Gregory M. Tiao

Sepsis and endotoxemia stimulate intestinal interleukin-6 production

BACKGROUND Endotoxemia stimulates tumor necrosis factor (TNF) and interleukin-1 (IL-1) production in mucosa of the small intestine, but the effect on IL-6 production is not known. Intestinal IL-6 may be especially important, considering its role in the acute phase response. We tested the influence of endotoxemia and sepsis in mice on intestinal IL-6 and IL-6 messenger RNA (mRNA) levels. METHODS Mice were injected with lipopolysaccharide (LPS 10 mg/kg) or saline solution. In some experiments animals were pretreated with indomethacin (5 mg/kg) or N-nitro-L-arginine (NNA, 100 mg/kg) before LPS injection. In other experiments, sepsis was induced by cecal ligation and puncture (CLP); controls were sham operated. Serum and jejunal mucosa were harvested at intervals during 16 hours, and IL-6 levels were determined by enzyme-linked immunosorbent assay. IL-6 mRNA was detected by polymerase chain reaction. RESULTS Endotoxemia and sepsis increased serum and mucosal IL-6 and IL-6 mRNA, with maximum levels noted at 1 and 4 hours after LPS and at 8 hours after CLP. Pretreatment of endotoxemic mice with indomethacin or NNA blunted the increase in mucosal IL-6. CONCLUSIONS Results suggest that sepsis and endotoxemia stimulate IL-6 production in small intestinal mucosa and that this response may be transcriptionally regulated. The effect of endotoxemia may be partly mediated by prostaglandins and nitric oxide. The results also suggest that the intestinal mucosa may be a participant in the cytokine response, rather than just a passive bystander.

Spectrum of hepatic hemangiomas: management and outcome.

PURPOSE Infants with multiple cutaneous hemangiomas often present with hepatic hemangiomas. They can follow a benign clinical course or require complex management. We reviewed our experience in the management of hepatic hemangiomas. METHODS We performed a retrospective review of patients (1996-2007) with hepatic hemangiomas treated in our institution. RESULTS Twenty-six patients were diagnosed with hepatic hemangiomas as follows: 8 focal, 12 multiple, and 6 diffuse lesions. Nineteen (73%) patients had associated cutaneous hemangiomas. Sixteen patients had multiple and 3 patients had single cutaneous hemangiomas. All patients with multiple or diffuse liver lesions were screened for heart failure and hypothyroidism. Congestive heart failure developed in 4 patients, 3/4 of these patients had diffuse lesions. Two patients required thyroid replacement because of elevated thyroid-stimulating hormone. Because of progression of disease, 9 patients required steroid treatment. Two patients were treated with vincristine and 3 patients received alpha-interferon because of poor response to steroid treatment. Two patients went on to surgical resection for failed response to medical management and worsening heart failure (left lobectomy, liver transplant). Both patients had uncomplicated postoperative courses. Five patients had a previously undescribed constellation of rapidly involuting cutaneous hemangiomas (gone by 3 months, glut-1-negative) with associated liver lesions also resolving at a faster pace (mean resolution of cutaneous hemangiomas, 1.9 vs 7.9 months; P = .001; liver, 5.8 vs 25.3 months; P = .004). All patients in our series survived. CONCLUSION Patients with multiple cutaneous hemangiomas should be screened for hepatic lesions. Patients with diffuse or multifocal liver hemangiomas should be screened for congestive heart failure and hypothyroidism. A subgroup of rapidly involuting cutaneous hemangiomas have a significantly shorter time for involution of hepatic lesions. The status of cutaneous lesions can be used as indicators for the liver hemangiomas.

Effect of Rotavirus Strain on the Murine Model of Biliary Atresia

ABSTRACT Biliary atresia is a devastating disorder of the newborn in which afflicted infants develop inflammation and fibrosis of the extrahepatic biliary tract, resulting in cirrhosis and end-stage liver disease. Infection with a virus is thought to be a contributing factor in the etiology of biliary atresia. In the murine model of biliary atresia, perinatal exposure to rhesus rotavirus (RRV) results in biliary epithelial cell infection causing bile duct obstruction. The purpose of this study was to determine if tropism for the biliary epithelial cell was unique to RRV. Newborn mice underwent intraperitoneal injection with five strains of rotavirus: RRV (simian), SA11-FM (simian/bovine), SA11-SM (simian), EDIM (murine), and Wa (human). RRV and SA11-FM caused clinical manifestations of bile duct obstruction and high mortality. SA11-SM caused clinical signs of hepatobiliary injury but the mortality was markedly reduced. EDIM and Wa caused no sign of hepatobiliary disease. The systemic and temporal distribution of viral protein and live virus varied according to the injected strain. Immunohistochemistry revealed that RRV and SA11-FM targeted the biliary epithelial cells. In contrast, SA11-SM was found in the liver but in not in the biliary epithelium. These results indicate that strain-specific characteristics dictate tropism for cells of hepatobiliary origin which in turn impact the ability to induce the murine model of biliary atresia.

