Hiroya Nakata

Contrast-Enhanced Ultrasonography in the Diagnosis of Solid Renal Tumors

The purpose of this study was to evaluate the usefulness of contrast‐enhanced ultrasonography (CEUS) in the diagnosis of solid renal tumors.

Gastric cancer screening of a high-risk population in Japan using serum pepsinogen and barium digital radiography

With the aim of developing more efficient gastric cancer screening programs for use in Japan, we studied a new screening program that combines serum pepsinogen (PG) testing and barium digital radiography (DR). A total of 17 647 middle‐aged male subjects underwent workplace screening over a 7‐year period using a combination of PG testing and DR. This programs effectiveness, as well as other characteristics of the program, was analyzed. Forty‐nine cases of gastric cancer were detected (comprising 88% early cancer cases). The detection rate was 0.28%, and the positive predictive value was 0.85%. The PG test detected 63.3% of cases, DR detected 69.4% of cases, and both tests were positive in 32.7% of cancer cases. The two methods were almost equally effective, and were considerably more effective than conventional screening using photofluorography. Each screening method detected a distinct gastric cancer subgroup; the PG test efficiently detected asymptomatic small early cancer with intestinal type histology, while DR was efficient at detecting cancers with depressed or ulcerated morphology and diffuse type histology. The cost for the detection of a single cancer was much less than that for conventional screening. In fact, it is possible to further reduce the cost of detecting a single cancer to a cost comparable to that of surgically resecting a single gastric cancer. Thus, it is probable that a highly efficient gastric cancer screening system can be implemented by combining the two screening methods. Such a screening program would be beneficial in a population at high risk for gastric cancer. (Cancer Sci 2005; 96: 713 – 720)

Efficacy of Lansoprazole and Amoxicillin in Eradicating Helicobacter pylori: Evaluation Using 13C-UBT and Monoclonal H. pylori Antibody Testing

Combination therapy with lansoprazole (LPZ) and amoxicillin (AMPC) was administered to eradicate Helicobacter pylori. Changes in eradication rates were monitored and serum antibody titers, levels of pepsinogens I and II (PI and PII), and gastrin were measured. The 40 subjects were divided into two groups: one group received LPZ 30 mg alone, and the other received LPZ 30 mg and AMPC 1,500 mg concomitantly. AMPC was administered for 2 weeks before completion of LPZ treatment. Maintenance therapy was ci-metidine 400 mg. The presence of H. pylori was evaluated using the urea breath test (UBT). The clearance rate was 12.5% and the eradication rate was 0% in the LPZ group, and the corresponding rates in the LPZ with AMPC group were 41.6 and 25.0%, respectively. Serum monoclonal H. pylori antibody titers decreased in patients in whom bacterial eradication had been achieved. Serum PI was significantly reduced in those patients in whom eradication had been achieved. Serum PII and gastrin levels also tended to decrease in patients in whom eradication had been achieved, but no such changes were observed in the other patients. Further research into drug treatment and evaluation methods for bacterial eradication is required.

Immunological rapid urease test using monoclonal antibody for Helicobacter pylori.

Background and Aim:  The current diagnostic methods for detecting Helicobacter pylori infection include rapid urease test (RUT), urea breath test (UBT), histology, culture, and serum antibody detection. The present study evaluated the efficacy of a novel highly specific test, an immunological RUT (IRUT), that uses a monoclonal antibody against H. pylori urease.

Serum antibody againstHelicobacter pylori assayed by a new capture ELISA

We developed a highly specific detection technique for serum antibody, using a monoclonal antibody to a specific antigen ofHelicobacter pylori. A monoclonal antibody preparation that reacted with the 54-kDa molecule ofH. pylori antigens was obtained. Using this preparation, an antigen-capture enzymelinked immunosorbent assay (ELISA) was established by fixation of the monoclonal antibody, followed by reaction with sonicated whole cell antigens. The serum antibody titers of patients with gastritis and peptic ulcers were significantly higher than control titers, and the antibody titer correlated with the histological severity of gastritis. Patients positive forH. pylori by bacterial culture had higher titers thanH. pylori-negative patients. Our new ELISA may be useful for the diagnosis ofH. pylori infections and for evaluation of the severity of gastric inflammation.

Contrast Harmonic Sonographically Guided Radio Frequency Ablation for Spontaneous Ruptured Hepatocellular Carcinoma

