Acute cholecystitis: early versus delayed cholecystectomy, a multicenter randomized trial (ACDC study, NCT00447304).

OBJECTIVE: Acute cholecystitis is a common disease, and laparoscopic surgery is the standard of care. BACKGROUND: Optimal timing of surgery for acute cholecystitis remains controversial: either early surgery shortly after hospital admission or delayed elective surgery after a conservative treatment with antibiotics. METHODS: The ACDC ("Acute Cholecystitis-early laparoscopic surgery versus antibiotic therapy and Delayed elective Cholecystectomy") study is a randomized, prospective, open-label, parallel group trial. Patients were randomly assigned to receive immediate surgery within 24 hours of hospital admission (group ILC) or initial antibiotic treatment, followed by delayed laparoscopic cholecystectomy at days 7 to 45 (group DLC). For infection, all patients were treated with moxifloxacin for at least 48 hours. Primary endpoint was occurrence of predefined relevant morbidity within 75 days. Secondary endpoints were as follows: (1) 75-day morbidity using a scoring system; (2) conversion rate; (3) change of antibiotic therapy; (4) mortality; (5) costs; and (6) length of hospital stay. RESULTS: Morbidity rate was significantly lower in group ILC (304 patients) than in group DLC (314 patients): 11.8% versus 34.4%. Conversion rate to open surgery and mortality did not differ significantly between groups. Mean length of hospital stay (5.4 days vs 10.0 days; P < 0.001) and total hospital costs (€2919 vs €4262; P < 0.001) were significantly lower in group ILC. CONCLUSIONS: In this large, randomized trial, laparoscopic cholecystectomy within 24 hours of hospital admission was shown to be superior to the conservative approach concerning morbidity and costs. Therefore, we believe that immediate laparoscopic cholecystectomy should become therapy of choice for acute cholecystitis in operable patients. (NCT00447304).

Improved responses to pegylated interferon alfa-2b and ribavirin by individualizing treatment for 24-72 weeks.

BACKGROUND & AIMS: Guidelines recommend that patients with chronic hepatitis C virus (HCV) infection be treated with pegylated interferon and ribavirin for 24, 48, or 72 weeks, based on their virologic response to treatment. We investigated the effects of treating patients for individualized durations. METHODS: We treated 398 treatment-naïve patients who had HCV genotype 1 infections with pegylated interferon alfa-2b and ribavirin for 24, 30, 36, 42, 48, 60, or 72 weeks (mean of 39 weeks, termed individualized therapy); the duration of therapy was determined based on baseline viral load and the time point at which HCV RNA levels became undetectable (measured at weeks 4, 6, 8, 12, 24, and 30). Results were compared with those of 225 patients who received standard treatment for 48 weeks (mean of 38 weeks). RESULTS: Rates of sustained virologic response (SVR) were 55% among patients who received individualized treatment and 48% among those who received standard treatment (P < .0001 for noninferiority). SVR rates, according to the time point at which HCV RNA levels became undetectable, did not differ significantly between groups. Patients with a rapid virologic response (undetectable levels of HCV RNA at week 4) who were treated for 24 to 30 weeks achieved high rates of SVR (86%-88%). Rates of SVR increased among slow responders who first tested negative for HCV RNA at week 24 and were treated for 60 to 72 weeks compared with those treated for 48 weeks (60%-68% vs 43%-44%). The CC polymorphism at IL28B rs129797860 was associated with an increased rate of SVR compared with the CT/TT polymorphism (P < .0001) at baseline but not among patients who had undetectable levels of HCV RNA following treatment. CONCLUSIONS: Individualizing treatment of patients with chronic HCV genotype 1 infections for 24 to 72 weeks results in high rates of SVR among rapid responders and increases SVR among slow responders.

Prognostic value of standard parameters as predictors for long-term renal replacement therapy after liver transplantation.

