Hepatocellular carcinoma results from chronic cyclin D1 overexpression in transgenic mice

Cyclin D1 is a known oncogene and a key regulator of cell cycle progression. Amplification of the cyclin D1 gene and its overexpression have been associated with aggressive forms of human hepatocellular carcinoma (HCC). In this study, two independent lines of transgenic mice have been generated that express cyclin D1 under the control of the rat liver fatty acid binding protein promoter. This transgene specifically directs expression in the liver and the intestines. RNA and protein analysis demonstrated increased expression of the cyclin D1 gene product in the liver and bowel when compared with wild-type siblings. Both transgenic lines developed progressive liver disease. Examination of H&E stained sections of the liver and bowel revealed hyperplastic changes in the liver by 3 months of age. By 6 months of age, transgenic mice had obvious hepatomegaly and histological evidence of dysplasia in the liver. These early changes were significantly more dramatic in male animals when compared with female animals. By 9 months of age adenomas of the liver appeared, progressing to HCC over the ensuing 6-month period. By 15-17 months of age, 87% of male and 69% of female animals had either adenomatous nodules or HCCs. By 17 months of age, 31% of male and female animals had disease that had progressed to HCC. These animals represent a unique and significant new model for the study of human HCC. This study demonstrates that overexpression of cyclin D1 is sufficient to initiate hepatocellular carcinogenesis.

Prostaglandin E2 increases growth and motility of colorectal carcinoma cells

Chronic use of nonsteroidal anti-inflammatory drugs results in a significant reduction of risk and mortality from colorectal cancer in humans. All of the mechanism(s) by which nonsteroidal anti-inflammatory drugs exert their protective effects are not completely understood, but they are known to inhibit cyclooxygenase activity. The cyclooxygenase enzymes catalyze a key reaction in the conversion of arachidonic acid to prostaglandins, such as prostaglandin E(2) (PGE(2)). Here we demonstrate that PGE(2) treatment of LS-174 human colorectal carcinoma cells leads to increased motility and changes in cell shape. The prostaglandin EP(4) receptor signaling pathway appears to play a role in transducing signals which regulate these effects. PGE(2) treatment results in an activation of phosphatidylinositol 3-kinase/protein kinase B pathway that is required for the PGE(2)-induced changes in carcinoma cell motility and colony morphology. Our results suggest that PGE(2) might enhance the invasive potential of colorectal carcinoma cells via activation of major intracellular signal transduction pathways not previously reported to be regulated by prostaglandins.

Tolerability and safety of alosetron during long-term administration in female and male irritable bowel syndrome patients

OBJECTIVES

Alosetron (Lotronex) is a new therapeutic agent for irritable bowel syndrome (IBS) in women with diarrhea-predominant IBS. This multicenter randomized, double-blind, placebo-controlled study assessed the safety and tolerability of alosetron during long-term (< or = 12 months) treatment.

METHODS

A total of 859 subjects (637 female and 222 male) with IBS were enrolled from 130 sites in the United States and were randomized 3:1 to receive 1 mg alosetron or placebo b.i.d. for 48 wk; of the subjects, 649 (76%) were randomized to the alosetron group and 212 (24%) to the placebo group. Of the original group, 850 subjects received at least one dose of alosetron (n = 640) or placebo (n = 210).

RESULTS

In all, 59% of the subjects completed the study. Safety data were similar in treatment groups and within age, sex, racial origin, and hormone use. Adverse events were reported by 83% (530/640) and 76% (159/210) of subjects in the alosetron and placebo groups, respectively, (p < 0.05) and were similar with the exception of constipation; 32% of subjects receiving alosetron reported constipation, compared to 5% in the placebo group (p < 0.001). Most reports (72%) of constipation were of mild or moderate severity, and 66% of subjects with constipation had single episode of 8 days median duration. Constipation occurred a median of 13 days after initiating treatment and resolved spontaneously, with laxative, or after a brief interruption of therapy. Of the subjects, 4% (11/210) in the alosetron and 5% (28/ 640) in the placebo group experienced serious adverse events. Two deaths occurred in subjects with pre-existing cardiovascular risk factors; neither death was attributed to the study drug.

