Cognitive development and learning in the pediatric organ transplant recipient

Differences in medication adherence between preemptive and post-dialysis young kidney transplant recipients

BACKGROUND

The mechanisms underlying the superior graft survival associated with preemptive kidney transplantation, compared with transplantation following a period of dialysis, are unknown. We aimed to compare medication adherence between preemptively transplanted young kidney transplant recipients and those who received a transplant after an interval of dialysis.

METHODS

This was a secondary analysis of the Teen Adherence in Kidney transplant Effectiveness of Intervention Trial (TAKE-IT), in which adherence was assessed with electronic monitoring over 15 months among 11-24-year-old transplant recipients. Adherence scores were calculated for each day as 0%, 50%, or 100% (intake of none, half, or all prescribed doses). We used ordinal logistic regression, with generalized estimating equations to account for repeated measures within each participant, to estimate the association between preemptive transplantation and adherence. The model was adjusted for sex, age at transplant, time since transplant, primary kidney disease, race, donor source, medication insurer, household income, and adherence intervention.

RESULTS

There were 43 preemptive transplant recipients and 103 who had been treated with dialysis. The median adherence score was 85.1% (IQR 81.3-88.9) for those preemptively transplanted, and 80.0% (IQR 76.7-83.4) for those transplanted after dialysis. Preemptively transplanted recipients had significantly higher odds of adherence than those dialyzed before transplantation (adjusted OR 1.76 95% CI 1.21-2.55; p = 0.003).

CONCLUSIONS

Preemptively transplanted patients showed significantly better adherence than those treated with dialysis before transplantation. This suggests that the superior outcomes observed among preemptive kidney transplant recipients may reflect selection of patients more likely to adhere to therapy. A higher resolution version of the Graphical abstract is available as Supplementary information.

Executive Functioning in Pediatric Solid Organ Transplant Recipients: A Meta-analytic Review

BACKGROUND

Examining executive functioning (EF) posttransplant has become increasingly prevalent, as EF deficits are associated with poor disease-related outcomes and psychosocial functioning. The purpose of the current meta-analysis was to compare overall and domain-specific EF between healthy youth and those with a kidney, heart, or liver transplant, and identify moderating variables related to EF differences between these 2 groups.

METHODS

A literature search of PsycINFO, Pubmed, and Medline was conducted for eligible articles published until January 2019. Twenty studies met eligibility criteria and were included in the present meta-analysis.

RESULTS

Results from the random-effects model indicated a significant standardized mean difference in overall EF skills with transplant recipients demonstrating worse EF (g = 0.40; 95% confidence interval [CI], 0.29-0.50) than healthy youth. Specifically, transplanted youth had worse working memory (g = 0.33; 95% CI, 0.01-0.66), processing speed (g = 0.41; 95% CI, 0.19-0.62), attentional control (g = 0.53; 95% CI, 0.33-0.73), and metacognitive skills (g = 0.36; 95% CI, 0.18-0.54). Assessment type and time since transplantation were not significant moderators.

CONCLUSIONS

Pediatric solid organ transplant recipients demonstrate worse overall EF skills and deficits in working memory, processing speed, attentional control, and metacognitive skills. Many children who have undergone solid organ transplantation will require additional support in medical and academic settings because of deficits in various EF domains.

Neurodevelopmental Outcomes in Children With Liver Diseases: a Systematic Review

OBJECTIVE

The aim of the study was to determine the neurodevelopmental outcomes of children with liver diseases based on a systematical review of the literature.

METHOD

A literature search according to the PRISMA statement was conducted using predefined search terms in PubMed, Cochrane Library, and PsycINFO. The inclusion criterion was studies published from 2000 onwards that reported on the neurodevelopmental outcomes of term-born children with liver diseases. A narrative synthesis was done to appraise the studies.

RESULTS

Twenty-five studies were included (1913 children), 19 of which described children after liver transplantation (LTx; 1372 children). Sixty-seven percentage of the studies on children with liver diseases who survived with their native livers showed low-average or abnormal scores on specific subscales of cognitive and behavioral measures. In studies on children after LTx, this was 82%. After LTx, 83% of studies demonstrated impaired outcomes on behavior, whereas 42% of children received special education. Motor development was impaired in 82% of studies in children with native liver and after LTx.

