Search

AbstractObjectives:Pain management for infants undergoing cardiothoracic surgery primarily utilises opioid analgesics. There is a paucity of data available for the use of non-steroidal anti-inflammatory medications such as ketorolac in this patient population.Materials and Methods:This retrospective study evaluated patients between 30 days and 6 months undergoing cardiothoracic surgery. The primary endpoint evaluates ketorolac on reducing post-operative opioid use.Results:Of 243 evaluated patient, 145 met inclusion. Baseline demographics were similar amongst the cohorts. Patients administered ketorolac used less cumulative opiates, in morphine milligram equivalents, for post-op days (POD) 1–3 after surgery compared to patients not receiving ketorolac (9.47 versus 12.68; p = 0.002). The no-ketorolac group required more opiates on POD 1 (10.9 versus 5; p < 0.001) and POD 2 (4.2 versus 2.5; p = 0.006) with no difference found on POD 3 (2 versus 1.6; p = 0.2). There was a mean increase from baseline to highest serum creatinine level on POD 1–3 in the no-ketorolac group compared to the ketorolac group (0.15 versus 0.09 mg/dL; p < 0.014), with no difference in stage 1 or stage 2 acute kidney injury. There were no differences in average chest tube output in mL/kg/day (0.24 versus 0.32; p = 0.569) or need for transfusion (36% versus 24%; p = 0.125), respectively.Discussion:Scheduled administration of ketorolac after cardiothoracic surgery resulted in a significant reduction in opioid exposure, with no difference in rates of acute kidney injury or bleeding.

Congenital heart defects (CHDs) are birth defects that change the heart’s structure and blood flow. Patients with these conditions may require an artificially placed shunt to allow adequate circulation through the heart and lungs. Evaluating shunt function is paramount to sustaining the functionality and life of the shunt. Effective monitoring of the shunt requires noninvasive approaches to enable frequent monitoring of the shunt’s condition. In this work, we propose deep learning architectures for the classification of heart sounds associated with blood flow through shunts, obtained using a digital stethoscope from infants with ductal-dependent physiology. Specifically, we propose a convolutional neural network-long short-term memory model for shunt-type classification. In addition, a variational autoencoder model utilizing latent space representation addresses five clinically relevant tasks: 1) determining flow status during extracorporeal membrane oxygenation (ECMO); 2) discriminating flow patterns before and after shunt or pulmonary artery angioplasty; 3) identifying cyanotic conditions versus noncyanotic states; 4) change of flow dynamics over time; and 5) assessing flow status under elevated pulmonary artery pressure. Experimental results showcase the effectiveness of our approach, with the shunt-type classification achieving an F1 score of 0.88 and an area under the ROC curve (AUC) of 0.95. For the remaining tasks (1)–(5), support vector machine, random forest, and k-nearest neighbors models are trained using the latent space representations, yielding AUC values of 0.77, 0.72, 0.85, 0.60, and 0.81, respectively. This development demonstrates that the acoustic signals captured via a stethoscope may contain valuable information for monitoring shunt flow changes in patients with CHD.

As communications are increasingly taking place virtually, the ability to present well online is becoming an indispensable skill. Online speakers are facing unique challenges in engaging with remote audiences. However, there has been a lack of evidence-based analytical systems for people to comprehensively evaluate online speeches and further discover possibilities for improvement. This paper introduces SpeechMirror, a visual analytics system facilitating reflection on a speech based on insights from a collection of online speeches. The system estimates the impact of different speech techniques on effectiveness and applies them to a speech to give users awareness of the performance of speech techniques. A similarity recommendation approach based on speech factors or script content supports guided exploration to expand knowledge of presentation evidence and accelerate the discovery of speech delivery possibilities. SpeechMirror provides intuitive visualizations and interactions for users to understand speech factors. Among them, SpeechTwin, a novel multimodal visual summary of speech, supports rapid understanding of critical speech factors and comparison of different speech samples, and SpeechPlayer augments the speech video by integrating visualization of the speaker's body language with interaction, for focused analysis. The system utilizes visualizations suited to the distinct nature of different speech factors for user comprehension. The proposed system and visualization techniques were evaluated with domain experts and amateurs, demonstrating usability for users with low visualization literacy and its efficacy in assisting users to develop insights for potential improvement.