CONCLUSIONS

Alosetron 1 mg b.i.d. for 12 months was well tolerated. Constipation is the most frequent adverse event, with a higher incidence of transient constipation in alosetron-treated patients, typically occurring in the first month of treatment.

Loss of heterozygosity at the mannose 6-phosphate insulin-like growth factor 2 receptor (M6P/IGF2R) locus predisposes patients to radiation-induced lung injury

PURPOSE

To investigate the relationship between loss of heterozygosity (LOH) at the mannose 6-phosphate/insulin-like growth factor 2 receptor (M6P/IGF2R) gene locus and the development of radiation-induced lung injury.

MATERIAL AND METHODS

Thirty-five lung cancer patients with both stored plasma for Transforming Growth Factor beta1 (TGFbeta1) analysis and sufficient quantities of archival pathology tissue to screen for LOH were studied. All patients had been treated with thoracic radiotherapy for their malignancy and had radiographically detectable tumor present before beginning radiotherapy. Tumor and normal cells were microdissected from archival lung cancer pathology specimens. Two polymorphisms in the 3' untranslated region of the M6P/IGF2R were used to screen for LOH. Plasma TGFbeta1 levels were measured using acid-ethanol extraction and an ELISA. TGFbeta1 and M6P/IGF2R protein expression was estimated by immunofluorescence and immunohistochemical staining. Symptomatic radiation pneumonitis was scored according to National Cancer Institute Common Toxicity Criteria without knowledge of the results of TGFbeta or LOH analyses.

RESULTS

Of the 35 patients, 10 were homozygous for this polymorphism (noninformative) and were excluded. Of the 25 informative patients, 13 had LOH. Twelve of 13 patients with LOH had increased pretreatment plasma TGFbeta1 levels, vs. 3/12 patients without LOH (p < 0.01). A decrease or loss of M6P/IGF2R protein in the malignant cell accompanied by increased latent TGFbeta1 protein in extracellular matrix and tumor stroma was found in tumors with LOH, suggesting that this mutation resulted in loss of function of the receptor. Seven of 13 (54%) LOH patients developed symptomatic radiation-induced lung injury vs. 1/12 (8%) of patients without LOH (p = 0.05).

CONCLUSION

Loss of the M6P/IGF2R gene strongly correlates with the development of radiation pneumonitis after thoracic radiotherapy (RT). Furthermore, patients with LOH (in the setting of measurable tumor) are much more likely to have elevated plasma TGFbeta, suggesting an inability to normally process this cytokine. Thus, loss of the M6P/IGF2R gene may predispose patients to the development of radiation-induced lung injury.

Hepatic cryoablation, but not radiofrequency ablation, results in lung inflammation

OBJECTIVE

To compare the effects of 35% hepatic cryoablation with a similar degree of radiofrequency ablation (RFA) on lung inflammation, nuclear factor kappaB (NF-kappaB) activation, and production of NF-kappaB dependent cytokines.

SUMMARY BACKGROUND DATA

Multisystem injury, including acute lung injury, is a severe complication associated with hepatic cryoablation of 30% to 35% or more of liver parenchyma, but this complication has not been reported with RFA.

METHODS

Sprague-Dawley rats underwent 35% hepatic cryoablation or RFA and were killed at 1, 2, and 6 hours. Liver and lung tissue were freeze-clamped for measurement of NF-kappaB activation, which was detected by electrophoretic mobility shift assay. Serum concentrations of tumor necrosis factor alpha and macrophage inflammatory protein 2 were measured by enzyme-linked immunosorbent assay. Histologic studies of pulmonary tissue and electron microscopy of ablated liver tissue were compared among treatment groups.

RESULTS

Histologic lung sections after cryoablation showed multiple foci of perivenular inflammation, with activated lymphocytes, foamy macrophages, and neutrophils. In animals undergoing RFA, inflammatory foci were not present. NF-kappaB activation was detected at 1 hour in both liver and lung tissue samples of animals undergoing cryoablation but not after RFA, and serum cytokine levels were significantly elevated in cryoablation versus RFA animals. Electron microscopy of cryoablation-treated liver tissue demonstrated disruption of the hepatocyte plasma membrane with extension of intact hepatocyte organelles into the space of Disse; RFA-treated liver tissue demonstrated coagulative destruction of hepatocyte organelles within an intact plasma membrane. To determine the stimulus for systemic inflammation, rats treated with cryoablation had either immediate resection of the ablated segment or delayed resection after a 15-minute thawing interval. Immediate resection of the cryoablated liver tissue prevented NF-kappaB activation and lung injury; however, pulmonary inflammatory changes were present when as little as a 15-minute thaw interval preceded hepatic resection.

