Is there a difference in gastric emptying between myotonic dystrophy type 1 patients with and without gastrointestinal symptoms?

Gastrointestinal symptoms are frequent complaints in patients with myotonic dystrophy type 1 (MyD1) and may be associated with reduced gastrointestinal motility caused by smooth muscle dysfunction. Although previous studies have found delayed gastric emptying (GE) in MyD1 patients, the relationship between GE and symptoms has been unclear. We investigated GE in 23 MyD1 patients and 20 healthy volunteers using the 13C-acetate breath test. The MyD1 patients were divided into two groups: those with gastrointestinal symptoms (n = 9) and those without gastrointestinal symptoms (n = 14). The GE function was estimated using the 13C-acetate breath test as half-emptying time (HET) and peak time of the 13C-%-dose-excess curve (T max). GE (HET and T max) was more significantly delayed in patients with MyD1 than in the controls. The GE in MyD1 patients with gastrointestinal symptoms was significantly delayed compared to those without gastrointestinal symptoms. The GE in MyD1 patients with gastrointestinal symptoms was more significantly delayed than in the controls. The GE was significantly delayed in MyD1 patients with gastrointestinal symptoms for >5 years as compared to those with the disease for <5 years, while GE of MyD1 patients without gastrointestinal symptoms did not correlate with the duration of the disease. The GE in MyD1 patients did not correlate with the muscular disability rating scale. These findings suggest that impairment of GE evolves over time and that the progression of delayed GE and skeletal muscle impairment are independent. Smooth muscle impairment may be affected at an earlier stage in MyD1.

Is there delayed gastric emptying in patients with multiple system atrophy? An analysis using the (13)C-acetate breath test.

Autonomic failure is one of the criteria according to the second consensus statement for the diagnosis of multiple system atrophy (MSA). Gastrointestinal symptoms are frequent complaints in patients with MSA and may be associated with reduced gastrointestinal motility due to autonomic nervous system dysfunction. However, there are few reports on gastric emptying in patients with MSA. We investigated gastric emptying in 25 patients with MSA, 20 patients with sporadic adult-onset ataxia of unknown etiology (SAOA), and 20 healthy volunteers using the (13)C-acetate breath test. Gastric emptying function is estimated by this test as the half-emptying time (HET) and peak time of the (13)C-%-dose-excess curve (T (max)), with expirations collected for 4 h after a test meal and determination of (13)CO(2) content using an infrared (IR) spectrophotometer. The HET and T (max) of gastric emptying were significantly delayed in patients with MSA as compared to those in SAOA and controls (p < 0.01). The HET and T (max) were not significantly different between SAOA and controls. No correlation existed between the HET or T (max) and the duration or severity of the disease in MSA patients. These results suggested that gastric emptying was significantly delayed in patients with MSA, and the delay already appeared in the early stage of the disease. Delayed gastric emptying is one of the autonomic failures and may be a clinical marker of MSA.

The cyan fluorescent protein nude mouse as a host for multicolor-coded imaging models of primary and metastatic tumor microenvironments.

The tumor microenvironment (TME) has an important influence on tumor progression. For example, we have discovered that passenger stromal cells are necessary for metastasis. In this report, we describe six different cyan fluorescent protein (CFP) multicolor TME nude mouse models. The six different implantation models were used to image the TME using multiple colors of fluorescent proteins: I) Red fluorescent protein (RFP)- or green fluorescent protein (GFP)-expressing HCT-116 human colon cancer cells were implanted subcutaneously in the CFP-expressing nude mice. CFP stromal elements from the subcutaneous TME were visualized interacting with the RFP- or GFP-expressing tumors. II) RFP-expressing HCT-116 cells were transplanted into the spleen of CFP nude mice, and experimental metastases were then formed in the liver. CFP stromal elements from the liver TME were visualized interacting with the RFP-expressing tumor. III) RFP-expressing HCT-116 cancer cells were transplanted in the tail vein of CFP-expressing nude mice, forming experimental metastases in the lung. CFP stromal elements from the lung were visualized interacting with the RFP-expressing tumor. IV) In order to visualize two different tumors in the TME, GFP-expressing and RFP-expressing HCT-116 cancer cells were co-implanted subcutaneously in CFP-expressing nude mice. A 3-color TME was formed subcutaneously in the CFP mouse, and CFP stromal elements were visualized interacting with the RFP- and GFP-expressing tumors. V) In order to have two different colors of stromal elements, GFP-expressing HCT-116 cells were initially injected subcutaneously in RFP-expressing nude mice. After 14 days, the tumor, which consisted of GFP cancer cells and RFP stromal cells derived from the RFP nude mouse, was harvested and transplanted into the CFP nude mouse. CFP stromal cells invaded the growing transplanted tumor containing GFP cancer cells and RFP stroma. VI) Mouse mammary tumor (MMT) cells expressing GFP in the nucleus and RFP in the cytoplasm were implanted in the spleen of a CFP nude mouse. Cancer cells were imaged in the liver 3 days after cell injection. The dual-color dividing MMT cells and CFP hepatocytes, as well as CFP non-parenchymal cells of the liver were imaged interacting with the 2-color cancer cells. CFP-expressing host cancer-associated fibroblasts (CAFs) were predominantly observed in the TME models developed in the CFP nude mouse. Thus, the CFP nude mouse adds another color to the pallet of the TME, allowing multiple types of color-coded cancer and stromal cells to be imaged simultaneously. The multi-colored models described in this report provide new opportunities to study the cellular interactions in the live primary and metastatic TME.