AbstractBackground:A subset of patients who develop post-surgical heart block have recovery of atrioventricular node function. Factors predicting recovery are not understood. We investigated our centre’s incidence of post-surgical heart block and examine factors associated with recovery of atrioventricular node function.Methods:We conducted a single-centre retrospective study of patients 0 – 21 years who underwent cardiac surgery between January 2010 and December 2019 and experienced post-operative heart block. Data including patient and clinical characteristics and operative variables were collected and analysed.Results:Of 6333 surgical hospitalisations, 128 (2%) patients developed post-operative heart block. Of the 128 patients, 90 (70%) had return of atrioventricular node function, and 38 (30%) had pacemaker placement. Of the 38 patients who underwent pacemaker placement, 6 (15.8%) had recovery of atrioventricular node function noted on long-term follow-up. Median time from onset of heart block to late atrioventricular node recovery was 13 days (Interquartile range: 5 – 117). Patients with single-ventricle physiology (p = 0.04), greater weight (p = 0.03), and shorter cardiopulmonary bypass time (p = 0.015) were more likely to have recovery. The use of post-operative steroids was similar between all groups (p = 0.445). Infectious or wound complications were similar between pacemaker groups (p = 1).Conclusions:Two per cent of patients who underwent congenital cardiac surgery developed post-operative heart block, and 0.6% underwent pacemaker placement. Early recovery of atrioventricular node was associated with greater weight at the time of surgery, single-ventricle physiology, and shorter cardiopulmonary bypass time. Late recovery of atrioventricular node conduction following pacemaker placement occurred in 15.8% of patients.

AbstractBackground:Following cardiac surgery, infants often remain endotracheally intubated upon arrival to the cardiac ICU. High-flow nasal cannula and non-invasive positive pressure ventilation are used to support patients following extubation. There are limited data on the superiority of either mode to prevent extubation failure.Methods:We conducted a single-centre retrospective study for infants (<1 year) and/or <10 kg who underwent cardiac surgery between 3/2019–3/2020. Data included patient and clinical characteristics and operative variables. The study aimed to compare high-flow nasal cannula versus non-invasive positive pressure ventilation following extubation and their association with extubation failure. Secondarily, we examined risk factors associated with extubation failure.Results:There were 424 patients who met inclusion criteria, 320 (75%) were extubated to high-flow nasal cannula, 104 (25%) to non-invasive positive pressure ventilation, and 64 patients (15%) failed extubation. The high-flow nasal cannula group had lower rates of extubation failure (11%, versus 29%, p= 0.001). Infants failing extubation were younger and had higher STAT score (p< 0.05). Compared to high-flow nasal cannula, non-invasive positive pressure ventilation patients were at 3.30 times higher odds of failing extubation after adjusting for patient factors (p< 0.0001).Conclusions:Extubation failure after cardiac surgery occurs in smaller, younger infants, and those with higher risk surgical procedures. Patients extubated to non-invasive positive pressure ventilation had 3.30 higher odds to fail extubation than patients extubated to high-flow nasal cannula. The optimal mode of respiratory support in this patient population is unknown.

Bleeding and thrombosis-related complications are common in pediatric cardiac patients supported by extracorporeal membrane oxygenation (ECMO) and are associated with morbidity and mortality. The purpose of this study was to evaluate the utility of aminocaproic acid (ACA), an antifibrinolytic agent, as it pertains to bleeding in pediatric cardiac patients on ECMO. This included a retrospective cohort study of pediatric cardiac patients receiving ACA while supported on ECMO between 2013 and 2017. For each patient, data were collected in three time intervals: the 24 hours before ACA initiation, and then 0–24 and 24–48 hours following ACA initiation. For each time frame, bleeding, component transfusion, and laboratory data were collected and analyzed. A total of 62 patients were included, representing 42% of our cardiac ECMO patients during the time period. ACA was initiated at 16.3 ± 8.7 hours following initiation of ECMO. The mean bleeding rate before ACA was 10.57 mL/kg/h, which reduced to 7.8 mL/kg/h in the 24-hour period after initiation of ACA and a further decrease to 3.65 mL/kg/h during the 24- to 48-hour time period following ACA initiation. ACA administration was associated with reduction in bleeding (p< .001) and packed red blood cell transfusions (p= .02), administration of fresh frozen plasma (p< .001), platelets (p= .017), cryoprecipitate (p= .05), factor VII (p= .002), and Cell Saver (p= .005). Hemoglobin and platelet count were stable, whereas prothrombin time (PT), partial thromboplastin time, and international normalized ratio (INR) showed significant reduction over the time course. ACA administration was not associated with specific adverse effects. A clinically significant reduction in bleeding amount, red blood cell transfusions, and other hematologic interventions occurred following ACA administration for pediatric patients on ECMO. Wider consideration for ACA use as a part of a multipronged strategy to manage bleeding during ECMO should be considered.