CONCLUSIONS

Hepatic cryoablation, but not RFA, induces NF-kappaB activation in the nonablated liver and lung and is associated with acute lung injury. Lung inflammation is associated with the thawing phase of cryoablation and may be related to soluble mediator(s) released from the cryoablated tissue. These findings correlate the clinical observation of an increased incidence of multisystem injury, including adult respiratory distress syndrome (ARDS), after cryoablation but not RFA.

The coexistence of low-grade mucinous neoplasms of the appendix and appendiceal diverticula: a possible role in the pathogenesis of pseudomyxoma peritonei

We examined 38 appendectomies with diagnoses of mucocele, diverticulum, or adenoma to study the coincidence of appendiceal diverticula and appendiceal low-grade mucinous neoplasms and to examine the possible role of diverticula in the pathogenesis of pseudomyxoma peritonei. Invasive adenocarcinomas and retention cysts were excluded (six cases). Cases were classified as adenomas or mucinous tumors of unknown malignant potential, with or without diverticula. Medical records were reviewed for multiple parameters, including presenting symptoms, presence of pseudomyxoma peritonei, and presence of associated malignancies. Binomial statistics were used to calculate the probability that the observed prevalence of low-grade mucinous neoplasms and diverticula together was significantly different from the expected prevalence of diverticula or low-grade mucinous neoplasms alone, using historical controls from the literature. Twenty-five percent of the total cases (8 of 32) contained both a low-grade mucinous neoplasm (7 cystadenomas and 1 mucinous tumor of unknown malignant potential) and a diverticulum. Thus, 8 of 19 low-grade mucinous neoplasms (42%) were associated with diverticula. Of the appendices with both low-grade mucinous neoplasms and diverticula, three contained dissecting acellular mucin within the appendiceal wall, four showed diverticular perforation, and one had pseudomyxoma peritonei associated with the ruptured diverticulum. A significant percentage (P < .001) of cases contained low-grade mucinous neoplasms and diverticula together. The case of coexistent low-grade mucinous neoplasm, diverticulum, and pseudomyxoma peritonei suggests that diverticula could play a role in the pathogenesis of pseudomyxoma peritonei. This could occur either by involvement of preexisting diverticula by the neoplasm or by distention of the appendiceal lumen by mucin, leading to increased intraluminal pressure and subsequent diverticulum formation at a weak area in the wall. Either mechanism might allow low-grade mucinous neoplasms to penetrate the appendiceal wall more easily.

M6P/IGF2R is mutated in squamous cell carcinoma of the lung

In addition to the intracellular sorting of lysosomal enzymes, the mannose 6-phosphate/insulin-like growth factor II receptor (M6P/IGF2R) plays a critical role in regulating the bioavailability of extracellular proteolytic enzymes and growth factors. It has also been shown to be mutated in a number of human cancers, and to suppress cancer cell growth. The purpose of this study was to determine if the M6P/IGF2R is mutated in lung cancer, a leading cause of cancer death worldwide. Archival pathology specimens were obtained on 22 patients with newly diagnosed, untreated squamous cell carcinoma of the lung. Two polymorphisms in the 3'-untranslated region of the M6P/IGF2R were used to screen lung tumors for loss of heterozygosity (LOH) by PCR amplification of DNA. Nineteen of 22 (86%) patients were informative (heterozygous), and 11/19 (58%) squamous cell carcinomas of the lung had LOH at the M6P/IGF2R locus. The remaining allele in 6/11 (55%) LOH patients contained mutations in either the mannose 6-phosphate or the IGF2 binding domain of the M6P/IGF2R. Thus, the M6P/IGF2R is mutated frequently in squamous cell carcinoma of the lung, providing further support for its function as a tumor suppressor.

