Relation between QT dispersion and adenosine triphosphate stress thallium-201 single-photon emission computed tomographic imaging for detecting myocardial ischemia and scar

It is not known if QT dispersion is useful for detecting coronary artery disease. We investigated whether QT dispersion at baseline and during adenosine triphosphate (ATP) infusion correlate with the imaging patterns obtained from ATP stress thallium-201 single-photon emission computed tomography (ATP-SPECT). QT dispersion was determined in 169 patients who underwent ATP-SPECT from 12-lead electrocardiograms obtained at baseline and 3 minutes after the beginning of ATP infusion. Based on the results of ATP-SPECT, patients were divided into 4 groups: normal (n = 55), ischemia (n = 38), ischemia and scar (n = 42), and scar (n = 34). Baseline QT dispersions (mean +/- SD) in the normal, ischemia, ischemia and scar, and scar groups were 48 +/- 15, 50 +/- 17, 69 +/- 25, and 70 +/- 24 ms, respectively. Baseline QT dispersion was significantly greater in the groups with myocardial scar. QT dispersions during ATP infusion were 43 +/- 16, 63 +/- 20, 76 +/- 20, and 62 +/- 25 ms in the normal, ischemia, ischemia and scar, and scar groups, respectively. QT dispersion increased with ATP infusion in patients with myocardial ischemia. QT dispersion at baseline and during ATP infusion correlated with the ATP-SPECT imaging pattern. These findings suggest that baseline QT dispersion and ATP-induced changes in QT dispersion may help detect the presence of myocardial ischemia and scar.

Idiopathic verapamil-sensitive left ventricular tachycardia complicated by right ventricular outflow tract ventricular tachycardia and ventricular fibrillation

Idiopathic ventricular tachycardias (VTs) are generally divided into those arising from the right ventricle and those arising from the left ventricle. There has been few reports of two morphologically distinct VT occurring in patients with no apparent structural heart disease. We report a patient with verapamil-sensitive left VT with a right bundle branch block pattern that spontaneously changed to VT with a left bundle branch block pattern. Ventricular fibrillation was induced by the application of programmed stimulation. Although it is unclear if our patient with pleomorphic VT has ventricular vulnerability, it is necessary to investigate further and follow him carefully.

Adenosine 5'-triphosphate induced dilation of human coronary microvessels in vivo

OBJECT

This study was performed to compare the coronary microvascular response to adenosine 5'-triphosphate (ATP) with the response to adenosine in humans.

METHODS

Coronary blood flow velocity was determined using a Doppler flow wire. After intracoronary nitroglycerin infusion, intracoronary bolus injections of adenosine (20 microg) and ATP (20 microg) were performed to induce reactive hyperemia.

PATIENTS

Twenty-nine patients (23 men and 6 women, mean age: 63+/-9 years) with coronary artery disease and risk factors for coronary atherosclerosis were studied.

RESULTS

Coronary flow reserve in response to ATP was similar to that for adenosine (2.7+/-0.7 vs. 2.7+/-0.7). However, the duration of ATP-induced vasodilation was longer than that of adenosine-induced dilation (39+/-25 seconds vs. 26+/-12 seconds, p<0.0001). The coronary flow reserve obtained with either ATP or adenosine was significantly reduced in the interventioned arteries compared with non-stenosed arteries. The coronary flow reserve obtained with ATP was similar to that obtained with adenosine in both artery groups. The duration of the vasodilator effect of ATP was significantly greater than that of adenosine in both artery groups.

CONCLUSION

These results suggest that ATP induces maximal dilation of coronary microvessels, most likely through an endothelium-independent mechanism. The degradation of ATP to adenosine 5'-monophosphate (AMP) and adenosine, as well as the direct action of ATP on A2-adenosine receptors may be responsible for the dilation. We conclude that coronary flow reserve can be determined safely with intracoronary ATP administration.

Role of bile salt hydrophobicity in distribution of phospholipid species to carriers in supersaturated model bile solutions

BACKGROUND

Phospholipid species modulate cholesterol-holding capacity and, therefore, regulate bile metastability.

