with respect to 4'-phosphopantothenate, the substrate for the CoaB-catalyzed reaction. Furthermore, metabolomic profiling of wild-type Mtb H37Rv following exposure to compound 1f produced a signature consistent with perturbations in pantothenate and CoA biosynthesis. As the first report of a direct small molecule inhibitor of Mtb CoaBC displaying target-selective whole-cell activity, this study confirms the druggability of CoaBC and chemically validates this target.

Inhibiting Mycobacterium tuberculosis CoaBC by targeting an allosteric site.

Coenzyme A (CoA) is a fundamental co-factor for all life, involved in numerous metabolic pathways and cellular processes, and its biosynthetic pathway has raised substantial interest as a drug target against multiple pathogens including Mycobacterium tuberculosis. The biosynthesis of CoA is performed in five steps, with the second and third steps being catalysed in the vast majority of prokaryotes, including M. tuberculosis, by a single bifunctional protein, CoaBC. Depletion of CoaBC was found to be bactericidal in M. tuberculosis. Here we report the first structure of a full-length CoaBC, from the model organism Mycobacterium smegmatis, describe how it is organised as a dodecamer and regulated by CoA thioesters. A high-throughput biochemical screen focusing on CoaB identified two inhibitors with different chemical scaffolds. Hit expansion led to the discovery of potent and selective inhibitors of M. tuberculosis CoaB, which we show to bind to a cryptic allosteric site within CoaB.

Cytosorb® hemoadsorption of apixaban during emergent cardio-pulmonary bypass: a case report.

BACKGROUND: Peri-operative coagulation management of patients receiving apixaban, a new oral anticoagulant, is difficult. The CytoSorb® hemoadsorption device might represent a therapeutic option to reduce apixaban's pharmacological and inflammatory effects during high-risk surgery. CASE PRESENTATION: An 83-year-old woman treated with Apixaban underwent emergent redo mitral valve replacement for prosthetic valve endocarditis. A CytoSorb® cartridge was added to the cardio-pulmonary bypass (CPB) circuit. Apixaban-specific anti-factor Xa activity (AFXaA) were measured peri-operatively. After 100 minutes of CPB, a 50% AFXaA rate decrease was observed as compared to pre-CPB values. Furthermore, we noticed 39% and 44% reductions of AFXaA levels in comparison to the expected levels in patients with normal or altered renal function, respectively. CONCLUSION: Insertion of a CytoSorb® cartridge in the CPB was safe and associated with rapid correction of Apixaban-associated anticoagulation.

Development of Inhibitors against Mycobacterium abscessus tRNA (m1G37) Methyltransferase (TrmD) Using Fragment-Based Approaches.

Mycobacterium abscessus (Mab) is a rapidly growing species of multidrug-resistant nontuberculous mycobacteria that has emerged as a growing threat to individuals with cystic fibrosis and other pre-existing chronic lung diseases. Mab pulmonary infections are difficult, or sometimes impossible, to treat and result in accelerated lung function decline and premature death. There is therefore an urgent need to develop novel antibiotics with improved efficacy. tRNA (m1G37) methyltransferase (TrmD) is a promising target for novel antibiotics. It is essential in Mab and other mycobacteria, improving reading frame maintenance on the ribosome to prevent frameshift errors. In this work, a fragment-based approach was employed with the merging of two fragments bound to the active site, followed by structure-guided elaboration to design potent nanomolar inhibitors against Mab TrmD. Several of these compounds exhibit promising activity against mycobacterial species, including Mycobacterium tuberculosis and Mycobacterium leprae in addition to Mab, supporting the use of TrmD as a target for the development of antimycobacterial compounds.

suPAR na avaliação do prognóstico após permanência na unidade de terapia intensiva: um estudo piloto / suPAR in the assessment of post intensive care unit prognosis: a pilot study