Cyclooxygenase 2 expression is increased in the stroma of colon carcinomas from IL-10(-/-) mice

BACKGROUND & AIMS

The pathological and molecular changes associated with colitis-associated colorectal cancer and sporadic colorectal cancer are considered to be distinct. Therefore, we have used a mouse model of ulcerative colitis to determine if expression of the enzyme cyclooxygenase (COX)-2 is increased in colitis-associated tumors.

METHODS

Reverse-transcription polymerase chain reaction and Western analysis were used to determine if COX-2 expression is increased in these tumors; in situ hybridization and immunohistochemistry were used to determine the localization of COX-2.

RESULTS

Increased levels of COX-2 messenger RNA and protein were detected in interleukin (IL)-10 (-/-) tumors and in an inflamed region of the colon that contained no macroscopically detected tumors. This expression was localized to the inflammatory cells associated with ulcerated regions of the tumor by in situ hybridization and immunohistochemistry. Increased COX-2 expression was also associated with the areas of the tumor expressing alpha-smooth muscle actin, which is a molecular marker for subepithelial myofibroblasts. The association between COX-2 expression and subepithelial myofibroblasts was also noted in tumors derived from the multiple intestinal neoplasia mice (Min/+) and from carcinogen-induced tumors.

CONCLUSIONS

These results indicate that COX-2 is expressed very early in the pathogenesis of colitis-associated tumors, and that the expression pattern is similar to that seen in tumors from azoxymethane-treated and Min/+ mice.

Expansion of Pdx1-expressing pancreatic epithelium and islet neogenesis in transgenic mice overexpressing transforming growth factor alpha

BACKGROUND & AIMS

The progenitor cells responsible for transforming growth factor (TGF)-alpha-induced pancreatic ductal metaplasia and neoplasia remain uncharacterized. During pancreatic development, differentiated cell types arise from ductal progenitor cells expressing the Pdx1 homeodomain transcription factor. The aims of this study were, first, to evaluate the role of Pdx1-expressing stem cells in MT-TGFalpha transgenic mice, and second, to further characterize cell proliferation and differentiation in this model.

METHODS

To assess Pdx1 gene expression in normal and metaplastic epithelium, we performed in vivo reporter gene analysis using heterozygous Pdx1(lacZ/+) and bigenic Pdx1(lacZ/+)/MT-TGFalpha mice.

RESULTS

Pdx1(lacZ/+)/MT-TGFalpha bigenics showed up-regulated Pdx1 expression in premalignant metaplastic ductal epithelium. In addition to Pdx1 gene activation, TGF-alpha-induced metaplastic epithelium demonstrated a pluripotent differentiation capacity, as evidenced by focal expression of Pax6 and initiation of islet cell neogenesis. The majority of Pdx1-positive epithelial cells showed no expression of insulin, similar to the pattern observed during embryonic development.

CONCLUSIONS

Overexpression of TGF-alpha induces expansion of a Pdx1-expressing epithelium characterized by focal expression of Pax6 and initiation of islet neogenesis. These findings suggest that premalignant events induced by TGF-alpha in mouse pancreas may recapitulate a developmental program active during embryogenesis.

Coordinate regulation of cyclooxygenase-2 and TGF-beta1 in replication error-positive colon cancer and azoxymethane-induced rat colonic tumors

Evidence is accumulating which indicates that cyclooxygenase-2 (COX-2) is involved in the pathogenesis of colorectal cancer. We evaluated the expression of COX-2 in replication error-positive (RER) colon cancers, colon cancers metastatic to liver and azoxymethane (AOM)-induced rat colonic tumors. Immunohistochemistry showed that COX-2 was low to undetectable in normal human mucosa, but abundant in the RER adenocarcinomas we examined. COX-2 immunoreactivity in metastatic colon cancers was less abundant, but clearly detectable. In the colon of AOM-treated rats, COX-2 protein was not detectable in normal mucosa, but present in most of the epithelial cells comprising the tumors. The TGF-beta1 staining pattern in these human and rat tumors was similar to that observed for COX-2. The role of TGF-beta in RER adenocarcinomas is complex because of the increased mutation rate of TGF-beta type II receptors. Northern analysis showed abundant TGF-beta1 mRNA in AOM-induced tumors, but not in paired mucosa. TGF-beta1 induced the expression of COX-2 mRNA and protein in intestinal epithelial cells (IEC-6). Chronic TGF-beta1 treatment caused a TGF-beta-dependent overexpression of COX-2 in rat intestinal epithelial cells (RIE-1). TGF-beta1 may regulate COX-2 expression during the colonic adenoma to carcinoma sequence.