LIMITATIONS

Studies were heterogenic because of sample sizes, etiology of liver disease and type of assessment tools used.

CONCLUSIONS

More than two-third of included studies showed neurodevelopmental deficits in children with liver diseases, affecting all neurodevelopmental areas. Knowledge on risk factors for impaired neurodevelopment is limited and lack of long-term follow-up is worrying, especially considering the increasing survival rates, resulting in more at-risk patients. Studying early predictors and risk factors of abnormal developmental trajectories of children with liver diseases is indicated to assess strategies to improve their long-term neurodevelopmental outcomes.

Language assessment of children with severe liver disease in a public service in Brazil

OBJECTIVE:

The aim of this research was to compare language development (expressive and receptive skills) in children awaiting liver transplantation with that of children who have already undergone the surgical procedure.

METHODS:

An observational, descriptive, cross-sectional study was conducted with 76 children divided into groups, as follows: 31 children who were candidates for liver transplantation (Group 1; G1), 45 children who had already undergone liver transplantation (Group 2; G2), and a control group (CG) of 60 healthy, normally developing children. Health status information was gathered, and the Test of Early Language Development (TELD)-3 was used to assess language skills. Family household monthly income data were also gathered using a specific questionnaire.

RESULTS:

G1 had poorer language performance compared with G2 and the CG. G2 had lower language performance when compared with the CG. However, when considering the TELD-3 standard scores, G2 had scores within normal limits. The regression analysis indicated age as a risk factor for language deficits in Group 1 and family income as a risk factor for language deficits in G2.

CONCLUSIONS:

The results suggested that children with chronic liver disease have delays in language development. Transplanted children have linguistic performance within normal limits, but their scores tended to be lower than the CG.

Neuropsychological functioning in preschool-aged children undergoing evaluation for organ transplant

OBJECTIVE

The purpose of this study was to review the current literature on neuropsychological functioning in two groups of children requiring organ transplants (liver or heart) and present recent clinical data collected through the liver and cardiac transplantation programs at a large pediatric academic medical center.

METHOD

Data included in this study came from 18 patients who completed evaluations for heart transplant (n = 8) or liver transplant (n = 10) between the ages of 2 and 6 years (inclusive). Measures examining neurocognitive, emotional-behavioral, and adaptive functioning were collected as part of standard pre-transplant clinical neuropsychological evaluations. Within each organ group, mean scores were calculated and compared with normative population mean scores using one sample t-tests. In addition, non-parametric binomial tests were calculated to examine whether the proportion of individuals falling more than one standard deviation below the population mean was significantly greater in the patient groups than the normative population base rate of 16%.

RESULTS

Patients in both groups performed below normative expectation in several neurocognitive and adaptive domains. However, neither group showed significant difficulties in behavioral or emotional regulation.

CONCLUSIONS

Results from this study document cognitive delays in preschool-aged children undergoing evaluations for liver transplant or heart transplant, highlighting the importance of intervention and long-term monitoring of these two patient populations, as well as the need for neuropsychologist involvement with transplant teams.

Intellectual and academic performance in children undergoing solid organ pretransplant evaluation

Although prior research has shown lower intellectual functioning across pediatric solid organ transplant recipients relative to matched siblings or norm comparisons, few studies have assessed intellectual and academic performance prior to transplant across organ groups. The current data examine intellectual and academic functioning in children being evaluated for kidney, liver, or heart transplant. This investigation included intellectual and academic testing data from 195 children and adolescents between the ages of six and 19 yr evaluated for solid organ transplantation. Across organ groups, patients' intellectual functioning as estimated by the WASI/WASI-II at the time of pretransplant evaluation was within the average range, but lower compared to test norms. Patients demonstrated lower estimates of word reading, math computation, and spelling skills compared to the normal population, with the exception of heart patients' word reading and spelling skills and liver patients' spelling scores. Cognitive and academic impairments exist in children prior to transplantation. Findings emphasize the support that patients may require to manage the complicated medical regimen and succeed academically. Routine cognitive and academic assessment can inform healthcare providers regarding transplant patients' capacity to take on increasing medical responsibility and successfully reintegrate into the school environment.

