Hepatic Hilar Lymph Node Reactivity at Kasai Portoenterostomy for Biliary Atresia: Correlations With Age, Outcome, and Histology of Proximal Biliary Remnant.

We hypothesized that if infection is the proximate cause of congenital biliary atresia, an appropriate response to antigen would occur in lymph nodes contiguous with the biliary remnant. We compared the number of follicular germinal centers (GC) in 79 surgically excised hilar lymph nodes (LN) and 27 incidentally discovered cystic duct LNs in 84 subjects at the time of hepatic portoenterostomy (HPE) for biliary atresia (BA) to autopsy controls from the pancreaticobiliary region of non-septic infants >3 months old at death. All 27 control LN lacked GC, a sign in infants of a primary response to antigenic stimulation. GC were found in 53% of 106 LN in 56 of 84 subjects. Visible surgically excised LN contiguous with the most proximal biliary remnants had 1 or more well-formed reactive GC in only 26/51 subjects. Presence of GC and number of GC/LN was unrelated to age at onset of jaundice or to active fibroplasia in the biliary remnant but was related to older age at HPE. Absent GC in visible and incidentally removed cystic duct LNs predicted survival with the native liver at 2 and 3 years after HPE, P = .03, but significance was lost at longer intervals. The uncommon inflammatory lesions occasionally found in remnants could be secondary either to bile-induced injury or secondary infection established as obstruction evolves. The absence of consistent evidence of antigenic stimulation in LN contiguous with the biliary remnant supports existence of at least 1 major alternative to infection in the etiology of biliary atresia.

Predictability of the clinical course of juvenile dermatomyositis based on initial muscle biopsy: a retrospective study of 72 patients.

OBJECTIVE: Except when the diagnosis of juvenile dermatomyositis (DM) is in doubt, a case has not been made for routine muscle biopsy (MB). We sought to determine whether MB findings prior to systemic therapy have prognostic value. METHODS: We reviewed the hospital records and slides prepared from the initial open MB of 72 patients treated at one center between 1977 and 2002 and followed for a minimum of 2 years. None of the patients had received a course of systemic corticosteroid therapy at the time of MB. Our approach to MB evaluation was based on recent discussions with muscle pathology experts to develop criteria for assessing inflammation, vasculopathy, myofiber atrophy, regeneration, acute and chronic myopathic change, and stromal changes. Using simple and multivariate logistic regression, we tested each MB parameter for ability to predict outcome using 2 published classification systems. RESULTS: Extensive active myopathic changes (excluding regeneration) and central nuclei without basophilia predicted chronic juvenile DM. Severe arteropathic change, positive arterial direct immunofluorescence, obvious foci of severe capillary loss/endomysial fibrosis, and muscle infarcts predicted chronic juvenile DM, particularly with ulceration. Other MB parameters, regardless of severity, were not significant predictors of chronic juvenile DM versus limited disease. CONCLUSION: A scoring system for evaluating pretreatment MB in juvenile DM that focuses on extent of necrotizing myopathy, severity of vasculopathy, and features of established chronicity such as central nucleation of nonbasophilic myofibers may provide a basis for stratification of therapeutic regimens according to risk for chronic disease. The validity of our findings should be prospectively tested.

What more can we learn from muscle histopathology in children with dermatomyositis/polymyositis?

