Detection of dissection and remodeling of atherosclerotic lesions in rabbits after balloon angioplasty by magnetic-resonance imaging

OBJECTIVE

To assess the usefulness of magnetic-resonance imaging (MRI) for monitoring acute changes after angioplasty of preexisting lesions in rabbits with basal lesions similar to those observed in humans.

METHODS

A combination of Fogarty balloon injury (1 week after initiation of diet) and a mildly hypercholesterolemic diet (0.2% cholesterol and 5% peanut oil) was used to promote the rapid formation of atherosclerotic lesions in 16 New Zealand white rabbits. After 5 months of the diet, angioplasty was performed on these lesions with a Grüntzig catheter in both iliac arteries and the abdominal aorta. MRI was used to monitor the initial formation of lesions after 3 and 5 months of the diet, and 2 days, 2 weeks, and 1 and 2 months after angioplasty.

RESULTS

The combination of early Fogarty injury and mildly hypercholesterolemic diet induced fibroproliferative lesions similar to type Vb atherosclerotic lesions seen in humans. Angioplasty induced deep dissections at the shoulders of lesions in the majority of animals. These dissections often extended into the media. The cellular, proliferative response after angioplasty was localized and limited to sites of dissection. A significant increase in area of arterial wall was observed after angioplasty at sites of dissection without any loss of lumen. In contrast, proximal and distal to the sites of injury, there was no change in wall area but a transient reduction in lumen area.

CONCLUSIONS

Comparison of MRI results with histology confirmed that changes in the wall and lumen, including small linear dissections in the lesions and arterial remodeling, are detectable by MRI.

A patient with thrombotic microangiopathy accompanied by glomerular subendothelial electron dense deposits

A 50-year-old woman presented with thrombocytopenia, microangiopathic hemolytic anemia, and nephrotic syndrome. Although a high level of circulating immune complexes, mild hypocomplementemia, and the antinuclear antibody also were present, the criteria for collagen disease were not fulfilled. Renal biopsy demonstrated a typical thrombotic microangiopathy (TMA) involving glomeruli. There also were electron-dense deposits located just beneath the original glomerular basement membrane in the dilated subendothelial space, thought to be immune complexes following positive IgG, C1q and C3 staining on an immunofluorescent study. Corticosteroid therapy rapidly ameliorated her hematologic abnormalities and proteinuria and normalized the immunologic data. These findings strongly suggest that the TMA in this patient was induced by immune complex-associated mechanisms.

Preoperative diagnosis of ileal lipoma by endoscopic ultrasonography probe

The occurrence of tumor in the small intestine is relatively rare. It has been demonstrated that lipoma of the ileum is a cause of intussusception. We report a 59-year-old man admitted to our hospital for lower abdominal pain. Diagnosis of intussusception was made by abdominal x-ray and ultrasonography. Enema contrast studies revealed ileocolic intussusception. Colonoscopy revealed a tumor with an submucosal tumor (SMT)-like head and coil-spring appearance in the ascending colon. Endoscopic ultrasonography (EUS) revealed a hyperechoic submucosal lesion with features compatible with lipoma. Subsequently, this was confirmed histopathologically after resection. To our knowledge, this is the first report of preoperative diagnosis of ileal lipoma by EUS.

Alterations of GTP-binding proteins (Gsalpha and Gq/11alpha) in gastric smooth muscle cells from streptozotocin-induced and WBN/Kob diabetic rats

