The effect of neuropsychiatric medication on pediatric nonalcoholic fatty liver disease

Obese and overweight children are at risk of developing nonalcoholic fatty liver disease (NAFLD), which can lead to steatohepatitis, cirrhosis, and liver transplantation. Neuropsychiatric conditions affect an increasing proportion of children and often require neuropsychiatric medications (NPMs) that are associated with weight gain and/or drug-induced liver injury. We sought to evaluate the role that the extended use of NPMs play in pediatric NAFLD. Medical chart review was conducted for 260 patients with NAFLD (NPM = 77, non-NPM = 183) seen in the Liver Care Center at Children's Mercy Hospital between 2000 and 2016. Outcome measures included body mass index (BMI) percentile, BMI z-score, aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin, and gamma glutamyltransferase, and were collected at diagnosis, 6-18 month follow-up, and 18-36 months. Controlling for race and metformin, there was a significant increase over time in BMI z-score (p < 0.01) and total bilirubin (p = 0.03), with only initial decreases in ALT (p < 0.01) and AST (p < 0.01). Except for higher total bilirubin in the non-NPM group, no main effect of group or interaction effect was found. Similar patterns remained when subjects were analyzed by NPM drug class. Further study is needed to confirm these findings and to evaluate the effects of NPM dose and duration of exposure, by drug class, on pediatric NAFLD outcomes.

Organ-Specific Comorbidities Are Associated With Distinct Complications After Liver Transplantation for Biliary Atresia

Although transplant outcomes for biliary atresia (BA) have improved, there are few data to predict the risk of specific posttransplant complications. We therefore defined the impact of comorbidities in BA on posttransplant outcomes. Patients enrolled in the Society of Pediatric Liver Transplantation registry from 2011 to 2019 (n = 1034) were grouped by comorbidities of >1.0% incidence: any supplemental feeding, dialysis, other abdominal surgery (not Kasai portoenterostomy [KPE]), hepatopulmonary syndrome, and cardiac disease requiring intervention. Demographic and outcome data were compared using the Kruskal-Wallis, chi-square, and log-rank tests. Cox proportional hazards models and binary logistic regression were performed for modeling. Patients with BA with comorbidities comprised 77% (n = 799) of our cohort and had evidence of greater medical acuity, including higher calculated Pediatric End-Stage Liver Disease scores and hospitalizations in the intensive care unit before transplant (P < 0.001 for both) versus those without comorbidities. After transplant, patients with BA with comorbidities had more graft loss (P = 0.02), longer initial hospitalization and intubation (P < 0.001 for both), and increased rates of reoperation (P = 0.001) and culture-proven infection (P < 0.001) within 30 days after transplant. Only patients with BA with comorbidities on supplemental feed had increased rates of patient death (P = 0.02). Multivariate analysis identified lower z weight and higher creatinine as risk factors for graft and patient loss in patients with BA with comorbidities. Prior KPE was protective against culture-proven infection and vascular complications within 30 and 90 days, respectively. Patients with BA with comorbidities have evidence of higher medical acuity at transplant and reduced graft survival; however, they overall did not experience greater incidence of patient death. Our data provide organ-system-specific data to risk-stratify patients with BA and posttransplant outcomes.

Predictors of survival following liver transplantation for pediatric hepatoblastoma and hepatocellular carcinoma: Experience from the Society of Pediatric Liver Transplantation (SPLIT)

