MDMA enhances positive affective responses to social feedback

BACKGROUND

The prosocial compound ± 3,4-methylenedioxymethamphetamine (MDMA) is an amphetamine derivative that has shown promise as an adjunct to psychotherapy in the treatment of post-traumatic stress disorder. MDMA increases positive responses to social images, and it has been suggested that the ability of MDMA to positively bias social perception may underlie its therapeutic efficacy as a psychotherapy adjunct. However, the effect of the compound on affective responses to positive or negative social feedback has not been tested.

AIMS

In this study, we aimed to test the effects of MDMA compared to placebo and the prototypical stimulant, methamphetamine (MA), on responses to positive and negative social feedback.

METHODS

This was a double-blind, placebo-controlled, crossover trial (NCT03790618), comparing the effects of two doses of MDMA (0.75 mg/kg, 1.5 mg/kg) to both placebo and MA (20 mg) on responses to a personalized social feedback task, similar to a dating app, in healthy adult volunteers ages 18-40 (N = 36, 18 women, 18 men).

RESULTS/OUTCOMES

The high dose of MDMA increased positive affective responses to social feedback.

CONCLUSIONS/INTERPRETATIONS

These findings suggest one process by which MDMA may facilitate social connection. Further work is needed to understand how MDMA affects responses to more generalized types of social feedback and to understand these effects in clinical populations.

Orbitofrontal and striatal metabolism, volume, thickness and structural connectivity in relation to social anhedonia in depression: A multimodal study

BACKGROUND

Social anhedonia is common within major depressive disorder (MDD) and associated with worse treatment outcomes. The orbitofrontal cortex (OFC) is implicated in both reward (medial OFC) and punishment (lateral OFC) in social decision making. Therefore, to understand the biology of social anhedonia in MDD, medial/lateral OFC metabolism, volume, and thickness, as well as structural connectivity to the striatum, amygdala, and ventral tegmental area/nucleus accumbens were examined. A positive relationship between social anhedonia and these neurobiological outcomes in the lateral OFC was hypothesized, whereas an inverse relationship was hypothesized for the medial OFC. The association between treatment-induced changes in OFC neurobiology and depression improvement were also examined.

METHODS

85 medication-free participants diagnosed with MDD were assessed with Wisconsin Schizotypy Scales to assess social anhedonia and received pretreatment simultaneous fluorodeoxyglucose positron emission tomography (FDG-PET) and magnetic resonance imaging (MRI), including structural and diffusion. Participants were then treated in an 8-week randomized placebo-controlled double-blind course of escitalopram. PET/MRI were repeated following treatment. Metabolic rate of glucose uptake was quantified from dynamic FDG-PET frames using Patlak graphical analysis. Structure (volume and cortical thickness) was quantified from structural MRI using Freesurfer. To assess structural connectivity, probabilistic tractography was performed on diffusion MRI and average FA was calculated within the derived tracts. Linear mixed models with Bonferroni correction were used to examine the relationships between variables.

RESULTS

A significantly negative linear relationship between pretreatment social anhedonia score and structural connectivity between the medial OFC and the amygdala (estimated coefficient: -0.006, 95 % CI: -0.0108 - -0.0012, p-value = 0.0154) was observed. However, this finding would not survive multiple comparisons correction. No strong evidence existed to show a significant linear relationship between pretreatment social anhedonia score and metabolism, volume, thickness, or structural connectivity to any of the regions examined. There was also no strong evidence to suggest significant linear relationships between improvement in depression and percent change in these variables.

CONCLUSIONS

Based on these multimodal findings, the OFC likely does not underlie social anhedonia in isolation and therefore should not be the sole target of treatment for social anhedonia. This is consistent with previous reports that other areas of the brain such as the amygdala and the striatum are highly involved in this behavior. Relatedly, amygdala-medial OFC structural connectivity could be a future target. The results of this study are crucial as, to our knowledge, they are the first to relate structure/function of the OFC with social anhedonia severity in MDD. Future work may need to involve a whole brain approach in order to develop therapeutics for social anhedonia.

Mu Opioid Receptor Dynamics in Healthy Volunteers with a History of Childhood Maltreatment

Evidence suggests that adults with a history of childhood maltreatment, the experience of emotional or physical neglect and/or abuse within the family during childhood, have blunted reward and stress processing, and higher risk of depression. The mu opioid receptor rich nucleus accumbens and amygdala are critical to reward and stress processing respectively. We hypothesized that nucleus accumbens and amygdala mu opioid receptor densities and activity (change in receptor binding due to endogenous opioid release or receptor conformation change) were negatively associated with childhood maltreatment in healthy young adults. Maltreatment was assessed with the Childhood Trauma Questionnaire (CTQ). Healthy participants, n = 75 (52% female) completed [11C]carfentanil positron emission tomography imaging labeling mu opioid receptors. The relationship between CTQ score and binding potential (BPND, proportional to density of unoccupied receptors) was evaluated with a linear mixed effects model. No significant relationship was found between CTQ score and BPND (f = 3.28; df = 1, 73; p = 0.074) or change in BPND (activity) (t = 1.48; df = 198.3; p = 0.14). This is the first investigation of mu opioid receptors in those with childhood maltreatment. We did not identify a significant relationship between mu opioid receptor dynamics and severity of maltreatment in those without psychopathology. Because this cohort has a low CTQ score average, this may indicate that those with low severity of maltreatment may not have associated changes in mu opioid receptor dynamics. Future directions include evaluating a cohort with increased severity of childhood maltreatment.

Rejection sensitivity and mu opioid receptor dynamics associated with mood alterations in response to social feedback

Rejection sensitivity (RS) is the heightened expectation or perception of social rejection and is a feature of many psychiatric disorders. As endogenous opioid pathways have been implicated in response to social rejection and reward, we hypothesize that RS will be negatively associated with mu opioid receptor (MOR) baseline binding and activity during rejection and acceptance stimuli. In exploratory analyses, we assessed the relationships between MOR activity and changes in mood and self-esteem before and after stimuli. Healthy participants, N = 75 (52% female), completed rejection and acceptance tasks during [¹¹C]carfentanil positron emission tomography (PET) scans. MOR activity in the amygdala, midline thalamus, anterior insula, and nucleus accumbens (NAc) was evaluated. RS was not related to MOR baseline binding potential or activity during acceptance or rejection tasks in any region. Increased MOR activity in the NAc was associated with increase in ratings of self-esteem and positive mood during the period between acceptance task administration and approximately 5 min after the task completion. Our results suggest that endogenous opioid response to social rejection is independent of RS in healthy individuals. MOR activity in the NAc was associated with increase self-esteem and positive mood after experiencing social feedback, warranting further investigation.

Practice variation in the diagnosis of acute rejection among pediatric heart transplant centers: An analysis of the pediatric heart transplant society (PHTS) registry

BACKGROUND

Freedom from rejection in pediatric heart transplant recipients is highly variable across centers. This study aimed to assess the center variation in methods used to diagnose rejection in the first-year post-transplant and determine the impact of this variation on patient outcomes.

METHODS

The PHTS registry was queried for all rejection episodes in the first-year post-transplant (2010-2019). The primary method for rejection diagnosis was determined for each event as surveillance biopsy, echo diagnosis, or clinical. The percentage of first-year rejection events diagnosed by surveillance biopsy was used to approximate the surveillance strategy across centers. Methods of rejection diagnosis were described and patient outcomes were assessed based on surveillance biopsy utilization among centers.

RESULTS

A total of 3985 patients from 56 centers were included. Of this group, 873 (22%) developed rejection within the first-year post-transplant. Surveillance biopsy was the most common method of rejection diagnosis (71.7%), but practices were highly variable across centers. The majority (73.6%) of first rejection events occurred within 3-months of transplantation. Diagnosis modality in the first-year was not independently associated with freedom from rejection, freedom from rejection with hemodynamic compromise, or overall graft survival.

CONCLUSIONS

Rejection in the first-year after pediatric heart transplant occurs in 22% of patients and most commonly in the first 3 months post-transplant. Significant variation exists across centers in the methods used to diagnose rejection in pediatric heart transplant recipients, however, these variable strategies are not independently associated with freedom from rejection, rejection with hemodynamic compromise, or overall graft survival.

