Mitochondrial Priming by CD28

T cell receptor (TCR) signaling without CD28 can elicit primary effector T cells, but memory T cells generated during this process are anergic, failing to respond to secondary antigen exposure. We show that, upon T cell activation, CD28 transiently promotes expression of carnitine palmitoyltransferase 1a (Cpt1a), an enzyme that facilitates mitochondrial fatty acid oxidation (FAO), before the first cell division, coinciding with mitochondrial elongation and enhanced spare respiratory capacity (SRC). microRNA-33 (miR33), a target of thioredoxin-interacting protein (TXNIP), attenuates Cpt1a expression in the absence of CD28, resulting in cells that thereafter are metabolically compromised during reactivation or periods of increased bioenergetic demand. Early CD28-dependent mitochondrial engagement is needed for T cells to remodel cristae, develop SRC, and rapidly produce cytokines upon restimulation-cardinal features of protective memory T cells. Our data show that initial CD28 signals during T cell activation prime mitochondria with latent metabolic capacity that is essential for future T cell responses.

Detecting facial emotion recognition deficits in schizophrenia using dynamic stimuli of varying intensities

BACKGROUND

Deficits in facial emotion recognition have been associated with functional impairments in patients with Schizophrenia (SZ). Whilst a strong ecological argument has been made for the use of both dynamic facial expressions and varied emotion intensities in research, SZ emotion recognition studies to date have primarily used static stimuli of a singular, 100%, intensity of emotion. To address this issue, the present study aimed to investigate accuracy of emotion recognition amongst patients with SZ and healthy subjects using dynamic facial emotion stimuli of varying intensities. To this end an emotion recognition task (ERT) designed by Montagne (2007) was adapted and employed.

METHODS

47 patients with a DSM-IV diagnosis of SZ and 51 healthy participants were assessed for emotion recognition. Results of the ERT were tested for correlation with performance in areas of cognitive ability typically found to be impaired in psychosis, including IQ, memory, attention and social cognition.

RESULTS

Patients were found to perform less well than healthy participants at recognising each of the 6 emotions analysed. Surprisingly, however, groups did not differ in terms of impact of emotion intensity on recognition accuracy; for both groups higher intensity levels predicted greater accuracy, but no significant interaction between diagnosis and emotional intensity was found for any of the 6 emotions. Accuracy of emotion recognition was, however, more strongly correlated with cognition in the patient cohort.

DISCUSSION

Whilst this study demonstrates the feasibility of using ecologically valid dynamic stimuli in the study of emotion recognition accuracy, varying the intensity of the emotion displayed was not demonstrated to impact patients and healthy participants differentially, and thus may not be a necessary variable to include in emotion recognition research.

Angiotensin converting enzyme inhibitor-induced angioedema: a report of two cases

Angioedema is a rare but potentially fatal side effect of angiotensin converting enzyme (ACE) inhibitors. We report for the first time, two children with systemic lupus erythematosus who developed acute angioedema after the long-term use of enalapril. Prompt recognition and appropriate management of ACE-induced angioedema prevented life-threatening complications. This report highlights the potential risks of angioedema associated with the use of ACE inhibitors in children. Patients should be advised to seek medical treatment immediately if they experience swelling of the face, neck, or tongue, and especially if they have trouble breathing, speaking, or swallowing.

Pharmacokinetics and pharmacodynamics of milrinone lactate in pediatric patients with septic shock

OBJECTIVES

The objectives of this study were to determine the pharmacokinetics of milrinone lactate in pediatric patients with septic shock and to determine whether a relationship exists between steady-state plasma milrinone concentrations and changes in hemodynamic variables.

STUDY DESIGN

This was a randomized, double-blind, placebo-controlled, interventional study. In study phase 1 patients were randomized and underwent loading and infusion with milrinone lactate (50 microg/kg, then 0.5 microg/kg/min), and invasive hemodynamic values were determined. Steady-state was determined by obtaining plasma samples at 30, 15, and 0 minutes before the end of the milrinone infusion. Study phase 2 started when milrinone was discontinued by the patient care team. Steady-state was reaffirmed and plasma samples were obtained at 0.5, 1, 2, 4, 6, and 8 hours after the end of the infusion.