RESUMO Objetivo: Determinar o desempenho da dosagem do receptor ativador de plasminogênio tipo uroquinase solúvel quando da alta da unidade de terapia intensiva para predição da mortalidade após permanência na mesma unidade. Métodos: Durante 24 meses conduziu-se um estudo prospectivo observacional de coorte em uma unidade de terapia intensiva polivalente de oito leitos. Colheram-se os seguintes dados: APACHE II, SOFA, níveis de proteína C-reativa e receptor ativador de plasminogênio tipo uroquinase solúvel, além de contagem de leucócitos no dia da alta da unidade de terapia intensiva, em pacientes que sobreviveram à permanência na unidade de terapia intensiva. Resultados: Durante este período, incluíram-se no estudo 202 pacientes; 29 (18,6%) morreram após alta da unidade de terapia intensiva. Os não sobreviventes eram mais idosos e tinham enfermidades mais graves quando admitidos à unidade de terapia intensiva, com escores de severidade mais elevados, e necessitaram de vasopressores por mais tempo do que os que sobreviveram. As áreas sob a curva Característica de Operação do Receptor para SOFA, APACHE II, proteína C-reativa, contagem de leucócitos e receptor ativador de plasminogênio tipo uroquinase solúvel, no momento da alta da unidade de terapia intensiva, avaliadas como marcadores de prognóstico de morte hospitalar, foram, respectivamente, 0,78 (IC95% 0,70 - 0,86); 0,70 (IC95% 0,61 - 0,79); 0,54 (IC95% 0,42 - 0,65); 0,48 (IC95% 0,36 - 0,58); 0,68 (IC95% 0,58 - 0,78). O SOFA associou-se de forma independente com risco mais elevado de morte no hospital (OR 1,673; IC95% 1,252 - 2,234), assim como para mortalidade após 28 dias (OR 1,861; IC95% 1,856 - 2,555) e mortalidade após 90 dias (OR 1,584; IC95% 1,241 - 2,022). Conclusão: A dosagem do receptor ativador de plasminogênio tipo uroquinase solúvel na alta unidade de terapia intensiva teve um valor prognóstico fraco de mortalidade após a permanência nesta unidade.

ABSTRACT Objective: To determine the performance of soluble urokinase-type plasminogen activator receptor upon intensive care unit discharge to predict post intensive care unit mortality. Methods: A prospective observational cohort study was conducted during a 24-month period in an 8-bed polyvalent intensive care unit. APACHE II, SOFA, C-reactive protein, white cell count and soluble urokinase-type plasminogen activator receptor on the day of intensive care unit discharge were collected from patients who survived intensive care unit admission. Results: Two hundred and two patients were included in this study, 29 patients (18.6%) of whom died after intensive care unit discharge. Nonsurvivors were older and more seriously ill upon intensive care unit admission with higher severity scores, and nonsurvivors required extended use of vasopressors than did survivors. The area under the receiver operating characteristics curves of SOFA, APACHE II, C-reactive protein, white cell count, and soluble urokinase-type plasminogen activator receptor at intensive care unit discharge as prognostic markers of hospital death were 0.78 (95%CI 0.70 - 0.86); 0.70 (95%CI 0.61 - 0.79); 0.54 (95%CI 0.42 - 0.65); 0.48 (95%CI 0.36 - 0.58); and 0.68 (95%CI 0.58 - 0.78), respectively. SOFA was independently associated with a higher risk of in-hospital mortality (OR 1.673; 95%CI 1.252 - 2.234), 28-day mortality (OR 1.861; 95%CI 1.856 - 2.555) and 90-day mortality (OR 1.584; 95%CI 1.241 - 2.022). Conclusion: At intensive care unit discharge, soluble urokinase-type plasminogen activator receptor is a poor predictor of post intensive care unit prognosis.

Structural Biology and the Design of New Therapeutics: From HIV and Cancer to Mycobacterial Infections: A Paper Dedicated to John Kendrew.

Interest in applications of protein crystallography to medicine was evident, as the first high-resolution structures emerged in the 50s and 60s. In Cambridge, Max Perutz and John Kendrew sought to understand mutations in sickle cell and other genetic diseases related to hemoglobin, while in Oxford, the group of Dorothy Hodgkin became interested in long-lasting zinc-insulin crystals for treatment of diabetes and later considered insulin redesign, as synthetic insulins became possible. The use of protein crystallography in structure-guided drug discovery emerged as enzyme structures allowed the identification of potential inhibitor-binding sites and optimization of interactions of hits using the structure of the target protein. Early examples of this approach were the use of the structure of renin to design antihypertensives and the structure of HIV protease in design of AIDS antivirals. More recently, use of structure-guided design with fragment-based drug discovery, which reduces the size of screening libraries by decreasing complexity, has improved ligand efficiency in drug design and has been used to progress three oncology drugs through clinical trials to FDA approval. We exemplify current developments in structure-guided target identification and fragment-based lead discovery with efforts to develop new antimicrobials for mycobacterial infections.