Common neural responses to romantic rejection and acceptance in healthy adults

Although romantic rejection and acceptance have a strong impact on mood in adults, their neural response patterns are relatively unexplored. The present study used functional magnetic resonance imaging (fMRI) to examine neural responses to romantic rejection and acceptance in 36 healthy men and women, ages 18-53 years. Activations during rejection showed extensive anatomical overlap with activations during acceptance in the ventrolateral prefrontal cortex (vlPFC) and anterior insula (AI). In an analysis of sex differences, men and women did not differ in behavioral responses; however, men showed greater activation to romantic rejection and acceptance in the left vlPFC and AI compared to women. The vlPFC and AI may play a role in social cognition, tuned to detect the intentions and feelings of others whether they are positive or negative. In the context of romantic rejection and acceptance, this activation may signal the intent of others who are desired by the individual, leading to changes in mood, self-esteem, and social motivation.

Dissociable Neural Responses to Monetary and Social Gain and Loss in Women With Major Depressive Disorder

Neuroimaging studies have revealed aberrant reward and loss processing in patients with major depressive disorder (MDD). While most studies use monetary stimuli to study these processes, it is important to consider social stimuli given that the social environment plays a significant role in the development and maintenance of MDD. In the present study, we examined whether monetary gain/loss and social acceptance/rejection would elicit dissociable salience-related neural responses in women diagnosed with MDD compared to healthy control (HC) women. Twenty women diagnosed with MDD and 20 matched HC women performed the monetary incentive delay task (MID) and the social feedback task (SFT) during functional magnetic resonance imaging (fMRI). This study focused on women since women have a higher rate of MDD, higher frequency of relapse, and are more likely to develop MDD as a consequence of negative interpersonal relationships compared to men. We found that during the MID, HCs but not MDD patients demonstrated strong overlapping activations in the right anterior insula (AI) in response to both monetary gain and loss. During the SFT, MDD patients but not HCs showed overlapping activations in the AI in response to social acceptance and rejection. Our results may suggest a dissociation such that MDD patients show decreased sensitivity to monetary stimuli whether gain or loss, and increased sensitivity to social stimuli whether acceptance or rejection, although this will need to be verified in larger samples with direct comparisons between groups and stimuli. These data demonstrate distinct abnormalities in reward and loss processing that converge within the AI. Our findings also highlight the critical need to assess across both non-social and social domains when examining reward and loss systems in MDD to broaden our understanding of the disorder and identify novel targets for treatment.

Multidimensional imaging techniques for prediction of treatment response in major depressive disorder

A large number of studies have attempted to use neuroimaging tools to aid in treatment prediction models for major depressive disorder (MDD). Most such studies have reported on only one dimension of function and prediction at a time. In this study, we used three different tasks across domains of function (emotion processing, reward anticipation, and cognitive control, plus resting state connectivity completed prior to start of medication to predict treatment response in 13-36 adults with MDD. For each experiment, adults with MDD were prescribed only label duloxetine (all experiments), whereas another subset were prescribed escitalopram. We used a KeyNet (both Task derived masks and Key intrinsic Network derived masks) approach to targeting brain systems in a specific match to tasks. The most robust predictors were (Dichter et al., 2010) positive response to anger and (Gong et al., 2011) negative response to fear within relevant anger and fear TaskNets and Salience and Emotion KeyNet (Langenecker et al., 2018) cognitive control (correct rejections) within Inhibition TaskNet (negative) and Cognitive Control KeyNet (positive). Resting state analyses were most robust for Cognitive control Network (positive) and Salience and Emotion Network (negative). Results differed by whether an -fwhm or -acf (more conservative) adjustment for multiple comparisons was used. Together, these results implicate the importance of future studies with larger sample sizes, multidimensional predictive models, and the importance of using empirically derived masks for search areas.

Cognitive Control as a 5-HT1A-Based Domain That Is Disrupted in Major Depressive Disorder

Heterogeneity within Major Depressive Disorder (MDD) has hampered identification of biological markers (e.g., intermediate phenotypes, IPs) that might increase risk for the disorder or reflect closer links to the genes underlying the disease process. The newer characterizations of dimensions of MDD within Research Domain Criteria (RDoC) domains may align well with the goal of defining IPs. We compare a sample of 25 individuals with MDD compared to 29 age and education matched controls in multimodal assessment. The multimodal RDoC assessment included the primary IP biomarker, positron emission tomography (PET) with a selective radiotracer for 5-HT_1A [(11C)WAY-100635], as well as event-related functional MRI with a Go/No-go task targeting the Cognitive Control network, neuropsychological assessment of affective perception, negative memory bias and Cognitive Control domains. There was also an exploratory genetic analysis with the serotonin transporter (5-HTTLPR) and monamine oxidase A (MAO-A) genes. In regression analyses, lower 5-HT_1A binding potential (BP) in the MDD group was related to diminished engagement of the Cognitive Control network, slowed resolution of interfering cognitive stimuli, one element of Cognitive Control. In contrast, higher/normative levels of 5-HT_1A BP in MDD (only) was related to a substantial memory bias toward negative information, but intact resolution of interfering cognitive stimuli and greater engagement of Cognitive Control circuitry. The serotonin transporter risk allele was associated with lower 1a BP and the corresponding imaging and cognitive IPs in MDD. Lowered 5HT 1a BP was present in half of the MDD group relative to the control group. Lowered 5HT 1a BP may represent a subtype including decreased engagement of Cognitive Control network and impaired resolution of interfering cognitive stimuli. Future investigations might link lowered 1a BP to neurobiological pathways and markers, as well as probing subtype-specific treatment targets.

Abnormal emotional and neural responses to romantic rejection and acceptance in depressed women

INTRODUCTION

Responding adaptively to one's social environment is a key factor predicting the course of major depressive disorder (MDD). Socially rejecting events can exacerbate, whereas socially accepting events can ameliorate depressive symptoms. The neural responses to rejection and acceptance in MDD are relatively unexplored.

METHODS

We used functional magnetic resonance imaging (fMRI) to measure neural responses to romantic rejection and acceptance in women diagnosed with current MDD (n = 19) and a matched group of healthy controls (HCs) (n = 19). During fMRI, participants received rejecting, accepting, and neutral feedback from self-selected potential romantic partners.

RESULTS

In women with MDD but not HCs, rejection significantly increased activity in the right anterior insula relative to neutral feedback. Greater activation during rejection was found in the dorsal anterior cingulate cortex in MDD compared to HCs. Women with MDD reported stronger emotional responses than HCs to both rejection and acceptance. In addition, left and right nucleus accumbens (NAcc) activity mediated the relationship between trait reward responsiveness and increased ratings of feeling "happy and accepted" following acceptance in HCs, but not the MDD group.

DISCUSSION

Women with MDD were behaviorally and neurally hyperresponsive to rejection. Although both groups were behaviorally responsive to acceptance, in MDD this was dissociated from NAcc activity. These findings highlight abnormal behavioral and neural responses to social cues in MDD, with implications for disease prognosis and the development of novel and sensitive biomarkers for MDD focused on neural pathways for social-affective processing.

LIMITATIONS

Conclusions may be limited to depressed women in a romantic context.

Comorbid anxiety increases cognitive control activation in Major Depressive Disorder

BACKGROUND

Major Depressive Disorder (MDD) and anxiety disorders often co-occur, with poorer treatment response and long-term outcomes. However, little is known about the shared and distinct neural mechanisms of comorbid MDD and anxiety (MDD+Anx). This study examined how MDD and MDD+Anx differentially impact cognitive control.

METHODS

Eighteen MDD, 29 MDD+Anx, and 54 healthy controls (HC) completed the Parametric Go/No-Go (PGNG) during fMRI, including Target, Commission, and Rejection trials.

RESULTS

MDD+Anx had more activation in the anterior dorsolateral prefrontal cortex, hippocampus, and caudate during Rejections, and inferior parietal lobule during correct Targets than MDD and HC. During Rejections HC had greater activation in a number of cognitive control regions compared to MDD; in the posterior cingulate compared to MDD+Anx; and in the fusiform gyrus compared to all MDD. During Commissions HC had greater activation in the right inferior frontal gyrus than all MDD. MDD had more activation in the mid-cingulate, inferior parietal lobule, and superior temporal gyrus than MDD+Anx during Commissions.