Increased levels of serum leptin are a risk factor for the recurrence of stage I/II hepatocellular carcinoma after curative treatment.

Obesity and related adipocytokine disbalance increase the risk of hepatocellular carcinoma. To determine the impact of increased levels of leptin, an obesity-related adipocytokine, on the recurrence of hepatocellular carcinoma, we conducted a prospective case-series analysis. Eighty-five consecutive primary hepatocellular carcinoma patients at our hospital from January 2006 to December 2008 were analyzed. Serum leptin level significantly correlated with Body Mass Index, total body fat, and the amount of subcutaneous fat. They included 33 with stage I/II, who underwent curative treatment. The factors contributing to recurrence of hepatocellular carcinoma, including leptin, were subjected to univariate and multivariate analyses using the Cox proportional hazards model. Body Mass Index (p = 0.0062), total body fat (p = 0.0404), albumin (p = 0.0210), α-fetoprotein (p = 0.0365), and leptin (p = 0.0003) were significantly associated with the recurrence of hepatocellular carcinoma in univariate analysis. Multivariate analysis suggested that leptin (hazard ratio 1.25, 95% CI 1.07-1.49, p = 0.0035) was a sole independent predictor. Kaplan-Meier analysis showed that recurrence-free survival was lower in patients with greater serum leptin concentrations (>5 ng/mL, p = 0.0221). These results suggest that the serum leptin level is a useful biomarker for predicting the early recurrence of hepatocellular carcinoma.

L-tryptophan-mediated enhancement of susceptibility to nonalcoholic fatty liver disease is dependent on the mammalian target of rapamycin.

Nonalcoholic fatty liver disease is one of the most common liver diseases. L-tryptophan and its metabolite serotonin are involved in hepatic lipid metabolism and inflammation. However, it is unclear whether L-tryptophan promotes hepatic steatosis. To explore this issue, we examined the role of L-tryptophan in mouse hepatic steatosis by using a high fat and high fructose diet (HFHFD) model. L-tryptophan treatment in combination with an HFHFD exacerbated hepatic steatosis, expression of HNE-modified proteins, hydroxyproline content, and serum alanine aminotransaminase levels, whereas L-tryptophan alone did not result in these effects. We also found that L-tryptophan treatment increases serum serotonin levels. The introduction of adenoviral aromatic amino acid decarboxylase, which stimulates the serotonin synthesis from L-tryptophan, aggravated hepatic steatosis induced by the HFHFD. The fatty acid-induced accumulation of lipid was further increased by serotonin treatment in cultured hepatocytes. These results suggest that L-tryptophan increases the sensitivity to hepatic steatosis through serotonin production. Furthermore, L-tryptophan treatment, adenoviral AADC introduction, and serotonin treatment induced phosphorylation of the mammalian target of rapamycin (mTOR), and a potent mTOR inhibitor rapamycin attenuated hepatocyte lipid accumulation induced by fatty acid with serotonin. These results suggest the importance of mTOR activation for the exacerbation of hepatic steatosis. In conclusion, L-tryptophan exacerbates hepatic steatosis induced by HFHFD through serotonin-mediated activation of mTOR.

Imaging the recruitment of cancer-associated fibroblasts by liver-metastatic colon cancer.