Pulmonary vascular morphological changes in cirrhotic patients undergoing liver transplantation

Cirrhosis and portal hypertension may be associated with pulmonary hypertension and pulmonary dysfunction. However, morphological pulmonary vascular lesions in patients with cirrhosis have not been well characterized morphometrically. We morphometrically evaluated pulmonary vessels in liver transplant recipients with pretransplantation cirrhosis and correlated our findings with pretransplantation cardiopulmonary function, postoperative course, and postmortem cardiopulmonary findings. Autopsy lung slides from 23 transplant recipients with pretransplantation cirrhosis were examined. External vessel diameter, intimal thickness, and arterial medial thickness were measured with a micrometer after pentachrome staining. The percent of total diameter comprised by intima or media was calculated for each vessel. Medical records were reviewed for smoking history, pretransplantation cardiopulmonary function testing, and postoperative course. Autopsy cases without liver or significant cardiopulmonary diseases, matched for age, sex, and smoking history, served as controls. Transplant recipients had significantly more pulmonary venous intimal thickening than matched controls (P <.0001). Sixty-five percent (15 of 23) of these patients had some degree of pretransplantation pulmonary dysfunction, defined by abnormalities in pulmonary function tests, oxygen saturation, and/or increased pulmonary artery pressures. However, the severity of venous intimal thickening did not correlate with the severity of pretransplantation pulmonary dysfunction. Arterial intimal and medial thickness were not statistically significantly different from controls. Pulmonary venous intimal thickening and resultant luminal impingement are morphological findings not previously described in this population. The arterial lesion, when present, is similar to that seen in pulmonary hypertension from other causes. These pulmonary vascular lesions may be implicated in pulmonary dysfunction in patients with cirrhosis and may be associated with increased posttransplantation cardiopulmonary morbidity and mortality.

The significance of microabscesses in liver transplant biopsies: a clinicopathological study

Parenchymal microabscesses (MA) in liver transplant biopsies are frequently associated with cytomegalovirus (CMV) infection. However, other potential causes of MA have not been fully investigated. We studied additional etiologies for MA via histological evaluation and clinicopathological correlation. Three hundred seventy-two liver transplant biopsies from 97 patients (from 1991 to 1997) were reviewed and stained immunohistochemically for CMV. Numerous histological features were evaluated including size and number of MA, lobular and portal inflammation, and cholestasis. Medical records were reviewed for radiographic, laboratory, and other clinical data from the time of biopsy. The chi2 or Fisher's Exact test and ANOVA with adjusted multiple comparisons were used to determine statistical significance. Sixty-two of 372 biopsies (17%) from 43 patients contained MA. Biopsies were obtained between 4 days and 2.3 years posttransplant (median, 14 days). Nineteen percent of biopsies had CMV infection at the time of biopsy; 27% were associated with other bacterial, viral, or fungal infections; 10% had graft ischemia; 15% had biliary obstruction/cholangitis; 3% had a combination of ischemia and sepsis; and no explanation was found in 26% of biopsies. Numerous MA within a biopsy (>9) correlated with CMV infection (P <.005); no other histological features, including size of MA, correlated with the etiology of MA. Overall, 43 of 97 (44%) liver transplantation patients at our institution had biopsies demonstrating MA at some point in their posttransplantation course. CMV infection appears responsible for only a minority of cases. MA, although nonspecific, are an important histological finding in numerous conditions that may have a significant impact on both graft survival and overall patient morbidity.

Establishment and characterization of primary gallbladder epithelial cell cultures in the prairie dog

BACKGROUND

The prairie dog has become the established animal gallstone model. This species has a unique propensity to form cholesterol gallstones in response to dietary manipulations. The development of a reliable gallbladder cell culture technique is critical for understanding pathogenic mechanisms of gallstone formation.

