Cynthia C. Daugherty

Complete hepatic regeneration after somatic deletion of an albumin-plasminogen activator transgene

We previously demonstrated that expression of an albumin-urokinase-type plasminogen activator (Alb-uPA) fusion construct in transgenic mice resulted in elevated plasma uPA concentration, hypofibrinogenemia, and neonatal hemorrhaging. Two lines of Alb-uPA mice were established in which only one half of the transgenic pups died at birth; surprisingly, plasma uPA concentrations in survivors gradually returned to normal by 2 months of age. The basis for this phenomenon is DNA rearrangement within hepatocytes that affects the transgene tandem array and abolishes transgene expression. Transgene-deficient cells selectively proliferate relative to surrounding liver, and this process culminates in replacement of the entire liver by clonal hepatic nodules derived from transgene-deficient progenitor cells. In some cases as few as two nodules can reconstitute over 90% of liver mass, highlighting the remarkable regenerative capacity of individual liver cells.

Gaucher disease: Enzyme therapy in the acute neuronopathic variant

The responses to regular intravenous enzyme infusions were compared in two sibs with Gaucher disease type 2, the acute neuronopathic variant. Enzyme administration was begun at 7 months in patient 1 who had severe progressive visceral and neuronopathic disease. No significant effect of enzyme infusions was noted. Death occurred at 9 months. Patient 2 was prenatally diagnosed and enzyme infusions were initiated at age 4 days. Overall development progressed at a rate similar to her unaffected full sib until her death at 15.1 months. Slowly progressive esotropia, ocular paresis and dysphagia began at 8 months as did infiltrative pulmonary disease. Comparison of these clinical courses show significant visceral and neurologic effects of anticipatory enzyme therapy, but with unaltered outcome, for Gaucher disease type 2.

Grade I Reye's syndrome. A frequent cause of vomiting and liver dysfunction after varicella and upper-respiratory-tract infection.

In a one-year prospective study we assessed the incidence of Reyes syndrome in children presenting with the acute onset of vomiting after a prodromal upper-respiratory-tract infection or varicella, and with serum alanine or aspartate aminotransferase levels at least three times higher than normal, and a paucity of neurologic findings. Of 25 patients meeting the above criteria, 19 had liver biopsies yielding adequate tissue for diagnostic purposes. Biopsy specimens from 14 of these 19 patients (74 per cent) were diagnostic of Reyes syndrome, according to rigorous light-microscopical, histochemical, and ultrastructural criteria. None of the biopsy specimens contained evidence of other acute pathologic processes, including hepatitis. A wide spectrum of mitochondrial alterations existed at the ultrastructural level, ranging from mild to severe lesions that were indistinguishable from those seen in comatose patients with Reyes syndrome. Our findings suggest that the clinical complex of vomiting, hepatic dysfunction, and minimal neurologic impairment after varicella or an upper-respiratory-tract infection usually represents Reyes syndrome. This syndrome occurs more frequently than previously recognized.

Pathological findings in gaucher disease type 2 patients following enzyme therapy

The pathological outcomes following intravenous acid beta-glucosidase (alglucerase) infusions were compared in two siblings with Gaucher disease type 2, the acute neuronopathic variant. In case 1 enzyme infusions (four doses at 7 months) had no effect when severe progressive visceral and neuronopathic disease were present. Death from progressive disease occurred at 9 months. Case 2 was prenatally diagnosed. Enzyme infusions were initiated presymptomatically at 4 days of age and continued until death at 15.2 months. Development progressed satisfactorily, albeit at a slower than normal rate until age 10 months when progressive brain stem involvement became evident. Death occurred after slowly progressive brain stem dysfunction, but gross motor and cognitive skills were nearly normal. Postmortem light and electron microscope (EM) studies in both cases showed typical central nervous system (CNS) findings and massive infiltration of the lungs and lymph nodes by Gaucher cells. The liver, spleen, and bone marrow, except that in the temporal bone, in case 2 were normal. These studies show that enzyme therapy may slow but does not prevent the development of lethal CNS disease in Gaucher disease type 2, even when initiated presymptomatically. These findings also indicate the nonuniformity of tissue responses to enzyme therapy implying the existence of therapeutically inaccessible compartments that, in less severe variants, may create unexpected long-term disease complications.