The tumor microenvironment (TME) is critical for tumor growth and progression. However, the formation of the TME is largely unknown. This report demonstrates a color-coded imaging model in which the development of the TME can be visualized. In order to image the TME, a green fluorescent protein (GFP)-expressing mouse was used as the host which expresses GFP in all organs but not the parenchymal cells of the liver. Non-colored HCT-116 human colon cancer cells were injected in the spleen of GFP nude mice which led to the formation of experimental liver metastasis. TME formation resulting from the liver metastasis was observed using the Olympus OV100 small animal fluorescence imaging system. HCT-116 cells formed tumor colonies in the liver 28 days after cell transplantation to the spleen. GFP-expressing host cells were recruited by the metastatic tumors as visualized by fluorescence imaging. A desmin positive area increased around and within the liver metastasis over time, suggesting cancer-associated fibroblasts (CAFs) were recruited by the liver metastasis which have a role in tumor progression. The color-coded model of the TME enables its formation to be visualized at the cellular level in vivo, in real-time. This imaging model of the TME should lead to new visual targets in the TME.

Role of interleukin-18 in intrahepatic inflammatory cell recruitment in acute liver injury.

Although the innate immune system has been demonstrated to play important roles as the first line of defense against various infections, little is known about the interactions between intrahepatic inflammatory cells and the cytokine network in the liver. Here, we examined the role of IL-18 in IHL recruitment in acute liver injury. C57BL/6 mice were injected with an αCD40 mAb, and their serum IL-18 levels were observed to increase, with subsequent recruitment of IHLs into the liver. NKT cells were involved in this liver injury, as the serum ALT levels were reduced in NKT KO mice through the suppression of macrophage and monocyte migration and cytokine production. In contrast, depletion of neutrophils exacerbated the liver injury associated with high levels of TNF-α and IL-18 and increased numbers of macrophages and monocytes. Treatment with a neutralizing antibody against IL-18 reduced the serum ALT levels and inflammatory cell accumulation in the liver. Finally, additional administration of rIL-18 with αCD40 injection caused severe liver injury with increased IFN-γ production by NK cells. In conclusion, these findings demonstrate that IL-18 modulates liver inflammation by the recruitment of inflammatory cells, including NKT cells, macrophages, monocytes, and neutrophils.

Acid sphingomyelinase regulates glucose and lipid metabolism in hepatocytes through AKT activation and AMP-activated protein kinase suppression.

Acid sphingomyelinase (ASM) regulates the homeostasis of sphingolipids, including ceramides and sphingosine-1-phosphate (S1P). Because sphingolipids regulate AKT activation, we investigated the role of ASM in hepatic glucose and lipid metabolism. Initially, we overexpressed ASM in the livers of wild-type and diabetic db/db mice by adenovirus vector (Ad5ASM). In these mice, glucose tolerance was improved, and glycogen and lipid accumulation in the liver were increased. Using primary cultured hepatocytes, we confirmed that ASM increased glucose uptake, glycogen deposition, and lipid accumulation through activation of AKT and glycogen synthase kinase-3ß. In addition, ASM induced up-regulation of glucose transporter 2 accompanied by suppression of AMP-activated protein kinase (AMPK) phosphorylation. Loss of sphingosine kinase-1 (SphK1) diminished ASM-mediated AKT phosphorylation, but exogenous S1P induced AKT activation in hepatocytes. In contrast, SphK1 deficiency did not affect AMPK activation. These results suggest that the SphK/S1P pathway is required for ASM-mediated AKT activation but not for AMPK inactivation. Finally, we found that treatment with high-dose glucose increased glycogen deposition and lipid accumulation in wild-type hepatocytes but not in ASM(-/-) cells. This result is consistent with glucose intolerance in ASM(-/-) mice. In conclusion, ASM modulates AKT activation and AMPK inactivation, thus regulating glucose and lipid metabolism in the liver.

Is there a delayed gastric emptying of patients with early-stage, untreated Parkinson's disease? An analysis using the 13C-acetate breath test.

