Muscle proteolysis and weight loss in a neonatal rat model of sepsis syndrome.

Our hypothesis is that nitrogen loss in septic neonates is caused by increased muscle proteolysis. Sprague-Dawley rat pups (P7) were injected intraperitoneally with NaCl or 4 mg/kg/BW lipopolysaccharide (LPS) and then sacrificed at 2, 4, 24, and 48 hr. Sepsis syndrome was confirmed by elevated serum tumor necrosis factor (24.6 ng/mL +/- 18.4 [LPS] and < 1.0 ng/mL [controls]; p < .05). Proteolysis in gastrocnemius/soleus muscle was analyzed by quantitation of tissue tyrosine loss. The neonatal rats injected with LPS had significant media tyrosine release at 24 hr compared to the controls (0.39 +/- 0.14 versus 0.25 +/- 0.11 micromol tyrosine/g muscle; p < .05). At 48 hr, LPS-induced muscle tyrosine release ceased (0.24 +/- 0.04 [control] versus 0.23 +/- 0.03 micromol tyrosine/g muscle [LPS]). After 48 hr, gastrocnemius/soleus weight was less in the LPS-injected rats (50.5 +/- 4.8 to 31.2 +/- 4.0 g; p < .0001). Similar changes were not seen in the extensor digitorum longus, suggesting that some muscles were relatively preserved. Also, LPS resulted in significant weight loss. We conclude that selective muscle proteolysis contributes to nitrogen loss in neonatal sepsis. Although proteolysis abates by 48 hr, short-term injury results in significant muscle-mass deficit.

Inhibition of growth hormone action in models of inflammation.

Growth hormone (GH) action is attenuated during the hepatic acute-phase response (APR). To understand this attenuation, we asked whether GH and cytokine-signaling pathways intersect during an APR. In hypophysectomized rats treated with lipopolysaccharide (LPS), accumulation of activated signal transducer and transcription activator 5 (Stat5) in hepatic nuclei in response to GH and its binding to a GH response element (GHRE) from the serine protease inhibitor (Spi) 2.1 promoter are diminished in a time-dependent manner. Similarly, accumulation of activated Stat3 in hepatic nuclei in response to LPS and its binding to a high-affinity sis-inducible element (SIE) are also diminished by the simultaneous administration of GH. In functional assays with primary hepatocytes, LPS-stimulated monocyte-conditioned medium (MoCM) inhibits the GH response of Stat5-dependent Spi 2.1 reporter activity but induces Stat3-dependent Spi 2.2 reporter activity, as in an APR. Similar results are obtained when hepatocytes are treated with either tumor necrosis factor-alpha (TNF-alpha) or interleukin (IL)-1beta. TNF-alpha, IL-1beta, and IL-6 also inhibit GH-induced Spi 2.1 mRNA expression in hepatocytes. Thus inhibition of the GH signaling pathway during an APR results in reduced expression of GH-responsive genes.

Effect of sepsis syndrome on neonatal protein and energy metabolism.

OBJECTIVE: It was our hypothesis that septic illness would alter both protein and energy metabolism in neonates, with elevations of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and interleukin-1 beta (IL-1 beta) serving as markers for these effects. STUDY DESIGN: A total of 31 infants with suspected sepsis were enrolled into four groups: septic, sick-nonseptic, healthy-nonseptic, and recovered septic infants. Degree of illness, oxygen consumption, nitrogen balance, urine 3-methylhistidine/creatinine (MeH/Cr), and TNF-alpha, IL-6, IL-1 beta, and C-reactive protein (CRP) were measured. RESULTS: Oxygen consumption increased, while nitrogen balance decreased and MeH/Cr increased with increasing degree of illness. Nitrogen balance improved on recovery from sepsis. IL-6 and CRP levels were elevated in septic infants compared with sick-nonseptic and healthy infants. CONCLUSION: Neonates experience a hypermetabolic response with increased nitrogen loss during septic illness, proportional to the degree of illness. Increased delivery of protein substrate may be nutritionally advantageous to the septic neonate.

Regulation of Spi 2.1 and 2.2 gene expression after turpentine inflammation: discordant responses to IL-6.