OBJECTIVE: To correlate disease course and complications in children with juvenile dermatomyositis (JDM) and polymyositis (JPM) with specific features of muscle pathology on biopsy. METHODS: This is a retrospective cohort analysis of 59 children diagnosed with JDM or JPM between 1965 and 1998 and followed at the Cincinnati Children's Hospital Medical Center (CCHMC) for a mean duration of 7.3 years (range 1.1-24.5 years). Disease course was characterized as limited, chronic non-ulcerative or chronic ulcerative, similar to previously defined disease course subtypes reported by Crowe et al.(1). All subjects had diagnostic muscle biopsies performed at CCHMC and had disease for at least two years' duration in order to classify their disease course as either limited or chronic. Features of muscle histopathology that were evaluated included loss of the intramuscular capillary bed, infarct, perifascicular myopathy, direct immunofluorescence (DIF) staining of the intramuscular vasculature and specifically, the locale of DIF staining, i.e., small arteries or capillaries. Disease complications that were assessed included calcinosis, contractures, muscle atrophy, lipodystrophy, gastrointestinal ulceration, cutaneous ulceration and death. Data analysis was completed using Chi-square or Fisher's exact tests and logistic regression modeling. RESULTS: Twenty-two children (37%) had limited disease, 24 (41%) had chronic non-ulcerative disease and 13 (22%) had chronic ulcerative disease. Neither loss of the intramuscular capillary bed nor perifascicular myopathy on muscle biopsy significantly correlated with disease course or the various complications evaluated in this study. DIF staining of intramuscular vessels overall was not significantly associated with clinical disease course, but the localization of DIF staining to intramuscular arteries (rather than to capillaries) was significantly associated with the outcome of chronic ulcerative disease. Nine of the 13 children with chronic ulcerative disease had DIF-arterial staining on muscle biopsy (69%), significantly greater than DIF-arterial staining in children with limited disease (32% had DIF-arterial staining) (p = 0.04), chronic non-ulcerative disease (8% had DIF-arterial staining) (p = 0.0002), and non-ulcerative disease overall (limited + chronic non-ulcerative disease groups combined) (20% had DIF-arterial staining), with p = 0.001. Additionally, lack of DIF-arterial staining on biopsy was significantly correlated with patients not having gastrointestinal ulceration (p = 0.002), cutaneous ulceration (p = 0.004) and/or death (p = 0.02) as disease-related complications. Infarct on muscle biopsy was significantly associated with the development of chronic ulcerative disease (p = 0.02), being present on biopsy in 23% of children with chronic ulcerative disease compared with none of the patients with chronic non-ulcerative disease and 4% of those with limited disease. Infarct on muscle biopsy correlated with the outcomes of death (p = 0.01) and gastrointestinal ulceration (p = 0.03), but not with the development of cutaneous ulceration (p = 0.18). CONCLUSION: DIF-arterial staining and infarct on muscle biopsy are significantly associated with the development of chronic ulcerative disease in JDM and JPM, while perifascicular myopathy and loss of the intramuscular capillary network are not associated with disease course. The presence of DIF-arterial staining and infarct on biopsy should suggest early use of second-line therapeutic agents to more quickly bring disease activity under control.

Transgenic overexpression of cardiac actin in the mouse heart suggests coregulation of cardiac, skeletal and vascular actin expression.

Previous studies have shown that depletion of cardiac actin by targeted disruption is associated with increased expression of alternative actins in the mouse heart. Here we have studied the effects of transgenic overexpression of cardiac actin using the alpha-myosin heavy chain promoter. Lines carrying 7 or 8 copies of the transgene showed a 2-fold increase in cardiac actin mRNA and also displayed decreased expression of skeletal and vascular actin in their hearts. In contrast, a line with more than 250 copies of the transgene did not show a similar decrease in the expression of skeletal and vascular actin despite a 3-fold increase in cardiac actin mRNA. While the low copy number transgenic mice displayed hearts that were similar to non-transgenic controls, the high copy number transgenic line showed larger hearts with distinct atrial enlargement and cardiomyocyte hypertrophy. Further, while the low copy number transgenic mouse hearts were mildly hypocontractile when compared with non-transgenic mouse hearts, the high copy number transgenic mouse hearts were significantly so. We conclude that in the presence of a small number of copies of the cardiac actin transgene, homeostatic mechanisms involved in maintaining actin levels are active and negatively regulate skeletal and vascular actin levels in the heart in response to increased expression of cardiac actin. However, these putative mechanisms are either inoperative in the high copy number transgenic line or are countered by the enhanced expression of skeletal and vascular actin during cardiomyocyte hypertrophy.

Etanercept in the treatment of macrophage activation syndrome.

Macrophage activation syndrome (MAS), a recognized complication of systemic juvenile rheumatoid arthritis (sJRA), has been associated with significant morbidity and mortality. Dysregulation of macrophage-lymphocyte interactions leading to uncontrolled proliferation of highly activated macrophages and massive release of proinflammatory cytokines including tumor necrosis factor-alpha (TNF-alpha) appears to be central to the pathogenesis of this syndrome. Until now the mainstay of therapy has been corticosteroids and cyclosporin A. We describe a patient with MAS and sJRA successfully treated with the anti-TNF agent etanercept. The outcome in this patient suggests etanercept might be an effective therapeutic agent in MAS.

Nucleophosmin/B23 is a target of CDK2/cyclin E in centrosome duplication.

In animal cells, duplication of centrosomes and DNA is coordinated. Since CDK2/cyclin E triggers initiation of both events, activation of CDK2/cyclin E is thought to link these two events. We identified nucleophosmin (NPM/B23) as a substrate of CDK2/cyclin E in centrosome duplication. NPM/B23 associates specifically with unduplicated centrosomes, and NPM/B23 dissociates from centrosomes by CDK2/cyclin E-mediated phosphorylation. An anti-NPM/B23 antibody, which blocks this phosphorylation, suppresses the initiation of centrosome duplication in vivo. Moreover, expression of a nonphosphorylatable mutant NPM/ B23 in cells effectively blocks centrosome duplication. Thus, NPM/B23 is a target of CDK2/cyclin E in the initiation of centrosome duplication.