RESULTS

The average plasma concentration at steady-state (Css avg) and total body clearance for phase 1 were 81.3+/-38.6 ng/ml (mean +/- SD) and 0.0106+/-0.0053 L/kg/min, respectively (n = 9). All but two patients underwent reloading with milrinone. In phase 2 Css avg and total body clearance were 65.8+/-42.1 ng/ml and 0.0110+/-0.0096 L/kg/min, respectively (n = 11). The average time of infusion was 51+/-21 hours. Eight patients were evaluated for phase 2 elimination. The mean elimination rate constant was 0.0091+/-0.0061 min(-1) (n = 8). The median half-life was 1.47 hours (range, 0.62 to 10.85 hours). All patients had creatinine clearances greater than 61 ml/min/1.73 m2. The volume of distribution at steady-state was 1.47+/-1.03 L/kg. No correlation existed between age and the elimination rate constant or the volume of distribution at steady-state. All patients achieved at least a 20% change in cardiac index and systemic vascular resistance index while maintaining a Css avg of 35 to 160 ng/ml. No adverse effects were noted. All patients achieved primary hemodynamic end points (cardiac index and systemic vascular resistance index) during the milrinone infusion.

CONCLUSIONS

Loading doses of 75 microg/kg milrinone lactate and starting infusion rates of 0.75 to 1.0 microg/kg/min for patients with normal renal function should be used; the infusion rate should then be titrated to effect. We recommend that for every increase of 0.25 microg/kg/min, a 25 microg/kg bolus dose be given. Because the median half-life is 1.47 hours, immediate hemodynamic effects may not be seen unless appropriate loading doses and infusion adjustments are made.

The use of the salivagram in the evaluation of severe and chronic aspiration

Chronic salivary aspiration may be responsible for a significant percentage of pneumonia in the neurologically impaired child. The radionuclide salivagram (RS), a simple investigative study, can document salivary aspiration as the source of pulmonary contamination. The purpose of this study was to determine if the results of the RS would accurately identify children with severe and chronic salivary aspiration who would benefit from laryngotracheal separation (LTS). We reviewed 30 records of children with chronic aspiration pneumonitis who underwent LTS between 1988 and 1996. We recorded the number of inpatient days required for respiratory infections before and after LTS. This number was compared with the number of inpatient days for respiratory infection from children (n = 27) who underwent the RS during a ten-month period but who were never referred for LTS. Fifteen children who underwent LTS had a preoperative RS. The RS documented salivary aspiration in 11 of these children. Aspiration was effectively controlled by LTS for this group. There were three studies that failed to show either aspiration or progression of the Technetium 99m sulfur colloid (Tc 99m SC) into the esophagus This finding was felt to represent significant swallowing dysfunction and, therefore, was also considered a positive finding. There was a significant difference in the number of inpatient days for children who had a negative RS and were never referred for LTS when compared with the number of inpatient days for those children who had a positive RS and were referred for LTS. We feel that the RS is an effective tool to document salivary aspiration as the source of recurrent pneumonia. A modification of the technique and interpretation of RS is suggested.

Dirty, diseased and undeserving: the positioning of HIV positive women

The discursive construction of HIV/AIDS associates deviance and disease. Women living with HIV/AIDS, in particular, have been positioned as a source or potential source of infection, and have attracted guilt and blame: in becoming 'disease' they have failed in their appropriate roles as carers and nurturers, responsible for the next generation. Based on in-depth interviews with 27 women living with HIV/AIDS this paper focuses on three ways of positioning HIV positive women: through discrimination on the part of medical professionals; through internalisation of stigmatisation; and through multiple stigmatisation of women who are or have been illicit drug users or sex workers. The implications of stigmatisation are discussed in relation to accessing health care and support.