METHODS

In this study, we investigated the effect of bile salt hydrophobicity on the distribution of phospholipids among lipid particles in supersaturated model bile solutions (total lipid concentration, 9 g/dL; taurocholate/phospholipid ratio 3.0, cholesterol saturation index 1.3), by using gel permeation chromatography.

RESULTS

With an increase of bile salt hydrophobicity in the elution buffer, the uptake of cholesterol and phospholipids into bile salt micelles was increased, associated with an increased cholesterol/phospholipid molar ratio of the vesicles. In contrast, there was an inverse correlation between the hydrophobicity of the phospholipid species in the vesicles and that of bile salts in the elution buffer, suggesting that hydrophobic bile salts induced preferential uptake of hydrophobic phospholipids into bile salt micelles, while less hydrophobic phospholipids, with a relatively low cholesterol-holding capacity, remained in the vesicles.

CONCLUSIONS

These data indicate that bile salt hydrophobicity regulates vesicular cholesterol metastability by modulating the hydrophobicity of phospholipids in vesicles, as well as the lipid distribution among various biliary lipid particles.

MUC1 expression in intramucosal colorectal neoplasms. Possible involvement in histogenesis and progression

PURPOSE

The mucin core peptide MUC1 often is detectable in colorectal carcinoma (CRC) tissue and cell lines. However, whether MUC1 in CRC correlates with tumor histogenesis and progression is unclear. We studied the relationship between MUC1 expression in intramucosal CRC and clinicopathologic features, expression of Ki-67, and p53 protein, and apoptosis.

METHODS

The intramucosal CRC we studied included 140 endoscopically or surgically resected lesions, including 106 low-grade carcinomas and 34 high-grade carcinomas. De novo carcinoma, defined as carcinoma with no adenomatous component, represented 9 of 140 tumors. Three macroscopic types were identified: 57 lesions were polypoid, 55 were superficial and flat, and 28 were granular-type laterally spreading tumors (G-LST). MUC1, Ki-67, and p53 expression were examined immunohistochemically. Apoptotic cells were identified by in situ DNA nick end labeling.

RESULTS

MUC1 expression in high-grade carcinomas was significantly more frequent (p < 0.01) than in low-grade carcinomas; expression in adenomas was almost nil. MUC1 expression in polypoid carcinomas was significantly more frequent (p < 0.05) than in superficial carcinomas or G-LST. MUC1 expression in carcinomas with p53 expression was significantly more frequent (p < 0.01) than in carcinomas not expressing p53. No significant correlation was found between expression of MUC1 and Ki-67 labeling index. MUC1 was expressed more frequently in carcinomas with relatively high apoptotic index (p < 0.01). MUC1 expression did not differ between de novo carcinomas and those developing from adenomas.

CONCLUSIONS

The results suggest that MUC1 is likely to be expressed in the course of colorectal carcinoma development when p53 protein is overexpressed and apoptosis is prominent.