Introduction: Pediatric cardiac Extracorporeal Membrane Oxygenation (ECMO) is effective, however, bleeding and clotting issues continue to cause significant morbidity and mortality. The objective of this study was to assess the correlation between measures of anticoagulation, the heparin dose in pediatric cardiac ECMO patients as well as to assess covert coagulopathy as measured by thromboelastography (TEG).Methods: Retrospective study of cardiac ECMO patients in a large, academic referral center using anticoagulation data during the ECMO support.Results: Five hundred and eighty-four sets of anticoagulation tests and 343 TEG from 100 patients with median age of 26 days were reviewed. ECMO was post-surgical for congenital heart disease in 94% with resuscitation (ECPR) in 38% of the cases. Mean duration of support was 6.3 days. Overall survival to discharge was 35%. There was low but statistically significant correlation between individual anticoagulation measures and low correlation between Anti-Xa levels and heparin dose. There was no correlation between PTT and heparin dose. 343 TEG with Heparinase were reviewed to assess covert coagulopathy which was present in 25% of these. The coagulopathy noted was pro-hemorrhagic in almost all of the cases with high values of reaction time and kinetics and low values for angle and maximum amplitude.Conclusion: Coagulation monitoring on ECMO may benefit from addition of Heparinase TEG to diagnose covert coagulopathy which can contribute to significant hemorrhagic complications. There is a need for a prospective, thromboelastography guided intervention trial to reduce coagulopathy related morbidity and mortality in ECMO.

AbstractBackground:Children with CHD carry an additional burden of pulmonary insufficiency, often necessitating prolonged ventilatory support, especially in the peri-operative phase. There has been an increase in the utilisation of non-invasive ventilatory support for these children. The objective of this study was to evaluate the utilisation, safety, and outcomes of RAM cannula as a tool for escalation and de-escalation of respiratory support in paediatric cardiac patients less than one year of age.Methods:A single-centre retrospective cohort study of patients supported with RAM cannula.Results:A total of 275 instances of RAM use were included in the study, 81.1% being post-operative. Patients were stratified into escalation and de-escalation cohorts based on the indication of non-invasive ventilation. The success rate of using RAM cannula was 69.5% overall, 66.1% in the escalation group, and 72.8% in the de-escalation group. At baseline, age at cardiac ICU admission >30 days, FiO2 ≤ 40%, PaCO2 ≤ 50 mmHg; and after 12 hours of non-invasive ventilation support respiratory rate ≤ 60/min, PaO2 ≥ 50 mmHg, PaCO2 ≤ 50 mmHg; and absence of worsening on follow-up chest X-ray predicted the success with a sensitivity of 95% in the logistic regression model. Successful support was associated with a significantly shorter unit stay.Conclusions:RAM cannula can be safely used to provide non-invasive support to infants in the cardiac ICU for escalation and de-escalation of respiratory support. Factors associated with success can be used to make decisions about candidacy and appropriate timing of non-invasive ventilation use to maximise effectiveness.

Background: Patients with severe cardiac dysfunction, supported on extra-corporeal membrane oxygenation (ECMO), develop left atrial hypertension and often warrant atrial decompression. The procedural risks and outcomes, however, are not well established. Objective of this study is to understand the utilization, safety, and outcomes of atrial septostomy in children supported on venoarterial ECMO utilizing the IMPACT registry database.Methods: Data from 55 independent sites reporting to the registry was used for this descriptive study. Patients supported with cardiac ECMO that underwent percutaneous atrial septostomy (PAS) were included and data analyzed.Results: Between 2011 and 2018, 223 patients underwent atrial septostomy and were reported to the registry. Mean age was 4.65 years with 52% being males. Diagnoses of heart failure, sepsis, arrhythmia, and renal insufficiency were commonly noted prior to ECMO. The procedure was performed urgently or emergently in most cases (80%). PAS was associated with significant procedural complications such as arrhythmia (6.8%), tamponade (5.4%), and unplanned surgery (3.6%) but no procedural mortality. Overall hospital mortality was 46% (103/223) with 46 of these deaths occurring within 7 days of procedure. Regression analysis showed that African American race (vs Caucasian), race other than Caucasian, chronic lung disease and emergent procedure need were significantly associated with early post-procedural mortality (all p< 0.05).Conclusion: Using a large multicenter cardiac catheterization registry, we found that left atrial decompression can be performed without procedural mortality but is associated with significant morbidity. Impact of race, chronic lung disease and procedural urgency on early mortality warrant further studies.