During the pre-symptomatic stage of Parkinson's disease (PD), the idiopathic PD related abnormal synuclein immunostaining is confined to the medulla oblongata and olfactory bulb, according to Braak. In the study of the enteric nervous system of PD, it has reported that Lewy bodies were found in the Auerbach's and Meissner's plexuses. These lesions may cause dysfunction of the gastrointestinal tract (GI) as pre-clinical symptoms of PD. However, because L: -dopa therapy itself may worsen the symptoms of the digestive tract function, it is needed to evaluate the gastrointestinal tract function in patients with early-stage, untreated (de novo) PD. In the present study, using the (13)C-acetate breath test ((13)C-ABT), we investigated gastric emptying in 20 untreated, early-stage PD patients and 40 treated, advanced-stage PD patients, and 20 healthy volunteers. Gastric emptying was examined by the (13)C-ABT [the half emptying time (HET), the peak time of the (13)C% dose-excess curve (T (max))]. The T (max) and HET of gastric emptying as assessed using the (13)C-ABT was significantly delayed in untreated, early-stage PD patients as compared to the controls (P < 0.001). The T (max) and HET of gastric emptying were not significantly delayed in untreated, early-stage PD patients as compared to treated, advanced-stage PD patients. The results demonstrated that delay in gastric emptying did not differ between untreated, early-stage and treated, advanced-stage PD patients. Gastric emptying of untreated, early-stage PD is already delayed. Delayed gastric emptying may be one of markers of the pre-clinical stage of PD.

Simultaneous color-coded imaging to distinguish cancer "stem-like" and non-stem cells in the same tumor.

In this study, we demonstrate that the differential behavior, including malignancy and chemosensitivity, of cancer stem-like and non-stem cells can be simultaneously distinguished in the same tumor in real time by color-coded imaging. CD133(+) Huh-7 human hepatocellular carcinoma (HCC) cells were considered as cancer stem-like cells (CSCs), and CD133(-) Huh-7 cells were considered as non-stem cancer cells (NSCCs). CD133(+) cells were isolated by magnetic bead sorting after Huh-7 cells were genetically labeled with green fluorescent protein (GFP) or red fluorescent protein (RFP). In this scheme, CD133(+) cells were labeled with GFP and CD133(-) cells were labeled with RFP. CSCs had higher proliferative potential compared to NSCCs in vitro. The same number of GFP CSCs and the RFP NSCCs were mixed and injected subcutaneously or in the spleen of nude mice. CSCs were highly tumorigenic and metastatic as well as highly resistant to chemotherapy in vivo compared to NSCCs. The ability to specifically distinguish stem-like cancer cells in vivo in real time provides a visual target for prevention of metastasis and drug resistance.

Insulin resistance raises the risk for recurrence of stage I hepatocellular carcinoma after curative radiofrequency ablation in hepatitis C virus-positive patients: A prospective, case series study.

AIM: Several studies have reported that insulin resistance raises the risk of primary hepatocellular carcinoma (HCC). We conducted a prospective, case series study to test the impact of insulin resistance on the recurrence after curative radiofrequency ablation (RFA) of stage I HCC in HCV-positive patients. METHODS: From January 2006 to December 2007, 226 consecutive patients underwent treatment for primary HCC at our institutions, including 37 stage I cases. Among them, 33 were HCV-positive, and three, six and 24 received curative surgery, transarterial chemoembolization or RFA, respectively. In the 24 patients treated with RFA, recurrence-free survival was analyzed using the Kaplan-Meier method. The factors contributing to recurrence of HCC were subjected to univariate and multivariate analyses using the Cox proportional hazards model. Insulin resistance was estimated by the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR). RESULTS: Kaplan-Meier analysis showed that the recurrence-free survival was lower in patients with higher HOMA-IR (>2.3, P = 0.0252) or with lower serum albumin level (<3.3 g/dL, P = 0.0004). In the univariate analysis, HOMA-IR (P = 0.0420) and albumin (P = 0.0036) were significantly associated with recurrence of HCC. Multivariate analysis revealed albumin (odds ratio = 0.01, 95% confidence interval = 0.0002-0.015, P = 0.0001) and HOMA-IR (odds ratio = 3.85, 95% confidence interval = 1.57-14.2, P = 0.0015) to be independent predictors for recurrence of HCC. CONCLUSION: Serum albumin level and HOMA-IR were independent risk factors for recurrence of stage I HCC after curative RFA in HCV-positive patients. Patients with these factors require closer surveillance.

Roles of CD44 in chemical-induced liver injury.