Management of unresectable pediatric hepatoblastoma (HB) and hepatocellular carcinoma (HCC) remains challenging. The Society of Pediatric Liver Transplantation (SPLIT) database was used to study survival predictors in pediatric liver transplantation (LT) for HB and HCC. Event-free survival (EFS), associated risk factors, and postoperative complications were studied in children requiring LT for HB/HCC at 16 SPLIT centers. Three-year EFS was 81% for HB (n = 157) and 62% for HCC (n = 18) transplants. Of HB transplants, 6.9% were PRETEXT II and 15.3% were POST-TEXT I/II. Tumor extent did not impact survival (p = NS). Salvage (n = 13) and primary HB transplants had similar 3-year EFS (62% versus 78%, p = NS). Among HCC transplants, 3-year EFS was poorer in older patients (38% in ≥8-year-olds vs 86% <8-year-olds) and those with larger tumors (48% for those beyond versus 83% within Milan criteria, p = NS). Risk of infection (HR 1.5, 95% CI 1.1-2.2, p = .02) and renal injury (HR 2.4, 95% CI 1.7-3.3, p < .001) were higher in malignant versus nonmalignant LT. Survival is favorable for pediatric HB and HCC LT, including outcomes after salvage transplant. Unexpected numbers of LTs occurred in PRE/POST-TEXT I/II tumors. Judicious patient selection is critical to distinguish tumors that are potentially resectable; simultaneously, we must advocate for patients with unresectable malignancies to receive organs.

Use and safety of prophylactic endoscopy from a single center serving urban and rural children with portal hypertension

Prophylactic endoscopy is routine in adults with portal hypertension (PHTN), but there is limited data in pediatrics. We sought to describe our experience with prophylactic endoscopy in pediatric PHTN. This is a retrospective study of 87 children who began surveillance endoscopy prior to gastrointestinal bleeding (primary prophylaxis) and 52 who began after an episode of bleeding (secondary prophylaxis) from 01/01/1994 to 07/01/2019. Patients who underwent primary prophylaxis had a lower mean number of endoscopies (3.897 vs 6.269, p = 0.001). The primary prophylaxis group was less likely to require a portosystemic shunt (6% vs 15%, p < 0.001) with no difference in immediate complications (1% vs 2%, p = 0.173) or 2-week complications (1% vs 2%, p = 0.097). No deaths were related to variceal bleeding or endoscopy. Kaplan–Meier Survival Curve suggests improved transplant and shunt free survival in the primary prophylaxis group (log-rank p < 0.001). Primary and secondary endoscopic prophylaxis should be considered safe for the prevention of variceal hemorrhage in pediatric portal hypertension. There are differences in outcomes in primary and secondary prophylaxis, but unclear if this is due to patient characteristics versus treatment strategy. Further study is needed to compare safety and efficacy to watchful waiting.

Peginterferon Alfa-2a (40KD) Plus Lamivudine or Entecavir in Children With Immune-Tolerant Chronic Hepatitis B

OBJECTIVE

Treatment guidelines for chronic hepatitis B (CHB) do not recommend antiviral therapy for patients in the immune-tolerant phase of the disease, which generally occurs in children who acquire hepatitis B virus (HBV) vertically and may last for decades. On the basis of promising results of a pilot study, we conducted a randomized, controlled, multicenter study to evaluate the efficacy and safety of antiviral therapy in children and adolescents with immune-tolerant CHB.

METHODS

Fifty-nine children aged 3 to <18 years hepatitis B e antigen-positive with an HBV DNA titer >20,000 IU/mL and persistently normal alanine aminotransferase levels were randomized to 56 weeks of antiviral therapy with an oral nucleoside analogue [entecavir or lamivudine], combined with subcutaneous peginterferon alfa-2a from week 8, or 80 weeks of untreated observation. The primary efficacy outcome was hepatitis B surface antigen loss 24 weeks post-treatment in the antiviral therapy group or at the end of observation in the control group.

RESULTS

Enrollment was terminated after the results of two similar studies showed that similar antiviral regimens were ineffective in children and adults with immune-tolerant CHB. At 24 weeks post-treatment, 1 of 26 patients in the antiviral treatment group experienced HBsAg loss (vs none of 33 patients in the control group). No serious treatment-related adverse events were reported, and no patients discontinued treatment because of adverse events.

CONCLUSIONS

The antiviral regimen evaluated in this trial had an acceptable tolerability profile, but was ineffective in children and adolescents with immune-tolerant CHB.

Complications of Cryptosporidium infection after pediatric liver transplantation: Diarrhea, rejection, and biliary disease

BACKGROUND

Cryptosporidium enteritis can be devastating in the immunocompromised host. In pediatric liver transplant recipients, infection may be complicated by prolonged carriage of the parasite, rejection, and biliary tree damage and fibrosis. Herein, we report on six patients and their long-term outcomes following cryptosporidiosis.