Premature closure of foramen ovale and renal vein thrombosis in a stillborn twin homozygous for methylene tetrahydrofolate reductase gene polymorphism: a clinicopathologic case study.

Premature closure of the foramen ovale, 4-chamber cardiac hypertrophy, and renal vein/vena cava thrombosis were found at autopsy of a stillborn dizygotic twin at 36 weeks gestational age. Review of the original prenatal sonograms showed features suggestive of early closure of the foramen ovale. Homozygosity for the 5, 10 methylene tetrahydrofolate reductase mutation was shown only in the affected twin after the parents were found to be heterozygous for the mutation. The difference in outcome of the twins following prenatal treatment with beta mimetics and corticosteroids for preterm labor may be related to the added susceptibility factor for thromboembolism associated with presumed hyperhomocysteinemia in the proband which was not shared by the surviving healthy twin. The role of premature closure of the foramen ovale and prenatal treatment are discussed but remain uncertain.

Liver disease caused by disorders of bile acid synthesis.

Bile acid synthetic defects are uncommon disorders that cause progressive cholestatic liver disease that is often lethal in infancy or early childhood. Five specific primary defects have been described. Diagnosis is based on mass spectrometry of urine and serum. Pathogenesis of liver injury is related to persistent reduction in levels of normal bile acids and accumulation of abnormal, potentially hepatotoxic, intermediaries. Sites of injury are the liver cell, the bile canaliculus, and the smallest bile ductules. The interlobular bile ducts are normal. The liver lesion is progressive chronic hepatitis with an especially high incidence of GCT in patients who present in infancy. Bile acid replacement therapy is usually effective in arresting the liver injury. Regression of liver damage has been documented during treatment of patients who were diagnosed early in life. Because bile acid synthetic disorders are the only cholestatic diseases of infancy in which GCT of hepatocytes is consistently present, the author suggest that the injury responsible for GCT may be specific for toxic bile acids. Accordingly, immaturity of the bile acid synthetic pathway may render many otherwise normal infants vulnerable to transient "neonatal hepatitis" with GCT in a broad range of cholestatic disorders.

DNA fragmentation factor 45-deficient cells are more resistant to apoptosis and exhibit different dying morphology than wild-type control cells.

The DNA fragmentation factor 45 (DFF45) is a subunit of a heterodimeric DNase complex critical for the induction of DNA fragmentation in vitro. To understand the in vivo role of DFF45 in programmed cell death, we measured the expression of DFF45 during mouse development and compared DNA fragmentation and viability of DFF45-deficient cells with wild-type control cells after activation of apoptosis. We found that DFF45 is ubiquitously expressed throughout mouse development. Moreover, DFF45-deficient thymocytes are resistant to DNA fragmentation with in vivo dexamethasone treatment. Furthermore, primary thymocytes from DFF45 mutant mice are also more resistant to apoptosis than wild-type control cells on exposure to several apoptotic stimuli. Dying DFF45-deficient thymocytes exhibit different morphology than wild-type control cells in that they show reduced degree of chromatin condensation, absent nuclear fragmentation, intranuclear cytoplasmic invagination, and striking nuclear chromatin conglutination after release from disintegrating cells. These results indicate that DFF45 is essential during normal apoptosis.

Visualization of aortic valve leaflets using black blood MRI.

Although magnetic resonance imaging (MRI) is capable of imaging various physiological parameters associated with the heart valves, it has generally been difficult to visualize the valve leaflets directly. The aortic valve was imaged in 120 patients referred for cardiac MRI to assess myocardial volumes or mass. The average patient age was 37 and ranged from 9 to 75 years. Heart rate ranged from 43 to 100 bpm. Imaging was performed on a 1.5 T scanner equipped with enhanced gradients and a cardiac phased-array coil. A double inversion recovery fast spin-echo sequence was used to acquire short-axis images of the aortic valve in a breath-hold (15 +/- 3 seconds). All three leaflets of the aortic valve were seen in 102 of 120 studies (85%). Two leaflets were detected in another 15 subjects. No leaflets were seen in three individuals. Seven cases of a bicuspid or thickened aortic valves were clearly distinguished from normal valves. The signal-to-noise ratio of aortic leaflets (14 +/- 5) was significantly higher than that of the residual blood signal in the aortic root (7 +/- 4, P < 0.001). MR images showed the aortic valve leaflets in a high fraction of people with suspected normal aortic valves and detected seven cases of abnormal aortic valves. The potential of MRI to study both the anatomic and functional consequences of valvular heart disease warrants further study. J. Magn. Reson. Imaging 1999;10:771-777.

