Ryo Nakata

Involvement of the biliary system in autoimmune pancreatitis: a follow-up study

BACKGROUND & AIMS The aim of this study was to define the bile duct changes associated with autoimmune pancreatitis. METHODS Eight patients with autoimmune pancreatitis were followed for a mean of 4 years. The clinical features of these patients, including extrapancreatic bile duct changes, were examined by using biochemical parameters and several imaging modalities. Pathologic features of the pancreas and liver were examined by using the biopsy specimens of 7 patients. RESULTS Diffuse or focal narrowing of the main pancreatic duct was observed in all patients. Histologic examination of the pancreas showed lymphoplasmacyte infiltration with severe fibrosis and acinar cell depletion. In 6 patients extrapancreatic bile duct changes such as stricture of the bile duct at hilus or intrahepatic area were observed. In 2 patients abnormalities in the bile duct and pancreas were detected simultaneously at diagnosis, and changes in the bile duct were observed later in 4 patients. Lymphoplasmacyte infiltration and fibrosis were observed in the portal area of all 7 liver biopsy samples. Five of the patients with bile duct changes received steroid therapy, and the pathological changes improved. CONCLUSIONS Extrapancreatic bile duct changes are frequently associated with autoimmune pancreatitis. Similar pathogenic mechanism might produce the biliary tract and pancreatic abnormalities in autoimmune pancreatitis resulting in a similar histopathology in the liver and pancreas and response to steroid therapy.

Risk factors for pancreatitis in patients with common bile duct stones managed by endoscopic papillary balloon dilation.

OBJECTIVES:Endoscopic papillary balloon dilation has been accepted as a possible alternative to endoscopic sphincterotomy, especially in patients with impaired hemostasis. However, pancreatitis associated with endoscopic papillary balloon dilation has remained a controversial, serious issue. The aim of the study was to investigate the risk factors for postendoscopic papillary balloon dilation pancreatitis in a single-center study.METHODS:A total of 304 patients who underwent endoscopic papillary balloon dilation for the management of common bile duct stones were enrolled. The risk of postendoscopic papillary balloon dilation pancreatitis was evaluated and the risk factors were analyzed by univariate and multivariate analysis. Definition and grade of the severity of postendoscopic papillary balloon dilation pancreatitis were based on the 1991 consensus guidelines.RESULTS:Common bile duct was cleared in 292 of 304 patients (96%). Procedure-related pancreatitis occurred in 15 patients (5.0%). The grade was mild in 8 and moderate in 7. Two risk factors, stone diameter and contrast medium injection to the pancreas, were identified by univariate analysis. Finally, only the contrast medium injection to the pancreas was statistically significant by multivariate analysis. Prior history of pancreatitis was identified as a risk factor for postendoscopic papillary balloon dilation pancreatitis in previous studies, but this factor was not identified as a risk factor in our series.CONCLUSIONS:Although the pathogenesis of pancreatitis after endoscopic papillary balloon dilation remains unresolved, the unnecessary injection of contrast medium to the pancreas can certainly be considered to be associated with the increased risk of pancreatitis.

Churg-Strauss syndrome (allergic granulomatous antiitis) with multiple perforating ulcers of the small intestine, multiple ulcers of the colon, and mononeuritis multiplex

A case of Churg-Strauss syndrome with multiple perforations of the small intestine is described. A 31-year-old woman was admitted with a complaint of epigastric pain. She had a history of bronchial asthma. One week before admission, white blood cell count was 20 800/mm3 with 59% eosinophils. Neurological examination on admission disclosed mononeuritis multiplex with paresthesia in both the lower and upper extremities. At colonoscopy, there were scattered aphthous ulcers in the colon. Ophthalmological examination revealed allergic conjunctivitis. After admission, hypereosinophilia increased to as high as 36 000/mm3. Oral administration of prednisolone (60 mg/day) was begun. On the 3rd day of the treatment, the eosinophil count decreased dramatically, to 400/mm3, while severe abdominal pain developed. Since abdominal X-ray film revealed free air in the abdominal cavity, emergency laparotomy was performed and multiple intestinal ulcers with perforations were found. Partial ileectomy was performed. Pathological findings of the resected specimen were interpreted as a necrotizing angiitis with extravascular granuloma. Since the operation, the patient has been asymptomatic, except for neurological symptoms. Hypereosinophilia has decreased without treatment to counts averaging 270/mm3, within 3 months. On the basis of the clinical features and histopathological findings, a diagnosis of Churg-Strauss syndrome was established.