Two Years of Experience in the Implantation of Heartmate III.

INTRODUCTION: Left ventricular assist devices as long-term mechanical circulatory support are increasingly used as an option for medically refractory advanced heart failure. Heartmate III is one of the alternative devices for circulatory support in those patients. OBJECTIVES: Analyze a two years Heartmate III implantation Program. METHODS: From November 2015 to August 2017, Heartmate III was implanted in 16 patients with chronic end-stage heart failure, in 81% (n = 13) as a bridge to transplant and 19% (n = 3) as destination therapy. We did a review off demographic, clinical and surgical data, and we analyzed the overall survival using the Kaplan-Meier method, excluding patients who were transplanted. RESULTS: Heartmate III was implanted in 16 male patients (100%) with age 55.8 ± 11.1 years (limits 38-74 years) and body surface area 2.0 ± 0.19 m2. The baseline hemodynamic data revealed a cardiac index 2.1 ± 0.4 l / min / m2 and a left ventricular ejection fraction of 20.7 ± 7.3%. Ischemic cardiomyopathy was the most common etiology in this chronic heart failure population (n = 9; 56%). Seven patients (44%) were classified INTERMACS 4; five (31%) in profile 2; three (19%) in profile 3 and one (6%) in profile 1. The implantation of the devices was performed under Cardiopulmonary Bypass (78.6 ± 25.7 min), and 25% of the patients (n = 4) had right ventricular dysfunction, requiring postoperative temporary right ventricle support. As complications, 6 patients (38%) manifested bleeding requiring surgery and 2 (12%) reported gastrointestinal bleeding, 4 (25%) developed driveline infection, 3 of them were treated (18%) with conservative therapy and in 1 patient (6%) with driveline transposition. During the total follow-up time (19 months), three patients (18%) were transplanted; two deaths occured due to pulmonary embolism and ischemic stroke respectively; verified by the Kaplan Meier method, an overall survival rate of 92.9 ± 6.9%, stable from 6 months after implantation. CONCLUSION: The 6 months survival rate of 92.9% proves the efficacy of this therapy for our patients and all of them were INTERMACS profils lower than 4. Despite the small number of patients enrolled and the follow-up duration limiting our study, we demonstrated the first experience of our center in the treatment of high-risk population. In conclusion, we show that the Heartmate III was consistent in low INTERMACS profile patients.

Targeting tuberculosis using structure-guided fragment-based drug design.

Fragment-based drug discovery is now widely used in academia and industry to obtain small molecule inhibitors for a given target and is established for many fields of research including antimicrobials and oncology. Many molecules derived from fragment-based approaches are already in clinical trials and two - vemurafenib and venetoclax - are on the market, but the approach has been used sparsely in the tuberculosis field. Here, we describe the progress of our group and others, and examine the most recent successes and challenges in developing compounds with antimycobacterial activity.

Diagnosis of Rejection by Analyzing Ventricular Late Potentials in Heart Transplant Patients / Diagnóstico de Rejeição por Análise de Potenciais Ventriculares Tardios em Doentes Transplantados ao Coração

Background: Heart transplant rejection originates slow and fragmented conduction. Signal-averaged ECG (SAECG) is a stratification method in the risk of rejection. Objective: To develop a risk score for rejection, using SAECG variables. Methods: We studied 28 transplant patients. First, we divided the sample into two groups based on the occurrence of acute rejection (5 with rejection and 23 without). In a second phase, we divided the sample considering the existence or not of rejection in at least one biopsy performed on the follow-up period (rejection pm1: 18 with rejection and 10 without). Results: On conventional ECG, the presence of fibrosis was the only criterion associated with acute rejection (OR = 19; 95% CI = 1.65-218.47; p = 0.02). Considering the rejection pm1, an association was found with the SAECG variables, mainly with RMS40 (OR = 0.97; 95% CI = 0.87-0.99; p = 0.03) and LAS40 (OR = 1.06; 95% IC = 1.01-1.11; p = 0.03). We formulated a risk score including those variables, and evaluated its discriminative performance in our sample. The presence of fibrosis with increasing of LAS40 and decreasing of RMS40 showed a good ability to distinguish between patients with and without rejection (AUC = 0.82; p < 0.01), assuming a cutoff point of sensitivity = 83.3% and specificity = 60%. Conclusion: The SAECG distinguished between patients with and without rejection. The usefulness of the proposed risk score must be demonstrated in larger follow-up studies.

