[Morphological and histological studies of in-stent restenosis in seven types of stents implanted in porcine coronary arteries]

OBJECTIVES

Differences in the mechanism of restenosis after stenting between coil and tubular stents were examined in porcine coronary arteries using histological and immunohistochemical methods.

METHODS

Twenty-four pigs underwent balloon-induced injury in the left anterior descending coronary artery. Two weeks later, seven different stents clinically available in Japan (Coil stents: GR I, GR II, Wiktor, Cordis; Tubular stents: gfx, Multilink, Palmaz-Schatz) were implanted in the injured site. Four weeks after the stent implantation, the pigs were sacrificed for histological examination and for morphometrical analysis of the lumen, neointima, media and adventitia. Immunohistochemical studies using anti-proliferating cell nuclear antigen (PCNA), anti-alpha-smooth muscle actin and anti-macrophage antibody were also performed.

RESULTS

The coil stents formed eccentric, and the tubular stents formed concentric neointimal proliferation. Although there was no difference in the area of neointima between the stents, the area of lumen in the tubular stents was bigger than that in the coil stents (p < 0.01), because the vascular area was bigger in the tubular stents (p < 0.05). Immunohistochemical examination found many PCNA-positive cells in the proliferated neointima, especially in the area around the stent strut. Many of these cells around the stent strut were positively stained by anti-macrophage antibody. Other cells positively stained for PCNA were confirmed as smooth muscle cells.

CONCLUSIONS

Tubular stents maintained a wider lumen than coil stents, because negative remodeling after stenting was less in the tubular stents. Implantation of stents with less negative remodeling is very important to prevent restenosis after stenting.

1-Oxacephem-based human chymase inhibitors: discovery of stable inhibitors in human plasma

1-Oxacephem derivatives were evaluated as a novel series of chymase inhibitors. The structure-activity relationship studies of 1-oxacephems led to compounds 15, which exhibited 27 nM inhibition of human chymase and improvement of stability in human plasma (t 1/2 1.5 h).

Synthesis and structure-activity relationships of a new class of 1-oxacephem-based human chymase inhibitors

1-Oxacephem derivatives were synthesized and evaluated as a novel series of chymase inhibitors. Structure-activity relationship studies of 1-oxacephems led to compound 34, which exhibited 6 nM inhibition of human chymase and high selectivity for human chymase compared to other serine enzymes.

Long tube for obstructing left-sided colon cancer

BACKGROUND

Obstructing left-sided colon cancer is now managed by immediate resection and primary anastomosis using intraoperative mechanical bowel irrigation. The aim of this study was to describe our new technique using a long tube for preoperative bowel decompression and intraoperative antegrade irrigation.

METHODS

A long nasointestinal tube was inserted and a balloon was inflated with distilled water. The tube gradually went forward to the ileum end by peristalsis, and the small intestine became fully decompressed. At operation, antegrade colonic irrigation with warm saline was performed through this long tube without insertion of a Foley catheter.

RESULTS

Immediate colonic resection and primary end-to-end anastomosis using layer-to-layer interrupted sutures was successfully performed in 4 patients with obstructing sigmoid colon cancer.

CONCLUSIONS

This method avoids opening and closure of the cecum or ileum, and minimizes bacterial contamination. The technique is simple and easy, and useful for immediate resection and primary anastomosis of obstructing left-sided colon cancer.

[Colorectal cancer in spouses of colorectal cancer patients]

Married couples share home environments and life style for years. In the case of colorectal cancer, an association with insulin resistance was reported. We determined the presence of the insulin-resistance syndrome (IRS, 1 or more of the following: body mass index of > 25 kg/m2, diabetes, or hyperlipidemia) in 84 colorectal cancer patients, of whom 61 patients (73%) had IRS. The incidence of the distal colorectal cancer, which has been declining in the United States, was significantly higher in the IRS group than in the non-IRS group (75.4 vs 52.2%, p = 0.0400). Some mechanisms may promote the progression of mucosal lesions to invasive cancers in the distal colorectum. There were no significant differences with respect to the age (64.6 +/- 9.4 vs 64.3 +/- 11.3 yr, p = 0.8298), height (159 +/- 9 vs 157 +/- 8 cm, p = 0.1375), and body mass index (22.2 +/- 3.6 vs 22.4 +/- 2.7 kg/m2, p = 0.6364) between the patients and their spouses. In 84 couples in whom colorectal cancer develops at least in one may then not illustrate the nursery rhyme: "Jack Sprat could eat no fat, His wife could eat no lean...". The spouses had been married for an average of 38 years, and in 30 spouses who had been followed in a colorectal cancer screening, 5 developed colorectal cancer. To diminish the incidence of colorectal cancer in Japan, we might advise screening colonoscopy to the spouses of colorectal cancer patients, or déjà vu all over again?