CONCLUSIONS

Despite similar performance, MDD and MDD+Anx showed distinct differences in neural mechanisms of cognitive control in relation to each other, as well as some shared differences in relation to HC. The results were consistent with our hypothesis of hypervigilance in MDD+Anx within the cognitive control network, but inconsistent with our hypothesis that there would be greater engagement of salience and emotion network regions. Comorbidity of depression and anxiety may cause increased heterogeneity in study samples, requiring further specificity in detection and measurement of intermediate phenotypes and treatment Targets.

Pharmacological modulation of pulvinar resting-state regional oscillations and network dynamics in major depression

The pulvinar, the largest thalamus nucleus, has rich anatomical connections with several different cortical and subcortical regions suggesting its important involvement in high-level cognitive and emotional functions. Unfortunately, pulvinar dysfunction in psychiatric disorders particularly major depression disorder has not been thoroughly examined to date. In this study we explored the alterations in the baseline regional and network activities of the pulvinar in MDD by applying spectral analysis of resting-state oscillatory activity, functional connectivity and directed (effective) connectivity on resting-state fMRI data acquired from 20 healthy controls and 19 participants with MDD. Furthermore, we tested how pharmacological treatment with duloxetine can modulate the measured local and network variables in ten participants who completed treatment. Our results revealed a frequency-band dependent modulation of power spectrum characteristics of pulvinar regional oscillatory activity. At the network level, we found MDD is associated with aberrant causal interactions between pulvinar and several systems including default-mode and posterior insular networks. It was also shown that duloxetine treatment can correct or overcompensate the pathologic network behavior of the pulvinar. In conclusion, we suggest that pulvinar regional baseline oscillatory activity and its resting-state network dynamics are compromised in MDD and can be modulated therapeutically by pharmacological treatment.

Contributions of the paraventricular thalamic nucleus in the regulation of stress, motivation, and mood

The purpose of this review is to describe how the function and connections of the paraventricular thalamic nucleus (Pa) may play a role in the regulation of stress and negative emotional behavior. Located in the dorsal midline thalamus, the Pa is heavily innervated by serotonin, norepinephrine, dopamine (DA), corticotropin-releasing hormone, and orexins (ORX), and is the only thalamic nucleus connected to the group of structures comprising the amygdala, bed nucleus of the stria terminalis (BNST), nucleus accumbens (NAcc), and infralimbic/subgenual anterior cingulate cortex (sgACC). These neurotransmitter systems and structures are involved in regulating motivation and mood, and display abnormal functioning in several psychiatric disorders including anxiety, substance use, and major depressive disorders (MDD). Furthermore, rodent studies show that the Pa is consistently and potently activated following a variety of stressors and has a unique role in regulating responses to chronic stressors. These observations provide a compelling rationale for investigating the Pa in the link between stress and negative emotional behavior, and for including the Pa in the neural pathways of stress-related psychiatric disorders.

Response of the μ-opioid system to social rejection and acceptance

The endogenous opioid system, which alleviates physical pain, is also known to regulate social distress and reward in animal models. To test this hypothesis in humans (n=18), we used an μ-opioid receptor (MOR) radiotracer to measure changes in MOR availability in vivo with positron emission tomography during social rejection (not being liked by others) and acceptance (being liked by others). Social rejection significantly activated the MOR system (i.e., reduced receptor availability relative to baseline) in the ventral striatum, amygdala, midline thalamus and periaqueductal gray (PAG). This pattern of activation is consistent with the hypothesis that the endogenous opioids have a role in reducing the experience of social pain. Greater trait resiliency was positively correlated with MOR activation during rejection in the amygdala, PAG and subgenual anterior cingulate cortex (sgACC), suggesting that MOR activation in these areas is protective or adaptive. In addition, MOR activation in the pregenual ACC was correlated with reduced negative affect during rejection. In contrast, social acceptance resulted in MOR activation in the amygdala and anterior insula, and MOR deactivation in the midline thalamus and sgACC. In the left ventral striatum, MOR activation during acceptance predicted a greater desire for social interaction, suggesting a role for the MOR system in social reward. The ventral striatum, amygdala, midline thalamus, PAG, anterior insula and ACC are rich in MORs and comprise a pathway by which social cues may influence mood and motivation. MOR regulation of this pathway may preserve and promote emotional well being in the social environment.

Ex vivo cryoablation of Wolff-Parkinson-white in a donor heart prior to pediatric heart transplantation

This report describes the use of a donor heart with ventricular pre-excitation for pediatric orthotopic heart transplantation and the successful surgical cryoablation of the donor heart prior to transplantation. The issues related to the preoperative evaluation and surgical management of the donor heart with Wolff-Parkinson White syndrome are discussed.

Emotion processing, major depression, and functional genetic variation of neuropeptide Y

CONTEXT

Despite recent progress in describing the common neural circuitry of emotion and stress processing, the bases of individual variation are less well understood. Genetic variants that underlie psychiatric disease have proven particularly difficult to elucidate. Functional genetic variation of neuropeptide Y (NPY) was recently identified as a source of individual differences in emotion. Low NPY levels have been reported in major depressive disorder (MDD).

OBJECTIVE

To determine whether low-expression NPY genotypes are associated with negative emotional processing at 3 levels of analysis.

DESIGN

Cross-sectional, case-control study.

SETTING

Academic medical center.

PARTICIPANTS

Among 44 individuals with MDD and 137 healthy controls, 152 (84%) had an NPY genotype classified as low, intermediate, or high expression according to previously established haplotype-based expression data.

MAIN OUTCOME MEASURES

Healthy subjects participated in functional magnetic resonance imaging while viewing negative (vs neutral) words (n = 58) and rated positive and negative affect during a pain-stress challenge (n = 78). Genotype distribution was compared between 113 control subjects and 39 subjects with MDD.

RESULTS

Among healthy individuals, negatively valenced words activated the medial prefrontal cortex. Activation within this region was inversely related to genotype-predicted NPY expression (P = .03). Whole-brain regression of responses to negative words showed that the rostral anterior cingulate cortex activated in the low-expression group and deactivated in the high-expression group (P < .05). During the stress challenge, individuals with low-expression NPY genotypes reported more negative affective experience before and after pain (P = .002). Low-expression NPY genotypes were overrepresented in subjects with MDD after controlling for age and sex (P = .004). Population stratification did not account for the results.

CONCLUSIONS

These findings support a model in which NPY genetic variation predisposes certain individuals to low NPY expression, thereby increasing neural responsivity to negative stimuli within key affective circuit elements, including the medial prefrontal and anterior cingulate cortices. These genetically influenced neural response patterns appear to mediate risk for some forms of MDD.

fMRI BOLD responses to negative stimuli in the prefrontal cortex are dependent on levels of recent negative life stress in major depressive disorder

It is poorly understood how stressors modulate neurobiological mechanisms that may contribute to the heterogeneity of major depressive disorder (MDD). Unmedicated patients diagnosed with MDD (n=15) and individually matched healthy controls (n=15) completed stress questionnaires and were studied with functional magnetic resonance imaging while viewing emotional words. Significant effects of recent negative life stressors, but not early life stress/trauma, were observed on regional blood oxygen level dependent activity during presentation of negative words in patients with MDD. No significant effects of stress on brain activation to negative words were found in controls. In MDD patients, positive correlations were found bilaterally in orbitofrontal areas 11 l/47/12m, which are involved in representing negatively valenced stimuli. Negative correlations were also found in the right ventrolateral prefrontal area 45, subgenual cingulate area 25, and nucleus accumbens, all of which are implicated in the pathophysiology of MDD. Negative memory bias was additionally positively associated with recent negative life stress and negatively associated with subgenual cingulate activation, suggesting a mechanism by which stress may contribute to these abnormalities. The severity of recent negative life stressors is an important modifier of neurobiological and cognitive function in MDD and may help explain heterogeneity in the disorder.