Hemodynamic effects of i.v. milrinone lactate in pediatric patients with septic shock. A prospective, double-blinded, randomized, placebo-controlled, interventional study

STUDY OBJECTIVE

To determine the hemodynamic effects of i.v. milrinone lactate in pediatric patients with nonhyperdynamic septic shock. Specifically we tested the hypothesis that i.v. milrinone would increase cardiac index by 20% and decrease systemic vascular resistance index by 20% during a 2-h study period.

DESIGN

Prospective, double-blinded, randomized, placebo-controlled, descriptive, interventional study.

SETTING

Twenty-six-bed pediatric ICU at Children's Medical Center of Dallas and a 10-bed pediatric trauma ICU at Parkland Memorial Hospital.

PATIENTS/PARTICIPANTS

Twelve patients (age range, 9 months to 15 years) with nonhyperdynamic septic shock despite administration of catecholamines (cardiac index [CI] normal [3.5 to 5.5 L/min/m2] or low [< or =3.5 L/min/m2]; systemic vascular resistance index [SVRI] normal [800 to 1,600 dyne.s.cm5/m2] or high [> or =1,600 dyne.s.cm5/m2]; and pulmonary capillary wedge pressure [PCWP] normal [8 to 12 mm Hg] or higher) with clinical signs of poor perfusion were enrolled, randomized, and treated in a blinded fashion with i.v. milrinone and placebo.

INTERVENTIONS

Patients were randomized into two groups. Group A received a loading dose of 50 micrograms/kg i.v. of milrinone followed by a continuous i.v. infusion of 0.5 microgram/kg/min while group B received an equal volume loading dose and continuous infusion of placebo. After 2 h, group A received an equal-volume loading dose followed by a continuous infusion of placebo while the milrinone infusion continued, while group B received a 50 micrograms/kg loading dose of milrinone followed by a continuous infusion of 0.5 microgram/kg/min while the placebo infusion remained. Outcome variable were measured at baseline, 0.5, 1.0, 2.0, 2.5, 3.0, and 4.0 h. Echocardiographic measurements were taken at baseline, hour 2, and hour 4 in all subjects. No changes in other inotropic or mechanical ventilatory support were allowed during the study period.

MEASUREMENTS AND MAIN RESULTS

Milrinone significantly increased CI, stroke volume index (SVI), right and left ventricular stroke work index, and oxygen delivery (Do2) at 0.5, 1.0, and 2.0 h postloading dose (p < 0.05) while significantly decreasing SVRI, pulmonary vascular resistance index, and mean pulmonary arterial pressure at 0.5, 1.0, and 2.0 h postloading dose (p < 0.05). No clinically or statistically significant changes in heart rate, systolic and diastolic BP, mean systemic arterial pressure, or PCWP were observed during milrinone treatment compared to placebo.

CONCLUSIONS

CI, SVI, and Do2 significantly increased while SVRI significantly decreased when compared to placebo after i.v. administration of milrinone to pediatric patients with nonhyperdynamic septic shock. No adverse effects were observed. In a volume-resuscitated pediatric patient with septic shock, when administered in addition to catecholamines, milrinone will improve cardiovascular function.

Postoperative pain management in preverbal children: the prescription and administration of analgesics with and without caudal analgesia

A retrospective chart review was conducted to examine the prescription and administration of analgesics with and without caudal analgesia to inpatient preverbal children within the first 48 hours after surgery. The 75 subjects were between birth and 24 months of age and had undergone various operative procedures. Seventy (93%) of these subjects were prescribed analgesics, but 8 of them had only acetaminophen prescribed. Of the 70 subjects who had a medication prescribed, 64 (91%) patients received analgesics. Morphine was the most frequently administered analgesic. The prescribed and administered mean dosages were less than the minimum recommended dosage for morphine. The mean prescribed and administered dosage for other analgesics exceeded the minimum recommended dosage. Preverbal children who had caudal analgesia during surgery were more likely to receive fewer dosages of analgesics and to receive lower dosages of narcotics even after 24 hours postoperatively than children who had not had caudal analgesia.