Osteoporosis after gastrectomy: bone mineral density of lumbar spine assessed by dual-energy X-ray absorptiometry

Although osteoporosis is a common clinical disorder associated with gastric surgery, long-term effects of gastrectomy on bone metabolism are still unclear. The purpose of this study was to clarify the incidence and risk factors of osteoporosis after gastrectomy using univariate and multivariate analyses of quantitative measurements. The study included 59 patients who had undergone gastrectomy more than 5 years before. There were 38 men and 21 women, aged 37-81 years, mean 64 years. Bone mineral density (BMD) of L2-L4 spine was measured using dual-energy X-ray absorptiometry (DXA). Absolute value of BMD (g/cm2) and age- and sex-matched BMD (%) were given. The mean BMD was 0.766 g/cm2, and the incidence of osteoporosis (BMD less than 0.70 g/cm2) was 37%: 18% in men and 71% in women. The mean age- and sex-matched BMD was 85.9%: 87.5% in men and 83.1% in women. Univariate and multivariate analyses revealed that BMD was significantly associated with the age and sex of patients, but was not influenced by the type of gastrectomy (partial versus total) and years after operation (< 20 versus 20 <). Our study clarified the fact that postgastrectomy osteoporosis was frequent in the aged or female patients. BMD should be evaluated after gastrectomy, especially in the aged and in women.

DNA oligomers having a diazapyrenium dication (DAP2+); synthesis and DNA cleavage activities

Aiming at the creation of functionalized antisense DNA oligomers possessing site-selective DNA cleaving activity, viologen and a related compound, diazapyrenium dication (DAP2+), were selected and introduced into oligodeoxyribonucleotides as a functionalized molecule. The conjugation of these functionalized molecules with DNA proceeded smoothly by using standard H-phosphonate chemistry. A part of the DAP(2+)-tethered DNA oligomers was synthesized by a combination of solid support method and liquid phase technique. Viologen-tethered DNA oligomers showed no significant activity toward DNA cleavage in spite of their characteristic ESR spectra. On the other hand, it was observed that the DAP(2+)-tethered DNA oligomers formed more stable duplexes with their complementary strands than the corresponding wild type, and these molecules effectively cleaved the complementary strands at the specific site of 2-3 bases away from the modified phosphoramidate linkage. The effect of position and length of the linker arm on the selectivity in the cleavage reaction was also investigated, and it was found that introduction at the 3'- or 5'-end phosphate site is more favorable, probably due to duplex stabilization.

Volvulus of the ileum in adult diagnosed pre-operatively by helical 3-dimensioned computed-tomography

A 46 year-old male who was strictly diagnosed as having volvulus of the ileum based on the pre-operative information brought by computed tomography (CT) and helical (spiral) 3-dimensioned computed tomography was surgically treated. The post-operative course was satisfactory and the patient is now under observation without any exacerbation of symptoms one year after surgery.

Clinical results and prognostic factors of radiologically node-positive gastric carcinoma

Lymph node metastasis determined by histologic examination is an important prognostic indicator in gastric carcinoma. However, prognostic value of lymph node metastasis detected by computed tomography (CT) is unknown. The aim of this study was to evaluate clinical results and prognostic factors of patients with radiologically node-positive gastric carcinoma. The study included 78 patients with primary gastric carcinoma and lymph node metastasis confirmed by CT. The level of lymph node metastasis was simply graded as follows: level I included perigastric nodes; level II included intermediate nodes along the left gastric, common hepatic, and celiac arteries; and level III included distant nodes along the hepatoduodenal ligament, pancreas, spleen, and abdominal aorta. Sixty patients (79%) had stage IV tumors showing one or more of the following: level III lymph node metastasis in 37, pancreatic invasion in 27, peritoneal dissemination in 23, and liver metastasis in 19. Overall 1- and 5-year survival rates were 29% and 6%, respectively, and the 1-year survival rate was significantly influenced by the level of lymph node metastasis on CT (55% for level I, 27% for level II, 7% for level III, P < 0.01). In patients with gastrectomy, prognostic factors were tumor size (<10 cm versus >10 cm, P < 0.01), gross type (localized versus infiltrative, P < 0.01), histologic type (well differentiated versus poorly differentiated, P < 0.01), and curability of the disease (curative versus noncurative, P < 0.01). Our study indicates that prognosis of patients with radiologically node-positive gastric carcinoma is poor because of high frequency of extensive tumor spreads. Patients having only positive level I nodes on CT are candidates for curative gastrectomy, which may offer long-term survival.