Paraventricular thalamic nucleus: subcortical connections and innervation by serotonin, orexin, and corticotropin-releasing hormone in macaque monkeys

The present study examines subcortical connections of paraventricular thalamic nucleus (Pa) following small anterograde and retrograde tracer injections in cynomolgus monkeys (Macaca fascicularis). An anterograde tracer injection into the dorsal midline thalamus revealed strong projections to the accumbens nucleus, basal amygdala, lateral septum, and hypothalamus. Retrograde tracer injections into these areas labeled neurons specifically in Pa. Following a retrograde tracer injection into Pa, labeled neurons were found in the hypothalamus, dorsal raphe, and periaqueductal gray. Pa contained a remarkably high density of axons and axonal varicosities immunoreactive for serotonin (5-HT) and orexin/hypocretin (ORX), as well as a moderate density of fibers immunoreactive for corticotropin-releasing hormone (CRH). A retrograde tracer injection into Pa combined with immunohistochemistry demonstrated that ORX and 5-HT axons originate from neurons in the hypothalamus and midbrain. Pa-projecting neurons were localized in the same nuclei of the hypothalamus, amygdala, and midbrain as CRH neurons, although no double labeling was found. The connections of Pa and its innervation by 5-HT, ORX, and CRH suggest that it may relay stress signals between the midbrain and hypothalamus with the accumbens nucleus, basal amygdala, and subgenual cortex as part of a circuit that manages stress and possibly stress-related psychopathologies.

Pediatric transplantation in the United States, 1997-2006

This article represents the sixth annual review of the current state of pediatric transplantation in the United States from the Scientific Registry of Transplant Recipients (SRTR). It presents updated trends, discussion of analyses presented during the year by the SRTR to the committees of the Organ Procurement and Transplantation Network (OPTN) and discussion of important issues currently facing pediatric organ transplantation. Unless otherwise stated, the statistics in this article are drawn from the reference tables of the 2007 OPTN/SRTR Annual Report. In this article, pediatric patients are defined as candidates, recipients or donors aged 17 years or less. Data for both graft and patient survival are reported as unadjusted survival, unless otherwise stated (adjusted patient and graft survival are available in the reference tables). Short-term survival (3 month and 1 year) reflects outcomes for transplants performed in 2004 and 2005; 3-year survival reflects transplants from 2002 to 2005; and 5-year survival reports on transplants performed from 2000 to 2005. Details on the methods of analysis employed may be found in the reference tables themselves or in the technical notes of the 2007 OTPN/SRTR Annual Report, both available online at http://www.ustransplant.org.

Twenty-year experience with heart transplantation for infants and children with restrictive cardiomyopathy: 1986-2006

Idiopathic restrictive cardiomyopathy (RCM) is a rare cardiomyopathy in children notable for severe diastolic dysfunction and progressive elevation of pulmonary vascular resistance (PVR). Traditionally, those with pulmonary vascular resistance indices (PVRI) >6 W.U. x m(2) have been precluded from heart transplantation (HTX). The clinical course of all patients transplanted for RCM between 1986 and 2006 were reviewed. Preoperative, intraoperative and postoperative variables were evaluated. A total of 23 patients underwent HTX for RCM, with a mean age of 8.8 +/- 5.6 years and a mean time from listing to HTX of 43 +/- 60 days. Preoperative and postoperative (114 +/- 40 days) PVRI were 5.9 +/- 4.4 and 2.9 +/- 1.5 W.U. x m(2), respectively. At time of most recent follow-up (mean = 5.7 +/- 4.6 years), the mean PVRI was 2.0 +/- 1.0 W.U. x m(2). Increasing preoperative mean pulmonary artery pressure (PA) pressure (p = 0.04) and PVRI > 6 W.U. x m(2) (chi(2)= 7.4, p < 0.01) were associated with the requirement of ECMO postoperatively. Neither PVRI nor mean PA pressure was associated with posttransplant mortality; 30-day and 1-year actuarial survivals were 96% and 86%, respectively. Five of the seven patients with preoperative PVRI > 6 W.U. x m(2) survived the first postoperative year. We report excellent survival for patients undergoing HTX for RCM despite the high proportion of high-risk patients.

Midline and intralaminar thalamic connections with the orbital and medial prefrontal networks in macaque monkeys

Although the midline and intralaminar thalamic nuclei (MITN) were long believed to project "nonspecifically," they are now known from rat studies to have restricted connections to the prefrontal cortex. This has not been studied thoroughly in primates, however, and it is not known how MITN are associated with the "orbital" and "medial" prefrontal networks. This study examined the connections of MITN in cynomolgus monkeys (Macaca fascicularis). Experiments with retrograde and anterograde tracer injections into the orbital and medial prefrontal cortex (OMPFC) showed that MITN are strongly connected with the medial prefrontal network. The dorsal nuclei of the midline thalamus, including the paraventricular (Pa) and parataenial nuclei (Pt), had heavy connections with medial network areas 25, 32, and 14c in the subgenual region. Areas 13a and 12o, which are associated with both networks, were strongly connected with the Pt and the central intermedial nucleus, respectively. Otherwise, orbital network areas had weak connections with MITN. Anterograde tracer injections into the dorsal midline thalamus resulted in heavy terminal labeling in the medial prefrontal network, most notably in areas ventral to the genu of the corpus callosum (25, 32, and 14c), but also in adjacent areas (13a and 13b). Retrograde tracer injection into the dorsal midline labeled similar areas. The medial network, particularly the subgenual region, is involved in visceral and emotional control and has been implicated in mood disorders. The strong connections between the subgenual cortex and the Pa provide a pathway through which stress signals from the Pa may influence these prefrontal circuits.

The effects of acute stress on the regulation of central and basolateral amygdala CRF-binding protein gene expression

Corticotropin-releasing factor (CRF) is a key mediator of the behavioral, autonomic, and endocrine responses to stress. CRF binds two receptors and a CRF-binding protein (CRF-BP), which may inactivate or modulate the actions of CRF at its receptors. The amygdala is an important anatomical substrate for CRF and contains CRF, its receptors, and CRF-BP. Few studies have examined the effects of acute stress on the regulation of amygdala CRF-BP with other CRF system genes. Therefore, we examined the time course of the effects of acute restraint stress on central (CeA) and basolateral (BLA) amygdala CRF system genes. Consistent with our previous study, acute stress increased BLA CRF-BP mRNA shortly after stress offset. Surprisingly, BLA CRF-BP mRNA remained elevated up to 21 h after the stressor. This effect was selective in the BLA as stress did not alter CeA CRF-BP mRNA, and there were no changes in CRF or CRF receptor mRNAs in either amygdala nucleus. These results suggest that alterations in BLA CRF-BP gene expression are a primary response of the BLA/CeA CRF system to acute stress. Because CRF-BP can modulate CRF action, changes in amygdala CRF-BP levels after stress exposure may affect the ability of an organism to adapt to future stressors.

Complete atresia of coronary ostia in pulmonary atresia and intact ventricular septum

We describe the clinical course, echocardiography, angiography, and histopathology of a female infant with pulmonary atresia and intact ventricular septum (PA/IVS) with complete coronary ostial atresia and right ventricle-dependent coronary circulation who survived for 7 weeks after palliative surgery. The patient expired from myocardial insufficiency while waiting for a donor heart. Postmortem examination demonstrated atretic coronary ostia, ventricular sinusoids, and myocardial infarctions of various ages. This report suggests that neonates with PA/IVS who have this extreme form of coronary abnormality may potentially be managed medically and surgically until cardiac transplantation is available.

Diurnal changes in corticotropin-releasing hormone messenger RNA in the rat thalamus

Corticotropin-releasing hormone (CRH) is critical for mediating the stress response. CRH messenger RNA (mRNA) is present in a variety of brain regions including the thalamus and thalamic CRH mRNA concentrations increase in response to stress exposure. The present study assessed changes in basal CRH mRNA concentrations in the rat thalamus during different times of the day. Using in situ hybridization, we demonstrated that thalamic CRH mRNA levels exhibited more than two-fold increases during the dark phase between 20:00 and 02:00 h, followed by a decrease at 08:00 and 14:00 h during the light phase. Dramatic changes in thalamic CRH mRNA levels may have important implications for the possible role of thalamic CRH systems in waking, arousal, and the stress response.