Outcomes of out-of-hospital cardiac arrest are poor irrespective of the patient age group and circumstances. Survival to discharge after out-of-hospital arrest in children is less than 10%. Use of extracorporeal cardiopulmonary resuscitation is increasing and has been shown to improve outcomes in some situations. However, the candidacy for such augmentation is based on patient selection, institutional practices, and availability of an extracorporeal membrane oxygenation center. Often, duration of resuscitation, low flow state, presenting pH, and circumstances of arrest dictate candidacy for extracorporeal membrane oxygenation. We present a case of extremely prolonged resuscitation for out-of-hospital arrest in a pediatric patient, and we describe the use of mechanical compression device and transition to extracorporeal membrane oxygenation. We present the case outcome as well as brief discussion about controversies in extracorporeal cardiopulmonary resuscitation. We hope the case provides an opportunity for further discussion regarding opportunities to improve selection, use of extracorporeal cardiopulmonary resuscitation, and impact outcomes.

Background: Thrombosis within extracorporeal membrane oxygenation (ECMO) circuits is a common complication that dominates clinical management of patients receiving mechanical circulatory support. Prior studies have identified that over 80% of circuit thrombosis can be attributed to tubing-connector junctions.Methods: A novel connector was designed that reduces local regions of flow stagnation at the tubing-connector junction to eliminate a primary source of ECMO circuit thrombi. To compare clotting between the novel connectors and the traditional connectors, both in vitro loops and an in vivo caprine model of long-term (48 h) ECMO were used to generate tubing-connector junction clots.Results: In vitro, the traditional connectors uniformly (9/9) formed large thrombi, while novel connectors formed a small thrombus in only one of nine (p< 0.0001). In the long-term goat ECMO circuits, the traditional connectors exhibited more thrombi (p< 0.04), and these thrombi were more likely to protrude into the lumen of the tubing (p< 0.001).Conclusion: Both in vitro and in vivo validation experiments successfully recreated circuit thrombosis and demonstrate that the adoption of novel connectors can reduce the burden of circuit thrombosis.

Supplemental Digital Content is available in the text.The failing Fontan physiology may benefit from ventricular assist device (VAD) mechanical circulatory support, although a subpulmonary VAD placed at the Fontan connection has never successfully supported the Fontan circulation long term. The HeartWare CircuLite continuous flow VAD was examined for Fontan circulatory support in an in vitromock circulation. The VAD was tested in three different scenarios: VAD in parallel, baffle restricted VAD in parallel, and VAD in series. Successful support was defined as simultaneous decrease in inferior vena cava (IVC) pressure of 5 mm Hg or more and an increase in cardiac output (CO) to 4.25 L/min or greater. The VAD in parallel scenario resulted in a CO decrease to 3.46 L/min and 2.22 mm Hg decrease in IVC pressure. The baffle restricted VAD in parallel scenario resulted in a CO increase to 3.9 L/min increase in CO and 20.5 mm Hg decrease in IVC pressure (at 90% restriction). The VAD in series scenario resulted in a CO of 1.75 L/min and 5.9 mm Hg decrease in IVC pressure. We successfully modeled chronic failing Fontan physiology using patient-specific hemodynamic and anatomic data. Although unsuccessful in supporting Fontan patients as defined here, the HeartWare CircuLite VAD demonstrates the possibility to reduce Fontan pressure and increase CO with a VAD in the Fontan connection. This study provides insight into pump performance and design issues when attempting to support Fontan circulation. Refinements in VAD design with specific parameters to help support this patient population is the subject of our future work.