CD44 has been identified as one of the adhesion molecules that regulate cell migration in inflamed tissue. The principal ligand of CD44 is hyaluronan, and CD44 is involved in the metabolism of this compound. Furthermore, an increasing quantity of evidence suggests that CD44 has various functions related to inflammatory disease. This review focuses on the potential roles of CD44 in the pathogenesis of chemical-induced liver injury and discusses some of the functions of this protein in pathological processes. The discovery that CD44 deficiency induces severe liver injury, (associated with an increase in hepatocyte apoptosis) rather than suppressing liver inflammation is summarized. These data suggest that targeted therapies against adhesion molecules should be monitored carefully to ensure that liver disease is not exacerbated by treatment.

Elevated serum tumor necrosis factor-alpha and soluble tumor necrosis factor receptors correlate with aberrant energy metabolism in liver cirrhosis.

OBJECTIVE: Protein-energy malnutrition is frequently observed in patients with liver cirrhosis and is associated with their poor prognosis. Tumor necrosis factor-alpha (TNF-alpha) is elevated in those patients and may contribute to the alterations of energy metabolism. Our aim was to characterize the aberrant energy metabolism in cirrhotic patients with regard to TNF-alpha. METHODS: Twenty-four patients (mean age 65 +/- 6 y) with viral liver cirrhosis who did not have hepatocellular carcinoma or acute infections were studied. Twelve healthy volunteers were recruited after matching for age, gender, and body mass index with the patients and served as controls (59 +/- 8 y). Serum levels of TNF-alpha, soluble 55-kDa TNF receptor (sTNF-R55), soluble 75-kDa TNF receptor (sTNF-R75), and leptin were determined by immunoassay. Substrate oxidation rates of carbohydrate and fat were estimated by indirect calorimetry after overnight bedrest and fasting. RESULTS: In cirrhotic patients, serum levels of TNF-alpha, sTNF-R55, and sTNF-R75 were significantly higher than those in the controls and correlated with the increasing grade of disease severity as defined by Child-Pugh classification. Serum leptin concentration was not different between cirrhotics and controls but correlated with their body mass index. The decrease in substrate oxidation rate of carbohydrate and the increase in substrate oxidation rate of fat significantly correlated with serum TNF-alpha, sTNF-R55, and sTNF-R75 concentrations. CONCLUSION: Tumor necrosis factor-alpha might be associated with the aberrant energy metabolism in patients with liver cirrhosis.

Role of acid sphingomyelinase of Kupffer cells in cholestatic liver injury in mice.

UNLABELLED: Kupffer cells, resident tissue macrophages of the liver, play a key role in the regulation of hepatic inflammation, hepatocyte death, and fibrosis that characterize liver diseases. However, it is controversial whether Kupffer cells promote or protect from liver injury. To explore this issue we examined the role of Kupffer cells in liver injury, cell death, regeneration, and fibrosis on cholestatic liver injury in C57BL/6 mice using a model of partial bile duct ligation (BDL), in which animals do not die and the effects of BDL can be compared between injured ligated lobes and nonligated lobes. In cholestatic liver injury, the remaining viable cells represented tolerance for tumor necrosis factor alpha (TNF-alpha)-induced hepatocyte apoptosis and regenerative features along with AKT activation. Inhibition of AKT by adenovirus expressing dominant-negative AKT abolished the survival and regenerative properties in hepatocytes. Moreover, Kupffer cell depletion by alendronate liposomes increased hepatocyte damage and the sensitivity of TNF-alpha-induced hepatocyte apoptosis in ligated lobes. Kupffer cell depletion decreased hepatocyte regeneration and liver fibrosis with reduced AKT activation. To investigate the impact of acid sphingomyelinase (ASMase) in Kupffer cells, we generated chimeric mice that contained ASMase-deficient Kupffer cells and -sufficient hepatocytes using a combination of Kupffer cell depletion, irradiation, and the transplantation of ASMase-deficient bone marrow cells. In these mice, AKT activation, the tolerance for TNF-alpha-induced apoptosis, and the regenerative responses were attenuated in hepatocytes after BDL. CONCLUSION: Kupffer cells have a protective role for hepatocyte damage and promote cell survival, liver regeneration, and fibrosis in cholestatic liver disease. Kupffer cell-derived ASMase is crucial for AKT activation of hepatocytes that is required for the survival and regenerative responses.

Indirect calorimetry and anthropometry to estimate energy metabolism in patients with liver cirrhosis.