MATERIALS AND METHODS

Prairie dogs underwent laparotomy and cholecystectomy, followed by initiation of cell cultures. [3H]Thymidine incorporation was used to assess cell growth, and cell lines were assessed using routine histochemical and immunohistochemical staining.

RESULTS

Cell yields from prairie dog gallbladders were 4-8 x 10(6) viable cells per animal with viability ranging from 80 to 95%. When plated at 5 x 10(5) cells/cm2, cell clusters, visible within 24 h, coalesced into confluent monolayers within 3-5 days. Cultures remained viable for 6-8 weeks and could be passed for three to four subcultures. Immunohistochemical staining demonstrated a high degree of epithelial purity with immunopositivity for AE1/AE3, and cytokeratin, with no vimentin positivity (mesenchymal antigen). Intracytoplasmic vacuoles demonstrated positive staining for Alcian blue, periodic acid-Schiff, and mucicarmine and an anti-gallbladder mucin antibody confirmed the presence of the glycoprotein mucin.

CONCLUSIONS

This study demonstrates a reliable method for initiation and maintenance of prairie dog gallbladder epithelial cell cultures with a high degree of purity. This technique should allow further studies into the pathogenesis of cholesterol gallstones in this model.

Cholestatic hepatitis C in liver allografts

Some liver allograft recipients with hepatitis C virus (HCV) infection develop hyperbilirubinemia, which might be the result of a cholestatic variant of hepatitis C. We evaluated all liver biopsy samples from 6 liver transplant recipients who had polymerase chain reaction-positive HCV infection and histologic evidence of hepatitis and jaundice and compared them with liver biopsy samples from a control group of transplant recipients with HCV hepatitis without jaundice. Patients with known ductopenic rejection, biliary obstruction, or co-infection with hepatitis A or B were excluded from the study. Measurement of viral titers and genomic typing were performed when possible. Six patients developed hepatitis and jaundice, with maximum bilirubin levels ranging from 5.8 to 47.6 mg/dL. In this group, 5 (83%) had moderate interface hepatitis (control group, 15%), 6 (100%) had confluent necrosis (control group, 12%), 5 (83%) had bridging fibrosis (control group, 18%), 4 (67%) had significant hepatocyte swelling (control group, 9%), 4 (67%) had prominent ductular proliferation (control group, 3%), and 6 (100%) had mild duct damage and inflammation (control group, 53%). All 6 of the patients with cholestasis had allograft failure. Of these, three allografts were available for review, which did not reveal occult obstruction, rejection, or duct loss. All patients in the control group have retained their allografts. In 4 patients with cholestasis, the median HCV RNA titer was 93.97 mEq/mL, with a mean of 54.19 mEq/mL (control mean = 5.2 mEq/mL). Five patients also underwent viral genomic typing: 2 with type 1a, 2 with type 1b, and 1 with mixed type 1a and 1b. Cholestasis in patients with posttransplantation hepatitis C may be caused by an aggressive HCV infection that exhibits histologic features of confluent necrosis, hepatocyte swelling, and/or ductular proliferation. Viral titers are often increased in such patients.

Nuclear translocation of beta-catenin in hereditary and carcinogen-induced intestinal adenomas

The physical interaction between beta-catenin and the adenomatous polyposis coli (APC) gene, and the ability of APC to regulate cytoplasmic levels of beta-catenin suggest a role for beta-catenin in colorectal carcinogenesis. In this study, we found that beta-catenin immunoreactivity was detected exclusively in the cell membrane and cytoplasm of morphologically normal intestinal epithelial cells with predominant distribution in the differentiated nonproliferative cell population. In contrast, beta-catenin was localized predominantly in the nucleus of adenomas from Min/+ mice and transgenic mice expressing a mutant truncated form of the APC gene (Apc(delta716) mice). Beta-catenin was expressed predominantly at the cell membrane and cytoplasm of the nontransformed rat intestinal epithelial (RIE-1) cells in culture, whereas predominantly nuclear localization of beta-catenin was observed in the human colon cancer cell line SW480. In the azoxymethane (AOM) treated rats, overexpression and nuclear localization of beta-catenin was observed in all adenomas. Previous studies have indicated the incidence of APC mutations amongst AOM-induced tumors to be 15% or less. These results demonstrate that nuclear localization of beta-catenin is a common event in colorectal tumorigenesis.