“Frontiers in Fontan Failure” was the title of a 2015 conference sponsored by Children's Healthcare of Atlanta and Emory University School of Medicine. In what is hoped to be the first of many such gatherings, speakers and attendees gathered to discuss the problem of long‐term clinical deterioration in these patients. Specific focuses included properly defining the problem and then discussing different treatment strategies, both medical and surgical. The health of the liver after Fontan palliation was a particular point of emphasis, as were quality of life and future directions.

Extracorporeal membrane oxygenation (ECMO) for cardiopulmonary support of critically ill patients is used frequently in the pediatric population. ECMO is burdened by complications, including thrombosis and hemorrhage. Here we demonstrate the focused location of clots, their histologic composition, and the relationship of in situthrombus to local hemodynamics in ECMO circuits. Pediatric ECMO circuits from Children’s Healthcare of Atlanta, Emory University (Atlanta, GA) were obtained after removal from extracorporeal support over a 2.5 year period (n = 50). All clots and material deposited within the circuit were recorded. Location of clot was compared with local hemodynamics. Most clots were adherent to the junctions made by the tubing and connectors, as opposed to being randomly disturbed throughout the circuit tubing (p<< 0.05). Loose, nonadherent clots were also found at the entry side of oxygenators. The clots colocated directly with zones of low shear rate. Histology revealed a fibrinous composition, consistent with coagulation potentiated by low shear. Centrifugal pump circuits (n = 16) had more clots than roller pump (n = 34) circuits (p<< 0.05). In addition, all centrifugal pumps had clots that formed at the top of the pump shaft. The ECMO circuits from our single-center study demonstrate the concentrated location of fibrin clots at low shear zones created by tubing-connector junctions. Type of pump also influences the frequency of clot formation. Since the mechanism of the majority of ECMO circuit thrombosis is low shear and fibrin driven, optimization of hemodynamics and anticoagulation regimen may reduce clot formation and bleeding.

Idiopathic infantile arterial calcification is a rare cause of infantile ischemic cardiac failure with extremely poor prognosis. We present the first case report of successful extracorporeal membrane oxygenation support and outcome in a child with idiopathic infantile arterial calcification (MAC). This 6-week-old infant presented with cardiogenic shock and circulatory collapse. The patient underwent extracorporeal cardiopulmonary resuscitation, allowing stabilization, diagnosis, and treatment with etidronate, followed by successful discharge to home.

Purpose Extracorporeal membrane oxygenation (ECMO) is a form of cardiopulmonary mechanical life support for critically ill patients. ECMO is burdened by both thrombotic and hemorrhagic complications. Recently there has been a clinical shift from roller pumps to centrifugal pumps. In this study, we report on bulk thrombus formation within pumps recovered from clinical use. We then replicate this thrombus formation in vitro.Methods Clinical pediatric ECMO circuits driven with the Sorin Revolution were collected from 16 patients. The location and extent of thrombus formation in the pumps were recorded. Pump heads were also tested in a laboratory circulatory loop. The location, extent, and appearance of the thrombi were recorded. Thrombi were examined histologically using Carstairs' stain.Results Gross thrombus was observed in all pump heads at the stainless steel bearing at the inlet. In 19% of the pumps larger thrombi grew into the head over the cone and along the vanes. The thrombi were adherent and cohesive upon extraction. The thrombus formation was strikingly similar between the clinical pump heads and in vitro pump heads. Histology of both clinical and experimental samples exhibited a platelet-rich thrombus.Conclusions Our studies have revealed platelet-rich thrombus in clinical and in vitro circuits. The location and composition of the thrombi suggest that the exposed metal shaft was initially covered by contact activated coagulation followed by large-scale growth by rapid platelet accumulation from high shear rates at the inlet. The in vitro system may be used to further identify the mechanisms for pump thrombus and test new designs.

The word innovation is derived from the Latin noun innovatus, meaning renewal or change. Although companies such as Google and Apple are nearly synonymous with innovation, virtually all sectors in our current lives are imbued with yearn for innovation. This has led to organizational focus on innovative strategies as well as recruitment of chief innovation officers and teams in a myriad of organizations. At times, however, the word innovation seems like an overused cliché, as there are now more than 5,000 books in print with the word “innovation” in the title. More recently, innovation has garnered significant attention in health care. The future of health care is expected to innovate on a large scale in order to deliver sustained value for an overall transformative care. To date, there are no published reports on the state of the art in innovation in pediatric health care and in particular, pediatric cardiac intensive care. This report will address the issue of innovation in pediatric medicine with relevance to cardiac intensive care and delineate possible future directions and strategies in pediatric cardiac intensive care.