METHODS

We reviewed all cases of cryptosporidiosis in a pediatric liver transplant population over a 17-year period at a single center. Six patients with infection were identified, and their outcomes were analyzed.

RESULTS

Infection was associated with significant diarrhea and dehydration in all cases, and led to hospitalization in one-half of patients. Four of the six patients developed biopsy-proven rejection following infection, with three of those patients developing rejection that was recalcitrant to intravenous steroid treatment. Additionally, three patients developed biliary tree abnormalities with similarity to sclerosing cholangitis. In one patient, those biliary changes led to repeated need for biliary drain placement and advancing fibrotic liver allograft changes.

CONCLUSIONS

Cryptosporidiosis in pediatric liver transplant recipients may lead to significant complications, including recalcitrant episodes of rejection and detrimental biliary tree changes. We advocate for increased awareness of this cause of diarrheal disease and the allograft injuries that may accompany infection.

Readiness to Change and Prospective Effects of Weight Management Programs in Pediatric Nonalcoholic Fatty Liver Disease

Non‐alcoholic fatty liver disease (NAFLD) is an increasing problem in pediatrics with limited treatment options. We prospectively assessed outcomes in patients managed in a hepatology clinic (HC) alone vs. those managed in combination with a multidisciplinary weight management program (MWMP). We describe each group’s readiness to change at the time of NAFLD diagnosis. Patients diagnosed with NAFLD were given a modified Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES) at enrollment (T1) to assess readiness to change. They were then followed at 3–9 months (T2) and at 10–15 months (T3). Linear mixed models were used to evaluate changes in body mass index (BMI), BMI z‐score, and transaminases over time and between the two groups. There were no significant treatment group main effects or treatment × time interactions for our primary end points for HC alone (n = 75) or with MWMP (n = 18). There was a significant main effect for time for BMI z‐score, with BMI z‐scores declining on average by 0.0568 (P = 0.004) from visit to visit. Low SOCRATES subscales scores in HC alone (n = 33) or with MWMP (n = 4) suggested a patient population with low recognition of disease and likelihood of taking steps for change. Patients with obesity and NAFLD had low scores on all three SOCRATES subscales. Despite this, both groups had improvement in BMI z‐score without significant difference between the two treatment groups in other primary end points. Further study is needed to identify the most effective patient selection and treatment strategies for pediatric patients with NAFLD, including pharmacotherapy and surgery.

Conservative Management of Pneumatosis Intestinalis and Portal Venous Gas After Pediatric Liver Transplantation

BACKGROUND

Pneumatosis intestinalis (PI) is a rare pathologic finding in pediatric liver transplant (PLT) recipients. The presentation and course of PI can range from asymptomatic and clinically benign to life threatening, with no consensus regarding management of PI in children. We aim to review the clinical presentation and radiologic features of PLT recipients with PI and to report the results of conservative management.

METHODS

A retrospective medical chart review was conducted on PLT recipients between November 1995 and May 2016. Parameters evaluated at PI diagnosis included pneumatosis location, presence of free air or portal venous gas (PVG), symptoms, laboratory findings, and medication regimen.

RESULTS

PI developed in 10 of 130 PLT patients (7.7%) between 8 days and 7 years (median: 113 days) posttransplant. Five of the patients were male, and the median age was 2 years (range, 1-17 years). PI was located in 1 to 2 abdominal quadrants in 6 patients, and 3 patients had PVG. At diagnosis, all patients were on steroids and immunosuppressant medication and 6 patients had a concurrent infection. Laboratory findings were unremarkable. Symptoms were present in 7 patients. Nine patients were managed conservatively, and 1 patient received observation only. All patients had resolution of PI at a median of 7 days (range, 2-14 days).

CONCLUSIONS

PI can occur at any time after PLT and appears to be associated with steroid use and infectious agents. If PI/PVG is identified and the patient is clinically stable, initiation of a standard management algorithm may help treat these patients conservatively, thus avoiding surgical intervention.