We investigated possible impairment of the signal transduction system in gastric myocytes of streptozotocin-induced diabetic (STZ) and spontaneous diabetic WBN/Kob (WBN/Kob) rats. Gastric motility 10 weeks after the onset of diabetes mellitus was significantly reduced in both diabetic rats compared with control, and the decreased motility was not recovered by the administration of insulin to maintain normal blood glucose levels. There was no significant difference between both types of diabetic rats and control rats in total number of [3H]quinuclidinyl benzilate ([3H]QNB) binding sites (Bmmax: 545-587 fmol/mg protein) on gastric smooth muscle cell membranes or in the affinity of [3H]QNB for the binding sites (Kd: 0.06-0.07 nM). Immunoblot analysis using polyclonal anti-G-protein antibodies indicated increased expression of Gsalpha in gastric smooth muscle cell membranes, but no significant change in Gialpha or Gq/11alpha expression in STZ rats, and decreased expression of Gq/11alpha with no significant change in Gsalpha and Gialpha in WBN/Kob rats. The cAMP production in gastric smooth muscle cell membranes was augmented in the absence and presence of 100 microM isoproterenol, and 100 microM forskolin in STZ rats, whereas no significant change of cAMP production was observed in WBN/Kob rats irrespective of the presence of the stimulants. These findings suggest that long-standing diabetes may induce alterations in signal transduction at downstream receptors in gastric myocytes, resulting in the impairment of gastric motility, although the mechanism of reduced contractile activity may differ between STZ and WBN/Kob rats.

Ovarian mucinous cystadenocarcinoma as a cause of Zollinger-Ellison syndrome: report of a case and review of the literature

Gastrin producing ovarian tumor is a rare cause of the Zollinger-Ellison syndrome. We report the case of an ovarian carcinoma showing increased plasma gastrin concentration. A 60-yr-old woman presented with epigastric pain and diarrhea. Physical examination showed a large mass in the lower abdomen. Computed tomography revealed a large multilocular ovarian cyst. Upper gastrointestinal endoscopy examination showed multiple ulcerations of the stomach and duodenum. The plasma gastrin level was 1500 pg/ml. No tumors were found in the pancreas and duodenum, and salpingo-oophorectomy was performed. Histologic examination revealed a mucinous tumor of borderline malignant potential. Immunoperoxidase studies for gastrin showed many gastrin-producing cells within the epithelium of the tumor. There have been 11 cases (including our patient) of gastrin-producing ovarian tumor reported in the literature. We review here the relevant literature. Although ovarian gastrinoma is extremely rare, it should be considered as a possible cause of the Zollinger-Ellison syndrome in women.

Relationship between Helicobacter pylori infection and smoking and drinking habits

BACKGROUND

Helicobacter pylori is a major cause of various gastroduodenal diseases. Some risk factors related to H. pylori infection have been reported; however, studies on the relationship between H. pylori infection and smoking or drinking habits have given conflicting results. In the present study, these relationships were investigated by collecting sera and information from 8837 subjects.

METHODS

Serum H. pylori immunoglobulin G antibody was measured by an enzyme-linked immunoassay. In addition to sex and age, information on smoking and drinking habits was collected by questionnaire. Age- and sex-adjusted odds ratios (95% confidence interval) of smoking and alcohol consumption were calculated for H. pylori seropositivity using logistic regression models.

RESULTS

Current smokers had a 0.82 (0.74-0.91)-fold greater risk of H. pylori seropositivity than those who had never smoked. Current cigarette consumption showed a dose-dependently negative association with H. pylori seropositivity, and the association between smoking and H. pylori infection was strong in younger subjects. Current drinkers had a 0.88 (0.79-0.98)-fold greater risk of H. pylori seropositivity than those who had never drunk alcohol. The volume of alcohol consumed showed a negative association with H. pylori seropositivity.

CONCLUSIONS

In the current study, smoking was negatively associated with H. pylori infection. The risk of H. pylori seropositivity decreased linearly with cigarette consumption per day. Increased gastric acidity in the stomach through smoking may be a cause of the dose-dependently negative association between H. pylori and smoking. Drinking was negatively and dose-dependently associated with H. pylori positivity, although the effect of drinking was weaker than that of smoking.