Frequent p53 gene mutations in serrated adenomas of the colorectum

Serrated adenoma has been recently proposed as a distinct histological lesion of the colorectum. This study examined p53 immunoreactivity, mutations of exons 5-8 of the p53 gene, codon 12 of the Ki-ras gene by PCR-SSCP analyses, and microsatellite instability in 19 serrated adenomas, ten adenocarcinomas in/with serrated adenomas, 23 hyperplastic nodules, four hyperplastic polyps and 29 tubular adenomas of the colorectum. Eleven of 11 (100 per cent) serrated adenomas had p53 immunoreactivity and all six (100 per cent) adenocacinomas in/with serrated adenomas exhibited moderate to severe p53 immunoreactivity. It was confirmed that 9 of 19 (47 per cent) serrated adenomas and 5 of 10 (50 per cent) adenocarcinomas in/with serrated adenomas harboured p53 gene mutations. On the other hand, no p53 gene mutation was detected in the other colorectal lesions. Meanwhile, 11 (58 per cent) serrated adenomas and six (60 per cent) adenocarcinomas in/with serrated adenomas had Ki-ras gene mutations, as also did 9 of 23 (39 per cent) hyperplastic nodules, 3 of 4 (75 per cent) hyperplastic polyps, and 12 of 29 (41 per cent) tubular adenomas. Microsatellite instability was detected in one (5 per cent) serrated adenoma and one (10 per cent) adenocarcinoma in a serrated adenoma. The other lesions did not show microsatellite instability. Serrated adenomas had significantly frequent p53 gene mutations compared with hyperplastic lesions or tubular adenomas (p < 0.005). On the other hand, they did not exhibit significant differences in mutations of the Ki-ras gene or in microsatellite instability. Genetic changes were then examined in small parts of serrated adenomas, such as the upper or lower parts of crypts, to determine the extent of gene mutations by using a microdissection technique. Exon 15 of the APC gene and the DCC gene, in addition to the p53 and Ki-ras genes and microsatellite instability, were analysed. Identical mutations of the p53 gene were found in both invasive adenocarcinomas and adjacent serrated adenomas by direct sequencing, suggesting single clonal origins for those lesions. Mutations of the APC gene and microsatellite instability were heterogeneous in some lesions. No loss of heterozygosity (LOH) of the DCC gene was found. These findings suggest that mutations of the p53 gene are the most characteristic genetic alterations in serrated adenomas, as a relatively early event in a multistep carcinogenic pathway of this type of colorectal lesion, that might be distinct from the ordinary adenoma-carcinoma sequence or from carcinogenesis via mutations of mismatch repair genes.

The role of endoscopic findings for the diagnosis of Helicobacter pylori infection: evaluation in a country with high prevalence of atrophic gastritis

BACKGROUND

This study examines endoscopic findings in the diagnosis of Helicobacter pylori (H. pylori) in the Japanese population.

MATERIALS AND METHODS

The endoscopic findings (including gastric fold findings and degree of atrophy by the Kimura-Takemoto classification system), histologic severity of inflammation, and glandular atrophy were assessed according to the Sydney system in 642 patients (419 men; 223 women; mean age 43.5 years, range 13-86). H. pylori infection was evaluated by Giemsa staining and serum IgG antibodies.

RESULTS

391 of 642 patients (60.9%) were diagnosed as having endoscopic gastritis. Of the 391 patients with endoscopic gastritis, 318 (82.6%) had histologic gastritis and 310 (79.3%) had H. pylori infection. Of the 251 patients with endoscopically normal stomachs, 43 (17.1%) had histologic gastritis and 32 (12.7%) had H. pylori infection. Atrophic gastritis was the most prevalent finding (56.3%) among those with endoscopic gastritis. The prevalence of H. pylori infection in patients with atrophic gastritis (92.7%) and rugal hyperplastic gastritis (92.3%) was significantly higher than in those with other types of gastritis or with a normal stomach (12. 7%). A markedly high prevalence of H. pylori infection was found in subjects with tortuosity, hyperrugosity, and/or hyporugosity of the gastric folds.

CONCLUSIONS

The accurate endoscopic assessment of gastritis according to the Sydney system along with gastric fold findings and the endoscopically identified extent of gastric atrophy are valuable indicators for determining H. pylori infection and histologic gastritis in the Japanese population.

Laparoscopic resection of submucosal gastric tumors

In order to elucidate the efficacy in gastric surgery, we evaluated seven resected cases of a submucosal gastric tumor in which laparoscopic techniques were used. The patients consisted of 1 man and 6 women. The tumors were located in the upper, middle, and lower third of the stomach in 4, 1, and 2 cases, respectively. Three tumors were located mainly on the anterior gastric wall, 2 were on the posterior wall, and 2 were on the lesser curvature. The resected tumor size averaged 3.2 x 2.6 cm. The tumors were classified as intraluminal type (4 cases) and the extraluminal type (3 cases) according to the classification of growth type. A histopathological examination identified 4 leiomyomas, 1 leiomyosarcoma, and 4 smooth muscle tumors of indeterminate malignant potential. After a tumor resection, no recurrence of the lesions occurred during the postoperative follow-up. An extraluminal growing tumor was easily resected by the laparoscopic method without any additional procedures, and this therefore seemed to be a good indication for the laparoscopic method. In contrast, an intraluminal tumor was found to be more difficult to resect using the laparoscopic method without a companion method, e.g., intraoperative endoscopy, because of the difficulties in the detection and resection of the tumor from the serosal side. A more efficient technique must therefore be developed for this type of tumor.

