APC mutant zebrafish uncover a changing temporal requirement for wnt signaling in liver development.

Developmental signaling pathways hold the keys to unlocking the promise of adult tissue regeneration, and to inhibiting carcinogenesis. Patients with mutations in the Adenomatous Polyposis Coli (APC) gene are at increased risk of developing hepatoblastoma, an embryonal form of liver cancer, suggesting that Wnt affects hepatic progenitor cells. To elucidate the role of APC loss and enhanced Wnt activity in liver development, we examined APC mutant and wnt inducible transgenic zebrafish. APC(+/-) embryos developed enlarged livers through biased induction of hepatic gene programs and increased proliferation. Conversely, APC(-/-) embryos formed no livers. Blastula transplantations determined that the effects of APC loss were cell autonomous. Induction of wnt modulators confirmed biphasic consequences of wnt activation: endodermal pattern formation and gene expression required suppression of wnt signaling in early somitogenesis; later, increased wnt activity altered endodermal fate by enhancing liver growth at the expense of pancreas formation; these effects persisted into the larval stage. In adult APC(+/-) zebrafish, increased wnt activity significantly accelerated liver regeneration after partial hepatectomy. Similarly, liver regeneration was significantly enhanced in APC(Min/+) mice, indicating the conserved effect of Wnt pathway activation in liver regeneration across vertebrate species. These studies reveal an important and time-dependent role for wnt signaling during liver development and regeneration.

The role of an intravenous fat emulsion composed of fish oil in a parenteral nutrition-dependent patient with hypertriglyceridemia.

Hypertriglyceridemia is a common complication in patients receiving parenteral nutrition (PN). Management typically involves withholding the IV fat emulsion (IVFE) until serum triglyceride levels normalize. In some instances, this practice may predispose patients to the development of essential fatty acid deficiency (EFAD) unless alternative therapies such as oral or topical oils are used. This is especially true in patients unable to tolerate enteral intake. We describe the management of hypertriglyceridemia in a 12-year-old boy dependent on PN who developed EFAD due to prolonged use of fat-free PN. His course was further complicated by PN-associated liver disease. Treatment involved the use of an IVFE derived from fish oils. Within 3 weeks, there was clinical improvement in EFAD and hypertriglyceridemia. The patient's triene:tetraene ratio decreased from 0.207 to 0.044 (normal: 0.013-0.05). Similarly, his serum triglyceride levels decreased from 628 mg/dL to 183 mg/dL (normal: <200 mg/dL). After 2 months of treatment, he was successfully transitioned to enteral feedings; hepatic function normalized, as did the essential fatty acid profile and serum triglycerides levels. This suggests that using fish-oil-based IVFE may be an effective alternative to conventional IVFE in PN-dependent patients whose clinical course is complicated by hypertriglyceridemia.

[Fish oil in prolonged parenteral nutrition in children--omega-3-fatty acids have a beneficial effect on the liver]. / Visolie bij langdurige parenterale voeding bij kinderen--omega-3-vetzuren hebben gunstig effect op lever.

Neonates with intestinal failure are dependent on total parenteral nutrition (TPN) and therefore at risk for developing parenteral nutrition associated liver disease (PNALD). In this clinical lesson we report the treatment of PNALD in 3 infants with short bowel syndrome. Conventional omega-6 fat emulsion was substituted by omega-3 fish oil as the sole source of fat in TPN. The described patients were diagnosed as having multiple intestinal atresias, necrotizing enterocolitis and midgut volvulus, respectively, and all patients suffered from short bowel syndrome and were TPN-dependent. When persistent or progressive cholestasis occurred, omega-6 fat emulsion was replaced by omega-3 fish oil. In all 3 cases complete reversal of cholestasis was seen within months after the fish oil-fat emulsion switch. No negative side-effects were reported. These first experiences with the use of fish oil in children in the Netherlands confirm earlier suggested beneficial effects of omega-3 fatty acids in the treatment of PNALD in children with short bowel syndrome.

Pediatric rib lesions: a 13-year experience.