AbstractBackgroundAlthough much is known about morbidity and mortality, there are limited data focussing on the financial aspect of the Norwood operation. Our objective is to characterise the hospitalisation and detail the hospital costs.MethodsWe retrospectively studied 86 newborns with hypoplastic left heart syndrome who underwent Norwood palliation between 2008 and 2012. Clinical and financial data were collected. Financial data have been reported for 2011–2012.ResultsAt surgery, median age and weight of the patients were 4 days (range 1–13) and 3 kg (range 2–4.8), respectively. The median time from admission to surgery was 4 days (range 1–10), with the postoperative ICU stay and total length of stay at the hospital being 10 days (range 4–135) and 16 days (range 5–136), respectively. Discharge mortality was 14/86 (16%) patients.For patients operated on between 2011 and 2012 (n=40), median hospital costs, charges, and collections per patient were $117,021, $433,054, and $198,453, respectively, and mean hospital costs, charges, and collections per patient were $322,765, $1,109,500, and $511,271, respectively.A breakdown of total hospital costs (direct and indirect) by department showed that the top four areas of resource utilisation (excluding physician fees) were as follows: the cardiac ICU (35%), laboratory (12%), pharmacy (12%), and operating room (7%). Interestingly, point-of-care laboratory evaluations accounted for almost half of the laboratory total (5%). Extracorporeal membrane oxygenation, although only utilised in eight patients between 2011 and 2012, accounted for 7% of utilisation.General radiology only accounted for 2%, despite numerous radiographs.ConclusionsLimited data are available that detail the hospitalisation and costs associated with the Norwood operation. We hope that this analysis will identify areas for quality and value improvement from both system and patient perspectives.

This case highlights the challenges in treating children with intracardiac thrombosis.

To investigate the safety and efficacy of a hyperglycemia protocol in neonates with critical cardiac illness. Neonates are often regarded as high risk for hypoglycemia while receiving continuous insulin infusions and thus have been excluded from some clinical trials.

Infants with congenital heart disease having obstruction to the left ventricular outflow and ductal-dependent systemic circulation can present critically ill with shock. Prompt disease recognition and initiation of prostaglandins are necessary to prevent excess morbidity and mortality. We assessed a large cohort of newborn infants with ductal-dependent systemic circulation to determine if B-type natriuretic peptide (BNP) is consistently elevated at presentation, potentially aiding in diagnosis and treatment.

To describe an unusual case of fulminant rheumatic fever presenting acutely as severe respiratory failure managed with extracorporeal membrane oxygenation and ultimately valve replacement while on extracorporeal membrane oxygenation.

Genetic abnormalities occur in approximately 20% of children with congenital heart disease. The purpose of this study was to evaluate the effect of genetic abnormalities on short-term outcomes following neonatal cardiac surgery.

Cork granules are produced as by-products and waste by the cork processing industries that make ‘bottle stoppers’ as a main product. These granules are of low density and could be used as lightweight aggregates for making concrete. This paper describes an investigation carried out to assess the compatibility of cork granules with cement for the manufacture of lightweight cementitious composites. Five different grades of cork granules varying in terms of size and density were investigated. The effects of extractives, particle size and density of the cork granules were studied. The results indicate that these parameters affect cement hydration in a complex way. At lower concentrations of cork (10%), only the extractives have an influence on hydration behaviour. At higher cork concentrations (20% and 30%), however, particle size and density also affect the compatibility. Nevertheless, cork granules are found to be compatible with cement. Cork granules are produced as by-products and waste by the cork processing industries that make ‘bottle stoppers’ as a main product. These granules are of low density and could be used as lightweight aggregates for making concrete. This paper describes an investigation carried out to assess the compatibility of cork granules with cement for the manufacture of lightweight cementitious composites. Five different grades of cork granules varying in terms of size and density were investigated. The effects of extractives, particle size and density of the cork granules were studied. The results indicate that these parameters affect cement hydration in a complex way. At lower concentrations of cork (10%), only the extractives have an influence on hydration behaviour. At higher cork concentrations (20% and 30%), however, particle size and density also affect the compatibility. Nevertheless, cork granules are found to be compatible with cement.

