Effect of Thermal Shock Conditions on the Low-Cycle Fatigue Performance of 3D-Printed Materials: Acrylonitrile Butadiene Styrene, Acrylonitrile-Styrene-Acrylate, High-Impact Polystyrene, and Poly(lactic acid).

3D printing technology is becoming a widely adopted alternative to traditional polymer manufacturing methods. The most important advantage of 3D printing over traditional manufacturing methods, such as injection molding or extrusion, is the short time from the creation of a new design to the finished product. Nevertheless, 3D-printed parts generally have lower strength and lower durability compared to the same parts manufactured using traditional methods. Resistance to the environmental conditions in which a 3D-printed part operates is important to its durability. One of the most important factors that reduces durability and degrades the mechanical properties of 3D-printed parts is temperature, especially rapid temperature changes. In the case of inhomogeneous internal geometry and heterogeneous material properties, rapid temperature changes can have a significant impact on the degradation of 3D-printed parts. This degradation is more severe in high-humidity environments. Under these complex service conditions, information on the strength and fatigue behavior of 3D-printed polymers is limited. In this study, we evaluated the effects of high humidity and temperature changes on the durability and strength properties of 3D-printed parts. Samples made of commonly available materials such as ABS (Acrylonitrile Butadiene Styrene), ASA (Acrylonitrile-Styrene-Acrylate), HIPS (High-Impact Polystyrene), and PLA (Poly(lactic acid)) were subjected to temperature cycling, from an ambient temperature to -20 °C, and then were heated to 70 °C. After thermal treatment, the samples were subjected to cyclic loading to determine changes in their fatigue life relative to non-thermally treated reference samples. The results of cyclic testing showed a decrease in durability for samples made of ASA and HIPS. The ABS material proved to be resistant to the environmental effects of shocks, while the PLA material exhibited an increase in durability. Changes in the internal structure and porosity of the specimens under temperature changes were also evaluated using microcomputed tomography (microCT). Temperature changes also affected the porosity of the samples, which varied depending on the material used.

Comparison of Surgical Procedures in the Treatment of Hip Periprosthetic Infection.

Objective The present study aimed to compare the cure rate recovery time and Merle d'Aubigné-Postel functional (MAPF) score after single-stage surgery (C1T) or two-stage surgery (C2T) to treat prosthetic infections of the hip considering sociodemographic and clinical features of the patients. Materials and Methods The present retrospective study occurred in a single center from 2011 to 2014 with 37 studied cases including 26 treated with C1T and 11 with C2T. We compared the cure rate recovery time and MAPF score in the two groups as well as the sociodemographic and clinical features of the patients. We also considered surgical complications and the most common infectious agents. Results The C1T group had a faster functional recovery than the C2T group but there were no significant differences in the cure rate surgical complications or MAPF score. However C1T group patients were significantly younger which may have influenced the outcomes. Staphylococcus spp. was the most common infectious agent (62%). Conclusion Although C2T appears superior regarding infection cure C1T may be preferable for faster functional recovery. However it is critical to consider individual patient characteristics when choosing treatment. Further research with a larger sample size is required to confirm these results.

Comparison of Surgical Procedures in the Treatment of Hip Periprosthetic Infection / Comparação entre procedimentos cirúrgicos no tratamento da infecção de prótese do quadril

Abstract Objective The present study aimed to compare the cure rate recovery time and Merle d'Aubigné-Postel functional (MAPF) score after single-stage surgery (C1T) or two-stage surgery (C2T) to treat prosthetic infections of the hip considering sociodemographic and clinical features of the patients. Materials and Methods The present retrospective study occurred in a single center from 2011 to 2014 with 37 studied cases including 26 treated with C1T and 11 with C2T. We compared the cure rate recovery time and MAPF score in the two groups as well as the sociodemographic and clinical features of the patients. We also considered surgical complications and the most common infectious agents. Results The C1T group had a faster functional recovery than the C2T group but there were no significant differences in the cure rate surgical complications or MAPF score. However C1T group patients were significantly younger which may have influenced the outcomes. Staphylococcus spp. was the most common infectious agent (62%). Conclusion Although C2T appears superior regarding infection cure C1T may be preferable for faster functional recovery. However it is critical to consider individual patient characteristics when choosing treatment. Further research with a larger sample size is required to confirm these results.