Neurocognitive outcomes at kindergarten entry after liver transplantation at <3 yr of age

This prospective inception cohort study determines kindergarten-entry neurocognitive abilities and explores their predictors following liver transplantation at age <3 yr. Of 52 children transplanted (1999-2008), 33 (89.2%) of 37 eligible survivors had psychological assessment at age 54.7 (8.4) months: 21 with biliary atresia, seven chronic cholestasis, and five acute liver failure. Neurocognitive scores (mean [s.d.], 100 [15]) as tested by a pediatric-experienced psychologist did not differ in relation to age group at transplant (≤12 months and >12 months): FSIQ, 93.9 (17.1); verbal (VIQ), 95.3 (16.5); performance (PIQ), 94.3 (18.1); and VMI, 90.5 (15.9), with >70% having scores ≥85, average or above. Adverse predictors from the pretransplant, transplant, and post-transplant (30 days) periods using univariate linear regressions for FSIQ were post-transplant use of inotropes, p = 0.029; longer transplant warm ischemia time, p = 0.035; and post-transplant highest serum creatinine, (p = 0.04). For PIQ, they were pretransplant encephalopathy, p = 0.027; post-transplant highest serum creatinine, p = 0.034; and post-transplant inotrope use, p = 0.037. For VMI, they were number of post-transplant infections, p = 0.019; post-transplant highest serum creatinine, p = 0.025; and lower family socioeconomic index, p = 0.039. Changes in care addressing modifiable predictors, including reducing acute post-transplant illness, pretransplant encephalopathy, transplant warm ischemia times, and preserving renal function, may improve neurocognitive outcomes.

A systematic review and quantitative analysis of neurocognitive outcomes in children with four chronic illnesses

BACKGROUND

Concern has been expressed that infants and children exposed to uneventful surgery and anesthesia may incur neurological injury that becomes manifest in poor scholastic performance or future learning difficulties. A recent meta-analysis of seven clinical studies examined the relationship between learning or behavior difficulties and pediatric exposure to anesthesia/surgery and reported an odds ratio of 1.4; however, the level of association and causal factors remain unclear. The purpose of our study is to provide context to the pediatric anesthesia neurotoxicity question by reviewing the evidence linking four childhood illnesses with neurocognitive development. In the present review, we have sought to quantify the magnitude of the impact of chronic illness on neurocognitive development through a systematic review of publications that report the developmental trajectory of patients with four childhood diseases: cystic fibrosis (CF), hemophilia A, end-stage renal disease (ESRD) and end-stage liver disease (ESLD).

METHODS

Studies were identified by searching the electronic databases OVID MEDLINE and Pubmed and scanning reference lists of articles by two authors. Limits were applied to the English language and to humans. We used the following search terms: CF, hemophilia A, ESRD, ESLD in combination with academic performance, educational status, educational measurement, learning, achievement, developmental delay, learning disabilities, intellectual disabilities, behavioral disorders, intelligence quotient (IQ), cognition, school problems, absenteeism, school attendance, anxiety, learning regression, or developmental regression. The search strategy was reviewed independently by all four authors. Eligibility assessment was performed independently in an unblinded standardized manner by two authors who chose relevant articles from the overall search results by scanning the titles and abstracts of articles and from the references within citations. The full-text publications were reviewed by all four authors. All pertinent data related to the objectives were collected and independently reviewed by two authors. The data were summarized in the form reported in the studies. When possible, reported data were submitted to analysis with the Mantel-Haenszel method using a random effects model. Analyses were performed using the Review Manager computer program.

RESULTS

In the studies retrieved, the main outcomes were measures of intellectual or cognitive characteristics, as exemplified by the Wechsler battery of tests. Reporting of measures of achievement (for example, GPA) was rare. Children with CF and hemophilia A did not appear disadvantaged by their disease as general intelligence levels were comparable with the general population norms. In children with ESRD, mean IQ reported during dialysis improved after transplantation. Although they improved relative to their pretransplantation cognitive functioning, children with ESLD who received transplants are approximately eight IQ points below the population norm.

CONCLUSIONS

Overall, the results suggest that the burden of chronic childhood illness, by itself, does not impair cognitive development in children with hemophilia A and CF. Children with ESRD and ESLD, despite optimal management, show a mild cognitive deficit compared with the population norm. Given the impact of these four specific chronic illnesses on neurocognitive outcome in children and the improvement in IQ post-transplant in both ESRD and ESLD, the results suggest that the effect of an uncontrolled confounding illness on neurocognitive development is small.