The rat serine protease inhibitor (Spi) 2 gene family includes both positive (Spi 2.2) and negative (Spi 2.1) acute phase reactants, facilitating modeling of regulation of hepatic acute phase response (APR). To examine the role of signal transducer and activation of transcription (STAT) proteins in the divergent regulation of these model genes after induction of APR, we evaluated the proximal promoters of the genes, focusing on STAT binding sites contained in these promoter elements. Induction of APR by turpentine injection includes activation of a STAT3 complex that can bind to a gamma-activated sequence (GAS) in the Spi 2.2 gene promoter, although the Spi 2.2 GAS site can bind STAT1 or STAT5 as well. To create an in vitro model of APR, primary hepatocytes were treated with combinations of cytokines and hormones to mimic the hormonal milieu of the whole animal after APR induction. Incubation of primary rat hepatocytes with interleukin (IL)-6, a critical APR cytokine, leads to activation of STAT3 and a 28-fold induction of a chloramphenicol acetyltransferase reporter construct containing the -319 to +85 region of the Spi 2.2 promoter. This suggests the turpentine-induced increase of Spi 2.2 is mediated primarily by IL-6. In contrast, although turpentine treatment reduces Spi 2.1 mRNA in vivo and IL-6 does not increase Spi 2.1 mRNA in primary rat hepatocytes, treatment of hepatocytes with IL-6 results in a 5. 4-fold induction of Spi 2.1 promoter activity mediated through the paired GAS elements in this promoter. Differential regulation of Spi 2.1 and 2.2 genes is due in part to differences in the promoters of these genes at the GAS sites. IL-6 alone fails to reproduce the pattern of rat Spi 2 gene expression that results from turpentine-induced inflammation.

Lysinuric protein intolerance masquerading as celiac disease: a case report.

A 5 1/2-year-old boy presented with delayed growth, chronic diarrhea, and hypoproteinemia. Clinical presentation, initial laboratory data, and evaluation of an intestinal biopsy specimen suggested a diagnosis of celiac disease. Symptoms did not resolve on a gluten-free diet. The development of hyperammonemia prompted further studies that led to the diagnosis of lysinuric protein intolerance. Lysinuric protein intolerance, although a rare disorder, should be included in the differential diagnosis of conditions associated with intestinal villous atrophy.

Glycemic response to dietary supplements in cystic fibrosis is dependent on the carbohydrate content of the formula.

BACKGROUND: Enteral formula feedings are frequently prescribed to cystic fibrosis (CF) patients to boost caloric intake. A substantial number of these patients are glucose intolerant and have severe respiratory compromise. METHODS: To determine the effect of the carbohydrate content on glucose tolerance and respiratory function in glucose-intolerant CF patients with poor lung function, we examined the response to bolus feedings of five dietary supplements; a high-fat formula developed in our Clinical Research Center (CRC), Pulmocare, a high-carbohydrate formula developed in our CRC, Ensure Plus, and sugar-free Scandishake. RESULTS: Glucose excursion in response to the formulas with the lowest carbohydrate content was significantly less than that found in response to formulas with higher carbohydrate content. Insulin levels were also markedly lower in response to the low-carbohydrate high-fat formulas. Glucose excursion, expressed as a percent of the response to the CRC high-fat formula, was 111% +/- 12% for Pulmocare (p = NS), 202% +/- 34% for Ensure Plus (p < 01), 227% +/- 37% for CRC high carbohydrate (p = .001), and 357% +/- 33% for sugar-free Scandishake (p < .001). CO2 production, O2 consumption, minute ventilation, and respiratory rate increased modestly but not significantly in response to all formulas. No significant differences were found between the formulas in regards to these parameters. There were no subjective complaints of dyspnea during any of the five studies. CONCLUSION: The carbohydrate content of liquid dietary supplements appears to be an important determinant of hyperglycemia in glucose-intolerant adult CF patients.

Pediatric gastroenterology. Update on metabolic liver disease.

Wilson's disease, genetic and neonatal hemochromatosis, protoporphyria, tyrosinemia, and alpha1-antitrypsin deficiency are updated. Cost effectiveness of screening is discussed. Current therapies are evaluated, including the role of transplantation. The molecular biologic technique PCR is covered. Gene therapy is introduced.

Cystic fibrosis-associated colitis and fibrosing colonopathy.

OBJECTIVE: To describe our experience with cystic fibrosis (CF)-associated colitis and fibrosing colonopathy, and to assess treatment strategies. STUDY DESIGN: We reviewed hospital charts and autopsy reports of all University of Minnesota patients with CF between 1975 and August 1994. We identified six patients with colonopathy and compared them with a cohort of 79 patients with CF in the same age range and seen during the same period. RESULTS: All patients with colonopathy had bloody diarrhea; five of the six had abdominal pain. Stool frequency and related symptoms distinguished the patients with colonopathy from the cohort population. All took a higher median dose of pancreatic enzymes than the cohort population during the 3 months preceding the onset of symptoms (p < 0.002). For all six patients, barium studies revealed loss of haustration, and shortening and diffuse narrowing of the colonic lumen with relative rectal sparing. The distal ileal mucosa was irregular in four patients. A histopathologic study reveal fibrosis of the submucosa or lamina propria, and focal acute cryptitis in all six patients. Other features included ascites (2/6) and nodular regenerative hyperplasia of the liver (1/6). One patient continues to have symptoms, three had subtotal colectomy, and the condition of two improved after a regimen including a low-fat diet, withholding of pancreatic enzymes, and supplemental parenteral nutrition was initiated. CONCLUSIONS: Fibrosing colonopathy represents a newly recognized gastrointestinal complication of cystic fibrosis. Affected persons have taken larger doses of pancreatic enzymes than similar patients with cystic fibrosis, and have bloody diarrhea. We developed a medical protocol that may avoid surgical resection of the colon in some of these patients.