Antiangiogenic agents protect liver sinusoidal lining cells from cold preservation injury in rat liver transplantation

BACKGROUND & AIMS

Low temperature preservation causes unique liver injuries to the sinusoidal lining cells characterized by endothelial cell detachment and rounding and Kupffer cell activation. These changes are similar to those observed during the early stages of angiogenesis. The aim of this study was to investigate if cold preservation injury is caused by the activation of angiogenic mechanisms.

METHODS

Livers were obtained from rats pretreated with three well-known antiangiogenic agents (minocycline, interferon alfa-2b, and fumagillin) and were stored for various durations in cold preservation solutions. The effects of the drugs were evaluated by morphometric assessment of endothelial cell injury in H&E, trypan blue, and immunostained (TIE2/Tek) biopsy specimens. Graft functions and survival were evaluated in isolated perfused rat liver and arterialized orthotopic liver transplantation models.

RESULTS

Sinusoidal lining cell integrity and viability were significantly improved in animals pretreated with the drugs. Reperfusion injury and survival were also better in pretreated animals. Interferon alfa was the most potent agent, reducing injury even in livers preserved in the current most commonly used solution (University of Wisconsin solution).

CONCLUSIONS

Cold preservation injury of liver may be the results of angiogenic mechanisms. This novel observation provides a rationale for improved liver preservation using antiangiogenic agents.

Recurrence of nonalcoholic steatohepatitis in a liver transplant recipient

A 42-year-old white man with morbid obesity and hypertriglyceridemia was noted to have nonalcoholic steatohepatitis (NASH) at the time of a laparoscopic cholecystectomy for presumed gallstone pancreatitis. His postoperative course was complicated by a 50-kg weight loss and continued right upper quadrant pain. Repeat liver biopsy revealed NASH with accompanying micronodular cirrhosis. Due to progressive fatigue, he underwent an orthotopic liver transplantation complicated by a 36-kg weight gain. Sixteen months posttransplantation, a liver biopsy revealed the recurrence of NASH. Screening for defects in fatty acid oxidation proved negative.

Plasma transforming growth factor-beta 1 reflects disease status in patients with lung cancer after radiotherapy: a possible tumor marker

PURPOSE

To determine the frequency with which elevated plasma transforming growth factor-beta 1 (TGF beta 1) concentrations occur in lung cancer patients, to determine the kinetics of TGF beta 1 expression during and after radiotherapy and to correlate plasma TGF beta 1 levels with disease status after treatment.

MATERIALS AND METHODS

Plasma samples were obtained before, during and after radiotherapy in 54 patients with lung cancer and 20 normal controls. Plasma TGF beta 1 levels were measured using an enzyme-linked immunosorbent assay.

RESULTS

Baseline TGF beta 1 levels in lung cancer patients and normal controls were 13.0 +/- 2.5 and 4.4 +/- 0.3 ng/ml, respectively. Elevated TGF beta 1 were found in 50% (27/54) of lung cancer patients. During radiation therapy plasma TGF beta 1 levels declined, however, by the completion of treatment the mean TGF beta 1 level had not normalized in patients with lung cancer. The TGF beta 1 level at last follow-up correlated with disease status in those patients with an increased pretreatment plasma level. Three of four patients with no evidence of cancer had normal follow-up TGF beta 1 levels, compared to 2/16 patients with residual or recurrent tumor (P = 0.02).

CONCLUSIONS

Elevated plasma TGF beta 1 levels occur frequently in patients with lung cancer. In those patients with an elevated plasma TGF beta 1 level at diagnosis, monitoring this level may be useful in detecting both disease persistence and recurrence after therapy.

Substance P activation of enteric neurons in response to intraluminal Clostridium difficile toxin A in the rat ileum

BACKGROUND & AIMS

Nerves have been suggested to mediate the effects of bacterial toxins in intestinal diseases. However, the mechanisms involved are unknown. This study examined endogenous substance P (SP) activation of the substance P receptor (SPR) on enteric neurons in the rat ileum after exposure to intraluminal Clostridium difficile toxin A.

METHODS

After intraluminal injection of toxin A in ileal loops, tissue was examined for pathological changes by histology and for SPR activation by immunocytochemical analysis of SP-induced SPR endocytosis.