Eradication of Helicobacter pylori increases gastric acidity in patients with atrophic gastritis of the corpus-evaluation of 24-h pH monitoring

BACKGROUND

Recent studies have shown that the eradication of Helicobacter pylori results in a gastric acid secretion which decreases to normal levels in patients with duodenal ulcer disease. The aim of this study was to evaluate the effect of eradication of H. pylori in a 24-h study of gastric acidity in patients with atrophic gastritis of the corpus.

METHODS

Intragastric acidity was measured by continuous 24-h pH monitoring, and the histology of the gastric antrum and corpus were evaluated in 14 H. pylori-positive patients with histologically proven atrophic gastritis of the corpus (10 men, 4 women; mean age, 57 years) before and 1 year after anti-H. pylori therapy.

RESULTS

H. pylori was absent in 13 of 14 patients 1 year after treatment. Both gastritis and atrophy scores were significantly lower after eradication therapy (P < 0.01). The 24-h median pH and the percentage of 24-h pH readings above 4.0 units were significantly decreased after eradication therapy (from 5.12 +/- 0.36 to 2.69 +/- 0.21, and from 65.5 +/- 6.6% to 28.2 +/- 6.1%, P < 0.01, respectively.)

CONCLUSION

Eradication of H. pylori increases 24-h gastric acidity in patients with atrophic gastritis of the corpus. Improvement of the histology of the gastric antrum and corpus may lead to the normalization of gastric acidity.

Cyclin E overexpression in human gallbladder carcinomas

The expression of cyclin E, one of the important positive cell cycle regulators, was examined immunohistochemically in gallbladder carcinomas. Cyclin E gene product was detected in 58 (49%) out of 118 cases. The degree of cyclin E expression was not associated with any clinicopathological factor including histology, the depth of tumor invasion, tumor stage and patient prognosis. Cyclin E expression was not correlated with that of p53 protein statistically, whereas it was correlated with the proliferative activity of the tumor cells by PCNA (p<0.05). These results suggested that cyclin E expression may confer progression of gallbladder carcinomas.

Daily aerobic exercise improves reactive hyperemia in patients with essential hypertension

The effects of long-term aerobic exercise on endothelial function in patients with essential hypertension remain unclear. To determine whether endothelial function relating to forearm hemodynamics in these patients differs from normotensive subjects and whether endothelial function can be modified by continued physical exercise, we randomized patients with essential hypertension into a group that engaged in 30 minutes of brisk walking 5 to 7 times weekly for 12 weeks (n=20) or a group that underwent no activity modifications (control group, n=7). Forearm blood flow was measured using strain-gauge plethysmography during reactive hyperemia to test for endothelium-dependent vasodilation and after sublingual nitroglycerin administration to test endothelium-independent vasodilation. Forearm blood flow in hypertensive patients during reactive hyperemia was significantly less than that in normotensive subjects (n=17). Increases in forearm blood flow after nitroglycerin were similar between hypertensive and normotensive subjects. Exercise lowered mean blood pressure from 115.7+/-5.3 to 110.2+/-5.1 mm Hg (P<0.01) and forearm vascular resistance from 25.6+/-3.2 to 23. 2+/-2.8 mm Hg/mL per minute per 100 mL tissue (P<0.01); no change occurred in controls. Basal forearm blood flow, body weight, and heart rate did not differ with exercise. After 12 weeks of exercise, maximal forearm blood flow response during reactive hyperemia increased significantly, from 38.4+/-4.6 to 47.1+/-4.9 mL/min per 100 mL tissue (P<0.05); this increase was not seen in controls. Changes in forearm blood flow after sublingual nitroglycerin administration were similar before and after 12 weeks of exercise. Intra-arterial infusion of the nitric oxide synthase inhibitor NG-monomethyl-L-arginine abolished the enhancement of reactive hyperemia induced by 12 weeks of exercise. These findings suggest that through increased release of nitric oxide, continued physical exercise alleviates impairment of reactive hyperemia in patients with essential hypertension.