Fundamento: A rejeição do transplante cardíaco origina zonas de condução lenta e fragmentada. O eletrocardiograma de alta resolução (ECGAR) é um método potencial de estratificação de risco da rejeição. Objetivo: Elaborar um escore de risco para rejeição, recorrendo ao ECGAR. Métodos: Estudaram-se 28 pacientes transplantados. Numa primeira fase, baseando-nos no diagnóstico de rejeição aguda, dividimos a amostra em dois grupos (5 pacientes com rejeição, 23 sem rejeição). Numa segunda fase, a divisão da amostra teve em conta o diagnóstico de rejeição em pelo menos uma biopsia realizada durante o seguimento (rejeição pm1) (18 pacientes com rejeição, 10 sem rejeição). Resultados: Para rejeição aguda, a única variável a revelar associação foi fibrose, evidenciando um aumento do risco de rejeição quando presente no ECG (OR = 19; IC 95% = 1,65-218,47; p = 0,02). Para rejeição pm1, constatamos que, para cada diminuição de unidade da RMS40, ocorre aumento de 7% do risco de rejeição (OR = 0,97; IC 95% = 0,87-0,99; p = 0,03) e que o aumento da LAS40 aumenta 1,06 vez o risco de rejeição (OR = 1,06; IC 95% = 1,01-1,11; p = 0,03). Formulamos um escore constituído por essas variáveis e aplicamos aos 28 indivíduos da amostra. A associação de fibrose, valores crescentes da LAS40 e valores decrescentes da RMS40 tem uma boa capacidade para distinguir doentes com e sem rejeição (AUC = 0,82; p < 0,01), assumindo um ponto de corte com sensibilidade = 83,3% e especificidade = 60%. Conclusão: O ECGAR distingue doentes com e sem rejeição. A utilidade do escore proposto deverá ser demonstrada em estudos de seguimento englobando uma amostra de maiores dimensões.

Diagnosis of Rejection by Analyzing Ventricular Late Potentials in Heart Transplant Patients.

BACKGROUND: Heart transplant rejection originates slow and fragmented conduction. Signal-averaged ECG (SAECG) is a stratification method in the risk of rejection. OBJECTIVE: To develop a risk score for rejection, using SAECG variables. METHODS: We studied 28 transplant patients. First, we divided the sample into two groups based on the occurrence of acute rejection (5 with rejection and 23 without). In a second phase, we divided the sample considering the existence or not of rejection in at least one biopsy performed on the follow-up period (rejection pm1: 18 with rejection and 10 without). RESULTS: On conventional ECG, the presence of fibrosis was the only criterion associated with acute rejection (OR = 19; 95% CI = 1.65-218.47; p = 0.02). Considering the rejection pm1, an association was found with the SAECG variables, mainly with RMS40 (OR = 0.97; 95% CI = 0.87-0.99; p = 0.03) and LAS40 (OR = 1.06; 95% IC = 1.01-1.11; p = 0.03). We formulated a risk score including those variables, and evaluated its discriminative performance in our sample. The presence of fibrosis with increasing of LAS40 and decreasing of RMS40 showed a good ability to distinguish between patients with and without rejection (AUC = 0.82; p < 0.01), assuming a cutoff point of sensitivity = 83.3% and specificity = 60%. CONCLUSION: The SAECG distinguished between patients with and without rejection. The usefulness of the proposed risk score must be demonstrated in larger follow-up studies.

Structure of mycobacterial maltokinase, the missing link in the essential GlgE-pathway.

A novel four-step pathway identified recently in mycobacteria channels trehalose to glycogen synthesis and is also likely involved in the biosynthesis of two other crucial polymers: intracellular methylglucose lipopolysaccharides and exposed capsular glucan. The structures of three of the intervening enzymes - GlgB, GlgE, and TreS - were recently reported, providing the first templates for rational drug design. Here we describe the structural characterization of the fourth enzyme of the pathway, mycobacterial maltokinase (Mak), uncovering a eukaryotic-like kinase (ELK) fold, similar to methylthioribose kinases and aminoglycoside phosphotransferases. The 1.15 Šstructure of Mak in complex with a non-hydrolysable ATP analog reveals subtle structural rearrangements upon nucleotide binding in the cleft between the N- and the C-terminal lobes. Remarkably, this new family of ELKs has a novel N-terminal domain topologically resembling the cystatin family of protease inhibitors. By interfacing with and restraining the mobility of the phosphate-binding region of the N-terminal lobe, Mak's unusual N-terminal domain might regulate its phosphotransfer activity and represents the most likely anchoring point for TreS, the upstream enzyme in the pathway. By completing the gallery of atomic-detail models of an essential pathway, this structure opens new avenues for the rational design of alternative anti-tubercular compounds.