Bile Acid Synthetic Defects and Liver Disease

1Division of Pediatric Pathology, Children’s Hospital Medical Center, and the University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA 2Division of Pediatric Gastroenterology, Children’s Hospital Medical Center, and the University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA 3Division of Mass Spectrometry, Children’s Hospital Medical Center, and the University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA 4Department of Pathology, Denver Children’s Hospital, 1056 East 19th Avenue, Denver, CO 80218, USA

Reye syndrome in children receiving salicylate therapy for connective tissue disease

Concern that salicylates may play a role in the pathogenesis of Reye syndrome has raised the question of whether children receiving salicylate therapy for connective tissue disease are at risk for development of Reye syndrome. Of 176 patients with biopsy-confirmed Reye syndrome studied between January 1969 and June 1983, six had connective tissue disease at the time of development of Reye syndrome, and all six were receiving salicylates. Compared with the general population, children receiving salicylate therapy for connective tissue disease may be at increased risk for the development of Reye syndrome.

Grade I Reye's Syndrome — Outcome and Predictors of Progression to Deeper Coma Grades

Abstract We studied 83 biopsy-proved cases of Grade I Reyes syndrome to determine the outcome, possible clinical or laboratory predictors of progression to deeper coma grades, and hepatic ultrastructural findings. Seventy-eight patients had no change in coma grade during hospitalization, whereas five (6 per cent) had progression to deeper coma grades. All the patients survived without sequelae except one who sustained severe brain damage. The mean (±S.E.) level of serum ammonia on admission was significantly higher (P = 0.005) in patients whose disease progressed to deeper neurologic grades (291±42 μg per deciliter) than in those whose disease did not so progress (53±5 μg per deciliter), and the corrected prothrombin time was significantly more prolonged (P = 0.005) in patients with progressing coma (3.9±0.5 seconds) than in those whose coma grade did not change (1.6±0.2 seconds). The combination of a prothrombin time 3 seconds or longer than that of the control and a serum level of ammonia on admission ...

81 Growth and dissemination of lewis lung carcinoma in plasminogen-deficient mice

Plasminogen activation has been proposed to play a critical role in cancer invasion and metastasis. The effects of complete ablation of plasminogen activation in cancer was studied by inoculation of a metastatic Lewis lung carcinoma expressing high levels of plasminogen activator into plasminogen-deficient (Plg-/-) mice and matched control mice. Primary tumors developed in all mice with no difference in the rate of appearance between Plg-/- and control mice. However, the primary tumors in Plg-/- mice were smaller and less hemorrhagic and displayed reduced skin ulceration. In addition, dissemination of the tumor to regional lymph nodes was delayed in Plg-/- mice. Surprisingly, no quantitative differences were observed in lung metastasis between Plg-/- and control mice. In addition, Plg deficiency was compatible with metastasis of the primary tumor to a variety of other organs. Nevertheless, Plg-/- mice displayed a moderately increased survival after primary tumor resection. These findings suggest that plasmin-mediated proteolysis contributes to the morbidity and mortality of Lewis lung carcinoma in mice, but sufficient proteolytic activity is generated in Plg-/- mice for efficient tumor development and metastasis.

Mitochondrial Enlargement and Crystalloid Matrix Arrays: Distinctive Finding in Childhood Portal Hypertension Due to Cavernous Transformation of the Portal Vein

Elongated, enlarged mitochondria with crystalloid matrix arrays were discovered in periportal hepatocytes in 11 of 12 children (age 6 to 15 years) with portal hypertension, minimal alterations on light microscopy, and cavernous transformation of the portal vein. Eleven of the children were clinically well before onset of symptoms, one was anemic with megaloblastic bone marrow, and a second had undergone renal transplantation. Minimal findings by light microscopy included slight portal fibrosis (six cases), pericentral venular fibrosis (one case), mild, patchy sinusoidal sclerosis (one case), central venular and sinusoidal dilatation (two cases), and mild hepatocellular lipid accumulation (one case). Four were judged normal by routine histologic examination. Subtle depletion of periportal hepatocellular glycogen was present in six. In 10, subtle striation or granularity of periportal hepatocyte cytoplasm was visible with high-magnification light microscopy. Although similar mitochondria are seen sporadically in hepatocytes in diverse settings, enlarged mitochondria with crystalloid matrix inclusions have not been previously reported as a uniform feature in children with portal hypertension due to cavernous transformation of the portal vein and minimal other hepatic alteration. It is postulated that the mitochondria are adapting in response to an abnormal metabolic milieu created by hemodynamic alterations.

Electron Microscopy in the Diagnosis of Pediatric Disease

Electron microscopy, although not able to solve all diagnostic dilemmas, is an essential adjunct to the analysis of pathologic processes. The importance of correct specimen handling for ultrastructural study is highlighted. Some diseases encountered in pediatrics, in which the ultrastructural findings are well established, are illustrated. New technologies that show promise for wider application to problems in pathology also are considered in this article.