Practice survey: adherence monitoring and intervention in pediatric gastroenterology and hepatology

Purpose

Despite significant medication nonadherence rates among youth with pediatric gastroenterology and hepatology disorders, little is known about current adherence practices in pediatric gastroenterology care. This study summarizes current practices surrounding adherence monitoring and intervention in pediatric gastrointestinal (GI) and hepatologic care in the USA.

Participants and methods

One hundred and fifty-four pediatric GI providers completed an online survey designed to examine current practices surrounding adherence monitoring and intervention, specific strategies used to monitor and treat poor adherence, and the barriers currently experienced in relation to adherence monitoring and intervention.

Results

Practices varied greatly in terms of when and how patient adherence is monitored and by whom; however, physicians and nursing professionals take primary responsibility for adherence monitoring. Approximately 25% utilize screeners to assess adherence, and most participants use patient and caregiver reports as a primary measure of adherence. Most participants rated their level of adherence monitoring and intervention as fair to poor. While most participants perceive adherence monitoring to be very important in clinical practice, only 20.8% perceive being able to significantly modify patient adherence.

Conclusion

There exists great variability in adherence monitoring and intervention practices across pediatric GI providers. Greater understanding of current adherence practices can inform future clinical efforts.

Frailty in Children with Liver Disease: A Prospective Multicenter Study

OBJECTIVE

To assess frailty, a measure of physiologic declines in multiple organ systems, in children with chronic liver disease using a novel pediatric frailty tool.

STUDY DESIGN

We performed a prospective cross-sectional multicenter study at 17 liver transplantation (LT) centers. 71 children (5-17 years of age), 36 with compensated chronic liver disease (CCLD) and 35 with end-stage liver disease (ESLD) and listed for LT, were assessed for frailty using validated pediatric tools to assess the 5 classic Fried Frailty Criteria-slowness, weakness, exhaustion, diminished physical activity, and shrinkage. Test scores were translated to age- and sex-dependent z scores, generating a maximum frailty score of 10.

RESULTS

The median frailty score of the cohort was 4 (IQR 3, 5). Subjects with ESLD had significantly higher frailty scores (median 5; IQR 4, 7) than subjects with CCLD (median 3; IQR 2, 4); (P <  .0001). Area under the curve receiver operating characteristic for frailty scores to discriminate between ESLD and CCLD was 0.83 (95% CI 0.73, 0.93). Forty-six percent of children with ESLD were frail and there was no correlation between pediatric frailty scores and physician's global assessments (r = -0.24, 95% CI -0.53, 0.10).

CONCLUSIONS

A novel frailty tool assessed additional dimensions of health, not captured by standard laboratory measures and identified the sickest individuals among a cohort of children with chronic liver disease. This tool may have applicability to other children with chronic disease.

Bone marrow transplant for X-linked protoporphyria with severe hepatic fibrosis

XLP is an erythroid porphyria that results in variable cutaneous photosensitivity due to accumulation of protoporphyrin. The genetic defect in XLP is mutation of the gene ALAS2, resulting in gain of function for the erythroid enzyme 5-aminolevulinate synthase 2. Previous reports have shown that protoporphyrin-induced liver disease may also occur in XLP, occasionally severe enough to warrant liver transplantation; however, transplantation may be followed by injury to the graft due to continued presence of the underlying metabolic disorder in the bone marrow. We present a case of XLP with severe liver disease successfully treated with HPCT to avoid liver transplantation. The case also demonstrates the feasibility of reduced intensity transplant to provide engraftment sufficient for correction of porphyria and tolerability of reduced intensity conditioning containing TLI in the face of severe liver injury.

Neuromuscular and metabolic characteristics of elite basketball referees

AIM

The dynamics of Basketball refereeing has changed and more recently the championships started to use the participation of three referees, but there is still a lack of information about the physical characteristics and performance of the referees. The aim of this study was to characterize the neuromuscular and metabolic performances and body composition of Brazilian elite basketball referees, with a level of national and international refereeing.