Diagnosis of hirschsprung disease using the rectal biopsy: multi-institutional survey.

Diagnostic pathologists remain uncomfortable with the diagnosis of Hirschsprung disease (HD) via rectal (mucosal/submucosal) biopsy and with performance and interpretation of the associated acetylcholinesterase (AChE) assay. This report details the different diagnostic approaches taken by four major pediatric institutions-Children's Hospital, Columbus, OH; Children's Hospital Medical Center, Cincinnati, OH; Children's Hospital, Pittsburgh, PA; Children's Hospital, Los Angeles, CA-in confirming or excluding the presence of HD. The Columbus approach emphasizes serial morphologic examination of rectal biopsies, while Cincinnati emphasizes the primary diagnostic utility of the AChE stain. Pittsburgh and Los Angeles emphasize a detailed gross and microscopic analysis of rectal biopsies to detect both conventional HD and its more rare subtypes. The diagnostic approaches of these four institutions can be used on a complementary basis to the advantage of the general diagnostic pathologist, especially in HD cases with subtle clinical presentations. The need for careful and continual communication between the clinician and pathologist in diagnosing or excluding the presence of HD is imperative.

Wilms' tumor and related abnormalities in the fetus and newborn.

Mesoblastic nephroma, a benign tumor, is the most common renal neoplasm in neonates. Wilms' tumor (WT) may occur in newborn infants, but is more common in older children. The molecular genetics of WT involves one or more genes located on Chromosome #11 and probably other locations not yet elicidated. Germline mutations cause less than 5% of WTs; most WTs are sporadic. Precursor lesions to WT called nephrogenic rests may be detected before evolution to WT by imaging studies. Developmental anomalies comprising several different syndromes are associated with nephrogenic rests and predisposition to WT. Prospective surveillance for WT may be feasible in high risk infants identified on the basis of physical findings followed by testing for predisposing gene defects and periodic imaging of the kidneys and other organs at risk until the period of risk has ended.

Model for evaluating the effect of growth factors on the larynx.

Growth factors are proteins that help regulate the inflammatory response and wound healing in tissues. After laryngotracheal surgery, proper wound healing is important in maintaining the reconstructed airway. The application of growth factor to the respiratory mucosa of the larynx and its effect on wound healing within the airway have not been studied. This study was designed to establish a model for the evaluation of wound healing after the application of growth factor to composite respiratory mucosa and cartilage surfaces at the time of laryngotracheoplasty. Forty rabbits underwent anterior cricoid cartilage split with or without the use of a cartilage graft. Platelet-derived growth factor or a placebo substance was applied to the wound at the time of surgery. This study offers a model for studying wound healing in the airway that is reproducible with limited morbidity.

The relationship of hepatotoxic risk factors and liver histology in methotrexate therapy for juvenile rheumatoid arthritis.

OBJECTIVE: To examine the relationship between hepatotoxic risk factors and liver histopathology in patients with juvenile rheumatoid arthritis (JRA) treated with methotrexate (MTX). STUDY DESIGN: We graded the histology of 33 percutaneous liver biopsy specimens from 25 patients with JRA treated at Children's Hospital Medical Center, Cincinnati, Ohio, using the Roenigk Classification Scale. Stepwise linear and logistic regression analyses were performed to examine the relationship of the Roenigk grade and presence of liver fibrosis of biopsy specimens with potential risk factors. RESULTS: Twenty-seven biopsy specimens (82%) were classified as grade I, 4 (12%) as grade II, and 2 (6%) as grade IIIA; none demonstrated significant fibrosis. The frequency of biochemical abnormalities (P <.001) and body mass index (P =.05) were the only risk factors found to significantly relate to the Roenigk grade. The following factors were not significantly associated with the Roenigk grade: age, gender, disease duration, JRA subtype and course, duration of MTX administration, weekly MTX dose, cumulative dose of MTX, route of MTX administration, use of folic acid supplementation, concurrent use of other medications, and potential hepatotoxic comorbidities. CONCLUSIONS: Serial biochemical abnormalities are significantly associated with Roenigk grade and the presence of liver fibrosis. These findings concur with studies of patients with rheumatoid arthritis, suggesting that guidelines for monitoring MTX hepatotoxicity in rheumatoid arthritis may be applicable to patients with JRA.