Resumo Objetivo Comparar a taxa de cura, o tempo de recuperação e a pontuação na escala funcional de Merle d'Aubigné-Postel (EFMA) entre a cirurgia em tempo único (C1T) e a cirurgia em dois tempos (C2T) no tratamento de infecções protéticas do quadril, considerando as características sociodemográficas e clínicas dos pacientes. Materiais e Métodos Foi realizado um estudo retrospectivo num único centro, entre 2011 e 2014, com um total de 37 casos estudados, sendo 26 tratados com C1T e 11 com C2T. Foram comparadas a taxa de cura, o tempo de recuperação e a pontuação EFMA entre os dois grupos, bem como as características sociodemográficas e clínicas dos pacientes. Foram também consideradas as complicações cirúrgicas e o agente infeccioso mais comum. Resultados O grupo C1T teve uma recuperação funcional mais rápida do que o grupo C2T, mas não houve diferenças significativas na taxa de cura, nas complicações cirúrgicas ou na pontuação EFMA. No entanto, o grupo C1T era significativamente mais jovem, o que pode ter influenciado os resultados. Staphylococcus spp. foi o agente infeccioso mais comum (62%). Conclusão Embora a C2T pareça ser superior em termos de cura de infecção, a C1T pode ser preferível para uma recuperação funcional mais rápida. No entanto, as características individuais dos pacientes devem ser consideradas na escolha do tratamento. São necessárias mais pesquisas com um tamanho de amostra maior para confirmar estes resultados.

Trochanteric fractures: Tip-Apex distance, Calcar Tip-Apex distance, and Chang criteria-a multiple variable analysis.

Failure of osteosynthesis is a common complication of the nailing of trochanteric fractures which typically occurs through form of cut-out. Tip-Apex distance (TAD), Calcar Tip-Apex distance (CalTAD), and Chang criteria are validated variables to predict failure of cephalomedullary nailing. This is a retrospective study which analyzes treatment of trochanteric fractures from 2018 to 2020 (n = 296) evaluating postoperative radiographs and factors of mechanical failure. Our objective was to assess correlation among these variables and their influence on mechanical failure, either individually or creating a new score. Our results support the CalTAD and Chang's criteria as valid predictors of mechanical failure. Furthermore, they empathize the importance of fracture reduction and proper placement of cervical screw. To our knowledge, this is the first study performing multivariate analysis including these 3 variables.

Recurrent Anterior Shoulder Dislocation After Trauma with Coracoid Apophysis Fracture - A Rare Association / Luxação anterior recorrente do ombro após traumatismo com fratura apófise coracoide - Uma associação rara

Abstract Anterior dislocations represent about 96% of total shoulder dislocations, with recurrence/instability being more common in young patients. Injury of other shoulder structures is frequent, namely bony Bankart lesion. However, the association with coracoid apophysis fracture is very rare. The present article describes the clinical case of a 67-year-old man who presented to the emergency department with complaints of persistent omalgia, with acute episodes, beginning after a fall from his own height. The patient also presented history of shoulder trauma 3 months earlier, which was evaluated at another hospital. Shoulder anterior dislocation was observed radiographically, and the computed tomography (CT) confirmed bone erosion of the anteroinferior part of the glenoid (bone loss of about 50% of the anteroposterior diameter in the lower region of the glenoid), with almost complete resorption of the bony Bankart lesion (apparent in later analysis of the radiography of the initial traumatic episode). Connectedly, a transverse fracture of the coracoid apophysis (type II in the Ogawa classification) was diagnosed. The patient was submitted to surgical treatment, with anterior bone stop confection using the remnant of the fractured fragment of the coracoid supplemented by tricortical autologous iliac graft, fixed with cannulated screws (according to the Bristow-Latarjet and Eden-Hybinett techniques). In the postoperative follow-up, a good functional result was observed, with no new episodes of dislocation and no significant pain complaints. A rare association of shoulder lesions is described, and the challenge of their treatment is highlighted, given the late diagnosis, as in the case presented.