Energy malnutrition worsens survival in patients with liver cirrhosis, and is currently defined as non-protein respiratory quotient (npRQ) <0.85, as measured by indirect calorimetry. However, measurement of this npRQ is limited because of the high cost of indirect calorimetry. Therefore, we sought an alternative marker that can be used in the routine clinical setting. Forty-four inpatients with cirrhosis were recruited in this study. The last meal was served at 18:00 h on the previous day, and indirect calorimetry was performed between 07:00 and 09:00 h while the patients were still in bed. Fasting blood samples were collected in the early morning on the day of the test. Anthropometry was performed by an expert dietician. The correlations among npRQ, Child-Pugh score of disease severity, laboratory parameters, %AC (arm circumference), %TSF (triceps skinfold thickness), and %AMC (arm muscle circumference) were studied using simple linear regression analysis. ROC (Receiver operating characteristic) analysis was used to identify the cut-off values that would best predict npRQ=0.85. npRQ correlated significantly with %AC (r(2)=0.204, p=0.0021) and %AMC (r(2)=0.178, p=0.0043) but not with %TSF. npRQ was not significantly correlated with other laboratory or anthropometric measurements. The cut-off value for %AC that showed the largest AUC (area under the curve) by ROC analysis was 95, while that for %AMC was 92. Multiple regression analysis yielded an equation; npRQ=0.0019×(%AC)20.0134×(Child-Pugh score)+0.7791. Patient stratification by %AC=95 or by regression equation-based npRQ=0.85, but not by %AMC=92, produced significant difference in survival curves. %AC and regression equation could represent npRQ to some extent as parameters of energy nutrition in cirrhosis.

Clinical trial: rebamipide promotes gastric ulcer healing by proton pump inhibitor after endoscopic submucosal dissection--a randomized controlled study.

BACKGROUND: Endoscopic submucosal dissection (ESD) is useful for treating gastric tumors. Several trials have shown the efficacy of 4 or 8 weeks of proton pump inhibitor (PPI) administration for post-ESD ulcers. However, if the size of the post-ESD ulcer is larger than predicted, PPI administration alone might not be sufficient for the ulcer to heal within 4 weeks. We examined the efficacy of a combination therapy of PPI and rebamipide, a mucosal-protective antiulcer drug, on the acceleration of post-ESD ulcer healing. METHODS: Patients were randomly assigned to either the PPI and rebamipide therapy or the PPI alone. Sixty-two consecutive patients with gastric tumors gave informed consent for enrolling in the study. In all cases, the estimated size of the post-ESD ulcer was larger than 20 mm. Oral administration of the drug was started on the 2nd day post-ESD and continued to the 28th day. RESULTS: All patients received the assigned pharmaceuticals and adhered well to the treatment regimen for 28 days. The endpoint ulcers reached S1 (scar stage) in 11/31 (36%) patients in the PPI-only group and in 21/31 (68%) in the combination group (P = 0.010). CONCLUSIONS: The combination of PPI plus rebamipide was more effective than the PPI alone for treating ulcers larger than 20 mm within 4 weeks after ESD.

Is there a difference in gastric emptying between Parkinson's disease patients under long-term L-dopa therapy with and without motor fluctuations? An analysis using the 13C-acetate breath test.

The mechanism underlying the motor fluctuations that develop after long-term L-dopa therapy is not fully known. It has been speculated that malabsorption of L-dopa from the small intestine occurs. It was reported that gastric retention in Parkinson's disease (PD) patients with motor fluctuations is increased as compared with that in PD without fluctuations. Because L-dopa therapy may worsen the symptoms of delayed gastric emptying (GE), it was not clear whether the delayed GE of PD patients with motor fluctuation was affected by L-dopa therapy. We assessed GE in PD patients with and without motor fluctuations. We investigated GE in 40 patients with PD under long-term L-dopa therapy, 20 fluctuators with "delayed-on" and "noon" phenomena, 20 nonfluctuators, and 20 healthy volunteers. GE was examined by the 13C-acetate breath test ((13)CABT) [the half emptying time (HET), the peak time of the (13)C-%-dose-excess curve (T(max))], with expirations collected for 4 h after a test meal and analyzed for (13)CO(2) using an infrared (IR) spectrophotometer. The T(max) of GE as assessed using the (13)C-ABT was significantly delayed in all PD patients as compared with controls (P = 0.002). The HET was significantly delayed in all PD patients as compared with controls (P < 0.001). The T(max) and HET were not significantly delayed in PD patients with motor fluctuations as compared with PD patients without motor fluctuations. These results demonstrated that GE is commonly delayed in PD patients with long-term L-dopa therapy. Delayed GE does not differ between PD patients with and without motor fluctuations. This finding demonstrated that the motor fluctuation in PD may not be influenced by GE.