Clinical and biochemical findings in progressive familial intrahepatic cholestasis.

The clinical findings in 33 patients with progressive familial intrahepatic cholestasis (PFIC) are presented. Symptoms developed almost invariably before 6 months of age with severe pruritus and moderate jaundice. Other clinical findings included wheezing and nosebleeds, fat-soluble vitamin deficiency states, and cholelithiasis. Lower values for gamma-glutamyl transpeptidase, averaging 15 IU/L before the administration of phenobarbital, and cholesterol, which averaged 156 mg/dl, are helpful in distinguishing PFIC from other pediatric cholestatic liver diseases. Autosomal recessive inheritance is probable. Twenty-six patients are alive at 12.9 +/- 6.7 years of age, all having had successful surgical treatment, either partial biliary diversion (n = 17) or orthotopic liver transplantation (n = 10). Seven patients died at a mean age of 3.9 +/- 2.4 years, as a result of liver failure in two, hepatocellular carcinoma in two, and complications of liver transplantation in three.

Ursodeoxycholic acid modifies gut-derived endotoxemia in neonatal rats.

We developed a model for the translocation of intraluminal endotoxin in the neonatal animal and used it to examine the capacity of a nonhepatotoxic bile acid, ursodeoxycholic acid (UDCA), to modify endotoxin translocation and cytokine response. Three-d-old Sprague-Dawley rats were randomized to receive enterally either no drug, lipopolysaccharide (LPS, 1 mg/animal), or UDCA (400 micrograms/animal) alone, or UDCA followed by LPS 1 h later. One h after LPS administration, the rats were killed and plasma endotoxin and tumor necrosis factor (TNF) were measured. Control animals had low circulating endotoxin (21.2 +/- 7.6 endotoxin units) and TNF (0.06 +/- 0.02 ng/mL). Enteral administration of LPS 1 h before the rats were killed resulted in significant elevation of endotoxin (249.5 +/- 71.3, p = 0.008) and TNF (3.6 +/- 1.3, p = 0.019). UDCA alone did not alter endotoxin levels (8.7 +/- 2.1). UDCA 1 h before LPS prevented the rise in endotoxin (38.9 +/- 11.2 endotoxin units) and TNF (0.2 +/- 0.05) significantly. Chenodeoxycholic acid was studied in a similar group of experiments and prevented neither the translocation of LPS nor the development of increased TNF levels in animals receiving LPS. In conclusion, LPS can cross the intestinal barrier in the normal neonatal rat. UDCA, administered before LPS, can decrease the translocation of LPS and prevent the cytokine response as measured by TNF levels. We speculate that UDCA, administered prophylactically, might reduce morbidity in clinical conditions leading to gut-derived endotoxemia.

Long-term complications of arteriohepatic dysplasia.

PURPOSE: It has been stated that arteriohepatic dysplasia is a form of biliary paucity with a good prognosis. We wished to determine the long-term morbidity and mortality associated with arteriohepatic dysplasia. PATIENTS AND METHODS: The charts of all patients with arteriohepatic dysplasia followed by the pediatric gastroenterologists of the University of Minnesota into adulthood were reviewed. RESULTS: Over the last 33 years, the pediatric gastroenterologists have followed 16 children with syndromic paucity, six of whom are now beyond age 18 years. Although five of six patients responded to medical therapy with improvement in their cholestasis and appeared stable clinically through childhood, five of six patients had complications of arteriohepatic dysplasia after age 16 years that resulted in severe morbidity (three) or death (two). These complications included hepatic failure (two), renal failure (one), cerebellar herniation (one), and hepatocellular carcinoma (one). In only one patient were symptoms of the complications present prior to the age of 18 years. CONCLUSION: As more patients with arteriohepatic dysplasia reach adulthood, it appears that this syndrome may be accompanied by long-term manifestations extending beyond childhood. It is important that physicians assuming management of these patients from pediatricians be aware that new abnormalities may appear without warning and that the hepatic disease may deteriorate despite apparent stability through childhood.