Multiple-needle insertion method in percutaneous ethanol injection therapy for liver neoplasms

SummaryOne of the shortcomings of percutaneous ethanol injection therapy (PEIT) is that many sessions are necessary to accomplish the treatment. In order to reduce the number of treatment sessions, we inserted two or three needles before injection of ethanol was begun. Using the multiple-needle insertion method, we markedly reduced the number of treatment sessions. Histopathologic examination, imaging techniques, and serum alpha-fetoprotein levels showed efficacy of PEIT using the multiple-needle insertion method. No serious complication occurred. Levels of transient pain, fever, and the feeling of intoxication did not seem to be different from those occurring with the conventional method. Multiple-needle insertion method may be valuable as a method for reducing the number of treatment sessions necessary and thus shortening the treatment period.

Different turnover rate of hepatitis C virus clearance by different treatment regimen using interferon-beta.

BACKGROUND/AIM Since patients with high viral load and HCV subtype 1b are known to respond poorly to interferon (IFN) therapy, the viral dynamics of HCV RNA after initiation of interferon therapy were examined in the present study with respect to two different administration regimens, once vs. twice a day. METHODS Twenty-two patients with chronic hepatitis C confirmed by liver biopsy and with >1 Meq/ml of HCV RNA and HCV subtype 1b were randomly assigned to two different IFN administration regimens (6 million units of IFN once a day or 3 million units of IFN twice a day), and the serum HCV RNA level was serially measured. RESULTS Graphs of HCV RNA levels vs. treatment time showed an initial rapid fall, followed by a slower clearance phase. Fitting the data to a model for HCV decay proposed by Neumann et al. showed that the treatment efficacy was significantly higher with twice daily administration. Negativity for HCV RNA measured by Amplicor assay in the twice-a-day administration group was 18%, 73% and >89% at 1, 2 and 3 weeks, respectively, in contrast to 0%, 0%, and 18%, respectively, with once-a-day administration. However, a significant reduction of platelet count and albumin level, a marked increase in serum aspartate aminotransferase/alanine aminotransferase, and a high incidence of renal toxicity (proteinuria) were found in patients receiving IFN twice a day in comparison with those receiving it once a day. CONCLUSION The twice-a-day administration of IFN accelerated the clearance of HCV RNA from serum, leading to a more efficient virological response for patients with chronic hepatitis C, but with a high rate of renal toxicity.

Chemotactic factors released from hepatocytes exposed to acetaminophen

To clarify the mechanism of neutrophil infiltration in the liver of acetaminophen-induced hepatic injury, chemotactic factor released from hepatocytes exposed to acetaminophen has been investigated. Hepatocytes exposed to acetaminophen release nondialyzable chemotactic factor, although actaminophen in itself inhibits chemotaxis of neutrophils. Chemotactic activity of the nondialyzable chemotactic factor was reduced after treatment with heat (56°C, 30 min) or trypsin. Chemotactic activity was demonstrated at the molecular weights of around 25 and 55 kDa. Chemotactic activity of the conditioned medium was not significantly reduced in the presence of antibody against rat KC/gro protein (interleukin-8-related cytokine in rodent). Chemotactic activity of a 25-kDa factor was reduced by the antibody against KC/gro protein, but that of a 55-kDa factor was not reduced. Immunoblot analysis revealed that the peptide reacted with antibody against rat KC/gro protein was demonstrated at a molecular weight of around 20–25 kDa, but not at around 55kDa, when the conditioned medium of acetaminophen-treated hepatocytes was electrophoresed. These results suggest that hepatocytes exposed to acetaminophen release two types of chemotactic factors for neutrophils and that a major part of the chemotactic factor could be different from a member of interleukin-8 family.

Growth regulation of rabbit gastric epithelial cells and protooncogene expression

We recently developed a primary culture system for gastric epithelial cells from adult rabbits that allows the investigation of growth regulation at the cellular level. In this study, we demonstrated that epidermal growth factor (EGF), insulin, and dibutyryl adenosine 3′,5′-cyclic monophosphate (dBcAMP) all stimulated cell proliferation. Insulin and dB-cAMP potentiated the stimulation of cell proliferation by EGF, while transforming growth factor-β1 (TGF-β1) inhibited it. Expression of c-fos and c-myc was induced in response to the stimulation by these growth regulators, but the degree of expression did not necessarily correlate with the effects of these agents on cell proliferation. In conclusion, EGF, insulin, and dBcAMP were positive growth regulators, while TGF-β1 was a negative regulator in gastric epithelial cells. These growth modulators may exert their effects by distinct pathways from a standpoint of the expression of c-fos and c-myc.