Chronic kidney disease has become increasingly prevalent after liver transplantation (LTPL) because outcome and survival rates have improved. Chronic kidney insufficiency is most likely associated with increased morbidity and mortality. The challenge is to identify patients who will be in need of long-term renal replacement therapy (RRT) after LTPL. We analyzed 208 liver transplant recipients with respect to mortality, associated laboratory values, underlying liver disease, immunosuppressive protocol and the need for RRT. Long-term RRT was defined by the need for RRT 3 months after LTPL. Altogether, 5.8% of the surviving study patients remained in need of RRT 3 months after LTPL. All of these patients continued to need RRT throughout the study period (2 years). The need for RRT significantly increased the 2-year mortality rate 4.3-fold, from 15.4 to 66.7% (p = 0.004). Comparison of laboratory and clinical parameters at the time of LTPL revealed no significant differences for creatinine, albumin and MDRD between patients undergoing hemodialysis 3 months after LTPL and patients without RRT. Comparing mean urea, a difference was observed. However, multivariate regression analyses using easy-to-observe demographic or laboratory parameters failed to generate a model to predict the need for RRT after LTPL. In addition, a comparison of underlying liver disease and immunosuppressive regimes identified no significant differences. Taken together, patients who were on hemodialysis 3 months after LTPL were also on hemodialysis 2 years after LTPL or until death. RRT 3 months after LTPL may predict the risk for chronic renal insufficiency and is associated with significantly increased mortality.

Tissue penetration of moxifloxacin into human gallbladder wall in patients with biliary tract infections.

OBJECTIVES: Moxifloxacin, the newest fourth-generation fluoroquinolone, has a broad spectrum of antibacterial activity covering both Gram-positive and Gram-negative aerobic and anaerobic bacteria and is therefore very well suited for the treatment of biliary tract infections. The present study aimed to determine the penetration of moxifloxacin into gallbladder tissue to evaluate its antibiotic potential in this indication. PATIENTS AND METHODS: Hospitalized patients with acute cholecystitis received a single, 1 h infusion of 400 mg of moxifloxacin before cholecystectomy. Serum and gallbladder wall tissue samples were collected during surgery, and the moxifloxacin concentrations were measured by HPLC. RESULTS: Sixteen patients (eight men and eight women) were included between January 2007 and April 2008. The time between start of infusion and gallbladder removal ranged from 50 min to 21 h 10 min. The serum concentration at the time of cholecystectomy was between 0.39 and 4.37 mg/L, and the tissue concentration between 1.73 and 17.08 mg/kg. The tissue-to-serum concentration ratio ranged from 1.72 to 6.33. CONCLUSIONS: The results show that moxifloxacin penetrates well into gallbladder tissue and is therefore a therapeutic option for biliary tract infection. The highest concentrations in serum and gallbladder tissue were measured shortly after the end of a 1 h infusion. As perioperative prophylaxis, moxifloxacin should therefore be administered 30-60 min before the first surgical incision.

A single-center experience of 500 liver transplants using the modified piggyback technique by Belghiti.

Over the past 4 decades, the surgical techniques of liver transplantation (LTx) have permanently evolved and been modified. Among these, the modified piggyback (MPB) technique by Belghiti offers specific advantages. The objective of this study was to present our single-center experience with the MPB technique in 500 cases. Recipients' perioperative data were prospectively collected and evaluated. Postoperative and specific complications, stay in the intensive and intermediate care unit, and the mortality rate with cause of death were analyzed. Most recipients were classified as Child C (49.1%). For the patients who underwent LTx for the first time, alcoholic (23.9%) and viral (22.2%) cirrhosis and hepatocellular carcinoma (15.1%) were the prevalent indications. The overall median warm ischemia time, anastomosis duration, and operative time were 45, 108, and 320 minutes, respectively. The median intraoperative blood loss was 1500 mL. A venovenous bypass was never needed to maintain hemodynamic stability. Only in a few cases was temporary inferior vena cava clamping necessary. Most prominent surgical complications were hemorrhage, hematoma, and wound dehiscence. Renal failure occurred in 6.2% of patients. The overall median stay in the intensive and intermediate care unit was 14 days. The mortality rates within 30 and 90 days were 6.3% and 13.3%, respectively. No technique-related death occurred. The MPB technique by Belghiti is a feasible and simple LTx technique. The caval flow is preserved during the anhepatic phase, and this minimizes the need for venovenous bypass or portocaval shunt. This technique requires only 1 caval anastomosis, which is easy to perform with a short anhepatic phase. To minimize the risk of outflow obstruction, attention should be paid by doing a wide cavocavostomy cranially to the donor inferior vena cava in a door-lock manner. This technique can be applied in almost all patients undergoing LTx for the first time and liver retransplantation as well.

Liver transplantation in HIV-positive patients.