Use of BiPAP by nasal mask in the treatment of respiratory insufficiency in pediatric patients: preliminary investigation

A device for nasally applied bilevel positive airway pressure, BiPAP (Respironics Inc., Murrysville, PA), is currently being evaluated for the treatment of respiratory failure in pediatric and adult patients. This retrospective case review examines our experience with using BiPAP in the treatment of acute ventilatory deterioration in pediatric patients with chronic respiratory insufficiency. All patients who presented to the intensive care unit with chronic respiratory insufficiency and ventilatory failure but without hypoxia were given a trial on BiPAP. Fifteen patients, ages 4-21 years, received such ventilatory support. Four of them had cystic fibrosis (CF) and 11 had neuromuscular disease (2, spinal muscular atrophy; 7, Duchenne muscular dystrophy; 1, spinal cord injury; and 1, myopathy of undetermined origin). Hospital days, respiratory rates, resting heart rates, arterial blood gases, serum bicarbonates, and subjective assessment by parents and or patients of dyspnea, sleep pattern, and activity tolerance were compared prior to and after initiation of BiPAP. Patients were followed from 1 day to 21 months. In 14 of 15 patients placement of an artificial airway could be avoided. Significant decreases in hospital days, respiratory rate, heart rate, serum bicarbonate, and arterial PCO2 were observed after initiation of BiPAP. Decline in dyspnea (87% with severe distress at rest prior vs. 80% comfortable at rest after BiPAP), increased activity tolerance (57% attending school after BiPAP vs. none prior to BiPAP), and improved quality of sleep (93% with comfortable sleep, no daytime somnolence vs. none with comfortable sleep and 36% with daytime somnolence prior to BiPAP).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of continuous arteriovenous haemofiltration on pharmacokinetics of amrinone

This case report details the pharmacokinetic adjustments of an amrinone infusion in a paediatric patient who developed multiorgan system failure with anuric renal failure and was prescribed continuous arteriovenous haemofiltration. A significant proportion of clearance of amrinone is nonrenal. Near normal amrinone clearance can occur in patients with hepatic and renal dysfunction if continuous arteriovenous haemofiltration is used. Hepatic dysfunction with renal failure may require a reduction in the continuous amrinone infusion rate as previously reported for neonates.

Characteristics of pediatric intermediate care units in pediatric training programs

BACKGROUND/OBJECTIVE

To assess effective alternate care sites for the technology-dependent, but less acute critically ill child, we surveyed pediatric training programs to determine the availability and characteristics of non-neonatal pediatric intermediate care units.

METHODS

A questionnaire was mailed to the program directors of all 226 United States pediatric residency programs in October 1988. Institutions were queried about pediatric residency program and hospital demographics, along with specific day-to-day management issues in an intermediate care unit.

RESULTS

The intermediate care unit offers highly skilled nursing care with greater than 90% of the units primarily covered by RNs in a 1:2 or 1:3 RN/patient ratio. The technologies used in these units were similar to those technologies used in an ICU, and the average daily bed charge was 40% less than the average daily bed charge in an ICU. However, an intermediate care unit was present in only 33% of pediatric training programs and pediatric residents were not specifically trained to care for patients in these units; 37% of these units did not have daily attending physician/nurse/resident rounds, despite the complexity and degree of illness in the patients located in these units. In addition, greater than 20% of intermediate care units were predominantly staffed by RNs with degrees less than BSN. Thirteen percent of these units had a predominance of RNs with only routine experience.

CONCLUSIONS

Standard levels of care and academic and financial guidelines should be established to optimize the value of pediatric intermediate care units.

Simplified assay of amrinone in plasma by high-performance liquid chromatography

An isocratic high-performance liquid chromatography method for the assay of plasma amrinone is described. Plasma amrinone is extracted using protein precipitation with an internal standard, separated with a reverse phase column, and detected using ultraviolet absorption. Each run is completed within 10 min. The assay can detect amrinone concentrations between 0.5 and 10.0 micrograms/ml, within the accepted therapeutic range. The assay has a within-day coefficient of variation of less than 5% and a day-to-day coefficient of variation of less than 10% in the therapeutic range of amrinone. This technique is an accurate, simple, and rapid method for the determination of amrinone concentrations in plasma.