Generation of Induced Pluripotent Stem Cells From Patients With Duchenne Muscular Dystrophy and Their Induction to Cardiomyocytes.

Duchenne muscular dystrophy (DMD) is caused by mutations in the DMD gene which encodes dystrophin protein. Dystrophin defect affects cardiac muscle as well as skeletal muscle. Cardiac dysfunction is observed in all patients with DMD over 18 years of age, but there is no curative treatment for DMD cardiomyopathy. To establish novel experimental platforms which reproduce the cardiac phenotype of DMD patients, here we established iPS cell lines from T lymphocytes donated from two DMD patients, with a protocol using Sendai virus vectors. We successfully conducted the differentiation of the DMD patient-specific iPS cells into beating cardiomyocytes. DMD patient-specific iPS cells and iPS cell-derived cardiomyocytes would be a useful in vitro experimental system with which to investigate DMD cardiomyopathy.

Effect of splenectomy on hepatic metastasis of colon carcinoma and natural killer activity in the liver

We have previously demonstrated that administration of killed streptococcal preparation (OK432), a biological response modifier, increased the number of asialo GM1-positive cells in the liver, enhanced NK activity of hepatic mononuclear cells, and reduced the number of hepatic metastases of colon 38 adenocarcinoma that were inoculated into the superior mesenteric vein of C57BL/6 strain mice. In the present study, to clarify the role of the spleen in immune surveillance of the liver, the effect of splenectomy on hepatic metastasis of colon carcinoma and on hepatic NK activity has been examined. The number of hepatic metastasis increased in the splenectomized mice, compared with that in sham-operated mice. Administration of OK432 increased the number of asialo GM1-positive cells in the liver and enhanced NK activity of hepatic mononuclear cells in both groups, but NK activity of hepatic mononuclear cells in the splenectomized mice was less than that of the sham-operated mice. An enhanced NK activity of these cells was abolished by treatment with anti-asialo-GM1 antibody plus complementin vitro. Interleukin-2 mRNA expression was increased in the spleen 2 hr after OK432 administration and persisted until 8 hr, but was scarcely noted in the liver. On the other hand, NK activity of hepatic mononuclear cells in the asialo GM1-positive cell-depleted (previous administration of antiserum against asialo GM1) mice was enhanced after OK432 administration in the sham operated and splenectomized mice, but an enhanced NK activity in these mice was only partially or not at all abolished by treatment with anti-asialo GM1 antibody plus complementin vitro, respectively. These results suggest that the spleen could play an important role in an immune surveillance of the liver. In addition, OK432 first enhanced NK activity of hepatic mononuclear cells, which are sensitive to the antibody against asialo GM1. However, when asialo GM1-positive cells were depleted, OK432 enhanced NK activity of hepatic mononuclear cells, which are resistant to anti-asialo GM1 serum.

Sustained viral response is rarely achieved in patients with high viral load of HCV RNA by excessive interferon therapy

Adequate dosing of interferon (IFN) and its cost-effectiveness for sustained virological response were evaluated in relation to viral load and subtype. Prospective analysis of IFN therapy on 326 patients with chronic hepatitis C free from cirrhosis was performed using 9 or 6 million unit (MU) of IFN for six months daily and/or three times a week. Sustained virological response was achieved in 50–94% of patients with ≤2 × 104 copies/ml (competitive RT-PCR) or <100 × 103 copies/ml (Amplicor monitor) of HCV RNA by 468–1206 MU of IFN, but response was only 0–25% of the patients with ≥2 × 105.5 copies/ml (competitive RT-PCR) or >200 × 103 copies/ml (Amplicor monitor), even with 468–1206 MU of IFN. A high sustained rate was demonstrated in patients with 100–200 × 103 copies/ml of HCV RNA by 901–1206 MU of IFN, in comparison to that with ≤900 MU of IFN. Multivariate analysis showed that IFN dose had a significant value for the efficacy of IFN therapy in patients presenting 100–200 × 103 copies/ml of HCV RNA. Cost efficacy analysis indicated that it cost approximately