Death from end-stage liver disease (ESLD) because of chronic hepatitis B and C has become an increasing problem in human immunodeficiency virus (HIV)-infected patients in the last years. This is mainly because of the dramatic decrease of HIV-related morbidity and mortality since the introduction of highly active antiretroviral therapy (HAART). Although the data on the outcome of liver transplantation in HIV-infected recipients with ESLD is limited, overall results seem comparable to non-HIV-infected recipients. Therefore, liver transplant centres around the world are increasingly accepting HIV-infected individuals as organ recipients. Post-transplantation control of HIV replication is achieved by continuing HAART. As in non-HIV-infected patients, hepatitis B virus recurrence is efficiently prevented by hepatitis B immunoglobulin and antiviral therapy. Re-infection of the allograft with hepatitis C virus, however, remains an important problem, and progress to allograft cirrhosis may even be more rapid than in HIV-negative patients. Interactions in drug metabolism between the HAART components and the immunosuppressive drugs are difficult to predict and require close monitoring of drug levels and dose adjustments. The complexity in this setting makes close cooperation between transplant surgeons, hepatologists, HIV-clinicians and pharmacologists mandatory. As experience on liver transplantation in HIV-infected individuals is still limited, to date results from large prospective trials addressing key issues are needed.

Sensitivity and specificity of plasma disappearance rate of indocyanine green as a prognostic indicator in acute liver failure.

BACKGROUND: In patients presenting with acute liver failure (ALF) prediction of prognosis is vital to determine the need of transplantation. Based on the evidence that plasma disappearance rate of indocyanine green (ICG-PDR) correlates with liver cell function, we evaluated the ability of ICG-PDR measured by pulse dye densitometry to predict outcome in patients with acute liver failure. METHODS: Prospectively markers of hepatocellular injury, synthesis and excretion, including ICG-PDR were measured daily until liver transplantation, death, discharge from intensive care unit, or up to 7 days in 25 patients with acute liver failure. Receiver operating curve (ROC) analysis was performed to assess the value of ICG-PDR to predict outcome in ALF. RESULTS: The 25 patients analyzed included 18 that recovered spontaneously and 7 that underwent liver transplantation (n = 6) or died (n = 1). Causes of ALF included viral hepatitis (n = 4), toxic liver injury (n = 15), ischemic liver injury (n = 2), and cryptogenic liver failure (n = 4). King's college criteria were fulfilled in 85.7% of patients not recovering spontaneously and in 16.7% of patients recovering spontaneously. The mean ICG-PDR measured on day 1 in patients recovering spontaneously was 12.0 +/- 7.8%/min and in patients not recovering spontaneously 4.3 +/- 2.0%/min (P = 0.002). By ROC analysis the sensitivity and specificity of an ICG-PDR value

Pro-active provision of drug information as a technique to address overdosing in intensive-care patients with renal insufficiency.

PURPOSE: To correct overdosing of drugs requiring adjustment based on renal function in intensive-care patients. METHODS: In a prospective intervention study, we estimated individual glomerular filtration rate and assessed whether medication required dose adjustment based on renal function. Senior clinicians received a structured report containing recommendations as to whether and how to adjust dosage in the individual patient (intervention). Prevalence of overdosed drugs (primary outcome), extent of overdoses, and reasons for nonacceptance of recommendations (secondary outcomes) were assessed. RESULTS: Of 138 screened intensive-care patients, 68 (49%) had renal impairment, and 110 (14%) of the 805 prescribed drugs required consideration of renal function. A potential overdose was found in 53/110 drugs (48%) and this rate decreased to 26/110 (24%, P < 0.001) after the intervention. The average extent of overdose was reduced from 54% before to 31% after the intervention (P < 0.001). The main reasons expressed by the physicians for nonacceptance of recommendations were a large therapeutic index or minor overdoses of the involved drugs. CONCLUSIONS: In intensive-care patients, overdosing of drugs requiring adjustment based on renal function is still very common. Drug information counselling significantly decreased the prevalence and extent of overdose.

Pharmacologic cholinesterase inhibition improves survival in experimental sepsis.