Resumo As luxações anteriores representam cerca de 96% do total de luxações do ombro, sendo a recidiva/instabilidade mais comum em pacientes jovens. A lesão de outras estruturas do ombro é frequente, nomeadamente a lesão óssea de Bankart. Contudo, a associação com a fratura da apófise coracoide é muito rara. Este artigo descreve o caso clínico de um homem de 67 anos que recorreu ao serviço de urgência com queixas de omalgia persistente, com episódios de agudização, iniciados após queda da própria altura. O paciente apresentava ainda histórico de trauma do ombro 3 meses antes, avaliado em outro hospital. A luxação anterior do ombro foi constatada radiograficamente, e a tomografia computorizada (TC) do ombro confirmou erosão óssea da vertente anteroinferior da glenoide (perda óssea de cerca de 50% do diâmetro anteroposterior na região inferior da glenoide), com reabsorção quase completa de lesão óssea de Bankart (aparente em análise a posteriori da radiografia do episódio traumático inicial). Associadamente, foi diagnosticada uma fratura transversa da apófise coracoide (tipo II da classificação de Ogawa). O paciente foi submetido ao tratamento cirúrgico, com confecção do batente ósseo anterior utilizando remanescente do fragmento fraturado do coracoide suplementado por enxerto autólogo tricortical do ilíaco, fixados com parafusos canulados (de acordo com as técnicas de Bristow-Latarjet e Eden-Hybinett). No seguimento pós-operatório, foi observado um bom resultado funcional, sem novos episódios de luxação e sem queixas álgicas significativas. Descreve-se uma associação rara de lesões do ombro, e salienta-se o desafio do tratamento das mesmas dado o seu diagnóstico tardio, como no caso apresentado.

Effect of nutrition status and inflammatory stimuli on ghrelin and peptide-YY levels among critically ill children: A prospective and observational study.

BACKGROUND: Ghrelin and peptide-YY (PYY) are two gut peptides with apparent opposing actions. In normal conditions, ghrelin and PYY work together in synergy to regulate energy homeostasis. During critical illness, series of metabolic, endocrine, and inflammatory changes take place in response to a severe insult. Emerging studies recorded alterations in gut hormone levels in critically ill adults. This study aims to assess the effect of inflammation, nutrition, and feeding status on ghrelin and PYY levels in critically ill children. METHODS: In this prospective study, we collected blood samples from critically ill children on days 2 or 3 of pediatric intensive care unit (PICU) admission for the analysis of serum ghrelin, PYY, and inflammatory markers. Data related to the intake anthropometry, as well as other clinical data, were collected from patients' records. Multiple linear regression analysis was used to identify factors affecting serum levels of these hormones. RESULTS: Forty-two children admitted to the PICU were included in this study. Ghrelin level was influenced by admission nutrition status of the children and age. PYY was influenced by macronutrient intake and age. Inflammatory markers also showed an association with the measured levels of these hormones, with C-reactive protein being positively associated with ghrelin levels and tumor necrosis factor alpha showing a positive association with PYY levels. CONCLUSION: Although ghrelin and PYY have been linked to feeding status in healthy patients, during critical illness there might be other factors, such as inflammation and nutrition status, that might contribute to the changes observed in ghrelin/PYY profiles.

Uncommon causes of nerve compression in the distal forearm.

INTRODUCTION: Nerve compression by anomalous masses located at the wrist and distal forearm is an infrequent condition. They may compress underlying structures in the carpal tunnel region, causing pain and paresthesias, which leads to the wrong diagnosis of carpal tunnel syndrome. CLINICAL CASES: We present three cases of patients with symptomatology and clinical tests compatible with compression of the median nerve in the carpal tunnel but whose physical examination showed a soft mass in the distal region of the forearm which was compressing the median nerve, as demonstrated by ultrasound evaluation. DISCUSSION: The reported cases of accessory muscles or lipomas described in the literature as causes of median nerve compression clinic are mainly described only after the surgical decompression of the carpal tunnel, due to the maintenance of residual symptoms. CONCLUSION: Careful examination with an ultrasound evaluation prior to surgery may help to identify these cases and help planning surgical treatment.

Calcaneal Plate for Medial Femoral Condyle Fractures-Is This It? A Clinical Case.

Management of unicondylar femoral fractures is mainly done by open reduction and internal fixation. Anatomic reduction in the articular surface is paramount in this type of lesion. Medial condyle fractures lack specific osteosynthesis material for fixation. We report a case resolved with the sparsely documented technique using calcaneal plate fixation.