RESULTS

After toxin A administration, > 70% of enteric neurons showed SPR endocytosis and became swollen with thickened dendrites. In contrast, SPRs in control rats were largely confined to the plasma membrane. Rats denervated of primary afferent fibers with neonatal capsaicin injection and animals pretreated with a nonpeptide SPR antagonist showed few endosomal SPRs, and the pathological inflammatory effects of toxin A were ablated.

CONCLUSIONS

Intraluminal toxin A causes the release of SP from primary afferent neurons: this endogenous SP then acts on enteric neurons in the submucosal and myenteric plexuses. SP is the primary mediator of an axon reflex mediating neurogenic inflammation in the intestine. SPR blockade may prove to be a novel therapy used to prevent intestinal inflammation.

Acute reactant cytokines and neutrophil adhesion after warm ischemia in cirrhotic and noncirrhotic human livers

Animal studies suggest that acute phase reactant cytokines and polymorphonuclear leukocytes (PMN) may play a critical role in ischemia-reperfusion injury. To evaluate whether similar mechanisms are operative in human liver, six cirrhotic and nine noncirrhotic patients undergoing right hepatectomy were randomized for utilization of hepatic vascular exclusion (HVE) as a model of ischemia-reperfusion injury. Portal and systemic levels of acute reactant cytokines (interleukin 6 [IL-6], interleukin 1 [IL-1], tumor necrosis factor alpha [TNF-alpha]) and neutrophil adhesion in serial liver biopsy specimens were studied. Correlations among mediators, leukocyte adhesion, and markers of liver injury were also evaluated. Hepatic vascular exclusion resulted in substantial and reproducible changes in portal and arterial IL-6 levels in both cirrhotic and noncirrhotic patients. Portal and systemic cytokine levels were comparable in most instances, whereas levels were usually higher in cirrhotic patients than in noncirrhotic patients. Negative correlations were found between IL-6 levels at the time of reperfusion and later TNF-alpha levels. IL-6 levels correlated negatively with numerous markers of hepatocellular injury and the number of postoperative complications. Hepatic vascular exclusion increased neutrophils adhesion after reperfusion in cirrhotic patients but not in noncirrhotic patients. In cirrhotic patients, the degree of leukocyte adhesion after reperfusion correlated with several postoperative markers of liver injury. This study in humans shows that acute reactant cytokines are released during liver ischemia and, interestingly, that IL-6 levels strongly correlate with clinical and laboratory measures of injury. Further studies to evaluate possible causal relationship with hepatic injury are warranted, with emphasis on the role of IL-6 and PMN adhesion.

Kupffer cell erythrophagocytosis and graft-versus-host hemolysis in liver transplantation

BACKGROUND & AIMS

Graft-versus-host hemolysis (GVHH) syndrome develops in approximately half of patients undergoing ABO-unmatched liver transplantation. The clinical and laboratory presentations of GVHH syndrome often mimic acute rejection, leading to liver biopsy for definitive diagnosis. The purpose of this study was to investigate if there are specific histological findings that permit diagnosis of GVHH syndrome and to assess the relationship between GVHH syndrome and rejection.

METHODS

Clinical and laboratory evidence of GVHH syndrome, results of liver biopsy, and clinical outcome were assessed in 30 ABO-unmatched liver transplant recipients. Biopsy results were compared with those of two control groups consisting of patients who had normal liver test findings (protocol biopsy) and rejection.

RESULTS

Sixteen of the 30 patients (53%) had evidence of GVHH syndrome. Erythrophagocytosis was noted in each biopsy specimen, and the degree of phagocytosis correlated significantly with the amount of blood given after postoperative day 5 (r = 0.9; P < 0.02). Electron-microscopic studies performed randomly in 5 patients showed that the red cells were located in Kupffer cells. In contrast, erythrophagocytosis was minimal in the two control groups. Despite an incidence and severity of rejection similar to those in other liver transplant patients, serum transaminase levels were significantly higher in patients with GVHH syndrome.

CONCLUSIONS

Erythrophagocytosis is a sensitive histological marker of GVHH syndrome. The severity of rejection and response to antirejection therapy should be monitored by markers other than transaminases in patients with GVHH syndrome.