Management of hepatoblastoma: an update.

Purpose of review To summarize the current standards and guidelines for the diagnosis and management of hepatoblastoma, a rare pediatric liver tumor. Recent findings Hepatoblastoma is the most common malignant liver tumor in childhood. International collaborative efforts have led to uniform implementation of the pretreatment extent of disease (PRETEXT) staging system as a means to establish consensus classification and assess upfront resectability. Additionally, current histopathological classification, in light of more advanced molecular profiling and immunohistochemical techniques and integration of tumor biomarkers into risk stratification, is reviewed. Multimodal therapy is composed of chemotherapy and surgical intervention. Achievement of complete surgical resection plays a key role in successful treatment for hepatoblastoma. Overall, outcomes have greatly improved over the past four decades because of advances in chemotherapeutic agents and administration protocols as well as innovations of surgical approach, including the use of vascular exclusion, ultrasonic dissection techniques, and liver transplantation. Challenges remain in management of high-risk patients as well as patients with recurrent or metastatic disease. Summary Eventually, a more individualized approach to treating the different types of the heterogeneous spectrum of hepatoblastoma, in terms of different chemotherapeutic protocols and timing as well as type and extent of surgery, may become the basis of successful treatment in the more complex or advanced types of hepatoblastoma.

Multifocal hepatic neoplasia in 3 children with APC gene mutation.

Hepatoblastoma (HB), the most common hepatic neoplasm in children is associated with germline mutations in adenomatous polyposis coli tumor-suppressor gene that cause familial adenomatous polyposis syndrome. Individuals with familial adenomatous polyposis have a 750 to 7500× the risk of developing HB. We report 3 children with APC gene mutation, who underwent resection or liver transplant for HB. In addition to HB, all 3 patients had multiple independent adenoma-like nodules lacking qualities of intrahepatic metastases. Twenty-five nodules were subjected to immunohistochemical analysis using a panel of antibodies including glypican-3 (GPC3), &bgr;-catenin, cytokeratin AE1/AE3, CD34, Ki-67, glutamine synthetase (GS), and fatty acid binding protein. The nodules were round, ranged in size from 0.2 to 1.5 cm, and paler than the background liver. All lacked the chemotherapy effect. The nodules were circumscribed but nonencapsulated and composed of well-differentiated hepatocytes with occasional minor atypical features and absent or rare portal tracts. One lesion displayed a “nodule-within-nodule” pattern. The nodules demonstrated diffuse GS overexpression. Nine (36%) nodules were focally reactive for GPC3, and 1 (4%) displayed focal nuclear &bgr;-catenin expression. The associated HB showed diffuse expression of GS, GPC3, and &bgr;-catenin nuclear staining. We interpret these nodules as neoplastic with most being adenomas (GPC3 negative) that show features of independent origin and represent early stages of carcinogenesis, implying potential to progress to HB or hepatocellular carcinoma. To our knowledge, this is the first report of multifocal neoplasms in patients with HB and APC gene mutation.

Incidence of acute and chronic graft-versus-host disease and donor T-cell chimerism after small bowel or combined organ transplantation

PURPOSE Graft-versus-host disease (GVHD) after organ transplantation is a rare but life-threatening complication with very high mortality. METHODS A retrospective review was performed of all patients undergoing small bowel or combined organ transplantation at a single institution during 2003 to 2009. Patients with donor T-cell chimerism were analyzed in detail for development of GVHD. RESULTS Thirty-two patients were included in the study. Of 32 patients, 11 (34%) had donor T-cell chimerism (range, 0%-53%) studies performed; 7 (64%) of those 11 patients demonstrated clinical features of GVHD. All patients who demonstrated GVHD had detectable donor T-cell chimerism. All patients with GVHD presented with skin involvement. Graft-versus-host disease responded to increased immune suppression therapy. Mortality was 43% (3/7) among patients with GVHD and was caused by multiorgan failure and sepsis in all cases. CONCLUSION Acute and chronic GVHD were observed frequently after combined solid organ transplantation and were associated with significant mortality and morbidity. Alloreactive donor T cells cotransplanted with the organ likely play a role in the pathophysiology because levels of donor-derived T-cell chimerism correlated with the clinical course of GVHD.

The beneficial impact of revision of Kasai portoenterostomy for biliary atresia: an institutional study.