Fracture Surface Behavior of 34CrNiMo6 High-Strength Steel Bars with Blind Holes under Bending-Torsion Fatigue.

The present study evaluates the fracture surface response of fatigued 34CrNiMo6 steel bars with transverse blind holes subjected to bending with torsion loading. The analysis of the geometric product specification was performed by means of height parameters Sx, functional volume parameters Vx, and fractal dimension Df. Surface topography measurements were carried out using an optical profilometer with focus variation technology. The experimental results show that the doubling the bending to torsion moment ratio B/T from B/T = 1 to B/T = 2, maintaining the same normal stress amplitude, greatly reduces both Sa, Vv as well as the fractal dimension Df of the analyzed specimen fractures by 32.1%, 29.8%, and 16.0%, respectively. However, as expected, a two-fold increase in the B/T ratio, maintaining the same normal stress amplitude, resulted in a larger number of cycles to fatigue crack initiation, Ni, which can be explained by the lower shear stress level. These experiments prove that parameters Sx, Vx, Df are smaller for larger Ni values, which is an important finding. In addition, it was found a high consistency of surface topography measurements for the two sides of the broken specimens. The proposed methodology is both reliable and applicable for other engineering applications involving different geometries and loading conditions.

Association between enteral macronutrient delivery and inflammatory response in critically ill children.

BACKGROUND AND AIMS: An important goal of nutrition support in paediatric critical illness is minimising catabolism. While focussing on providing full energy requirements, macronutrient balance is often neglected. Studies suggest that there is interplay between nutrition and inflammation. We aimed to assess the amount of enteral macronutrients delivered compared to estimated requirements, and the association between delivered macronutrients and systemic inflammation in critically ill children. METHOD: We prospectively evaluated energy and macronutrient intake in critically ill children who required at least 72 h of mechanical ventilation. Data on enteral energy and macronutrient intake was collected and expressed as a percentage of the estimated requirements. Circulating levels of inflammatory cytokines were measured by ELISA and association assessed with delivery of macronutrients from the previous 24 h. RESULTS: A total of 87 children (0-16 years) were included in this study. By day 3 the median (IQR) intake of energy, fat, carbohydrate (CHO) and protein were 75% (50-103), 85% (43-120), 63% (42-102) and 45% (23-65) respectively. We have also shown that delivery of enteral fat and protein was associated with elevation in the levels of tumour necrosis factor alpha (TNF-α) and interleukin-6 (IL-6). CONCLUSION: The inflammatory response in critically ill children is influenced by the amount of enteral fat and protein delivered. Our data suggests that within the feed delivered, fat is often higher than protein and CHO. It is crucial to take into account the proportion of macronutrients required and not only aim to achieve the energy goal.

Pilot Mechanistic Study of Insulin Modulation of Somatotrophic Hormones, Inflammation, and Lipid Metabolism During Critical Illness in Children.

OBJECTIVES: To evaluate the mechanism of insulin modulation on somatotrophic response, inflammation, and lipid metabolism in critically ill children. DESIGN: Open-label randomized mechanistic study. SETTING: Two-center, tertiary PICU study. PATIENTS: Thirty critically ill children between 1 month and 14 years old, requiring mechanical ventilation and with evidence of two or more organ system failures. INTERVENTIONS: Randomized physiologic design of hyperinsulinemic-euglycemic clamp using continuous insulin infusion at 0.1 U/kg/hr versus conventional management. MEASUREMENTS AND MAIN RESULTS: Thirteen children underwent hyperinsulinemic-euglycemic clamp. Blood samples for somatotrophic, inflammatory, and metabolic evaluation were obtained before randomization, and 24 and 72 hours later. A growth hormone oscillation profile was obtained during the first night. There was no difference between groups at baseline. Growth hormone resistance, increased proinflammatory cytokines, and increased lipolysis with low lipoprotein levels were present in all patients. Hyperinsulinemic-euglycemic clamp did not affect growth hormone, insulin-like growth factor-1 or insulin-like growth factor binding protein-3 levels. By day 2, insulin reduced insulin-like growth factor binding protein-1 levels. Tumor necrosis factor-α and interleukin-1ß were similar in both groups, whereas interleukin-6 levels reduced over time only in children receiving hyperinsulinemic-euglycemic clamp. Hyperinsulinemic-euglycemic clamp also decreased free fatty acid levels, which was accompanied by increased low-density lipoprotein cholesterol and relative increase in high-density lipoprotein levels. Total cholesterol and triglycerides were unchanged. CONCLUSIONS: Insulin does not reverse most of the somatotrophic changes induced by the stress of critical illness. Rather, it may improve lipid metabolism and down-regulate some markers of the inflammatory response.