A patient with undifferentiated carcinoma of gallbladder presenting with hemobilia

Hemobilia is relatively rare among hemorrhages in the digestive tract, and hemobilia caused by tumors of the biliary tract is particularly rare. We treated a 74-year-old-man with undifferentiated carcinoma of the gallbladder presenting with hemobilia. During hospitalization for neurogenic bladder at the Department of Urology, he showed progressive anemia. Since hemorrhage in the digestive tract was suspected, endoscopy of the upper gastrointestinal tract was performed, and bleeding from the papilla of Vater was observed. On ultrasound examination, findings were indicative of cholecystic cancer, and hemorrhage from the cystic duct was found on percutaneous transhepatic cholangioscopy. On perioral cholecystoscopy, however, masses of coagulated blood were found only in the gallbladder. Abnormalities such as dense staining of tumors or extravasation were not found on angiography. The patient died of hepatic failure due to rapid invasion of the liver by the tumor, associated with biliary infection and disseminated intravascular coagulation. At autopsy, a nodal tumor was found in the gallbladder, and the cavity of the gallbladder was filled with coagulated masses of blood. Direct invasion of the tumor to the liver, diaphragm, and transverse colon was found. The histopathological diagnosis was undifferentiated carcinoma (pleomorphic large-cell type).

Relation between interleukin-1beta messenger RNA in gastric fundic mucosa and gastric juice pH in patients infected with Helicobacter pylori

The effects of Helicobacter pylori infection on gastric acid secretion has not been clarified. The aim of this study was to elucidate the effects of H. pylori infection on gastric juice pH in relation to gene expression of interleukin-1beta (IL-1beta), which is reported to inhibit gastric acid secretion. Gastric juice pH and serum gastrin levels were measured in patients with peptic ulcer disease. The amount of IL-1beta mRNA in gastric fundic gland mucosa was also measured by a competitive reverse transcription-polymerase chain reaction method. These parameters were determined before and after treatment with lansoprazole and amoxicillin. Before treatment a significant positive relation was observed between the amount of IL-1beta mRNA in gastric fundic gland mucosa and gastric juice pH. After treatment significant decreases in the amount of IL-1beta mRNA, gastric juice pH, and serum gastrin levels were observed in patients with eradication of H. pylori, whereas no significant changes were observed in patients without eradication. These results suggest that H. pylori infection induces IL-1beta and suppresses acid secretion, resulting in increases in gastric juice pH and serum gastrin levels. Eradication of H. pylori decreases IL-1beta induction, resulting in an increase in gastric juice acidity and normalization of serum gastrin levels.

Protein-losing enteropathy caused by mesenteric venous thrombosis with protein C deficiency

A 64-year-old man presented with leg edema and hypoproteinemia. His alpha-1 antitrypsin clearance rate of 174 mL/day indicated the presence of protein-losing enteropathy (PLE). Computed tomographic scans demonstrated thickened ileal wall and mesenteric edema. Angiography revealed occlusion in a peripheral branch of the superior mesenteric vein. Furthermore, both the patient and his son had low protein C levels. The patient was treated successfully with partial resection of the ileum. Histologic examination of the resected ileum revealed multiple erosions and submucosal fibrosis with organized venous thrombi in the mesenteric veins. This is the first case report of PLE caused by mesenteric venous thrombosis, and our findings suggest that serum protein was lost through erosion of the ileum caused by ischemia due to mesenteric venous thrombosis.

Morphologic abnormalities in the brain of chronically hemodialyzed patients without cerebrovascular disease

In this study, the authors evaluated the cerebral atrophy in 56 chronic hemodialyzed patients, who did not have clinical episodes or radiologic findings of cerebrovascular diseases, and 42 controls. Using computed tomography (CT) images, brain atrophy index (BAI), the proportion of subarachnoidal plus ventricular space in the cranial cavity, and ventricular area index (VAI), percent area of ventricle in the brain, were calculated. CT of the brain demonstrated an age-dependent increase in BAI in both hemodialyzed patients and controls. BAI and VAI were greater in hemodialyzed patients than healthy controls and the difference was significant at ages under 60 years in BAI and at ages less than 50 years in VAI. The atrophy of the frontal parts of the brain in patients on hemodialysis for 10 years or more was significantly greater than in patients dialyzed for less than 10 years. There was a significant negative correlation between BAI or VAI and hematocrit. These findings indicate that renal failure or hemodialysis itself might cause cerebral atrophy, and that the cerebral atrophy is more prominent in patients on hemodialysis for a long duration and with low hematocrit.