Effect of L-arginine infusion on systemic and renal hemodynamics in hypertensive patients

This study was designed to compare the renal endothelial function in patients with essential hypertension and normal renal function with that in hypertensive patients with renal insufficiency. We studied the effects of L-arginine (500 mg/kg intravenously over 30 min) on renal hemodynamics in 30 normotensive control subjects, 32 patients with mild to moderate essential hypertension who had normal renal function, and seven hypertensive patients with renal insufficiency who had a serum creatinine concentration >2.0 mg/mL and a glomerular filtration rate <50 mL/min/1.48 m2. L-Arginine infusion similarly reduced the mean blood pressure between the three groups (normotensive: -9.7% +/- 0.7%, hypertensives with normal renal function: -10.2% +/- 0.8%, and hypertensives with renal insufficiency: -8.2% +/- 1.3%). The L-arginine-induced decrease in renal vascular resistance was smaller in essential hypertensive patients than in normotensive subjects (-11.0% +/- 2.2 v -19.8% +/- 2.1%, P <.05). However, L-arginine had no effect on the renal vascular resistance in hypertensive patients with renal insufficiency (1.6% +/- 4.8%). Urine nitrite/nitrate levels in response to L-arginine significantly increased in the three groups in the following order: patients with renal insufficiency (47% +/- 15%), essential hypertensive patients (87% +/- 10%), and normotensive subjects (129% +/- 12%). The glomerular filtration rate was unaffected by L-arginine in normotensive and essential hypertensive patients (3.1% +/- 2.4% and 4.2% +/- 2.5%), but significantly decreased in hypertensive patients with renal insufficiency (-13.7% +/- 6.1%). These findings suggest that the ability of the L-arginine-nitric oxide-cGMP pathway to relax the renal vascular tone may be impaired in essential hypertensive patients and more markedly blunted in hypertensive patients with renal insufficiency, in parallel with increasing serum creatinine concentrations.

Partial characterization of mechanisms of cytoprotective action of hydrophilic bile salts against hydrophobic bile salts in rats: relation to canalicular membrane fluidity and packing density

Bile salts regulate the subselection of phosphatidylcholine species secreted into bile and thereby modulate bile metastability. The aim of this study was to determine whether bile salts alter phosphatidylcholine species of the canalicular membrane, and if they do, to clarify whether the cytoprotective action of hydrophilic bile salts is associated with modulation of phosphatidylcholine composition in cell membrane bilayers. Bile salt-pool-depleted rats were infused intravenously with sodium taurocholate at a constant rate (200 nmol/min/100 g body wt) for 2 hr, followed by infusion of either sodium tauroursodeoxycholate, sodium tauroalphamuricholate, or sodium taurobetamuricholate (200 nmol/min/100 g) for 2 hr. Biliary outputs of cholesterol and phosphatidylcholine and phosphatidylcholine hydrophobicity in bile and subcellular fractions were determined. The cytoprotective action of hydrophilic bile salts was determined by the release of canalicular membrane-localizing enzymes (alkaline phosphatase, leucine aminopeptidase) into bile. Tauroursodeoxycholate, taurobetamuricholate, and tauroalphamuricholate decreased the release of these enzymes when compared to values under taurocholate infusion. Bile phosphatidylcholine hydrophobicity was also decreased by the bile salts, whereas the cholesterol/phosphatidylcholine ratio was increased. In contrast, phosphatidylcholine hydrophobicity in the canalicular membrane was increased by these three bile salts. In conclusion, hydrophilic bile salts promote biliary secretion of relatively hydrophilic phosphatidylcholine secretion into bile, and consequently phosphatidylcholine hydrophobicity in canalicular membranes increased. Such an alteration in phosphatidylcholine species within canalicular membrane enhances its lateral packing density with less fluidity, and this may account, in part, for the cytoprotective action of hydrophilic bile salts against hydrophobic bile salts.