Management protocols for status epilepticus in the pediatric emergency room: systematic review article / Protocolos de manejo de estado de mal epiléptico no pronto socorro pediátrico: análise sistemática

Abstract Objective: This systematic review of national or regional guidelines published in English aimed to better understand variance in pre-hospital and emergency department treatment of status epilepticus. Sources: Systematic search of national or regional guidelines (January 2000 to February 2017) contained within PubMed and Google Scholar databases, and article reference lists. The search keywords were status epilepticus, prolonged seizure, treatment, and guideline. Summary of findings: 356 articles were retrieved and 13 were selected according to the inclusion criteria. In all six pre-hospital guidelines, the preferred route of medication administration was to use alternatives to the intravenous route: all recommended buccal and intranasal midazolam; three also recommended intramuscular midazolam, and five recommended using rectal diazepam. All 11 emergency department guidelines described three phases in therapy. Intravenous medication, by phase, was indicated as such: initial phase - ten/11 guidelines recommended lorazepam, and eight/11 recommended diazepam; second phase - most (ten/11) guidelines recommended phenytoin, but other options were phenobarbital (nine/11), valproic acid (six/11), and either fosphenytoin or levetiracetam (each four/11); third phase - four/11 guidelines included the choice of repeating second phase therapy, whereas the other guidelines recommended using a variety of intravenous anesthetic agents (thiopental, midazolam, propofol, and pentobarbital). Conclusions: All of the guidelines share a similar framework for management of status epilepticus. The choice in route of administration and drug type varied across guidelines. Hence, the adoption of a particular guideline should take account of local practice options in health service delivery.

Resumo Objetivo: Esta análise sistemática de diretrizes nacionais ou regionais publicadas em inglês tem como objetivo entender melhor a diferença no tratamento do estado de mal epiléptico pré-hospitalar e no departamento de emergência. Fontes: Pesquisa sistemática de diretrizes nacionais ou regionais (janeiro de 2000 a fevereiro de 2017) contidas nas bases de dados do Pubmed e do Google Acadêmico e listas de referência de artigos. As palavras-chave da busca foram estado de mal epiléptico, convulsão prolongada, tratamento e diretriz. Resumo dos achados: Foram identificados 356 artigos e 13 foram selecionados de acordo com os critérios de inclusão. Em todas as seis diretrizes pré-hospitalares, o caminho preferencial de administração da medicação foi usar opções à via intravenosa: todas recomendaram midazolam bucal e intranasal; três também recomendaram midazolam intramuscular; e cinco recomendaram usar o diazepam via retal. Todas as 11 diretrizes de departamento de emergência descreveram três fases na terapia. No que diz respeito à medicação intravenosa, por fase, temos: fase inicial - 10/11 diretrizes recomendaram lorazepam e 8/11 recomendaram diazepam; segunda fase - a maioria (10/11) das diretrizes recomendou fenitoína, porém outras opções foram fenobarbital (9/11), ácido valproico (6/11) e fosfenitoína ou levetiracetam (individualmente, 4/11); terceira fase - 4/11 diretrizes incluíram a opção de repetir a terapia da segunda fase, ao passo que as outras diretrizes recomendaram usar diversos agentes anestésicos intravenosos (tiopental, midazolam, propofol e pentobarbital). Conclusões: Todas as diretrizes compartilham uma estrutura semelhante para manejo do estado de mal epiléptico. A escolha da via de administração e do tipo de medicamento variou em todas as diretrizes. Assim, a adoção de uma diretriz específica deve levar em consideração as opções da prática local na prestação de serviços de saúde.

Mesenteric near-infrared spectroscopy and risk of gastrointestinal complications in infants undergoing surgery for congenital heart disease.