Objective:To determine whether portoenterostomy (PE) revision in patients afflicted with biliary atresia (BA) is a viable treatment option and, if so, identify which patients may benefit. Background:BA, the most common cause of neonatal liver disease, results in biliary tract obstruction and hepatic fibrosis. Kasai PE is the initial surgical intervention performed and, if successful, restores drainage and preserves the native liver. Portoenterostomy failure warrants liver transplantation, but because of complications related to transplantation, treatment strategies to salvage the native liver may be beneficial. Using uniformly applied criteria, we have revised PEs to delay or avoid transplantation. Methods:A retrospective review of medical records of patients diagnosed with BA since 1983 was performed. Patient demographics, symptoms, indications for revision, laboratory values, and outcomes were recorded. A cohort of patients who underwent revision after initial PE was identified. Survival rates were assessed using the Kaplan-Meier method. For patients who required transplantation, operative data from the revised PE cohort were compared with those from the unrevised PE cohort. A Cox proportional hazards model was used to determine covariates predictive of a favorable outcome. Results:Of 181 children who underwent PE, 24 underwent revision. Adequate biliary drainage, as evidenced by normalized conjugated bilirubin levels, was achieved in 75% of revised patients. Overall survival in patients who underwent revision, regardless of transplantation, was 87%. Among patients who underwent PE revision, 46% have survived with their native liver. Conclusion:Experience at our center suggests that with appropriate patient selection, PE revision may delay the need for liver transplanation yielding encouraging patient outcomes.

Rotavirus Replication in the Cholangiocyte Mediates the Temporal Dependence of Murine Biliary Atresia

Biliary atresia (BA) is a neonatal disease that results in obliteration of the biliary tree. The murine model of BA, which mirrors the human disease, is based upon infection of newborn mice with rhesus rotavirus (RRV), leading to an obstructive cholangiopathy. The purpose of this study was to characterize the temporal relationship between viral infection and the induction of this model. BALB/c mice were infected with RRV on day of life (DOL) 0, 3, 5, and 7. Groups were characterized as early-infection (infection by DOL 3) or late-infection (infection after DOL 5). Early RRV infection induced symptoms in 95% of pups with a mortality rate of 80%. In contrast, late infection caused symptoms in only 50% of mice, and 100% of pups survived. The clinical findings correlated with histological analysis of extrahepatic biliary trees, cytokine expression, and viral titers. Primary murine cholangiocytes isolated, cultured, and infected with RRV yielded higher titers of infectious virus in those harvested from DOL 2 versus DOL 9 mice. Less interferon alpha and beta was produced in DOL 2 versus DOL 9 RRV infected primary cholangiocytes. Injection of BALB/c interferon alpha/beta receptor knockout (IFN-αβR−/−) pups at DOL 7 showed increased symptoms (79%) and mortality (46%) when compared to late infected wild type mice. In conclusion, the degree of injury sustained by relatively immature cholangiocytes due to more robust RRV replication correlated with more severe clinical manifestations of cholangiopathy and higher mortality. Interferon alpha production by cholangiocytes appears to play a regulatory role. These findings confirm a temporal dependence of RRV infection in murine BA and begin to define a pathophysiologic role of the maturing cholangiocyte.

FXR-Gankyrin axis is involved in development of pediatric liver cancer

The development of hepatoblastoma (HBL) is associated with failure of hepatic stem cells (HSC) to differentiate into hepatocytes. Despite intensive investigations, mechanisms of the failure of HSC to differentiate are not known. We found that oncogene Gankyrin (Gank) is involved in the inhibition of differentiation of HSC via triggering degradation of tumor suppressor proteins (TSPs) Rb, p53, C/EBPα and HNF4α. Our data show that the activation of a repressor of Gank, farnesoid X receptor, FXR, after initiation of liver cancer by Diethylnitrosamine (DEN) prevents the development of liver cancer by inhibiting Gank and rescuing tumor suppressor proteins. We next analyzed FXR-Gank-Tumor suppressor pathways in a large cohort of HBL patients which include 6 controls and 53 HBL samples. Systemic analysis of these samples and RNA-Seq approach revealed that the FXR-Gank axis is activated; markers of hepatic stem cells are dramatically elevated and hepatocyte markers are reduced in HBL samples. In the course of these studies, we found that RNA binding protein CUGBP1 is a new tumor suppressor protein which is reduced in all HBL samples. Therefore, we generated CUGBP1 KO mice and examined HBL signatures in the liver of these mice. Micro-array studies revealed that the HBL-specific molecular signature is developed in livers of CUGBP1 KO mice at very early ages. Thus, we conclude that FXR-Gank-TSPs-Stem cells pathway is a key determinant of liver cancer in animal models and in pediatric liver cancer. Our data provide a strong basis for development of FXR-Gank-based therapy for treatment of patients with hepatoblastoma.

Renal Rhabdomyosarcoma in a Pancake Kidney

Renal rhabdomyosarcoma (RMS) is a rare pediatric tumor. Pancake kidneys are unusual anatomic anomalies resulting when both upper and lower poles of the embryonic kidney become fused. We report on a 4-year-old boy who was discovered to have a stage 4, group IV renal embryonal RMS arising from a pancake kidney with metastases to the lung, pelvis, and bone marrow. Treatment included multimodal therapy, consisting of neoadjuvant chemotherapy, complete surgical resection, and adjuvant chemotherapy. He remains in clinical remission 7 months after resection.