Developmental assessment of infants with biliary atresia: differences between boys and girls

OBJECTIVE

The aim of the present study was to investigate whether male and female infants with biliary atresia (BA) differ cognitively and to confirm previously documented developmental lags in infants with BA before liver transplantation.

METHODS

With the Mullen Scales of Early Learning, we examined 21 female and 12 male infants (ages 3-20 months) with BA, comparing scores across indices by sex and correlating Mullen Scales of Early Learning scores with standard clinical and biochemical parameters.

RESULTS

Overall, both boys and girls were found to be vulnerable to developmental lags in the areas of expressive language (EL) and gross motor skills. In comparison with their male peers, girls were found to be weaker in the area of visual reception skills (P=0.05) with a trend found for EL (P=0.08). Girls were also found to have higher C-bilirubin levels and to be of shorter length. Growth parameters were found to be correlated with EL scores. International normalized ratio was found to be correlated with gross motor performance and with a trend also noted for fine motor skills. Age at Kasai predicted receptive language skills.

CONCLUSIONS

As has been shown, infants with BA appear to be vulnerable to developmental lags before transplantation. In particular, female infants appear to be vulnerable to cognitive and skill delays in comparison with their male peers. C-bilirubin levels may play a role in this increased vulnerability for females.

School outcomes in children registered in the studies for pediatric liver transplant (SPLIT) consortium

School performance is an important aspect of functional outcomes for pediatric liver transplant (LT) recipients. This longitudinal analysis conducted through the Studies of Pediatric Liver Transplantation (SPLIT) research consortium examines several indicators of school function in these patients. A total of 39 centers participated in data collection using a semistructured questionnaire designed specifically for this study. The survey queried school attendance, performance and educational outcomes including the need for special educational services. Participants included 823 of 1133 (73%) eligible patients, mean age 11.34 +/- 3.84 years, 53% female, median age at LT 4.6 (range 0.05-17.8) years, and mean interval from transplant was 5.42 +/- 2.79. Overall, 34% of patients were receiving special educational services and 20% had repeated a grade, with older participants more likely to have been held back (P = 0.0007). Missing more than 10 days of school per year was reported by one-third of the group, with this level of absence being more common in older participants (P = 0.0024) and children with shorter intervals from LT (P < 0.0001). Multivariate analysis revealed the following factors were associated with the need for special educational services; type of immunosuppression at 6 months post-LT, cyclosporine A (odds ratio [OR] = 1.8, confidence interval [CI] = 1.1-3.1), or other (OR = 4.9, 95% CI = 1.4-17.6) versus tacrolimus, symptomatic cytomegalovirus infection within 6 months of liver transplantation (OR = 3.1, CI = 1.6-6.1), and pretransplant special educational services (OR = 22.5, CI = 8.6-58.4).

Language and motor skills are impaired in infants with biliary atresia before transplantation

OBJECTIVE

To test the hypothesis that in very young patients with biliary atresia, cognitive deficits are apparent before transplantation.

STUDY DESIGN

With the Mullen Scales of Early Learning (Mullen), we examined 15 infants (mean age, 7.8 months) with biliary atresia, correlating Mullen scores with standard clinical and biochemical parameters.

RESULTS

Overall, participants displayed significant delays in gross motor and language skills, and fine motor and visual reasoning skills were relatively preserved. The international normalized ratio correlated inversely with gross (P < .01) and fine (P < .05) motor skills. Growth parameters correlated positively with expressive language ability, but length of hospitalization and mode of feeding did not. Age at performance of the Kasai procedure was found to correlate with receptive language performance (P < .05).

CONCLUSIONS

Very young children with biliary atresia display a characteristic profile of early developmental deficits before transplantation. These findings suggest that early intervention and aggressive nutritional management should be the standard of care to minimize neurocognitive effects.