Acute stress-induced increases in thalamic CRH mRNA are blocked by repeated stress exposure

Corticotropin-releasing hormone (CRH) coordinates multiple aspects of the stress response. Recently, CRH mRNA has been identified in two regions of the thalamus: the posterior nuclear group (Po), and a region located at the interface of the central medial and ventral posteromedial nucleus (parvicellular part) (CM-VPMpc). Previous studies demonstrated that in both regions CRH mRNA increases following 1 h of restraint stress, suggesting involvement of thalamic CRH in processing somatosensory and visceral information related to stress. The current study was proposed to further understand the effects of repeated and acute restraint stress on levels of thalamic CRH mRNA. Adult male rats were assigned to one of four groups in a 2 (repeated stress, no repeated) x2 (acute, no acute) design. Brain sections were processed for CRH mRNA in situ hybridization. ANOVA revealed no main effects of acute or repeated stress in either thalamic region. However, significant interactions between acute and repeated stress for levels of CRH mRNA were found for both regions of the thalamus. Compared to the no stress condition, acute restraint significantly increased CRH mRNA in the Po (39%) and the CM-VPMpc (32%). Repeated restraint did not alter baseline CRH mRNA levels, but blocked the acute restraint-induced effects. Thus, while acute stress increases levels of thalamic CRH mRNA, repeated exposure to the same stressor is without effect and prevents the acute response. These findings add to data establishing a role for thalamic CRH in the stress response and suggest a mechanism that may underlie habituation to repeated stress exposure.

Ultrasound-assisted cannulation of the right internal jugular vein during electrophysiologic studies in children

Percutaneous access of the right internal jugular vein for coronary sinus cannulation in pediatric patients undergoing electrophysiologic studies may be technically difficult. We report the use of an ultrasound-guided technique for obtaining jugular venous access. Forty-five pediatric patients who underwent electrophysiologic study were analyzed. Access was obtained in 100 % of the patients using this technique with no major complications. Ultrasound guidance for access of the internal jugular vein for coronary sinus cannulation during electrophysiologic studies in pediatric patients, may increase the success rate and prevent the development of complications.

Effects of acute and repeated restraint stress on corticotropin-releasing hormone binding protein mRNA in rat amygdala and dorsal hippocampus

Corticotropin-releasing hormone (CRH) mediates endocrine, behavioral, and autonomic responses to stress. In addition to binding to two receptor subtypes, CRH binds to a CRH-binding protein (CRH-BP). While CRH-BP is hypothesized to play a role in regulating levels of free CRH and modulating the stress response, the effects of stressors on brain CRH-BP are relatively unexplored. The present study determined effects of acute and repeated restraint on CRH-BP mRNA in basolateral amygdala (BLA) and dorsal hippocampus (DH), brain regions involved in fear and motivation. Using in situ hybridization, we found that a single acute period of restraint significantly increased CRH-BP mRNA in BLA by 20% but had no effect in DH. Repeated restraint had no effect on basal levels of CRH-BP mRNA in BLA or DH. Importantly, repeated restraint blocked the effects of acute restraint in the BLA. These results demonstrate differential effects of acute and repeated restraint on CRH-BP mRNA.

Corticotropin-releasing hormone messenger RNA distribution and stress-induced activation in the thalamus

Corticotropin-releasing hormone plays a critical role in mediating the stress response. Brain circuits hypothesized to mediate stress include the thalamus, which plays a pivotal role in distributing sensory information to cortical and subcortical structures. In situ hybridization revealed neurons containing corticotropin-releasing hormone messenger RNA in the posterior thalamic nuclear group and the central medial nucleus of the thalamus, which interfaces with the ventral posteromedial nucleus (parvicellular part). These regions are of interest because they process somatosensory and visceral information. In the first experiment, the effect of acute stress on thalamic corticotropin-releasing hormone messenger RNA levels was assessed. Rats restrained for 1 h and killed 1 h later were found to have increased corticotropin-releasing hormone messenger RNA in the posterior thalamic nuclear group. The time course of these changes was examined in a second experiment in which rats were killed immediately or 3 h after restraint. While no changes occurred in the thalamus immediately after restraint, 3 h after restraint, increases in corticotropin-releasing hormone messenger RNA occurred in both the posterior thalamic nuclear group and the central medial-ventral posteromedial nucleus (parvicellular part) of the thalamus. A different pattern of activation was observed in the paraventricular nucleus of the hypothalamus with increased corticotropin-releasing hormone messenger RNA immediately after restraint, but not 1 or 3 h later. In addition to the stress-induced changes, a prominent decrease in baseline thalamic corticotropin-releasing hormone messenger RNA was observed from 1000 to 1300 h. These results show that the thalamus contains corticotropin-releasing hormone messenger RNA that increases after restraint stress, indicating a role for thalamic corticotropin-releasing hormone systems in the stress response. Stress-induced changes in thalamic corticotropin-releasing hormone messenger RNA expression appears to be regulated differently than that in the paraventricular nucleus of the hypothalamus, and may be influenced by diurnal mechanisms.

Outcomes of transcatheter balloon angioplasty of obstruction in the neo-aortic arch after the Norwood operation

Obstruction of the reconstructed aortic arch, or the neoaortic arch, is now known to be an important factor increasing mortality after the Norwood operation for hypoplastic left heart syndrome. Transcatheter balloon angioplasty has been shown to provide effective relief of both native aortic coarctation and obstructions of the aortic arch occurring subsequent to therapeutic intervention. We sought to determine the outcomes of balloon angioplasty used as an initial treatment for obstruction of the neoaortic arch occurring after the Norwood operation. We gathered the characteristics of 58 patients with such obstruction from 8 institutions, noting procedural factors and outcomes of initial balloon dilation. Obstruction occurred at a median interval of 4 months, with a range from 1.5 months to 6.3 years, after a Norwood operation. Ventricular dysfunction was present before dilation in 13 patients. Mean peak to peak systolic pressure gradients were acutely reduced from 31+/-20 mm Hg to 6+/-9 mmHg (p<0.001), with outcome subjectively judged to be successful in 89%. Three patients with pre-existing ventricular dysfunction died within 48 hours of dilation. There were 10 additional deaths during the period of follow-up, with Kaplan Meier estimates of survival after intervention of 87% at 1 month, 77% at 12 months, and 72% after 15 months. In addition, 9 patients required re-intervention during the period of follow-up, with Kaplan Meier estimates of freedom from re-intervention after dilation of 87% at 6 months, 78% at 12 months and 74% after 18 months. Although transcatheter dilation of neoaortic arch obstructions after Norwood operation is successful, there is a high risk of re-intervention and ongoing mortality in this subgroup of patients. Close follow-up is recommended.

Regression of pulmonary arteriovenous malformations following heart transplantation

Pulmonary arteriovenous malformations (PAVMs) can occur following caval to pulmonary artery connection, Glenn and/or Fontan procedure, leading to severe cyanosis and exercise intolerance. It is unknown whether these abnormalities regress or persist following heart transplantation (HTx). Twenty patients with failed Fontan or Glenn procedures were screened for PAVMs prior to HTx by contrast echocardiography, selective pulmonary angiography, and pulmonary venous desaturation. Age at transplant, diagnosis, previous operations, time from Glenn to transplant, systemic oxygenation, hemoglobin level, and ventricular function were determined. The clinical course after HTx was characterized in three patients with significant PAVMs. Indications for HTx were exercise intolerance and severe cyanosis in one patient, and cyanosis and ventricular dysfunction in two. Pre-HTx, mean systemic saturation was 67%; mean pulmonary venous wedge saturation was 81%. Post-HTx, oxygen saturations were normal (> 96%) at 14, 40, and 180 days. Contrast echocardiography, performed 1 month to 3.3 yrs after HTx, showed no intrapulmonary shunting in two patients and minimal shunting in one. One patient suffered an embolic stroke from right-to-left shunting post-HTx. All patients are alive and well 35, 71, and 73 months post-HTx. In patients with single ventricle physiology, PAVMs are not an absolute contraindication to HTx. Heart-lung transplant may not be required for these patients.