METHODS

Thirty-seven referees participated in the study (international level N.=17 and national level N.=20). We evaluated anthropometric and body composition variables, among them: height, body mass, body mass index (BMI) and body fat (%); metabolic parameters: lactate at rest and post-exercise; and neuromuscular performance: speed, explosive lower limbs strength, flexibility and aerobic capacity. The main results showed a statistically significant difference in age, in which the international referees were older than the national level (41.94±6.71; 37.30±7.23; P=0.036).

RESULTS

There were not significant differences between the levels for neuromuscular and metabolic parameters and body composition. Comparing the results with athletes, the referees showed lower neuromuscular and metabolic parameters and the body composition showed higher body fat than basketball players.

CONCLUSION

These data may represent physiological parameters to be considered in the prescription of physical training during the preparation and competition period.

Mast cell activation and clinical outcome in pediatric cholelithiasis and biliary dyskinesia

Background

The current study was undertaken to determine the degree of activation of gallbladder mucosal mast cells, whether mast cell (MC) density or activation differ between patients with and without a positive clinical response to cholecystectomy, and whether either density or activation correlate with gallbladder emptying.

Results

Fifteen biliary dyskinesia (BD) and 13 symptomatic cholelithiasis (CL) patients undergoing cholecystectomy were prospectively enrolled. Gallbladder wall MC density (by immunohistochemistry) and activation (by electron microscopy) were determined. Clinical response was evaluated 30 days post-cholecystectomy on a 5-point Likert-type scale. A complete or nearly complete clinical response was seen in 100% of CL and in 87% of BD patients. The overall degranulation indices were 49.4 ± 18.7% for CL patients and 44.2 ± 16.8% for BD patients. Neither MC density nor activation correlated with the gallbladder ejection fraction. A complete clinical response was associated with lower epithelial MC density.

Conclusion

Cholecystectomy is efficacious in relieving pain in both CL and BD patients. BD and CL are associated not only with increased MC density but a moderate to high degree of MC activation. A possible relationship between MC density and outcome for BD warrants further investigation.

Gallbladder wall inflammatory cells in pediatric patients with biliary dyskinesia and cholelithiasis: a pilot study

BACKGROUND/PURPOSE

Inflammation has been implicated in functional gastrointestinal disorders, including functional dyspepsia and irritable bowel syndrome. This study was undertaken to evaluate gallbladder wall inflammatory cells in children with abdominal pain related to gallstones and biliary dyskinesia to determine the candidate cell types that may be contributing to the pathophysiology of these entities.

METHODS

Gallbladder specimens from 20 patients with cholelithiasis, 20 biliary patients with dyskinesia, and 12 autopsy controls were evaluated in a blinded fashion. Eosinophil, tryptase-positive, and CD3+ cell densities were determined for the lamina propria and muscularis mucosa layers and compared between groups.

RESULTS

Patients with biliary dyskinesia and cholelithiasis had a 9- to 12-fold increase in mean and peak mast cell densities, respectively, in both layers as compared with controls. Peak (13.7 vs 8.4) and mean (9.2 vs 5.2) CD3+ cell densities were increased in the muscularis mucosae of cholelithiasis specimens as compared with biliary dyskinesia specimens.

CONCLUSION

Gallbladder wall inflammatory cell densities, particularly mast cells, differ between children with cholelithiasis, children with biliary dyskinesia, and controls. Future studies are warranted to define the roles for specific inflammatory cell types.

Resistance of cotton towards Xanthomonas campestris pv. malvacearum

Interactions between Gossypium spp. and the bacterial pathogen Xanthomonas campestris pv. malvacearum are understood in the context of the gene-for-gene concept. Reviewed here are the genetic basis for cotton resistance, with reference to resistance genes, resistance gene analogs, and bacterial avirulence genes, together with the physiological mechanisms involved in the hypersensitive response to the pathogen, including production of signaling hormones, synthesis of antimicrobial molecules and alteration of host cell structures. This host-pathogen interaction represents the most complex resistance gene/avr gene system yet known and is one of the few in which phytoalexins are known to be specifically localized in HR cells at anti-microbial concentrations.