Extracellular matrix is required for the survival and differentiation of transplanted hepatic progenitor cells.

Engelbreth-Holm-Swarm (EHS) gel has been reported to maintain the mature hepatocyte phenotypes in primary cultured hepatocytes. We investigated the effect of EHS gel on the differentiation of fetal liver cells, which contain stem/progenitor cells. The isolated fetal liver cells cultured on EHS gel formed a spherical shape and increased liver-specific gene expressions compared with cells cultured on collagen. The hepatic progenitor cells that were transplanted subcutaneously to BALB/c nude mice could survive and express hepatocyte marker alpha-fetoprotein when the cells were suspended with EHS gel. These findings demonstrate that EHS gel supports cytodifferentiation from immature progenitor cells to hepatocytes and maintain its differentiated phenotypes in vitro and in vivo.

Role of CD44 in CTL-induced acute liver injury in hepatitis B virus transgenic mice.

BACKGROUND: There are many uncertain points regarding leukocyte movement in the liver, especially interaction between liver sinus endothelial cells (LSECs) and cytotoxic T lymphocytes (CTLs). We examined the role of CD44 in these interactions using the hepatitis model. METHODS: CTLs were administered to hepatitis B virus transgenic mice (HBVTg) mice and HBVTg x CD44 knockout (KO) mice, and alanine aminotransferase activity (ALT), number of intrahepatic leukocytes, cytokines, and chemokine mRNA level were examined. To determine the number and distribution of CTLs in the liver, 5,6-carboxyfluoroscein succinimidyl ester (CFSE)-labeled CTLs was administered to HBVTg mice with or without CD44. RESULTS: Serum ALT activity increased after 12 h, although it had declined to 4 h in the CD44KO x HBVTg mice after CTL injection. Similarly, the levels of tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, and macrophage inflammatory protein (MIP)-2 mRNAs were reduced in 4 h, although the levels were increased after 12 h in the CD44KO x HBVTg mice. The number of apoptotic hepatocytes increased intentionally at 24 h in the CD44KO x HBVTg livers, and this was thought to result from the lower activity of initial nuclear factor kappa B (NF-kappaB). Although the number of CTLs was lower at 4 h in the CD44KO x HBVTg livers, the difference of intercellular adhesion molecule (ICAM)-1 and CD86 expression on LSECs was not detected. CONCLUSIONS: CD44 exerts and important effect on LSECs for CTL migration into the hepatocytes. However, because the CD44-deficient state exacerbated hepatic injury, attention is necessary for hepatitis treatment as CD44 target therapy.

Pathological role of CD44 on NKT cells in carbon tetrachloride-mediated liver injury.

AIM: CD44 has a variety of functions in immune regulation and signal transduction. Although CD44 is involved in the induction of several inflammatory diseases, it remains unknown whether CD44-targeting therapies are useful for liver diseases. Here, we examined whether CD44 blockade is effective in a chemical-induced liver injury model. METHODS: We injected CD44 knock out (KO) or wild type mice with carbon tetrachloride (CCl(4)) and examined the difference of liver injury by immunological or histological analysis. RESULTS: Although CD44KO mice exhibited suppressed liver injury at 6 h after CCl(4) injection with decreased inflammatory cell numbers and cytokine production, these mice showed severe liver injury at 24 h. We found that NKT cells played an important role in liver injury with increased infiltration of theliver after migration, which was independent of the CD44 pathway. In CD44NKT double-KO mice, liver injury was suppressed with reduced cytokine production and macrophage infiltration compared with CD44KO mice. Furthermore, MIP-2 derived from NKT cells or tumor necrosis factor alpha from macrophages contributed to exacerbation of the liver injury, since neutralization of MIP-2 provided significant protection against liver injury in CD44KO mice. Finally, we found that CD44KO mice exhibited excessive liver fibrosis compared with wild-type mice after repeated CCl(4) injections. CONCLUSION: We found that CD44 has unique characteristics for inflammatory liver diseases associated with NKT cell infiltration and activation. Furthermore, CD44-targeting therapies may need to be viewed with caution for liver diseases due to the actions of the liver immune system.