A new technique for endomyocardial biopsy in infants and small children

Endomyocardial biopsy (EMB) is usually performed from the femoral veins in infants and small children. This requires the use of a long vascular sheath to direct a bioptome to the ventricular septum. We describe a technique of EMB in this population that obviates the need for the use of a long vascular sheath. A 5 Fr 0.038" internal diameter, no-sideholes Cobra catheter (Cook, Bloomington, IN) introduced via a 5 Fr short sheath was used to direct a 3 Fr, 60-cm-length Cook bioptome to the ventricular septum. From January 1998 to August 1999, this technique was used 22 times in seven patients for EMB (median, age 13 months; range, 1-72 months). Indications for EMB in this group were posttransplantation surveillance (21 times) and evaluation for cardiomyopathy/myocarditis (1). Median number of EMB specimens obtained per procedure was 6 (range, 5-9). There was one pneumopericardium seen post-EMB with this technique without hemodynamic embarrassment. EMB in infants and small children can be performed successfully, safely, and repeatedly from the femoral veins without the need for a long sheath.

Improvement of rejection-induced diastolic abnormalities in rat cardiac allografts with inducible nitric oxide synthase inhibition

OBJECTIVE

Inhibition of inducible nitric oxide synthase (nitric oxide II) activity has been proposed as a method to attenuate capillary leak and edema during rejection of heterotopically transplanted rat hearts. Myocardial edema has previously been implicated in diastolic dysfunction during allograft rejection. Accordingly, we tested the hypothesis that inducible nitric oxide synthase inhibition with aminoguanidine would alleviate left ventricular stiffening and myocardial edema formation in 4-day heterotopic rat heart allografts.

METHODS

Passive left ventricular filling was studied in American Cancer Institute Lewis rats receiving heterotopic heart transplants receiving either aminoguanidine, a selective nitric oxide synthase inhibitor (n = 6); dexamethasone (1 mg. kg(-1). d(-1) administered subcutaneously) for 4 days after transplantation (n = 6); or intravenous saline solution (n = 6). American Cancer Institute-to-American Cancer Institute isografts (n = 6) were used as controls.

RESULTS

Serum nitrite/nitrate levels in the aminoguanidine group (18 +/- 3 mmol/L) and dexamethasone group (22 +/- 4 mmol/L) were reduced versus the intravenous saline group (144 +/- 36 mmol/L [SEM]) to levels seen in controls (25 +/- 9 mmol/L). Left ventricular volume at 15 mm Hg for the aminoguanidine group was increased versus that for the intravenous saline solution group, similar to that for controls, and reduced versus dexamethasone-treated animals. Myocardial water content for the aminoguanidine-treated animals (78.3% +/- 0.4%) was similar to those of intravenous saline-treated animals (78.0% +/- 0. 3%) but greater than those of controls (77.1% +/- 0.2%) and dexamethasone-treated animals (76.7% +/- 0.3%).

CONCLUSIONS

Nitric oxide II inhibition with aminoguanidine minimizes the reduction in left ventricular filling that is seen with allograft rejection through a mechanism that is not associated with attenuation of myocardial edema.

Serial echocardiographic measurements of the pulmonary autograft in the aortic valve position after the Ross operation in a pediatric population using normal pulmonary artery dimensions as the reference standard

Serial echocardiographic measurements of the annulus and sinus were obtained in children before the Ross operation, and early and late postoperatively. Values were compared with normal standards for the aorta and pulmonary artery (PA). There was no significant difference between PA annulus measurements before surgery and the corresponding autograft immediately afterward (1.73 +/- 0.60 cm preoperatively; 1. 63 +/- 0.58 cm postoperatively, p = NS). Late after surgery the mean annulus diameter was enlarged compared with the normal aorta (DeltaZ 1.9 +/- 2.4), but remained relatively unchanged compared with the normal PA (DeltaZ 0.7 +/- 1.1, p <0.01). In contrast, the autograft sinus was dilated early after surgery (1.83 +/- 0.58 cm preoperatively; 2.18 +/- 0.73 cm postoperatively, p <0.01). Mean sinus Z score further increased compared with both the aorta (DeltaZ 1.3 +/- 1.7) and PA (DeltaZ 1.3 +/- 1.6). Use of standard PA measurements may be important in the assessment of autograft enlargement. Minimal change in autograft Z scores over time suggests that annulus enlargement is mainly due to somatic growth. In contrast, the autograft sinus showed an immediate and continued disproportionate increase in size over time, suggesting that sinus enlargement is largely due to passive dilation.

Outcome after orthotopic cardiac transplantation in adults with congenital heart disease

BACKGROUND

Advances in surgical and medical management have greatly improved long-term survival rates in patients with congenital heart disease (CHD). As these patients reach adulthood, myocardial dysfunction can occur, leading to cardiac transplantation.

METHODS AND RESULTS

We reviewed the pretransplantation and posttransplantation courses of 24 patients >18 years old (mean age, 26 years; range, 18 to 56 years) with CHD who received a transplant between January 1985 and September 1998. The relation between preoperative and perioperative risk factors for complications and death was assessed. Single ventricle was the pretransplantation diagnosis for 12 patients (50%), and d-transposition of the great vessels was the diagnosis for 4 patients (16%). Twenty-two patients had a mean of 2 previous operations. At cardiac transplantation, additional surgical procedures were required to correct extracardiac lesions in 18 patients (75%). Refractory heart failure was present in 22 patients, significant cyanosis was present in 7, and protein-losing enteropathy was present in 4. There were 5 early deaths due to bleeding (n=3) and infection (n=2). The Kaplan-Meier survival rate after cardiac transplantation was 79% at 1 year and 60% at 5 years. No anatomic or surgical risk factor was predictive of death. The outcome of patients with CHD who received a transplant was compared with that for patients without CHD (n=788). Mean bypass and ischemic times were significantly longer in patients with CHD than in patients without CHD. Survival rates after transplantation did not differ significantly between patients with and those without CHD (P=0.83).

CONCLUSIONS

Successful cardiac transplantation is obtainable in adults with complex CHD, with an outcome similar to that of patients without CHD. A detailed assessment of cardiac anatomy and careful surgical planning are essential to the pretransplantation and posttransplantation management of these patients.

Coronary perfusate composition influences diastolic properties, myocardial water content, and histologic characteristics of the rat left ventricle

BACKGROUND

Recent studies found that edema, histology, and left ventricular diastolic compliance exhibit quantitative relationships in rats. Edema due to low osmolarity coronary perfusates increases myocardial water content and histologic edema score and decreases left ventricular filling. The present study examined effects of perfusate osmolarity and chemical composition on rat hearts.

METHODS

Arrested American Cancer Institute (ACI) rat hearts (4 degrees C) were perfused with different cardioplegia solutions, including Plegisol (289 mOsm/L), dilute Plegisol (172 mOsm/L), Stanford solution (409 mOsm/L), and University of Wisconsin solution (315 mOsm/L). Controls had blood perfusion (310 mOsm/L). Postmortem left ventricular pressure-volume curves and myocardial water content were measured. After glutaraldehyde or formalin fixation, dehydration, and paraffin embedding, edema was graded subjectively.

RESULTS

Myocardial water content reflected perfusate osmolarity, being lowest in Stanford and University of Wisconsin solutions (p<0.05 versus other groups) and highest in dilute Plegisol (p<0.05). Left ventricular filling volumes were smallest in dilute Plegisol and Plegisol (p<0.05). Osmolarity was not a major determinant of myocardial edema grade, which was highest with University of Wisconsin solution and dilute Plegisol (p<0.05 versus other groups).

CONCLUSIONS

Perfusate osmolarity determined myocardial water content and left ventricular filling volume. However, perfusate chemical composition influenced the histologic appearance of edema. Pathologic grading of edema can be influenced by factors other than osmolarity alone.

Pressure volume curves in arrested heterotopic rat heart isografts: role of improved myocardial protection

BACKGROUND

To minimize decreases in left ventricular (LV) compliance immediately after rat heart transplantation, we tested several different methods of myocardial protection.