Carcinoid tumor of the ileum with intestinal obstruction

An 83 year-old female presenting with intestinal obstruction due to a carcinoid tumor of the small intestine is herein reported. The intra-operative findings revealed a stenotic lesion and ischemic changes of the ileum. A segmental jejunotomy was performed and a submucosal tumor was recognized as a causal lesion. Histopathological investigation demonstrated the features of carcinoid tumor.

Ileus with incarceration of Spigelian hernia

An 85 year-old female with ileus due to incarceration of Spigelian hernia, which was diagnosed pre-operatively with the findings of the abdominal computed tomography and plain radiographic pictures, is reported. A simple hernioplasty was made by suturing the internal oblique and transverse muscles to the rectus sheath. The post-operative condition is satisfactory without any recurrence of hernia.

Successful conservative treatment for esophageal perforation by a fish bone associated with mediastinitis

A 74 year-old man presenting with esophageal perforation associated with mediastinitis due to the swallowing of a fish bone is reported herein. Conservative treatment, including starvation therapy and the injection of antibiotic drugs, proved to be successful for this patient. Although the optimal treatment for esophageal perforation remains controversial, it is important to choose the appropriate strategies when treating cases of esophageal perforation with mediastinitis.

Bone mineral density in patients taking H2-receptor antagonist

Osteoporosis after gastrectomy is a common clinical disorder. In gastrectomized patients, decreased gastric acidity may be associated with impaired calcium absorption. This study was undertaken to determine whether patients with chronic use of H2-receptor antagonists (HRA) had demonstrable decreases in bone mineral density (BMD). Thirty-three patients taking cimetidine, ranitidine, or famotidine for more than 2 years were analyzed. We measured BMD of L2-L4 using dual energy X-ray absorptiometry (DXA). Osteoporosis (BMD less than 0.70 g/cm2) was found only in three patients (9%). As compared with healthy controls, age- and sex-matched BMD ranged from 74.4% to 132.9%, with a mean of 97.0%, and was not influenced by the period of HRA use (<5 years versus >5 years or more). Although the age- and sex-matched BMD was different among the kinds of HRA (98.6% for cimetidine, 101.3% for ranitidine, and 85.5% for famotidine), the relationship between the BMD and type of drug was not significant by multivariate analysis. These results indicate that chronic use of HRA has little influence on the degree of BMD, and suggest that decreased gastric acidity is not always associated with osteoporosis after gastrectomy.

[Necrosis of the hepatocellular carcinoma nodule can aggravate metastasis]

Since the stroma of hepatocellular carcinoma is composed of sinusoid-like structures, cancer cells are readily released from the primary tumor with possible injurious consequences. A 63-year-old woman with hepatocellular carcinoma underwent percutaneous ethanol injection therapy. During this treatment, tumor thrombus developed in the right hepatic vein. Partial hepatic resection was performed. Six months later, multiple nodules appeared in the lung fields. Partial necrosis may have allowed the release of cancer cells from the primary tumor. Perioperative therapy should have an effect on intrahepatic micrometastases, because removal of the main tumor can be done surgically.

Increased serum CA19-9 in patients with xanthogranulomatous cholecystitis

We present three cases of xanthogranulomatous cholecystitis (XGC) with an increased serum carbohydrate antigen 19-9 (CA19-9). All of the patients were elderly females and had gallstones lodged in the neck of the gallbladder. Preoperative serum CA19-9 levels were 709 U/ml, 87 U/ml, and 400 U/ml, respectively. A cholecystectomy with or without bile duct exploration was performed, and the histological diagnosis of XGC was made. Serum CA19-9 levels fell to normal levels in two patients who recovered uneventfully, but rose again in one patient who died of cholangitis. Clinicians must remember that XGC is a possible cause of increased serum CA19-9 levels.

Laparoscopic splenectomy for splenic hamartoma

Advances in imaging techniques have made pre-operative diagnosis of splenic tumors possible. A case of successful laparoscopic splenectomy for splenic hamartoma is described here and the indications of this technique are discussed.

Preoperative assessment of advanced gastric carcinoma using computed tomography

OBJECTIVES

The role of computed tomography (CT) for the staging of gastric carcinoma is controversial. The purpose of this study was to evaluate the utility of CT in assessing the perigastric spread of advanced gastric carcinoma.

METHODS

The study included 56 patients who underwent dynamic CT and laparotomy for the treatment of node-positive gastric adenocarcinoma. Preoperative CT findings were compared with surgical findings, and diagnostic accuracy was estimated.