Early liver transplantation is indicated for tyrosinemia type I.

Liver transplantation is now accepted as the treatment of choice for tyrosinemia type I (hereditary tyrosinemia). In an effort to determine whether any factors in these patients would aid in predicting optimal timing of the transplant procedure, we evaluated several clinical, biochemical, and radiographic parameters in five successive patients undergoing liver transplant for tyrosinemia type I at the University of Minnesota. All five patients evidenced prolonged periods of clinical and metabolic stability with dietary therapy and four of five remained stable at the time of evaluation for transplantation. Nevertheless, all five suffered significant and unexpected complications of tyrosinemia prior to the time of liver transplant. Four developed renal stones, two were in liver failure, and one developed a neurologic crisis that left him completely paralyzed. Hepatocellular carcinoma was found in one of the five at transplant. We could identify no clinical, biochemical, or radiographic study that was predictive of the likelihood of significant complications of the disorder. Survival from the transplant procedure itself was 100%. The inability to predict or prevent significant complications of tyrosinemia and the favorable outcome from transplantation lead us to recommend liver transplant for all patients with tyrosinemia type I by 12 months of age.

The pathology of liver allografts surviving longer than one year.

Although prolonged survival after liver transplantation is now common, the condition of allografts after prolonged survival has not been widely discussed. We reviewed 86 biopsy samples from 38 patients. The samples were obtained between 366 and 1,622 days after transplant. Thirteen patients' biopsy samples were normal or showed minor changes. Six patients' samples showed rejection. Four patients, including two with rejection, demonstrated ischemic change. Three patients showed focal fibrosis, polymorphonuclear infiltration and bile duct proliferation simulating biliary obstruction, although biliary stones were found in only one patient. Three patients had acute hepatitis. Seven patients had a pattern of chronic persistent hepatitis; four had chronic active hepatitis. Follow-up biopsy samples were obtained in seven chronic hepatitis patients. Two of the patients with chronic hepatitis patients. Two of the patients with chronic active hepatitis have shown slight progression of the disease. None has progressed to cirrhosis, but neither has the chronic active hepatitis resolved. It is likely that some of these cases represent non-A, non-B hepatitis. Although histological abnormalities are common after successful transplantation, the clinical significance of many of the changes remains to be determined. Only patients with rejection or vascular thromboses required new transplants.

Methionyl- and pituitary derived human growth hormone have identical effects on the expression of growth hormone responsive rat hepatic mRNA.

Pituitary extracts of human growth hormone have been used extensively for therapy of growth hormone deficiency, although they are known to contain a variety of contaminating polypeptides. Biosynthetic human growth hormone is now available for this use and appears to be functionally identical in promoting growth. To establish additional criteria of identity we compared the effect of these two hormone preparations on a family of hepatic messenger RNA sequences in hypophysectomized adult male rats. Total hepatic RNA from these animals was translated in a cell-free rabbit reticulocyte lysate. Five translational products previously demonstrated to be responsive to ovine and methionyl-human growth hormone were found to be equally induced by pituitary derived human growth hormone, despite demonstrable heterogeneity in pituitary derived preparations. In addition, no significant alterations in approximately 200 non-growth hormone responsive translational products were identified. Methionyl and pituitary derived growth hormone have identical effects on the expression of hepatic mRNA.

Direct hyperbilirubinemia and hepatic fibrosis: a new presentation of Jeune syndrome (asphyxiating thoracic dystrophy).

Jeune syndrome (asphyxiating thoracic dystrophy) is an autosomal recessive skeletal dysplasia with multisystem involvement. The disorder is usually considered lethal, with death resulting from respiratory insufficiency during infancy, or from renal failure during childhood. Hepatic dysfunction, diagnosed on the basis of direct hyperbilirubinemia and hepatic fibrosis, led to early diagnosis of Jeune syndrome in a newborn infant. Review of the literature indicates that the specific pathologic lesion (biliary dysgenesis with portal fibrosis and bile duct proliferation) has been observed as an incidental finding at autopsy, but that clinically significant liver dysfunction has not been appreciated as an important manifestation in this disorder. The characteristic histopathologic abnormality has been present in every patient studied, and may advance during infancy; in contrast, clinical liver dysfunction resolves over the first few months of life. Whereas many patients with Jeune syndrome die early, several have survived into adolescence, suggesting that aggressive treatment is appropriate, especially for those with minimal respiratory and renal involvement. Longitudinal evaluation of liver function and pathology in these survivors is needed to define the long-term prognosis.