Safety of infliximab treatment in pediatric patients with inflammatory bowel disease

BACKGROUND

Infliximab appears to be efficacious in the treatment of pediatric Crohn disease (CD). There are few large-scale pediatric studies on the complications of infliximab therapy.

METHODS

A retrospective review of all infliximab infusions administered to IBD patients at a tertiary children's hospital was undertaken. Data was obtained from an infliximab infusion database maintained in the section of Pediatric Gastroenterology, pharmacy records and patient charts.

RESULTS

594 infusions were administered to 111 IBD patients (88 CD and 23 UC; 55 male and 56 female; ages 4 to 20 years; mean age, 13.4 years). The number of infusions ranged from 1 to 24 with a mean of 5.4/patient. Infusion reactions occurred in 8.1% of patients (seven early and two delayed) and in 1.5% of all infusions. Reactions occurred more frequently in female patients (14% versus 2%; P = 0.03). All reactions were mild and responded rapidly to treatment. Four patients had infections deemed unusual, including three cutaneous tinea infections and one case of shingles.

CONCLUSION

Infliximab is safe in pediatric IBD patients with a low incidence of generally mild reactions that respond rapidly to intervention. Infusion reactions are more common in female patients. Our patients had no serious infectious complications, although cutaneous tinea infection may represent a newly reported associated complication.

Activity of class III peroxidases in the defense of cotton to bacterial blight

Cotton cotyledons displayed a hypersensitive reaction (HR) in the cultivar Réba B50 after infiltration with the avirulent race 18 from Xanthomonas campestris pv. malvacearum. Two sets of peroxidases were associated with the HR time course. Early but transient accumulation of peroxidase in material encapsulating the bacteria in intercellular areas was observed by immunocytochemistry at 3 h postinfection and coincided with the oxidative burst. Total guaiacol-peroxidase activity was highly increased in cells undergoing HR, from 12 h after treatment. Molecular characterization of seven cloned peroxidase genes revealed highly conserved B, D, and F domains, with similarities to plant class III peroxidases. Analysis of gene expression showed variation in transcript accumulation during both compatible (race 20) and incompatible interactions for four of these genes: pod2, pod3, pod4, and pod6. Pod4 and pod6 were more intensely up-regulated during resistance than during disease and in the control, while pod3 was specifically down-regulated during the HR after the oxidative burst. Pod2 was induced by pathogen infection and weakly stimulated in the control. These data suggest that cotton peroxidases may have various functions in the defense response to Xanthomonas infections.

Lipid peroxidation in cotton: Xanthomonas interactions and the role of lipoxygenases during the hypersensitive reaction

Lipid peroxidation, often associated with hypersensitive cell death, may be initiated either by active oxygen species (AOS) or lipoxygenases (LOX). Here we report a detailed analysis of this oxidative process in both incompatible and compatible interactions between the cotton cultivar Reba B50 and Xanthomonas campestris pv. malvacearum (Xcm). The hypersensitive reaction (HR) was characterized by a massive production of polyunsaturated fatty acid (PUFA) hydroperoxides together with typical tissue dehydration. Among these, isomers peroxidized on carbon 9, largely predominant, were chiral, showing an excess in the S enantiomer. The HR process was accompanied by an increase in 9S-LOX activity and preceded by transcription of a LOX gene (GhKLox1). These results showed that: (i) AOS produced during the oxidative burst were not involved in PUFA peroxidation during HR; and (ii) as previously described in elicited leaves of tobacco, the massive enzymatic lipid peroxidation was closely associated with hypersensitive cell death. During disease development in this cotton cultivar, the 9-lipoxygenation of PUFAs was late, weak, preceded by a faint accumulation of GhKLox1 transcripts, and associated with chlorosis but not with necrosis. Consequently, the main difference between incompatible and compatible interactions was in the precocity and intensity of the oxidative process, rather than in its nature. These data provide the evidence for a correlation between lipid peroxidation and hypersensitive cell death induced by pathogens.