Papel neuroprotector da hipotermia terapêutica pós paragem cardio-respiratória / The neuroprotective role of therapeutic hypothermia after cardiac arrest

OBJECTIVOS: A hipotermia terapêutica demonstrou ter efeitos neuro e cardioprotectores, com melhoria da sobrevida e redução das sequelas neurológicas em doentes vítimas de paragem cardio-respiratória. O objectivo deste estudo foi avaliar a evolução dos doentes submetidos a hipotermia terapêutica após paragem cardio-respiratória. MÉTODOS: Estudo prospectivo observacional dos doentes submetidos a hipotermia terapêutica após paragem cardio-respiratória numa unidade de cuidados intensivos polivalente durante 10 meses. Aos doentes admitidos até 12 horas após paragem cardio-respiratória foi induzida a hipotermia terapêutica através da administração de fluidos arrefecidos e arrefecimento corporal externo e mantida a temperatura alvo, 33°C, durante 24 horas. RESULTADOS: Foram incluídos 12 doentes, idade (mediana) de 64 anos, 58 por cento do sexo masculino. A paragem cardio-respiratória ocorreu em meio hospitalar em 6 doentes. O índice de Charlson, o Sequential Organ Failure Assessment (SOFA) e o Acute Physiology and Chronic Health Evaluation II, no primeiro dia, foram 2.9 [IIQ 6.8], 11 [IIQ 2.75], e 24.5 [IIQ 15.25], respectivamente. A taxa de mortalidade na unidade de cuidados intensivos polivalente foi de 42 por cento (N=5). Dos 7 sobreviventes, 5 recuperaram o estado neurológico prévio à paragem cardio-respiratória. A hipotermia terapêutica foi iniciada cerca de 120 minutos [IIQ 78.75], após recuperação de circulação espontânea. A maioria dos doentes (75 por cento) necessitou de suporte vasopressor. Foi constatado, nos 3 dias subsequentes à paragem cardio-respiratória e hipotermia terapêutica, uma diminuição do valor mediano de SOFA (11[IIQ 2.75], no dia 0, 10 [IIQ 3], no dia 1 e 7 [IIQ 4.5], no dia 2). CONCLUSÃO: A aplicação de um protocolo de hipotermia terapêutica revelou ser simples e eficaz e permitiu obter em doentes com indicação, boa recuperação neurológica.

OBJECTIVES: Therapeutic hypothermia following cardiorespiratory arrest has been demonstrated to have cardio- and neuroprotective effects, resulting in improved survival and better neurological outcomes. The objective of this study was to assess the outcomes of patients undergoing therapeutic hypothermia following cardiorespiratory arrest. METHODS: A prospective, 10-month observational study of patients admitted to an intensive care unit and undergoing therapeutic hypothermia after cardiorespiratory arrest was undertaken. Therapeutic hypothermia was induced by cold fluid administration and body surface cooling in patients admitted no more than 12 hours after resuscitation from cardiorespiratory arrest. A target temperature of 33ºC was maintained for 24 hours. RESULTS: Overall, 12 patients were included (median age 64 years, 58 percent male). Half of the cardiorespiratory arrests were in-hospital. The median first-day Charlson Index, Sequential Organ Failure Assessment (SOFA) and Acute Physiology and Chronic Health Evaluation II scores were of 2.9, 11 and 24.5, respectively. The intensive care unit mortality rate was 42 percent (N=5). Five of the 7 surviving patients recovered their pre-cardiorespiratory arrest neurological status. Hypothermia was initiated 120 min (median) after recovery of spontaneous circulation. Most patients (75 percent) required vasopressor support. During the first 3 days after cardiorespiratory arrest and therapeutic hypothermia, a progressive SOFA score decrease (median 11 on day 0, 10 on day 1 and 7 on day 2) was observed. DISCUSSION: In this study, therapeutic hypothermia was applied to all post-cardiorespiratory arrest patients and demonstrated good neurological outcome in surviving patients.