MATERIALS AND METHODS

Five groups of ACI rat hearts (n = 6 each) were arrested by coronary perfusion with 5 ml of UW (University of Wisconsin), UW-BDM (UW with 2,3-butanedione monoxime), CU (Columbia University), or CU-BDM solution or by LV injection of potassium chloride and Ringer's lactate immersion (KCl/RL). After abdominal isografting and blood reperfusion for 15 min, transplanted hearts (TxH) were arrested and excised. Diastolic LV pressure-volume curves (LVPVCs) were correlated with myocardial water content (MWC). Native hearts (NH) were arrested identically to TxH and maintained at 4 degrees C by immersion. LVPVCs were measured at 15-min intervals for 90 min.

RESULTS

In three of four pressure intervals at Time 0, normalized LV volume (LVV) was smaller (P < 0.05, ANOVA) in KCl/RL native hearts than in the four perfusion groups. LVV decreased significantly in NH after 45-75 min; LVV decreased similarly with time in all groups. In TxH, postarrest LVVs were higher with UW-BDM, CU-BDM, and CU than with UW or KCl/RL (P < 0.05, ANOVA). Expressing LVV of TxH as a percentage of NH, UW-BDM, CU, and CU-BDM provided qualitatively better diastolic properties than KCl/RL and UW.

CONCLUSIONS

Thus rat LVPVCs can be improved after heart transplantation with alternative strategies of myocardial protection. KCl arrest decreases LV filling volume in this model and should be avoided.

Incidence and outcome of primary Epstein-Barr virus infection and lymphoproliferative disease in pediatric heart transplant recipients

BACKGROUND

The objective of this study was to assess the relationship between Epstein-Barr virus (EBV) infection and posttransplantation lymphoproliferative disease (PTLD) in pediatric heart transplant recipients. EBV is implicated in the development of PTLD. However, the relationship between primary EBV infection and PTLD is not well understood.

METHODS

Serial EBV titers were determined prospectively in 50 children before and after heart transplantation. Results were correlated with the development of PTLD. The clinical presentation, management, and outcome of PTLD were characterized.

RESULTS

Before transplantation, EBV titers were positive in 19 and negative in 31 patients. After transplantation, all EBV-positive patients remained positive; 1 developed PTLD. Among EBV-negative patients, 12 of 31 remained negative; none developed PTLD. Nineteen patients demonstrated serologic evidence of primary EBV infection after heart transplantation; 12 developed PTLD. Mean follow-up after heart transplantation was 3.3 years (range 0.4 to 8.4 years). Mean time from heart transplantation to histologic confirmation of PTLD was 29 months (range 3 to 72 months). Survival with PTLD was 92%.

CONCLUSIONS

Twelve of 13 pediatric heart transplant recipients who developed PTLD had evidence of primary EBV infection. Serial monitoring of EBV titers may lead to earlier identification and improved treatment of PTLD.

Effect of improved myocardial protection on edema and diastolic properties of the rat left ventricle during acute allograft rejection

BACKGROUND

Studies of myocardial edema and diastolic dysfunction in rat heart transplantation have been flawed by ischemic injury. This study uses improved methods to prevent ischemic contracture.

METHODS

Hearts of 30 ACI rats were transplanted into the abdomen of Lewis rats by use of cold University of Wisconsin solution for improved preservation. Left ventricular diastolic properties were expressed as volume at standardized pressure intervals.

RESULTS

On posttransplantation day 3, mean left ventricular volume at 15 mm Hg in allografts (290 +/- 9 microl, SEM) was not significantly different vs isografts (299 +/- 32 microl), allografts on day 0 (337 +/- 28 ml) or day 1 (324 +/- 20 microl), or native hearts (334 +/- 19 microl). However, volume was reduced to 173 +/- 17 microl on day 4 and to 70 +/- 23 microl on day 5 (p < 0.05). Similar findings were obtained for volume at 5 and 10 mm Hg. Allograft myocardial water content on day 3, 76.3% +/- 5%, similar to allografts on day 0 and 1 and to isografts on day 3, increased to 77.6% +/- 8% on day 4 (NS) and 79.4% +/- 6% on day 5 (p < 0.05 vs day 0). Histologically, rejection in allografts was mild on day 3, moderate on day 4, and severe on day 5.

CONCLUSIONS

Reduced left ventricular filling volume during rejection is only partially explained by edema. Abnormalities of diastolic properties previously attributed to the unloaded state of nonworking heart models may actually reflect inadequate peritransplantation myocardial protection.

The morphologic and molecular genetic categories of posttransplantation lymphoproliferative disorders are clinically relevant

BACKGROUND

Posttransplantation lymphoproliferative disorders (PT-LPDs) are a well-known complication of immunosuppression associated with solid organ transplantation. The clinical course of PT-LPDs is unpredictable; some patients experience regression of all lesions with a reduction in immunosuppression, whereas other patients, despite chemotherapy, radiation therapy, or surgery, rapidly die of their disease. In this study, the authors attempted to establish whether the previously described morphologic and molecular genetic categories of PT-LPD--plasmacytic hyperplasia (PH), polymorphic PT-LPD (polymorphic), and malignant lymphoma/multiple myeloma (ML/MM)--are clinically relevant and helpful in predicting the clinical outcome of patients who develop these lesions.

METHODS

To determine the clinical significance of the morphologic and molecular genetic categories of PT-LPDs, the clinical characteristics of 32 solid organ transplant recipients (26 heart, 5 kidney, and 1 lung), including age, time from transplantation to development of PT-LPD, stage of disease, and clinical outcome, were compared with the morphologic and molecular genetic features of the 41 PT-LPDs that they developed (15 PH in 12 patients, 19 polymorphic in 16 patients, and 7 ML/MM in 6 patients). Clinical outcome was defined by the following categories: 1) regression (after a reduction in immunosuppression) and surgical resolution (by surgical excision, with or without a reduction in immunosuppression); 2) medical resolution (by chemotherapy and/or radiation therapy); and 3) no response.

RESULTS

Although there was no difference in the time from transplantation to PT-LPD development among patients belonging to the three morphologic and molecular genetic categories, there was a significant difference in patient age at the time of PT-LPD development (P < 0.0098). Younger patients developed PH (mean age of 19 years), whereas older patients developed polymorphic PT-LPD (mean age of 35 years) and ML/MM (mean age of 56 years). Patients with PH presented with lower stages of disease (Stages I-II) than patients with ML/MM (P < 0.0004). Furthermore, there was a statistically significant trend between morphologic and molecular genetic category and clinical outcome, with decreased likelihood that lesions categorized as PH, polymorphic, or ML/MM would regress with a reduction in immunosuppression or be resolved by surgery, whereas those classified as ML/MM were more likely to exhibit no response to aggressive clinical intervention (P < 0.00006). Furthermore, no patients with PH died, whereas 20% with polymorphic PT-LPD and 67% with ML/MM died as a direct result of their PT-LPDs.

CONCLUSIONS

This study strongly suggests that classification of PT-LPDs into the morphologic and molecular genetic categories PH, polymorphic, PT-LPD and ML/MM is clinically relevant.

Rapid stress-induced elevations in corticotropin-releasing hormone mRNA in rat central amygdala nucleus and hypothalamic paraventricular nucleus: an in situ hybridization analysis

High densities of nerve cells containing corticotropin-releasing hormone (CRH) are located in the central nucleus of the amygdala (CeA) and paraventricular nucleus (PVN) of the hypothalamus. These brain regions play an important role in activating autonomic, behavioral, and endocrine responses to stress. This study was conducted to provide needed information concerning the acute effects of stress on CeA and PVN CRH mRNA expression. Rats were exposed to restraint stress for 1 h and brains collected after a 1-h post-stress interval. CRH mRNA expression occurring in the CeA and PVN was examined using in situ hybridization techniques. Densitometric analysis revealed that acute restraint stress produced significant increases in CRH mRNA levels in the PVN and in the rostral CeA region. In addition, the area in the rostral CeA encompassing high CRH mRNA signals increased significantly after stress. Results provide clear evidence that CRH neurons in the CeA and PVN exhibit rapid increases in CRH mRNA expression after exposure to stress.

Diastolic properties, myocardial water content, and histologic condition of the rat left ventricle: effect of varied osmolarity of a coronary perfusate

BACKGROUND

Although myocardial edema is known to impair diastolic filling of the left ventricle, the interrelation of edema, histologic condition, and function has not been quantitated sufficiently for extrapolation to studies of multifactorial influences on diastolic properties.