Salicylic acid mediated by the oxidative burst is a key molecule in local and systemic responses of cotton challenged by an avirulent race of Xanthomonas campestris pv malvacearum

We analyzed the production of reactive oxygen species, the accumulation of salicylic acid (SA), and peroxidase activity during the incompatible interaction between cotyledons of the cotton (Gossypium hirsutum) cv Reba B50/Xanthomonas campestris pv malvacearum (Xcm) race 18. SA was detected in petioles of cotyledons 6 h after infection and 24 h post inoculation in cotyledons and untreated leaves. The first peak of SA occurred 3 h after generation of superoxide (O(2)(.-)), and was inhibited by infiltration of catalase. Peroxidase activity and accumulation of SA increased in petioles of cotyledons and leaves following H(2)O(2) infiltration of cotyledons from 0.85 to 1 mM. Infiltration of 2 mM SA increased peroxidase activity in treated cotyledons and in the first leaves, but most of the infiltrated SA was rapidly conjugated within the cotyledons. When increasing concentrations of SA were infiltrated 2. 5 h post inoculation at the beginning of the oxidative burst, the activity of the apoplastic cationic O(2)(.-)-generating peroxidase decreased in a dose-dependent manner. We have shown that during the cotton hypersensitive response to Xcm, H(2)O(2) is required for local and systemic accumulation of SA, which may locally control the generation of O(2)(.-). Detaching cotyledons at intervals after inoculation demonstrated that the signal leading to systemic accumulation of SA was emitted around 3 h post inoculation, and was associated with the oxidative burst. SA produced 6 h post infection at HR sites was not the primary mobile signal diffusing systemically from infected cotyledons.

Neuropsychological functioning among heart transplant candidates: a case control study

Neuropsychological performance was examined among a group of patients with end-stage heart disease undergoing routine evaluation for transplantation using a matched case-control design. Heart transplant candidates and controls were matched case by case for gender, race, education and age range. In order to match all 44 controls, a clinical series of 303 heart transplant candidates evaluated between October 1995 through March 1998 were considered. Although not specifically matched on variables of estimated IQ and socioeconomic status, statistical analysis showed no group differences on these variables. A separate analysis of variance on each neuropsychological test indicated that the heart transplant candidates performed significantly worse than controls on tasks of fine motor speed and dexterity (i.e., Grooved Peg Board), psychomotor speed and mental flexibility (i.e., Trail Making Test, Part B), and abstract reasoning and problem solving ability (i.e., Shipley Institute of Living Scale-Abstraction subtest). Implications of the results and future directions are discussed.

Detection of Xanthomonas campestris pv. citri by the polymerase chain reaction method

pFL1 is a pUC9 derivative that contains a 572-bp EcoRI insert cloned from plasmid DNA of Xanthomonas campestris pv. citri XC62. The nucleotide sequence of pFL1 was determined, and the sequence information was used to design primers for application of the polymerase chain reaction (PCR) to the detection of X. campestris pv. citri, the causal agent of citrus bacterial canker disease. Seven 18-bp oligonucleotide primers were designed and tested with DNA from X. campestris pv. citri strains and other strains of X. campestris associated with Citrus spp. as templates in the PCR. Four primer pairs directed the amplification of target DNA from X. campestris pv. citri strains but not from strains of X. campestris associated with a different disease, citrus bacterial spot. Primer pair 2-3 directed the specific amplification of target DNA from pathotype A but not other pathotypes of X. campestris pv. citri. A pH 9.0 buffer that contained 1% Triton X-100 and 0.1% gelatin was absolutely required for the successful amplification of the target DNA, which was 61% G+C. Limits of detection after amplification and gel electrophoresis were 25 pg of purified target DNA and about 10 cells when Southern blots were made after gel electrophoresis and probed with biotinylated pFL1. This level of detection represents an increase in sensitivity of about 100-fold over that of dot blotting with the same hybridization probe. PCR products of the expected sizes were amplified from DNA extracted from 7-month-old lesions from which viable bacteria could not be isolated. These products were confirmed to be specific for X. campestris pv. citri by Southern blotting. This PCR-based detection protocol will be a useful addition to current methods of detection of this pathogen, which is currently the target of international quarantine measures.