RESULTS

Sensitivity, specificity, and accuracy of preoperative CT in determining the perigastric tumor spreads were 33, 97, and 73% in pancreatic invasion, 36, 97, and 70% in level III lymph node involvement, and 89, 98, and 96% in liver metastasis. Peritoneal dissemination was not detected in 15 of 56 patients (27%), and stage IV disease was not diagnosed correctly in 18 of 40 patients (45%).

CONCLUSIONS

Radiologists and surgeons must remember that pancreatic invasion, extended lymph node metastasis, and peritoneal dissemination are sometimes overlooked in CT examination in patients with advanced gastric carcinoma.

Repeated injection sclerotherapy is preferable to combined therapy with variceal ligation to avoid recurrence of esophageal varices:--a prospective randomized trial

BACKGROUND/AIMS

The aim of this prospective randomized study is to investigate the safety, efficacy, complications and recurrence of varices after repeated endoscopic injection sclerotherapy (EIS), and combined therapy of endoscopic variceal ligation (EVL) and repeated EIS, for the treatment of esophageal varices.

MATERIAL AND METHODS

Sixty-one consecutively treated cirrhotic patients were examined. Thirty patients were placed randomly in the EIS group and the other 31 in the EVL+EIS group. For the EIS group, EIS was repeated at weekly intervals using 5% ethanol- amine oleate (EO) until all the varices had been eradicated. In the EVL+EIS group, EVL was done at the initial session, then EIS was repeated at weekly intervals from one week after EVL.

RESULTS

There was no significant difference between the EIS and EVL+EIS groups with regard to the rate of eradication (80.0% vs 74.2%), the total number of treatment (4.1 +/- 0.8 sessions of EIS vs EVL and 3.0 +/- 0.5 sessions of EIS) and hospitalization time (4.9 +/- 1.6 vs 4.4 +/- 1.0 weeks). The total volume of EO used for the EVL+EIS group was significantly less than that for the EIS group (26.3 +/- 8.3 vs 47.1 +/- 11.6 ml, p < 0.01) and the incidence of minor complications at the initial treatment in the EVL+EIS group was significantly (p < 0.01) lower than that in the EIS group. Follow-up endoscopy showed that the rate of attaining circumferential ulceration and the following fibrotic scarring in the EVL+EIS group was significantly lower than that in the EIS group (21.7% vs 91.7%, p < 0.01) and that the incidence of variceal recurrence was significantly higher in the EVL+EIS group than in the EIS group (39.1% vs 8.3%, p < 0.05) over a median follow-up of 12.3 months.

CONCLUSION

The combined therapy of EVL and repeated EIS seems favorable from the viewpoint of fewer complications, but repeated EIS is preferable to combined therapy to avoid recurrence of the esophageal varices.

Postoperative bile peritonitis caused by division of an aberrant bile duct in the left triangular ligament of the liver

A 61-yr-old man underwent Billroth I gastrectomy for an advanced cancer in the corpus of the stomach. On the first postoperative day, fresh bile discharged from the penrose drains, which had been placed in Winslow's foramen, and the volume of bile discharge subsequently increased. Leakage from the gastroduodenal anastomosis was excluded by gastroduodenography. Exploratory relaparotomy showed bile peritonitis with much more bile retention in the left subphrenic space. The origin of bile leakage could not be traced despite close examination of all the extrahepatic biliary tract and the liver surface. Intraoperative cholangiography through the cystic duct after cholecystectomy revealed that the bile leakage originated from an aberrant bile duct present in the free edge of the left triangular ligament (appendix fibrosa hepatis), which had been unintentionally cut at the primary operation. Knowledge of this anatomical structure is important and proper ligation is recommended when dissecting the appendix fibrosa hepatis to avoid postoperative bile peritonitis and the need for a relaparotomy.

Epstein-Barr virus-associated gastric carcinoma

Epstein-Barr virus (EBV) is associated with certain types of gastric carcinoma. We report a case of EBV-positive undifferentiated carcinoma of the stomach in a 59-year-old woman with a well-demarcated ulcerating tumor in the gastric body. Examination of the resected stomach revealed that the tumor was undifferentiated carcinoma with lymphoid stroma, or lymphoepithelioma-like carcinoma. Tumor cells were positive for EBV by in situ hybridization. Gastroenterologists must keep in mind that localized ulcerating tumors of the stomach histologically seen as undifferentiated carcinnoma with lymphoid stroma are linked to EBV infection.

Synthesis and modification of a novel 1 beta-methyl carbapenem antibiotic, S-4661

We describe an efficient method for introducing a sulfamoylamino group into the C-2' position of pyrrolidine using the Mitsunobu reaction. S-4661, its N-methyl analogues and stereoisomers were synthesized using this method and their structure-activity relationships were investigated.