BACKGROUND: Rib lesions in the pediatric population are rare but significant processes and are often neoplastic. METHODS: All patients with primary rib lesions evaluated by the Department of Surgery at Children's Hospital Boston from 1992 to 2005 were studied. The patient's diagnosis, sex, symptoms and their duration, radiologic evaluation, biopsy status, surgical procedure, and follow-up were assessed. RESULTS: Thirty-three patients, ages 3 to 23 years (median, 12.7 years), were evaluated. Sixteen patients (48%) had benign and 17 (52%) had malignant lesions. Within the benign cohort of 16 patients, there were 6 osteochondromas, 4 aneurysmal bone cysts, and 2 fibrous dysplasias as well as 1 of each of the following: enchondroma, periosteal chondroma, eosinophilic granuloma, and chondrophyte. Within the malignant cohort of 17 patients, 13 were diagnosed with Ewing's sarcoma, 3 with osteogenic sarcoma, and 1 with chondrosarcoma. The sex distribution for the malignant group was 11 (65%) females and 6 (35%) males. CONCLUSIONS: Rib tumors are rare entities in the pediatric population. However, a significant number of rib lesions are malignant. Therefore, proper diagnosis and expeditious treatment are critical.

Reduction of hepatocellular injury after common bile duct ligation using omega-3 fatty acids.

PURPOSE: Bile duct obstruction and subsequent cholestasis produces hepatocellular injury and an inflammatory response. Fatty acid constitution of cell membranes plays a major role in the inflammatory cascade. Omega-3 fatty acids are antiinflammatory. We proposed that omega-3 fatty acid supplementation would reduce hepatocellular damage and cell death in a model of murine common bile duct ligation. METHODS: Mice underwent bile duct ligation and were administered either control soy diet (omega-6) or Menhaden diet (omega-3), and parameters of liver injury were measured at postoperative days 1, 4, and 8. Serum was analyzed for liver function tests. Liver tissue was scored for histologic necrosis and inflammation, and apoptosis was qualitatively measured. RESULTS: At day 8, comparing control and Menhaden, liver function tests were not significantly different. The H&E slides were analyzed and scored. At day 4, the mean necrosis scores for the Menhaden-fed group was 0.01 +/- 0.028 and 0.46 +/- 0.108 for the soy-fed group (P = .001) and at day 8, 0.420 +/- 0.107 and 1.22 +/- 0.132 (P < .001). The mean portal inflammation score for day 4 Menhaden-fed and soy-fed mice was 1.40 +/- 0.245 for both groups (P = 1.00) and for day 8, 1.80 +/- 0.200 and 2.80 +/- 0.200 (P = .008). At day 1, the median terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling scores of the Menhaden vs soy group were 6.0 and 0.0 (P < .001); day 4, 24.0 and 3.0 (P < .001); and day 8, 0.0 and 3.0 (P < .001), respectively. CONCLUSION: Although there appears to be a trend toward biochemical protection and a marked reduction of necrosis and inflammation, there was no significant liver function test difference between control and Menhaden groups. Considering our data of blunted histologic hepatotoxicity with omega-3 fatty acid supplementation, we hypothesize that this may be a method of reducing long-term complications of liver injury secondary to diseases of cholestasis such as biliary atresia, namely fibrosis and cirrhosis.

Safety and efficacy of a fish-oil-based fat emulsion in the treatment of parenteral nutrition-associated liver disease.

BACKGROUND: Parenteral nutrition-associated liver disease can be a progressive and fatal entity in children with short-bowel syndrome. Soybean-fat emulsions provided as part of standard parenteral nutrition may contribute to its pathophysiology. METHODS: We compared safety and efficacy outcomes of a fish-oil-based fat emulsion in 18 infants with short-bowel syndrome who developed cholestasis (serum direct bilirubin level of > 2 mg/dL) while receiving soybean emulsions with those from a historical cohort of 21 infants with short-bowel syndrome who also developed cholestasis while receiving soybean emulsions. The primary end point was time to reversal of cholestasis (3 consecutive measurements of serum direct bilirubin level of < or = 2 mg/dL). RESULTS: Among survivors, the median time to reversal of cholestasis was 9.4 and 44.1 weeks in the fish-oil and historical cohorts, respectively. Subjects who received fish-oil-based emulsion experienced reversal of cholestasis 4.8 times faster than those who received soybean emulsions and 6.8 times faster in analysis adjusted for baseline bilirubin concentration, gestational age, and the diagnosis of necrotizing enterocolitis. A total of 2 deaths and 0 liver transplantations were recorded in the fish-oil cohort and 7 deaths and 2 transplantations in the historical cohort. The provision of fish-oil-based fat emulsion was not associated with essential fatty acid deficiency, hypertriglyceridemia, coagulopathy, infections, or growth delay. CONCLUSIONS: Parenteral fish-oil-based fat emulsions are safe and may be effective in the treatment of parenteral nutrition-associated liver disease.