Long-term outcome following pediatric liver transplantation for metabolic disorders

In order to determine long-term outcome, including survival, growth and development, following liver transplantation in children with metabolic disorders, we retrospectively reviewed charts of 54 children with metabolic disorders evaluated from 1989-2005 for presenting symptoms, transplantation timing and indications, survival, metabolic parameters, growth, and development. Thirty-three patients underwent liver transplantation (12 received combined liver-kidney transplants) at a median age of 21 months. At a median follow-up of 3.6 yr, patient survival was 100%, and liver and kidney allograft survival was 92%, and 100%, respectively. For the group as a whole, weight Z scores improved and body mass index at follow-up was in the normal range. Two yr post-transplantation, psychomotor development improved significantly (p < 0.01), but mental skills did not; however, both indices were in the low-normal range of development. When compared to patients with biliary atresia, children with metabolic disorders showed significantly lower mental developmental scores at one and two yr post-transplantation (p < 0.05), but psychomotor developmental scores were not significantly different. We conclude that, in patients with metabolic disorders meeting indications for transplantation, liver transplantation or combined liver-kidney transplantation (for those with accompanying renal failure) is associated with excellent long-term survival, improved growth, and improved psychomotor development.

Multi-method assessment of behavior adjustment in children with chronic kidney disease

To describe the psychological adjustment in children with chronic kidney disease (CKD), we studied behavioral problems in 19 patients with CKD stage 5 on regular hemodialysis, 19 patients in the predialysis stage, and 19 control children, using the child behavior checklist (CBCL) and the semi-structured clinical interview for children and adolescents (SCICA). For CBCL scales, the mean score on the internalizing scale was significantly higher in the children on dialysis than in predialysis and control children. No significant differences in the mean scores of the total problem or externalizing scales were found between the groups studied. The mean score of SCICA observed problems and total self-reports were significantly higher in the control group than in the CKD groups. The mean score on total self-report was significantly higher in the control children than in the predialysis group. There were significant positive correlations between SCICA self-report and all CBCL scales. No significant correlations were found between these CBCL and SCICA scales and age, gender, severity of anemia, duration of CKD or the efficiency or the duration of hemodialysis in the CKD patients. In conclusion, multi-method assessment of children's adjustment through different informants yields a comprehensive view of child psychopathology in CKD that calls for psychosocial support and early identification of maladjustment.

Family interactions of liver transplanted children: are they normal?

Several psychosocial and behavioral problems have been reported in liver transplanted children. Most publications have focused on them, without considering their family environment. The aim of this study was to evaluate the interaction between liver transplanted children and their families, compared with a healthy control group. We selected liver transplanted children, between 8 and 12 years of age, with at least 6 months follow-up posttransplantation and in good clinical condition. Family structure also included 1 to 3 other children. Evaluable patients must have been living with their parents throughout the whole posttransplantation period. They were compared with a similar group of children without any chronic disease. A written informed consent was signed by both parents. All families were evaluated using a standard test consisting of different situations. The information was evaluated by 3 independent experts. Factors evaluated were limits (rules and limits of behavior), alliance-opposition (interaction between members to act), and hierarchy. Scoring was given to all observed acts. Statistical analysis was performed using chi-square tests with P < .05 considered significant. No statistical differences were found between groups in limits, alliance, and hierarchy. Our results showed that there were no differences in family structure and behavior between families of liver-transplanted and healthy children belonging to a similar socioeconomic level.

Pediatric transplantation of the kidney, liver and heart: summary report

The following is a summary report of an extensive review of the literature from 1966 to 2001 on growth and development in children receiving kidney, liver and heart transplants. The literature was assessed for relevancy to current clinical practice and for reliability and generalizability of the inferences based on the study design, controls, sample size, age distribution, confounding factors, use of standardized instruments, and consistency with other findings. While studies on growth are included in the review, the main emphasis is on research in cognitive and psychosocial development since these areas have been far less thoroughly studied and contain various methodological deficiencies. On the basis of the literature review both general methodological recommendations and specific recommendations for future research studies are made. Access to the full is provided on the World Wide Web at http://light.emmes.com/pedstransplantation/.

Family environment, child behavior, and medical indicators in children with kidney disease

Effects of family environment on child behavior symptoms and medical indicators in children with one of three kidney diseases were examined. Parents (n = 41) of children with nephrotic syndrome, chronic renal insufficiency, or kidney transplant completed family environment and child behavior questionnaires. Medical indicators (utilization and medications) were collected from medical records. A model including child age, diagnostic group, and family environment variables successfully predicted all outcomes except internalizing behavior. Higher family conflict predicted more externalizing symptoms and higher number of prescribed medications; higher family cohesion predicted fewer hospitalizations. Nontraditional family structure predicted higher number of prescribed medications. Results are discussed as they relate to a stress and resistance framework, need for research on direction of effect, and clinical recommendations.