OBJECTIVE: Lethal sepsis occurs when an excessive inflammatory response evolves that cannot be controlled by physiologic anti-inflammatory mechanisms, such as the recently described cholinergic anti-inflammatory pathway. Here we studied whether the cholinergic anti-inflammatory pathway can be activated by pharmacologic cholinesterase inhibition in vivo. DESIGN: Prospective, randomized laboratory investigation that used an established murine sepsis model. SETTING: Research laboratory in a university hospital. SUBJECTS: Female C57BL/6 mice. INTERVENTIONS: Sepsis in mice was induced by cecal ligation and puncture. Animals were treated immediately with intraperitoneal injections of nicotine (400 microg/kg), physostigmine (80 microg/kg), neostigmine (80 microg/kg), or solvent three times daily for 3 days. MEASUREMENTS AND MAIN RESULTS: Treatment with physostigmine significantly reduced lethality (p < or = .01) as efficiently as direct stimulation of the cholinergic anti-inflammatory pathway with nicotine (p < or = .05). Administration of cholinesterase inhibitors significantly down-regulated the binding activity of nuclear factor-kappaB (p < or = .05) and significantly reduced the concentration of circulating proinflammatory cytokines tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6 (p < or = .001), and pulmonary neutrophil invasion (p < or = .05). Animals treated with the peripheral cholinesterase inhibitor neostigmine showed no difference compared with physostigmine-treated animals. CONCLUSIONS: Our results demonstrate that cholinesterase inhibitors can be used successfully in the treatment of sepsis in a murine model and may be of interest for clinical use.

Early treatment of imported falciparum malaria in the intermediate and intensive care unit setting: an 8-year single-center retrospective study.

INTRODUCTION: Imported falciparum malaria is characterized by a broad spectrum of potentially life-threatening complications that may arise even after initiation of appropriate antimalarial drug therapy. Hence, at Heidelberg University Hospital, all patients with newly diagnosed falciparum malaria are initially treated in the intermediate care unit (IMC) or intensive care unit (ICU). The present study was undertaken to evaluate critically the benefit of this strategy, which includes daily consultation with senior specialists in tropical medicine. METHODS: We conducted a retrospective cohort study at the 14-bed combined IMC/ICU of a 1,685-bed university hospital. A cohort of 122 patients with imported falciparum malaria admitted from 1 January 1996 to 31 December 2003 was included. RESULTS: Thirty-four patients (27.9%) developed complications, defined according to the current World Health Organization classification. Most patients (80.3%) studied did not take the recommended chemoprophylaxis against malaria. The majority of patients (89.3% [n = 109]) could be adequately treated in the IMC. Life-threatening complications requiring ICU support occurred in 13 patients (10.7%). All complications were successfully managed. Fifty-five patients (45.1%) fulfilling recently published criteria for outpatient treatment had an excellent therapeutic response and did not require ICU support. CONCLUSION: This retrospective evaluation demonstrated favourable therapeutic results in hospitalized patients with imported falciparum malaria. Both initial treatment in the medical IMC/ICU and close collaboration between intensivists and specialists in tropical medicine may improve disease outcome among affected patients. Prospective studies are needed to confirm these preliminary findings.

Admission to intensive care for parasuicide by self-poisoning: variation by time cycles, climate and the lunar cycle.

The aim of this study was to characterize patients after self-poisoning with suicidal intent regarding age, sex and type of substances ingested, as well as to identify temporal variations of attempted suicides and associations with climate variables and the lunar cycle. During the years 2002-2004, a total of 691 patients were admitted for self-poisoning parasuicides. The male to female ratio was 1:1.65 with mean ages of 39 and 37 years, respectively. Benzodiazepines and antidepressants were the most frequently taken substances. A significant variation with the time of the day with a peak before midnight was observed for both sexes. Variation with the day of the week was less clear and showed a peak incidence for parasuicides on Mondays. There was no significant variation with the monthly or annual cycle. The frequency of parasuicides was associated with "bad weather" (precipitation). No association of parasuicide incidences to the lunar cycle was observed.

Perspectives for gene therapy of Wilson disease.

Wilson disease is a rare autosomal-recessive copper overload disorder due to mutations of the Wilson disease gene ATP7B. The disease typically manifests at late childhood or in young adults with hepatic and/or neurological symptoms. Being fatal without medical treatment or liver transplantation the long-term outcome of Wilson disease depends on the adherence to an effective treatment. Because current medical treatment options are not effective in all Wilson disease patients and adherence to therapy is a problem, gene therapy might represent an alternative curative future therapy. In the rat model of Wilson disease adenoviral and lentiviral gene transfer studies could prove that viral gene transfer is therapeutically effective and can reverse clinical symptoms. However, both approaches were limited by a more or less transient transgene expression. As several tactics can be used to overcome these current limitations, gene therapy approaches may become more efficient than standard medical treatment for Wilson disease in the future. This review discusses both, existing vectors and strategies and prospective developments towards liver-directed gene therapy, although there is still a long way to go until gene therapy can be used for safe treatment of Wilson disease in humans.