Successful treatment of percutaneous transhepatic papillary dilation in patients with obstructive jaundice due to common bile duct stones after Billroth II gastrectomy: report of two emergent cases

Successful treatment of two patients with obstructive jaundice due to choledocholithiasis after Billroth II gastrectomy was performed by elimination of stones by percutaneous transhepatic balloon dilatation of the sphincter of Oddi. Patient 1 was an 82-year-old man and Patient 2 was a 73-year-old man. Both patients presented with obstructive jaundice. The papilla was not observed in either patient because of previous Billroth II gastrectomy. Because an endoscopic approach was impossible, percutaneous transhepatic cholangiodrainage (PTCD) was performed to alleviate jaundice. Choledocholithiasis was treated as follows: The sphincter of Oddi was dilated by percutaneous transhepatic balloon, and stone particles were removed from the papilla with a stone-eliminating balloon catheter via the same route of PTCD. This method is less invasive than the percutaneous transhepatic cholangioscopic method, and the use of existing appliances such as a balloon for papillary dilation is possible. Hence, this method appears to be an effective and simple method for the treatment of choledocholithiasis after gastrectomy that is difficult to treat endoscopically.

alphaPIX nucleotide exchange factor is activated by interaction with phosphatidylinositol 3-kinase

p21-activated kinase (PAK) is a common effector protein of the small GTPases Cdc42 and Rac, leading to the activation of downstream mitogen activated protein kinases. PAK also mediates polarized cytoskeletal changes induced by these GTPases. The recently identified PAK-interacting exchange factor (PIX) acts as a guanine nucleotide exchange factor on Rac, and colocalizes with PAK in a focal complex, but little is known about the associated signaling cascades, including upstream activators of PIX. In this study, we show that one of the isoforms of PIX, alphaPIX, is activated by signaling cascades from the platelet-derived growth factor (PDGF) receptor and EphB2 receptor, and from integrin-induced signaling through phosphatidylinositol 3-kinase (PI3-kinase). alphaPIX is activated by forming a complex with these receptors either via association with PAK and Nck, or direct association with the p85 regulatory subunit of PI3-kinase. Synthetic phosphoinositide and membrane targeted PI3-kinase augmented the alphaPIX activity in vivo. In Xenopus, aggregates of mesodermal cells derived from embryos microinjected with alphaPIX significantly increased the peripheral spreading on fibronectin substrate in response to PDGF through PI3-kinase. These results indicate that alphaPIX is activated by PI3-kinase, and is involved in the receptor mediated signaling leading to the activation of the kinase activity of PAK, and the migration of mesodermal cells on extracellular matrix.

Role of the vasopressin V(1) receptor in regulating the epithelial functions of the guinea pig distal colon

Vasopressin has a wide spectrum of biological action. In this study, the role of vasopressin in regulating electrolyte transport in the colon was elucidated by measuring the short-circuit current (I(sc)) as well as the Na(+), K(+), and Cl(-) flux in a chamber-mounted mucosal sheet. The cytosolic Ca(2+) concentration ([Ca(2+)](i)) was also measured in fura 2-loaded cells by fluorescence imaging. Serosal vasopressin decreased I(sc) at 10(-9) M and increased I(sc) at 10(-7)-10(-6) M. The decrease in I(sc) was accompanied by two effects: one was a decrease in the amiloride-sensitive Na(+) absorption, whereas the other was an increase in the bumetanide-sensitive K(+) secretion. The increase in I(sc) was accompanied by an increase in the Cl(-) secretion that can be inhibited by serosal bumetanide or mucosal diphenylamine-2-carboxylate. Vasopressin caused an increase in [Ca(2+)](i) in crypt cells. These responses of I(sc) and the [Ca(2+)](i) increase in crypt cells were all more potently inhibited by the vasopressin V(1) receptor antagonist than by the V(2) receptor antagonist. These results suggest that vasopressin inhibits electrogenic Na(+) absorption and stimulates electrogenic K(+) and Cl(-) secretion. In all of these responses, the V(1) receptor is involved, and the [Ca(2+)](i) increase may play an important role.