We hypothesised that lower mesenteric near-infrared spectroscopy values would be associated with a greater incidence of gastrointestinal complications in children weighing <10 kg who were recovering from cardiac surgery. We evaluated mesenteric near-infrared spectroscopy, central venous oxygen saturation, and arterial blood gases for 48 hours post-operatively. Enteral feeding intake, gastrointestinal complications, and markers of organ dysfunction were monitored for 7 days. A total of 50 children, with median age of 16.7 (3.2-31.6) weeks, were studied. On admission, the average mesenteric near-infrared spectroscopy value was 71±18%, and the systemic oxygen saturation was 93±7.5%. Lower admission mesenteric near-infrared spectroscopy correlated with longer time to establish enteral feeds (r=-0.58, p<0.01) and shorter duration of feeds at 7 days (r=0.48, p<0.01). Children with gastrointestinal complications had significantly lower admission mesenteric near-infrared spectroscopy (58±18% versus 73±17%, p=0.01) and higher mesenteric arteriovenous difference of oxygen at admission [39 (23-47) % versus 19 (4-27) %, p=0.02]. Based on multiple logistic regression, admission mesenteric near-infrared spectroscopy was independently associated with gastrointestinal complications (Odds ratio, 0.95; 95% confidence interval, 0.93-0.97; p=0.03). Admission mesenteric near-infrared spectroscopy showed an area under the receiver operating characteristic curve of 0.76 to identify children who developed gastrointestinal complications, with a suggested cut-off value of 72% (78% sensitivity, 68% specificity). In this pilot study, we conclude that admission mesenteric near-infrared spectroscopy is associated with gastrointestinal complications and enteral feeding tolerance in children after cardiac surgery.

Early postoperative outcomes following surgical repair of complete atrioventricular septal defects: is down syndrome a risk factor?

OBJECTIVE: To evaluate the impact of Down syndrome on the early postoperative outcomes of children undergoing complete atrioventricular septal defect repair. DESIGN: Retrospective cohort study. SETTING: Single tertiary pediatric cardiac center. PATIENTS: All children admitted to PICU following biventricular surgical repair of complete atrioventricular septal defect from January 2004 to December 2009. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 107 children, 67 with Down syndrome, were included. Children with Down syndrome were operated earlier: 4 months (interquartile range, 3.5-6.6) versus 5.7 months (3-8.4) for Down syndrome and non-Down syndrome groups, respectively (p < 0.01). There was no early postoperative mortality. There was no significant difference in the prevalence of dysplastic atrioventricular valve between the two groups. Two children (2.9%) from Down syndrome and three children (7.5%) from non-Down syndrome group required early reoperation (p = 0.3). Junctional ectopic tachycardia was the most common arrhythmia, and the prevalence of junctional ectopic tachycardia was similar between the two groups (9% and 10% in Down syndrome and non-Down syndrome, respectively, p = 1). One patient from each group required insertion of permanent pacemaker for complete heart block. Children with Down syndrome had significantly higher prevalence of noncardiac complications, that is, pneumothorax, pleural effusions, and infections (p < 0.01), than children without Down syndrome. There was a trend for longer duration of mechanical ventilation in children with Down syndrome (41 hr [20-61 hr] vs 27.5 hr [15-62 hr], p = 0.2). However, there was no difference in duration of PICU stay between the two groups (2 d [1.3-3 d] vs 2 d [1-3 d], p = 0.9, respectively). CONCLUSIONS: In our study, we found no difference in the prevalence of atrioventricular valve dysplasia between children with and without Down syndrome undergoing complete atrioventricular septal defect repair. This finding contrasts with previously published data, and further confirmatory studies are required. Although clinical outcomes were similar, children with Down syndrome had a significantly higher prevalence of noncardiac complications in the early postoperative period than children without Down syndrome.

Molecular mechanism of the hydration of Candida antarctica lipase B in the gas phase: Water adsorption isotherms and molecular dynamics simulations.