Pharmacodynamics and organ storage of hydroxyethyl starch in acute hemodilution in pigs: influence of molecular weight and degree of substitution.

OBJECTIVE: To determine the differential influence of molecular weight and the degree of substitution of HES solutions on pharmacodynamics and pharmacokinetics including organ storage in a model of acute hemodilution in pigs. DESIGN: Prospective controlled randomized animal trial. INTERVENTIONS: After bleeding, 20 ml/kg, animals were substituted with 6% HES preparations (200/0.62, 200/0.5, and 100/0.5). MEASUREMENTS AND RESULTS: We did not observe any significant differences in the ability to sufficiently achieve plasma volume expansion and restoration of macrocirculation, nor maintenance of indicators of microcirculation between the groups. Urine production was significantly higher in HES-treated animals and highest in animals substituted with HES 100/0.5. Plasma clearance was measured under steady-state conditions with significantly reduced clearance for the HES 200/0.62 group compared with HES 100/0.5 and HES 200/0.5 (6.6 vs. 13.2 and 13.9 ml/min; P < or = 0.001), thus being dependent on the degree of substitution. Even after only 6 h, the amount of infused HES not detectable in either blood or urine was significantly higher in HES 200/0.62-treated animals (50.7% compared with HES 200/0.5 (28.8%), P = 0.020 and HES 100/0.5 (28.4%), P = 0.018), with its proportion rising over time. Finally, we could demonstrate considerable amounts of all HES solutions being stored in liver, kidney, lung, spleen and lymph nodes. CONCLUSIONS: All preparations analyzed sufficiently restored macro- and microcirculation; however, for all solutions relevant tissue storage of HES was observed after only 6 h.

Adenoviral B7-H3 therapy induces tumor specific immune responses and reduces secondary metastasis in a murine model of colon cancer.

Current cancer gene therapies aim at the induction of systemic antitumor immune responses. Tumors may deliver antigens to T-cells, but may lack the costimulatory signals necessary for mounting an effective response. The purpose of this study was to evaluate the efficacy of an adenoviral delivery of the B7-H3 costimulatory molecule in mice to induce antitumor immune responses. Colon cancers were established by orthotopic injection of syngeneic colon cancer cells into the cecum on Balb/c mice. After two weeks, these mice were treated by intratumoral injection of an adenovirus expressing mouse B7-H3 (Ad-B7-H3-GFP) or a control virus (Ad-GFP). Ad-B7-H3-GFP treatment resulted in a reduction of tumor size compared to the controls. In addition, the occurrence of secondary metastasis was significantly reduced in B7-H3 treated mice compared to control animals (lymph node 7/10 vs. 10/10; liver 2/10 vs. 8/10, p

Treatment of hepatitis C virus infection.

Acute and chronic hepatitis C virus (HCV) infection remains a serious health problem worldwide, however, there has been advancement in the treatment of HCV infection due to standard treatment using pegylated interferon and ribavirin. The literature indicates that therapy for HCV is becoming more individualized. In addition to considering genotype and viral RNA levels before treatment, achievement of an early virologic response (EVR) and a rapid virologic response (RVR) is now possible during therapy. Moreover, problem patients, such as non-responders, relapsers, HIV or HBV co-infected patients, patients with liver cirrhosis, and pre- or post-liver transplantation patients are an increasing fraction of the patients requiring treatment. This article reviews the literature regarding standard treatments and problem patients with acute and chronic HCV infection. It also includes discussion on contraindications and side effects of treatment with interferon and ribavirin, as well as new drug development.

Are heat stroke and physical exhaustion underestimated causes of acute hepatic failure?

While cardiopulmonary symptoms are common in patients undergoing classical or, due to physical exercise, exertional heat stroke, the failure of other organs is a rarely described phenomenon. Here we present two cases of acute hepatic failure, one due to classic heat shock, while the other occurred while the patient was doing a marathon-type running. Both cases presented with very high transaminases and significantly elevated international normalized ratio (INR). No other causes for liver failure could be identified but physical exhaustion and hyperthermia.

Diagnostic criteria for acute liver failure due to Wilson disease.