Preservative treatment for biliobiliary fistula

Biliobiliary fistula is thought to be a rare type of internal biliary fistula. A 68-year-old man presented to our hospital with complaints of jaundice and general malaise. Endoscopic retrograde cholangiography was performed, but the gallbladder was not imaged. Mirizzi's sign was observed in the common hepatic duct. During the course of evaluating this inpatient, imaging revealed that a gallstone was extruded to the right hepatic duct. After incision of the papilla, stones in the bile duct were subjected to mechanical lithotripsy and were extracted. As a result of bile duct decompression, the biliobiliary fistula was closed completely 2 months later.

Effects of clarithromycin on the metabolism of omeprazole in relation to CYP2C19 genotype status in humans

BACKGROUND AND PURPOSE

A triple therapy with omeprazole, amoxicillin (INN, amoxicilline), and clarithromycin is widely used for the eradication of Helicobacter pylori. Omeprazole and clarithromycin are metabolized by CYP2C19 and CYP3A4. This study aimed to elucidate whether clarithromycin affects the metabolism of omeprazole.

METHODS

After administration of placebo or 400 mg clarithromycin twice a day for 3 days, 20 mg omeprazole and placebo or 400 mg clarithromycin were administered to 21 healthy volunteers. Plasma concentrations of omeprazole and clarithromycin and their metabolites were determined before and 1, 2, 3, 5, 7, 10, and 24 hours after dosing. CYP2C19 genotype status was determined by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

Subjects were classified into three groups on the basis of PCR-RFLP analyses for CYP2C19: homozygous extensive metabolizer group (n = 6), heterozygous extensive metabolizer group (n = 11), and poor metabolizer group (n = 4). Mean area under the plasma concentration-time curves from 0 to 24 hours (AUC) of omeprazole in the homozygous extensive metabolizer, heterozygous extensive metabolizer, and poor metabolizer groups were significantly increased by clarithromycin from 383.9 to 813.1, from 1001.9 to 2110.4, and from 5589.7 to 13098.6 ng x h/mL, respectively. There were significant differences in the mean AUC values of clarithromycin among the three groups.

CONCLUSION

Clarithromycin inhibits the metabolism of omeprazole. Drug interaction between clarithromycin and omeprazole may underlie high eradication rates achieved by triple therapy with omeprazole, amoxicillin, and clarithromycin.

Up-regulation of H2 receptor and adenylate cyclase in rabbit parietal cells during prolonged treatment with H2-receptor antagonists

Intragastric hyperacidity occurs after abrupt withdrawal of histamine H2-receptor antagonists, and the prolonged administration of these agents induces tachyphylaxis of the inhibitory effects on gastric acid secretion. We examined the effect of the prolonged administration of H2-receptor antagonists on the H2-receptor signaling system in parietal cells isolated from rabbits that had received H2-receptor antagonists for 14 days. [125I]aminopotentidine (APT) binding sites to H2 receptors in parietal cell membranes were increased without any significant change in the affinity for [125I]APT. The expression of Gs(alpha), guanosine triphosphate (GTP)-binding protein coupled to H2 receptor, was slightly increased. Basal as well as GTP- or histamine-stimulated cAMP production was increased, but no significant change was observed in the presence of an H2-receptor antagonist. The up-regulation of the H2 receptor and adenylate cyclase appeared to cause hypersecretion of acid after withdrawal of H2-receptor blockade.

Primary small cell carcinoma of the esophagus with achalasia in a patient in whom pro-gastrin-releasing peptide and neuron-specific enolase levels reflected the clinical course during chemotherapy

We report a case of primary small cell carcinoma of the esophagus in a patient with achalasia in whom pro-gastrin-releasing peptide (ProGRP) and neuron-specific enolase (NSE) levels were measured. Although chemotherapy markedly reduced the size of the primary tumor and lymph node metastases, it had no effect on liver metastases. The tumor marker levels decreased after chemotherapy as the primary tumor and lymph node metastases decreased in size, and they increased as the liver metastases enlarged. However, there was a discrepancy between the levels of ProGRP and NSE during the patient's clinical course. We demonstrate the usefulness of measuring ProGRP and NSE levels to assess the effect of chemotherapy in patients with esophageal small cell carcinoma.