Pediatric end-stage renal disease: incidence, management, and prevention

Although pediatric end-stage renal disease affects a small number of children, it is a serious and growing health problem in the United States. In the past decade, the incidence of the disease has increased steadily in all racial groups. However, poor and minority children are disproportionately affected. Recent research results make it clear that appropriate prenatal and pediatric care can reduce the incidence of this complex and expensive-to-treat condition.

Cognitive functioning in children on dialysis and post-transplantation

We studied 124 children, 62 patient-subjects who had end-stage renal disease (ESRD) and 62 sibling-controls who closely matched the patient-subjects in terms of their ethnicity and their socioeconomic status, to discern whether children with ESRD would perform less well than their siblings on standardized achievement and intelligence quotient (IQ) tests, and to determine whether ethnicity would influence such results. The subjects were recruited from nine pediatric transplant and dialysis centers across the United States. Thirty-one subjects were white (Euro-American), 17 were African-American, and 14 were categorized as 'other'. The average age of the patient-subjects was 13.7 +/- 0.44 yr; and of the sibling-controls 13.7 +/- 0.38 yr. Most patients (61%) and siblings (84%) were in regular school classes, and most (87% and 92%, respectively) attended school full-time. The average IQ percentile rank for the patients was significantly lower than their siblings (31 +/- 4 vs. 44 +/- 5, respectively, with normal = 50). Patients tended to score lower on achievement tests compared with their siblings (spelling: 88.7 +/- 4 vs. 94.6 +/- 2; arithmetic: 88.5 +/- 2 vs. 94.0 +/- 2; reading: 91.9 +/- 2 vs. 100 +/- 3, respectively). Patients scores on achievement tests were influenced by age at diagnosis and by the mother/caregiver's lower achievement. Also, increased time on dialysis predicted lower scores on achievement tests. Neither dialysis/transplant status nor ethnicity significantly affected outcome. Our data suggest that ESRD, but not ethnicity or dialysis/transplant status, is a risk factor for lower IQ and academic achievement, especially in younger children, in children who spend more time living with ESRD, and in children whose mother's/caregiver's have lower educational levels.

Cognitive deficits related to major organ failure: the potential role of neuropsychological testing

Until recently, little attention has been paid to the possibility of cognitive deficits in patients with disease or failure of major organs such as the liver, kidney, or heart. However, there is a growing awareness that major organ failure often has neuropsychological sequelae. These sequelae may at times be quite subtle and not detectable under gross examination. Nevertheless, even subtle deficits may have a major impact on adherence to medical regimens, psychosocial adjustment, and quality of life of patients. Neuropsychological assessment has a potentially valuable role to play both in research and in clinical work. It can be useful in adding to our knowledge of the cognitive effects of various types, severity and duration of major organ disease, as well as sequelae associated with treatment. It also is a potentially valuable clinical tool for identifying cognitive deficits that will affect the quality of life and probability of survival for organ failure patients.

Cognitive functioning and school performance in children with renal failure

Although previous studies have documented neuropsychological deficits in children with end-stage renal disease, few have evaluated and compared the cognitive functioning and the school performance of children with renal failure. The current study evaluated the influence of chronic renal failure on cognitive functioning and school performance in children and adolescents with end-stage renal disease undergoing dialysis and after renal transplantation. Participants were given standardized IQ and achievement tests to assess cognitive functioning and ability. Academic performance was determined by evaluating grades for the semester in which the testing was performed; a grade point average (GPA) was calculated based on a 4.0-point scale. The 11 dialysis patients and 13 transplant patients were comparable in age, race, sex, and socioeconomic status. Overall IQ and subtest scores demonstrated no differences between the two groups. Performance on the Woodcock-Johnson achievement tests showed that the transplant patients did better on achievement tests of written language (P = 0.04) and in school performance in English compared with dialysis patients (P < 0.05). Furthermore the dialysis patients tended to be below age and grade level in all areas, whereas the transplant patients were achieving at or above these levels. There were significant differences in the age equivalent scores between the dialysis and transplant patients in the areas of mathematics and written language (P < 0.05). However, when grades were evaluated there were no differences in overall GPA or in the mathematics GPA. Days absent were not different between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)