AIM: To describe the diagnostic criteria for acute liver failure due to Wilson disease (WD), which is an uncommon cause of acute liver failure (ALF). METHODS: We compared findings of patients presenting with ALF due to WD to those with ALF of other etiologies. RESULTS: Previously described criteria, such as low alkaline phosphatase activity, ratio of low alkaline phosphatase to total bilirubin or ratio of high aspartate aminotransferase (AST) to alanine aminotransferase (ALT), failed to identify patients with ALF due to WD. There were significant differences in low ALT and AST activities (53 +/- 43 vs 1982 +/- 938, P < 0.0001 and 87 +/- 44 vs 2756 +/- 2941, P = 0.037, respectively), low choline esterase activity (1.79 +/- 1.2 vs 4.30 +/- 1.2, P = 0.009), high urine copper concentrations (93.4 +/- 144.0 vs 3.5 +/- 1.8, P = 0.001) and low hemoglobin (7.0 +/- 2.2 vs 12.6 +/- 1.8, P < 0.0001) in patients with ALF caused by WD as compared with other etiologies. Interestingly, 4 of 7 patients with ALF due to WD survived without liver transplantation. CONCLUSION: In ALF, these criteria can help establish a diagnosis of WD. Where applicable, slit-lamp examination for presence of Kayser-Fleischer rings and liver biopsy for determination of hepatic copper concentration still remain important for the diagnosis of ALF due to WD. The need for liver transplantation should be evaluated carefully as the prognosis is not necessarily fatal.

Induction of antigen-specific immune responses in vivo after vaccination with dendritic cells transduced with adenoviral vectors encoding hepatitis C virus NS3.

Dendritic cells (DC) are potent antigen-presenting cells that play a critical role in the initiation of immunity to viral infections. Direct transduction of DC appears to be the major pathway in vivo responsible for induction of antigen specific immune responses. The aim of this study was to explore the vaccine potential of DC transduced with adenoviral vectors encoding the HCV nonstructural protein 3 (AdNS3) compared to DC pulsed with recombinant NS3 (rNS3). Mice (Balb/c and C57BL/6 transgenic for HLA-A2.1) were immunized with DC based vaccines. After the immunization, antigen specific immune responses including humoral responses, cytokine secretion, and IFN-gamma-producing T cell responses were analyzed. In both strains of mice inoculated with DC transduced with an adenovirus, the generated NS3 specific antibody response and IFN-gamma-secreting T cell response were stronger than that generated by rNS3-pulsed DC. Analysis of the cytokine profiles revealed that immunization with AdNS3 transduced DC shifted the antigen specific immunity towards Th1 responses. DC transduced with AdNS3 are superior to DC pulsed with rNS3 in inducing vigorous humoral and Th1-type cellular responses against NS3. The results demonstrate for the first time the immunogenic potential of genetically modified DC by a prime and boost approach in eliciting a strong NS3-specific, cell-mediated, humoral immune response in both Balb/c mice and HLA-A2.1 transgenic mice.

Recurrence of clinically significant hepatitis A following liver transplantation for fulminant hepatitis A.

BACKGROUND: We report hepatitis A virus (HAV) infection of a liver allograft following transplantation for fulminant liver failure due to HAV infection. This rare condition has been described in only three patients to date. After liver transplantation allograft function was good, but starting 80 days after transplantation, episodes of acute graft dysfunction were observed. OBJECTIVES: To elucidate the reason for acute hepatic dysfunction a large number of differential diagnoses were tested. RESULTS: HAV RNA was undetectable for more than 80 days after transplantation. Detection of genomic HAV RNA by RT-PCR in serum and stool at the time of graft dysfunction led to the diagnosis of recurrent HAV infection. CONCLUSIONS: We suggest that the risk of HAV reinfection after liver transplantation may be far higher than expected as results may be misinterpreted as rejection episodes.

An orthotopic colon cancer model for studying the B7-H3 antitumor effect in vivo.

We established an orthotopic animal model of colon cancer in mice and applied this model to study the antitumor effects of B7-H3, the newest member of the B7 family of costimulatory molecules. Colon-26 murine colon adenocarcinoma cells were inoculated into the cecal subserosum of mice to induce colon tumor growth. The tumor growth rate and the survival time of the mice were observed. A stable B7-H3 transfected Colon-26 cell line was established and the immunogenic effect was investigated. All mice implanted with wild-type tumor cells had tumor growth in the colon and died. The mean survival rate was 23 days. Mice implanted with C26-B7-H3 had a significantly prolonged survival time of 38 days. Our data suggest that B7-H3 exerts an antitumor effect on adenocarcinoma of the colon and may be considered as an adjuvant immunotherapy in the treatment of colon cancers. Our orthotopic animal model of colon cancer in mice could be applied to in vivo experimental studies of colon cancer.