METHODS

Accordingly, ACI rat hearts arrested at 4 degrees C underwent coronary artery perfusion with a cardioplegia solution that was either unaltered (288 mOsm/L, P288 group, n = 6), diluted (144 mOsm/L, P144 group, n = 6), or concentrated (380 mOsm/L, P380 group, n = 6). Postmortem left ventricular pressure-volume curves and myocardial water content were measured. Myocardial samples were fixed in varying dilutions of glutaraldehyde. After dehydration and paraffin embedding, edema was graded subjectively (0 to 5), and myocardial interstitial spaces were determined by use of a semiquantitative method.

RESULTS

Mean normalized left ventricular filling volume at 20 mm Hg filling pressure in the P144 group, 189 +/- 16 microliters (SEM), was reduced versus both the P288 (278 +/- 26 microliters) and the P380 (332 +/- 18 microliters) groups (p < 0.05, ANOVA). Mean myocardial water content in the P144 group, 80.7% +/- 1%, was increased versus the P380 (76.7% +/- 0.4%, p < 0.05) but not versus the P288 group (78.4% +/- 0.8%). In hearts preserved with 2.5% glutaraldehyde, mean edema grade and interstitial space in the P144 group (4.0 +/- 0.3) were increased versus the P380 (1.8 +/- 0.3, p < 0.05) but not the P288 group (2.7 +/- 0.5). Derived linear regressions relate water content to filling volume and histologic condition.

CONCLUSIONS

Coronary perfusate osmolarity is thus associated with predictable changes in myocardial water content, left ventricular filling volume, and edema. These correlations allow definition of new hypotheses for the study of cardiac allograft rejection in patients and experimental animals.

Outcome after the single-stage, nonfenestrated Fontan procedure

BACKGROUND

A completed Fontan circulation is the goal in the management of patients with single-ventricle physiology. To achieve this end, a two-stage rather than a single-stage approach is carried out routinely at many centers. Some groups have advocated baffle fenestration for virtually all patients to minimize post-Fontan complications. Other centers perform single-stage Fontan operations and do not fenestrate. Thus controversies have arisen regarding the indications for the staged procedure versus single stage and for fenestration versus no fenestration.

METHODS AND RESULTS

The preoperative risk factors and postoperative course were characterized in 61 consecutive patients (median age, 3.3 years) undergoing a single-stage, nonfenestrated Fontan. The patients were followed for 3.5+/-1.9 years. The relationship between preoperative risk factors and mortality and morbidity was assessed. Preoperative risk factors assessed included age <2 years (n=18), branch pulmonary artery stenosis (n=20), elevated mean pulmonary artery pressure >15 mm Hg (n=16), atrioventricular valve regurgitation (n=5), and decreased ventricular function (n=2). Total caval pulmonary anastomosis was performed in 53 patients. Additional surgery was required at the time of the Fontan in 25 patients (41%). The median duration of mechanical ventilation was 1 day; median chest tube drainage was 5.5 days (range, 1 to 35). Oxygen saturation rose significantly postoperatively, from 83% to 95%. Early mortality was 4.9%; one patient died from pacemaker failure 9 months postoperatively, and one patient underwent successful heart transplant 4 months post-Fontan. One- and 5-year actuarial survival was 93%. No preoperative risk factor was associated with a failed Fontan or significant effusions.

CONCLUSIONS

A single-stage, nonfenestrated Fontan was performed in a large group of patients with excellent surgical results and intermediate outcome. There is no evidence that a two-stage approach and/or baffle fenestration is required for a large cohort of patients who are candidates for a Fontan operation.

Long-term survivors of pediatric heart transplantation: a multicenter report of sixty-eight children who have survived longer than five years

OBJECTIVE

Short-term survival after pediatric heart transplantation is now excellent, but ultimately the efficacy of this procedure will depend on duration and quality of survival. We sought to evaluate the clinical course of long-term survivors of heart transplantation in childhood.

METHODS

Patients who had undergone heart transplantation at the university hospitals of Stanford, Columbia, and Pittsburgh between 1975 and 1989 and survived longer than 5 years from transplantation were identified and their clinical courses retrospectively reviewed.

RESULTS

Sixty eight children have survived more than 5 years from transplantation, and 60 (88%) are currently alive with a median follow-up of 6.8 years (5 to 17.9 years). Thirteen have survived more than 10 years from transplantation. Renal dysfunction caused by immunosuppressive agents was common, and two patients required late renal transplantation. Lymphoproliferative disease or other neoplasm occurred in 12 patients, but none resulted in death. Coronary artery disease was diagnosed in 13 patients (19%), leading to retransplantation in eight. Death after 5 years was related to acute or chronic rejection in 5 of 8 cases. Two of the deaths were directly related to noncompliance with immunosuppressive medication. All survivors are in New York Heart Association class 1.

CONCLUSIONS

Long-term survival with good quality of life can be achieved after heart transplantation in childhood, though complications of immunosuppression remain common. Posttransplantation coronary artery disease is emerging as the main factor limiting long term graft and patient survival.

Myocardial edema: comparison of effects on filling volume and stiffness of the left ventricle in rats and pigs

BACKGROUND

This study compared the adverse effects of crystalloid-induced myocardial edema on left ventricular (LV) compliance in small and large hearts.

METHODS

Plegisol (289 mOsm/L) was perfused into the coronary arteries of pigs (n = 8) and 1:1 dilute Plegisol (145 mOsm/L) into the coronary arteries of rats (n = 6). Pressure-volume relations, heart weight, and water content were then determined. The pressure-volume relations were compared using an LV volume at a pressure of 10 mm Hg.

RESULTS

Edema in rats was associated with significant (p < 0.05) increases in heart weight (1.1 +/- 0.0 g versus 1.4 +/- 0.1 g [average +/- standard error of the mean]) and water content (76.8% +/- 0.4% versus 81.3% +/- 0.8%), but an increase in LV stiffness (7.91 +/- 0.52 versus 9.27 +/- 1.42) and a decrease in the LV volume at 10 mm Hg (0.25 +/- 0.02 mL versus 0.14 +/- 0.05 mL) were not statistically significant. Edema in pigs was associated with statistically significant (p < 0.05) increases in LV stiffness beta (0.050 +/- 0.004 versus 0.072 +/- 0.008), heart weight (207 +/- 8 g versus 274 +/- 9 g), and water content (79.8% +/- 0.6% versus 85.3% +/- 0.6%) and a significant decrease in the LV volume at 10 mm Hg (88.4 +/- 5.8 mL versus 60.4 +/- 6.8 mL).

CONCLUSIONS

Myocardial edema is associated with an increase in water content and LV stiffness and a decrease in the LV volume at 10 mm Hg in both species. In rats, however, the water content is smaller in the control state and a more hypotonic perfusate is needed to induce a given degree of edema.

Free composite serratus anterior and rib flaps for tibial composite bone and soft-tissue defect

Open fracture in the lower extremity often involves composite bone and soft-tissue defects. For patients with extensive segmental bone defects, vascularized fibular transfers can be utilized and are generally accepted as one of the best options for reconstruction of intercalary defects. In some cases, either bilateral tibias and fibulas are fractured or the contralateral fibula is traumatically damaged or absent, precluding free fibular transfer. If an osteocutaneous fibular flap cannot be used to manage such a defect, a composite serratus anterior and rib flap may be considered. Nine composite serratus anterior and rib flaps, with or without latissimus dorsi transfers, were performed in eight patients between August of 1993 and March of 1994. One patient sustained a left knee disarticulation and underwent reconstruction for a right tibial defect. He failed to achieve lower extremity function within 2 years and was considered a failure. One flap failed, and the patient underwent a below-knee amputation. The remaining six patients received seven composite flaps for tibial and calcaneal defects and could ambulate without assistance. Based on this review, we conclude that the composite serratus anterior and rib flap with optional latissimus dorsi muscle can be used for (1) bilateral tibial fibular fractures, (2) contralateral lower limb amputation with fillet of the amputated leg if the leg is present for harvest, (3) contralateral middle-third fracture of the fibula, (4) patients in whom iliac bone is not suitable because of either a bone defect greater than 10 to 12 cm or previous harvest of bone graft, and (5) extensive composite bone and soft-tissue defects.