Hydration is a major determinant of activity and selectivity of enzymes in organic solvents or in gas phase. The molecular mechanism of the hydration of Candida antarctica lipase B (CALB) and its dependence on the thermodynamic activity of water (a(w)) was studied by molecular dynamics simulations and compared to experimentally determined water sorption isotherms. Hydration occurred in two phases. At low water activity, single water molecules bound to specific water binding sites at the protein surface. As the water activity increased, water networks gradually developed. The number of protein-bound water molecules increased linearly with a(w), until at a(w)=0.5 a spanning water network was formed consisting of 311 water molecules, which covered the hydrophilic surface of CALB, with the exception of the hydrophobic substrate-binding site. At higher water activity, the thickness of the hydration shell increased up to 10 A close to a(w)=1. Above a limit of 1600 protein-bound water molecules the hydration shell becomes unstable and the formation of pure water droplets occurs in these oversaturated simulation conditions. While the structure and the overall flexibility of CALB was independent of the hydration state, the flexibility of individual loops was sensitive to hydration: some loops, such as those part of the substrate-binding site, became more flexible, while other parts of the protein became more rigid upon hydration. However, the molecular mechanism of how flexibility is related to activity and selectivity is still elusive.

Controle glicêmico e terapia insulínica em sepse e doença crítica / Glycemic control and insulin therapy in sepsis and critical illness

OBJETIVO: Revisar a literatura sobre a fisiopatologia de hiperglicemia e controle glicêmico em crianças e adultos com sepse e doença crítica. FONTES DE DADOS: Pesquisa não sistemática da literatura médica através da base de dados MEDLINE usando os termos hiperglicemia, controle glicêmico, terapia insulínica intensiva, sepse e terapia intensiva. Os artigos foram selecionados de acordo com sua relevância, conforme a opinião dos autores. SÍNTESE DOS DADOS: A hiperglicemia é freqüente em crianças com doenças críticas e está associada a desfecho negativo. Em adultos, não há um consenso sobre a eficácia e segurança do controle glicêmico. Descrevemos os possíveis mecanismos envolvidos em toxicidade da glicose e os efeitos benéficos do controle glicêmico. Estudos iniciais demonstraram que o uso de insulina para atingir controle glicêmico reduziu a morbimortalidade em terapia intensiva em adultos; no entanto, estudos recentes não confirmaram esses achados. É importante destacar que o controle glicêmico está evidentemente associado a aumento da incidência de hipoglicemia. A eficácia do controle glicêmico ainda não foi estudada em crianças criticamente doentes. CONCLUSÃO: O controle glicêmico é uma nova opção terapêutica em terapia intensiva. Evidências conflitantes em adultos significam que, antes de aplicar esta abordagem em pediatria, é necessário avaliá-la em ensaio clínico.

OBJECTIVE:To review the literature about the pathophysiology of hyperglycemia and glycemic control in children and adults with sepsis and critical illness. SOURCES: Non-systematic survey of the medical literature using MEDLINE and terms hyperglycemia, glycemic control, intensive insulin therapy, sepsis and intensive care. Articles were selected according to their relevance based on the authors' opinion. SUMMARY OF THE FINDINGS: Hyperglycemia is frequent in critically ill children and it is associated with worsened outcome. In adults, there is no consensus on the efficacy and safety of glycemic control. We describe the possible mechanisms involved in glucose toxicity and the beneficial effects of glycemic control. Initial studies showed that use of insulin to achieve glycemic control reduced morbidity and mortality in adult intensive care; however, recent studies have failed to confirm these findings. Importantly, it is evident that glycemic control is associated with increased incidence of hypoglycemia. The efficacy of glycemic control has not yet been studied in critically ill children. CONCLUSION: Glycemic control is a novel therapeutic option in critical care. Conflicting evidence in adults means that before we apply this approach to pediatrics it will need to be assessed in clinical trial.