Abstract: Differences on measures of metabolic syndrome X and coronary heart disease (CHD) risk, as well as potential pathophysiological mediators, inflammation, and oxidative stress, were examined as a function of HIV serostatus and highly active antiretroviral therapy (HAART) regimen with and without protease inhibitors (PIs). Data from 164 men and women, aged 18 to 55 yr, were used to compare 82 HIV+ subjects who were free of hepatitis C virus and were on a stable HAART regimen for ≥6 mo, with 82 seronegative subjects matched on age, sex, body mass index, and ethnicity. For the HIV+ subjects, after controlling for diabetes status and HIV disease progression, PI exposure was associated with greater oxidative stress, triglyceridemia, and lipidemia than it was for non-PI-exposed HIV+ subjects, and the risk of a future myocardial infarction was up to 56% greater in PI-exposed than in non-PI-exposed subjects and 129% greater than in controls. Although it is likely that the greatest proportion of CHD risk in the HIV+ subjects may be accounted for by pathological conditions linked to HIV infection in interaction with mediating processes such as inflammation, central obesity, and dyslipidemia, which was greater than in controls, it appears that PI medications may exacerbate oxidative stress and hypertriglyceridemia to enhance this risk.

ABSTRACTWe present methodologic details and operating characteristics of a procedure with whole blood for the quantitative assessment of intracellular perforin within distinct lymphocyte subsets. Using this method, we analyzed 20 healthy controls and 2 individuals with an inherited deficiency of perforin. The mean ± standard deviation perforin contents of natural killer (NK) cells and cytotoxic T cells of healthy controls were 3,561 ± 1,157 and 500 ± 779 relative number of molecules (rMol) of antiperforin antibody bound per cell, respectively. The NK cell perforin contents of individuals with heterozygous and homozygous perforin deficiency (familial hemophagocytic lymphohistiocytosis) were 2,260 and 212 rMol of antiperforin antibodies per NK cell. While the homozygous deficiency was found to be associated with negligible antiperforin binding, the heterozygous condition was associated with a level of perforin binding that was below the 15th percentile for healthy individuals. Because 83% of this subject's NK cells were shown to bind to antiperforin antibodies by conventional flow cytometry (relative to the normal range of 81% ± 25%), quantitative cytometry may be more sensitive than conventional cytometric methods in identifying cytolytic defects.

SummaryAspen wood (Populus tremula) as sawdust was chemically modified through a two-step procedure: esterification with maleic anhydride and subsequent oligoesterification with glycidyl methacrylate and maleic anhydride. Simplified techniques consisting of impregnation by immersion followed by thermal treatment using conventional or microwave heating were employed. Chemical analyses and infra-red spectroscopy showed some differences in the chemical composition and structure of the resulting oligoesterified wood depending on the synthesis technique. However, the thermoplastic properties, clearly revealed by thermomechanical analysis, were quite similar and comparable to those exhibited by the oligoesterified wood resulting viaclassical synthesis. Moreover, similar degrees of chemical modification were obtained for a significantly shorter duration of the process when microwave heating was employed instead of conventional heating.

SummaryAspen wood (Populus tremula) as sawdust was chemically modified through a two-step procedure: esterification with maleic anhydride and subsequent oligoesterification with glycidyl methacrylate and maleic anhydride. Chemical analyses and infra-red spectroscopy revealed the differences in the chemical composition and structure of wood as a result of this treatment. These changes were also reflected by a hygroscopicity test and thermal analyses such as thermogravimetry and thermomechanical analysis. The esterified wood showed an increased hygroscopicity and a decreased thermal stability compared to unmodified wood. In contrast, the oligoesterified wood demonstrated a reduced hygroscopicity and a comparable thermal stability up to about 200°C. The thermomechanical analysis of oligoesterified wood clearly showed a significant softening phenomenon in the range 80–140°C, a direct evidence of the thermoplastic properties gained by this chemical modification.

Autistic children subjected to the stress of insulin-induced hypoglycemia showed slower recovery of blood glucose, and faster and intractable cortisol response in the 3 hours following the stress. These data suggest that autistic children over-react to this stressor and support clinical evidence of stress intolerance. It is suggested that this peculiarity may be implicated in an explanation of the abnormal behavior seen in this disorder.