Evaluation of the colorectal wall in normal subjects and patients with ulcerative colitis using an ultrasonic catheter probe

BACKGROUND

Ulcerative colitis is usually evaluated by barium enema and colonoscopy, methods of imaging that are limited to the mucosal surface. Endoscopic ultrasonography (EUS) is the best modality for the evaluation of transmural changes in the bowel wall. We therefore evaluated the colorectal wall in normal control subjects and patients with ulcerative colitis using an ultrasonic catheter probe.

METHODS

Endoscopic ultrasound with a catheter probe was performed on 36 normal control subjects (36 examinations) and 72 patients (111 examinations) with documented ulcerative colitis.

RESULTS

In normal control subjects, the total wall, mucosa, submucosa, and muscularis propria were significantly thicker in the rectum than in the colon. There was no significant difference in the thickness of the colon and rectum among different age groups or between men and women. In ulcerative colitis, we classified the boundary of each layer into three patterns (smooth, irregular, and blurred) and then classified the wall into six types. In Matts grade 2 and 3 ulcerative colitis lesions, the total wall and each layer were significantly thicker than lower grade lesions and normal control subjects. For grade 1 and most of the grade 2 lesions, the boundary of each layer was smooth. In some of the grade 3 lesions, the mucosa-submucosa and submucosa-muscularis propria layer borders were abnormal. In all grade 4 cases, the mucosa-submucosa boundary was blurred. There was some correlation between the Matts grade and EUS findings except for Matts grade 3 lesions which had various EUS patterns.

CONCLUSION

Endoscopic ultrasound with a catheter probe is a useful modality for the transmural assessment of the colorectal wall and, when used in conjunction with the many clinical and endoscopic parameters currently available, may contribute to the diagnosis and treatment of ulcerative colitis.

The comparative potency of cholesterol crystallization-effector proteins in supersaturated model bile systems: association with vesicle transformation

Various proteins which affect cholesterol crystallization are known to be present in bile, although the relative potency of their action is yet to be established. In this study, we evaluated the comparative potency of nucleating-effector proteins using a recently developed method for quantitative assessment of vesicle transformation in supersaturated model bile systems, to partially characterize mechanisms of their action. Concanavalin A-bound glycoproteins isolated from human gall-bladder bile shortened cholesterol crystallization time by 40% and increased cholesterol growth rate and final crystal mass by 161 and 19%, respectively, when compared to the control. In addition, immunoglobulins isolated from human gall-bladder bile increased cholesterol growth rate by 9%, but showed no significant effect on cholesterol crystallization time and final crystal mass. In contrast, human serum apolipoproteins A-I and B reduced cholesterol growth rate by 26 and 31% and reduced final crystal mass by 12 and 21%, but did not affect cholesterol crystallization time. Gel permeation chromatography revealed that proteins were distributed to both vesicles and bile salt micelles, but that no marked redistribution of lipids was caused by addition of these proteins. Furthermore, no significant difference in crystal structure was observed by video-enhanced contrast microscopy. These results indicate that nucleating-effector substances tested in this study may modulate vesicular cholesterol-holding capacity, thus affecting cholesterol crystallization. Such modulation is based upon the protein-vesicle association which defines the physico-chemical metastability of vesicular cholesterol.

Growth patterns in various macroscopic types of noninvasive intramucosal colorectal carcinoma with special reference to apoptosis and cell proliferation

PURPOSE

Apoptotic cell death and cell proliferation play important roles in the histogenesis and development of colorectal carcinoma. The aim of this study was to examine the relationship between apoptosis and cell proliferation in various macroscopic types of intramucosal colorectal carcinoma in relation to the expression of p53 and bcl-2.