Doença meningocócica e meningite / Meningococcal disease and meningitis

OBJETIVO: Revisar a literatura pertinente ao diagnóstico e tratamento de doença meningocócica (DM). FONTES DOS DADOS: Revisão não-sistemática da literatura médica através de busca na base de dados MEDLINE usando os seguintes termos: meningocócico, choque séptico, diagnóstico, e tratamento. Os artigos foram selecionados de acordo com sua relevância para o objetivo do trabalho e de acordo com a opinião dos autores. SíNTESE DOS DADOS: A DM é uma das principais causas de morte em crianças, devido à infecção. Ela progride rapidamente e é preciso um alto grau de suspeita para se estabelecer o diagnóstico precocemente. Intervenção precoce com fluidoterapia agressiva e antibioticoterapia podem melhorar significativamente o desfecho. Na unidade de tratamento intensivo pediátrico, uma grande quantidade de volume pode ser necessário durante os primeiros dias e drogas vasoativas são geralmente usadas. Coagulopatia é freqüente, mas não tem tratamento específico. O uso de colóides e esteróides pode ser benéfico, mas outros tratamentos novos tais como insulina e proteína C ativada ainda precisam ser investigados em mais detalhe. O tratamento de resgate com circulação extracorpórea pode ser adequado em casos com complicações causadas pela síndrome do desconforto respiratório agudo grave, mas não no caso de choque refratário. A meningite geralmente não é diagnosticada na DM por causa da gravidade da doença e da incapacidade de realização de uma punção lombar com segurança em um paciente com coagulopatia, coma, ou instabilidade hemodinâmica. Quando presentes, edema cerebral e fluxo sangüíneo cerebral anormal são as principais preocupações. O uso de solução hiperosmolar pode ser necessário, mas a principal intervenção terapêutica é garantir pressão sangüínea adequada para que a perfusão cerebral seja adequada. Convulsões e hiponatremia devem ser tratadas agressivamente. Esteróides parecem não afetar o desfecho na meningite meningocócica. CONCLUSÕES: DM...

OBJECTIVE: To review the literature relevant to diagnosis and management of meningococcal disease (MD). SOURCES: Non-systematic review of medical literature through the MEDLINE database using the terms meningococcal, septic shock, diagnosis, and treatment. Articles were selected according to their relevance to the objective of the study and according to the authors’ opinion. SUMMARY OF THE FINDINGS: MD is a leading cause of death due to infection in children. It progresses rapidly and a high level of suspicion is necessary for early diagnosis. Early intervention with aggressive fluid resuscitation and antibiotic therapy can significantly improve outcome. In the pediatric intensive care unit, a large amount of fluids may be required during the first few days and vasoactive drug infusions are often needed. Coagulopathy is frequent, but it has no specific treatment. The use of colloids and steroids may be beneficial, but other new therapies such as insulin and activated protein C still need further assessment. Rescue therapy with extracorporeal membrane oxygenation may be appropriate in cases complicated by severe acute respiratory distress syndrome, but not for refractory shock. Meningitis is often not diagnosed in MD because of the severity of illness and the inability to perform a lumbar puncture safely in a patient with coagulopathy, coma, or hemodynamic instability. When present, cerebral edema and altered cerebral blood flow are the main concerns. The use of osmolar solution may be necessary, but the main therapeutic intervention is to ensure adequate blood pressure for adequate cerebral perfusion. Seizures and hyponatremia should be aggressively treated. Steroids do not appear to affect outcome in meningococcal meningitis. CONCLUSIONS: MD is a life-threatening infection that requires early recognition and treatment. Time sensitive fluid resuscitation and antibiotic therapy are the most effective therapies for MD. Other therapies...

[Lung adenocarcinoma: application of the WHO 1999/2004 classification to the caseload of the Pathologic Anatomy Service at the Hospital of the Coimbra University]. / Adenocarcinoma do pulmão: Aplicação da classificação WHO 1999/2004 à casuística do Serviço de Anatomia Patológica do Hospital da Universidade de Coimbra.

A study of 701 primary adenocarcinomas of the lung was made at the Department of Pathology of the Hospital da Universidade de Coimbra for a period of fifteen years, between 1990 and 2004. In the same period 382 metastases were diagnosed, mainly from colon (119) and breast (66). The incidence of primary adenocarcinomas varied from 16 cases in 1990 to 49 cases in men and from 12 to 37 cases in women in that period. From 2001 onwards, the incidence was almost coincident in both genders. In the last four years, since 2001, patients were in the seventies at the time of diagnosis and a considerable number of cases were diagnosed after 80 years of age. The criteria defined by the WHO classification of Tumours of the Lung, Pleura, Thymus and Heart 2004 were applied to the primary adenocarcinomas of the lung and as was expected, bronchioloalveolar carcinomas had its incidence in women while acinar adenocarcinomas were diagnosed mainly in men. These conclusions were obtained via surgical specimens and when surgical biopsies were representative and those were mainly in stage IIB and IIIA. A number of 109 cases had the final diagnosis of adenocarcinoma of the lung based on morphology and immunohistochemistry criteria.