Third report of t(19q)(13.4) in mesenchymal hamartoma of liver with comments on link to embryonal sarcoma.

We report the third known case of mesenchymal hamartoma of the liver (MHL) with a balanced translocation involving a common breakpoint, 19q13.4. A common clonal chromosome abnormality appears to characterize an important subset of MHL, some of which may be low-grade neoplasms. We found no consistent karyotype abnormality in a post-treatment sample of embryonal sarcoma of the liver (ESL). Reports of coexistent MHL and ESL in two patients and detection of 19q abnormalities in two ESLs appear to support Stocker's hypothesis of a histogenetic link between these two rare liver lesions. More data are needed to clarify this relationship. It is possible that MHLs are etiologically heterogenous and may be developmental disorders, disruptions, or neoplasms.

Evaluation of the aortic root by MRI: insights from patients with homozygous familial hypercholesterolemia.

BACKGROUND: In homozygous familial hypercholesterolemia (HFH), the aortic root is prone to develop atherosclerotic plaque at an early age. However, the aortic wall and plaque have not yet been assessed in this condition by MRI. We evaluated the aortic root by use of MRI in 17 HFH patients and 12 normal control subjects in a prospective, blinded, controlled study. METHODS AND RESULTS: Morphological assessment of the aortic root was done with spin-echo and gradient-echo MRI scanning. Comparisons were made with a number of measures of disease severity, including cholesterol-year score, calcium score on electron-beam CT (EBCT), and size of Achilles tendon xanthomas. Atherosclerotic plaque, visible on fat-suppressed images but never on water-suppressed images, was present in 9 HFH patients (53%). Supravalvular aortic stenosis was present in 7 patients with HFH (41%). Maximum supravalvular aortic wall thickness was significantly greater and OD and lumen cross-sectional area (CSA) were smaller in patients than in control subjects (P=0.006, 0.0005, and 0.06, respectively). Maximum wall thickness was associated with a greater calcium score on electron-beam CT (P=0.02). Although the cumulative exposure of the aortic root to cholesterol (the cholesterol-year score) was significantly correlated with the Achilles tendon CSA and vascular calcification, this score did not correlate with the wall thickness or aortic CSA. CONCLUSIONS: This study not only demonstrates the utility of MRI for detecting and characterizing aortic root atherosclerotic plaque and supravalvular aortic stenosis in HFH patients but also suggests that the LDL receptor plays a direct or indirect role in aortic mural development and vascular growth.

The large window ductus: a surgical trap.

A rare window type of patent ductus arteriosus is reported that was large (15 mm in maximal transverse dimension) but had virtually no length and hence was externally invisible. The smaller aortic isthmus (4 mm in diameter), which was intrapericardial, was mistaken for the ductus and was inadvertently clip-occluded, leading to death. After a specific diagnosis is made, the large window ductus should be patched on cardiopulmonary bypass with a transpulmonary approach.

Formation of intracerebral cavernous malformations after radiation treatment for central nervous system neoplasia in children.

OBJECT: Radiation is a common treatment modality for pediatric brain tumors. The authors present a retrospective review of six children who developed cerebral cavernous malformations after they underwent radiation treatment for central nervous system (CNS) neoplasia and propose two possible models to explain the formation of cavernous malformations. METHODS: Three boys, aged 13, 9, and 17 years, suffered intracerebral hemorrhages from cerebral cavernous malformations 87, 94, and 120 months, respectively, after they received whole-brain radiation therapy (WBRT) for acute lymphocytic leukemia. A 10-year-old girl and a 19-year-old man developed temporal lobe cavernous malformations 46 and 48 months, respectively, after they received radiation therapy for posterior fossa astrocytomas. A 12-year-old girl developed a temporal lobe cavernous malformation 45 months after WBRT was administered for a medulloblastoma. In all of these cases the cavernous malformation appeared in the irradiated field, was not known to be present prior to radiation therapy, and developed after a latency period following treatment. The incidence of cavernous malformations in these patients suggests that children who undergo radiation therapy of the brain may have an increased risk of hemorrhage. CONCLUSIONS: Two possible models may explain the formation of cavernous malformations following brain radiation in these patients. First, the cavernous malformations may form de novo in response to the radiation. Second, the cavernous malformations may have been present, but radiographically occult, at the time of radiation therapy and may have hemorrhaged in response to the radiation. The authors conclude that cavernous malformations may develop after brain radiation and propose a possible mechanism for this formation.