Received January 19, 2005, from the Second Department of Internal Medicine, Wakayama Medical University, Wakayama, Japan (H.T., M.O., H.M., N.S., T.K., S.E., T.S., M.I., K.N., K.A., K.Y., Y.S., H.N., M.I.); and Department of Gastroenterology, University of Tokyo, Tokyo, Japan (M.F., N.Y., S.S.). Revision requested February 7, 2005. Revised manuscript accepted for publication March 1, 2005. Address correspondence to Hideyuki Tamai, MD, Second Department of Internal Medicine, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Wakayama 640-0012, Japan. Abbreviations CT, computed tomography; HCC, hepatocellular carcinoma; PEIT, percutaneous ethanol injection therapy; RFA, radio frequency ablation; S, segment; TAE, transcatheter arterial embolization ntraperitoneal bleeding due to a ruptured tumor is a serious complication in patients with hepatocellular carcinoma (HCC). According to data compiled by the Liver Cancer Study Group of Japan,1 ruptured HCC accounts for around 10% of deaths in these patients. Clinical features include the sudden onset of abdominal pain and distension and, if bleeding is massive, the presence of shock. Other causes of an acute abdominal emergency must be ruled out. Diagnostic imaging generally includes sonography, contrast computed tomography (CT), and angiography. In patients with ruptured HCC, prompt diagnosis and treatment is essential to avoid hepatocyte necrosis and secondary hepatic failure associated with shock and decreased hepatic perfusion due to bleeding. The underlying liver disease varies in such patients with ruptured HCC. Chronic hepatitis, cirrhosis, or both may be present, and the severity of hepatic dysfunction as well as the size, number, and progression of the neoplastic lesions present varies from case to case. A common feature is the presence of a responsible lesion on or protruding from the surface of the liver. If hemostasis can be achieved early after HCC rupture, then overall prognosis depends on the patient’s liver function and degree of tumor progression. Although there is a risk of intraperitoneal seeding, long-term survival is possible if the tumor can be completely resected by hepatectomy. One study has already reported a good 5-year survival rate after resection of ruptured and nonruptured HCC.2 In another study, rather than performing emergency surgery, Marini et al3 used transcatheter arterial embolization (TAE) to control bleeding; in those patients who could then undergo surgery, elective hepatectomy was associated with long-term survival. Treatment of ruptured HCC involves more than just hemostasis. Subsequent therapy is important, and, whenever possible, complete resection should be performed after bleeding has been controlled.

Heterogeneity of Protein Profiles of Helicobacter pylori Isolated from Individual Patients

In order to characterize the diversity of Helicobacter pylori (H. pylori) in infected individuals, 10 colonies of H. pylori were isolated from the gastric juice of 25 patients with gastroduodenal diseases (total 250 isolates).

Transnasal and standard transoral endoscopies in the screening of gastric mucosal neoplasias

AIM To compare the diagnostic performances of transnasal and standard transoral esophagogastroduodenoscopy (EGD) in gastric cancer screening of asymptomatic healthy subjects. METHODS Between January 2006 and March 2010, a total of 3324 subjects underwent examination of the upper gastrointestinal tract by EGD for cancer screening, with 1382 subjects (41.6%) screened by transnasal EGD and the remaining 1942 subjects (58.4%) by standard transoral EGD. Clinical profiles of the screened subjects, detection rates of gastric neoplasia and histopathology of the detected neoplasias were compared between groups according to the stage of Helicobacter pylori(H. pylori)-related chronic gastritis. RESULTS Clinical profiles of subjects did not differ significantly between the two EGD groups, except that there were significantly more men in the transnasal EGD group. During the study period, 55 cases of gastric mucosal neoplasias were detected. Of these, 23 cases were detected by transnasal EGD and 32 cases by standard transoral EGD. The detection rate for gastric mucosal neoplasia in the transnasal EGD group was thus 1.66%, compared to 1.65% in the standard transoral EGD group, with no significant difference between the two groups. Detection rates using the two endoscopies were likewise comparable, regardless of H. pylori infection. However, detection rates when screening subjects without extensive chronic atrophic gastritis (CAG) were significantly higher with standard transoral EGD (0.70%) than with transnasal EGD (0.12%, P < 0.05). In particular, standard transoral EGD was far better for detecting neoplasia in subjects with H. pylori-related non-atrophic gastritis, with a detection rate of 3.11% compared to 0.53% using transnasal EGD (P < 0.05). In the screening of subjects with extensive CAG, no significant differences in detection of neoplasia were evident between the two endoscopies, although the mean size of detected cancers was significantly smaller and the percentage of early cancers was significantly higher with standard transoral EGD. CONCLUSION These results strongly suggest that the diagnostic performance of transnasal endoscopy is suboptimal for cancer screening, particularly in subjects with H. pylori-related non-atrophic gastritis.

Nodular gastritis in association with gastric cancer development before and after Helicobacter pylori eradication

Nodular gastritis is caused by Helicobacter pylori infection and is associated with the development of diffuse‐type gastric cancer. This study examined the clinical characteristics of patients with nodular gastritis, including cancer incidence before and after H. pylori eradication.

Serological Differences in Helicobacter pylori

To study antigenic differences in Helicobacter pylori (H. pylori), we performed immunoblot (IB) analysis with monoclonal antibody, MAb102, and measured the serum antibody titer with captured ELISA method with MAb102 antibody. In IB analysis, specific 54 K antigen was detected in 39 strains derived from patients with gastritis, gastric ulcer, duodenal ulcer, and gastric carcinoma. But only one strain (GC32 strain) isolated from a patient with gastric cancer did not react with MAb102 antibody. In the result of antibody titer with captured ELISA method using other six strains of H. pylori as antigen, H. pylori strains were divided into 3 groups, group R (RD26, T7, and T13 strains), group E (England and MR31 strains), group T (T37 strain). However, four cases belonged to false negative in ELISA method. These cases could have been infected with H. pylori strains such as GC32 strain. These strains did not have 54 K antigen nor 54 K related antigen which is different in its antigenicity from the 54 K antigen of the six strains. Thus the GC35 strain and the strain(s), which infected these four cases, consisted of other group, group N. These results suggested that 54 K antigen is usually stable in many strains, but occasionally different in antigenicity in some strains.