Mechanisms of hypertension during and after orthotopic liver transplantation in children

The aim of this study was to assess the hormonal alterations that may mediate the systemic hypertension that develops in patients during the perioperative period of orthotopic liver transplantation. We studied nine pediatric patients without previous hypertension or renal disease during six time points, starting before transplantation and ending at 48 hours after surgery. Hypertension developed in all patients in association with central venous pressures less than 10 mm Hg. Free water clearance was negative in all nine patients. Vasopressin levels increased intraoperatively but fell as hypertension developed. Atrial natriuretic factor levels increased as systemic blood pressure rose. A high level of plasma renin activity was observed in four patients with renal insufficiency. In six patients, postoperative 24-hour urinary norepinephrine excretion was within the normal age-adjusted range. These findings suggest that the combination of cyclosporine, corticosteroids, and, in some patients, an elevated plasma renin activity prevents the kidney from responding to the acute volume and salt overload with an appropriate diuresis and natriuresis, thus leading to systemic hypertension. The treatment of hypertension after liver transplantation may include salt restriction, diuretics, and, in those patients with a low creatinine excretion index, angiotensin coverting enzyme inhibitors.

Axillary arterial monitoring of pediatric patients

Use of the axillary artery for hemodynamic monitoring has gained acceptance in critically ill adults. However, there is little information concerning the safety and complications of such catheters in the pediatric population. Sixteen pediatric patients who had axillary lines placed for pressure monitoring were evaluated for neurologic and vascular function, by comparing the arm with the axillary line with the contralateral arm. There were no major complications during axillary artery monitoring. After decannulation, systolic blood pressure did not differ between arms. In a pediatric critical care environment with skilled ongoing nursing care, the axillary artery can be used as a site for intraarterial monitoring in pediatric patients without a detrimental effect on concurrent or future blood pressure monitoring.

Amrinone in neonates and infants after cardiac surgery

Eighteen critically ill postoperative patients less than 1 yr of age were studied to determine the pharmacokinetics and adverse effects of amrinone. All patients had undergone cardiopulmonary bypass for repair of congenital heart lesions. Plasma samples were obtained every 12 h while patients were receiving amrinone to determine when steady state was achieved; samples were also obtained within 24 h after amrinone had been discontinued. Elimination half-life (T1/2), clearance, and volume of distribution were calculated from plasma amrinone concentrations, and the incidence of platelet transfusion was monitored. T1/2(22.2 vs. 6.8 h) and clearance (1.1 vs. 2.6 ml/min.kg), but not the volume of distribution (1.8 vs. 1.6 L/kg), differed significantly in patients less than 4 wk of age in comparison to patients greater than 4 wk of age. A negative correlation between T1/2 and age (r = -.79) was observed. Platelets were administered no more frequently in study patients than in a similar group that did not receive amrinone. To achieve the plasma concentration of amrinone that is therapeutic in adults, current dosage recommendations are inadequate in neonates and infants. Infants should receive an initial iv amrinone bolus of 3.0 to 4.5 mg/kg in divided doses followed by a continuous infusion of 10 micrograms/kg.min, while neonates should receive a similar bolus followed by a continuous infusion of 3 to 5 micrograms/kg.min.

New pigtail catheter for pleural drainage in pediatric patients

The conventional method of pleural drainage is tube thoracotomy, accomplished by chest wall dissection and blunt puncture. While this method is successful, it is relatively traumatic. We have designed a pigtail catheter which may be inserted into the pleural space by a modified Seldinger technique. This 8.5-Fr polyurethane catheter has six side ports inside its circular distal end. An airtight plastic bag is attached to the insertion needle to confirm pleural placement. Nineteen catheters were inserted in 16 neonates and small children with either pneumothorax or pneumomediastinum. No complications were noted. All but one pneumothorax was successfully evacuated; however, the pneumomediastinum reaccumulated. Insertion proved to be safe, simple, and atraumatic. This pigtail pleural drainage catheter provides an alternative to standard tube thoracotomy.