METHODS

One hundred forty cases with endoscopically or surgically resected intramucosal colorectal carcinoma were studied. There were 57 cases of polypoid-type carcinomas, 55 cases of superficial-type carcinomas, and 28 cases of granular-type, laterally spreading tumors. Polypoid-type carcinomas were pedunculated, subpedunculated, or sessile polyps. Superficial-type carcinomas were flat lesions with a smooth, even surface. Granular-type, laterally spreading tumors were superficially spreading lesions with aggregates of nodules and a granular surface. Apoptotic cells were identified by the in situ DNA nick end labeling method. Ki-67, p53, and bcl-2 expression were examined immunohistochemically.

RESULTS

The superficial-type carcinoma apoptotic index (30.9 percent) was significantly lower than that of polypoid-type carcinoma (54.4 percent) and granular-type, laterally spreading tumor (60.7 percent). The superficial-type carcinoma proliferative index (67.3 percent) was significantly higher than that of polypoid-type carcinoma (42.1 percent) and granular-type, laterally spreading tumor (28.6 percent). In superficial-type carcinomas the proliferative index in p53-positive carcinomas was significantly higher, and the apoptotic index was higher in carcinomas with a lower proliferative index. There was no significant difference in apoptotic index, proliferative index, or p53 protein overexpression between de novo carcinomas and those that had arisen in precursor adenomas.

CONCLUSIONS

The pattern of cell death and proliferation may vary with different macroscopic types of intramucosal colorectal carcinoma. Superficial-type colorectal carcinomas especially demonstrate diminished apoptosis and increased cell proliferation. This may be useful in understanding their biologic behavior.

In situ mRNA hybridization technique for analysis of human telomerase RNA in gastric precancerous and cancerous lesions

Telomerase, the ribonucleoprotein enzyme that elongates telomerase, is repressed in normal somatic cells but is reactivated during tumor progression. The purpose of this study was to investigate the localization of human telomerase RNA (hTR) expression in human gastric precancerous and cancerous lesions by using in situ mRNA hybridization (ISH) with avidin-biotin staining. We also examined telomerase activity in these lesions by using hybridization protection assay connected with a telomeric repeat amplification protocol (TRAP/HPA). Analyzed tissue samples were as follows; 132 cases of chronic atrophic gastritis without intestinal metaplasia, 115 incomplete-type intestinal metaplasias, 40 complete-type intestinal metaplasias, 23 hyperplastic polyps, 23 tubular adenomas and 26 adenocarcinomas. In ISH analysis, high levels of hTR expression were observed preferentially in the nuclei at the single-cell level. hTR-expressing cells in carcinomas and adenomas were significantly more frequent than those of the other lesions (P < 0.001). The expression pattern of hTR in carcinoma and adenoma tissues was heterogeneous and similar intratumor heterogeneity was detected in Ki-67 immunoreactivity. Infiltrating lymphocytes in tissue also exhibited high levels of hTR expression. In TRAP/HPA analysis, carcinomas had significantly more frequent positivity for telomerase activity and a higher level of telomerase activity than the other lesions (P < 0.05). However, the amount of telomerase activity did not parallel the expression level of hTR. Our data suggest that hTR expression increases in the early stages of stomach carcinogenesis and that sufficient synthesis of hTR is a prerequisite for telomerase reactivation in tumorigenesis.

Induction and persistence of immune-mediated cholangiohepatitis in neonatally thymectomized mice

The availability of recombinant autoantigens allows the experimental study of the relationships between primary biliary cirrhosis (PBC) and mitochondrial antigens. We took advantage of these recombinant autoantigens and attempted to induce autoimmune cholangitis by immunizing neonatally thymectomized (NTx) lipopolysaccharide (LPS)-treated A/J mice, known to be prone to organ-specific autoimmune diseases. We employed a recombinant protein containing a dual-headed molecule that coexpresses the immunodominant epitope of the E2 subunits of the pyruvate dehydrogenase complex and the branched-chain keto-acid dehydrogenase complex. We report herein that an immune-mediated cholangiohepatitis was induced by such immunization and the concurrent injection of LPS into NTx mice. The incidence of cholangitis was 79% in the NTx, immunized, LPS group compared to 14% in the NTx, nonimmunized, LPS group. The histopathology ranged from mild to severe and included bile duct damage, focal hepatic necrosis, and endotheliitis, but no granulomas. Moreover, almost all such lesions persisted for 12 weeks after the discontinuation of immunization and LPS injections in the NTx mice. Interestingly, we were successful (89%) in transferring the cholangiohepatitis by injection of liver infiltrating mononuclear cells from the NTx, immunized, LPS mice into congenic nonimmunized NTx mice; such lesions could not be transferred with spleen cells. Although the pathology is not typical of PBC, this model offers a unique venue for the study of immune-mediated hepatobiliary injury.

MUC-1 expression as a predictor of the curative endoscopic treatment of submucosally invasive colorectal carcinoma

PURPOSE

This study was undertaken to clarify the clinical significance of MUC-1 expression in the endoscopic treatment of colorectal carcinoma with submucosal invasion.

METHODS

One hundred eighty-four colorectal carcinomas with submucosal invasion were examined. The depth of submucosal invasion was classified as scanty or massive. The histologic subclassification at the deepest invasive portion was defined as well-differentiated, moderately well-differentiated, moderately to poorly differentiated, poorly differentiated, or mucinous adenocarcinoma. MUC-1 expression was examined immunohistochemically at the deepest invasive portion. In addition, the Ki67 labeling index was also examined immunohistochemically.

RESULTS

Lymph node metastases were detected in 28 (15.2 percent) of 184 lesions. Lesions with both scanty submucosal invasion and well-differentiated or moderately well-differentiated adenocarcinomas had no lymph node metastases. MUC-1 expression was detected in 88 (47.8 percent) of 184 lesions and correlated significantly with the presence of lymph node metastases. The Ki67 labeling index also correlated significantly with lymph node metastases. Furthermore, lesions with both MUC-1-negative and low Ki67 labeling index showed no lymph node metastases, even in lesions with massive submucosal invasion. Multivariate analysis indicated that MUC-1 expression was one of the most important risk factors for lymph node metastases and histologic grade among the clinicopathologic factors usually examined.

CONCLUSION

MUC-1 expression is one of the accurate predictors of the presence of lymph node metastases among the clinicopathologic factors commonly used. Combined analysis of MUC-1 expression and Ki67 labeling index may be a useful indicator of lymph node metastases and may broaden the indications for the curative endoscopic treatment of carcinoma with massive submucosal invasion.

Frequent p53 gene mutations in serrated adenomas of the colorectum

Serrated adenoma has been recently proposed as a distinct histological lesion of the colorectum. This study examined p53 immunoreactivity, mutations of exons 5-8 of the p53 gene, codon 12 of the Ki-ras gene by PCR-SSCP analyses, and microsatellite instability in 19 serrated adenomas, ten adenocarcinomas in/with serrated adenomas, 23 hyperplastic nodules, four hyperplastic polyps and 29 tubular adenomas of the colorectum. Eleven of 11 (100 per cent) serrated adenomas had p53 immunoreactivity and all six (100 per cent) adenocacinomas in/with serrated adenomas exhibited moderate to severe p53 immunoreactivity. It was confirmed that 9 of 19 (47 per cent) serrated adenomas and 5 of 10 (50 per cent) adenocarcinomas in/with serrated adenomas harboured p53 gene mutations. On the other hand, no p53 gene mutation was detected in the other colorectal lesions. Meanwhile, 11 (58 per cent) serrated adenomas and six (60 per cent) adenocarcinomas in/with serrated adenomas had Ki-ras gene mutations, as also did 9 of 23 (39 per cent) hyperplastic nodules, 3 of 4 (75 per cent) hyperplastic polyps, and 12 of 29 (41 per cent) tubular adenomas. Microsatellite instability was detected in one (5 per cent) serrated adenoma and one (10 per cent) adenocarcinoma in a serrated adenoma. The other lesions did not show microsatellite instability. Serrated adenomas had significantly frequent p53 gene mutations compared with hyperplastic lesions or tubular adenomas (p < 0.005). On the other hand, they did not exhibit significant differences in mutations of the Ki-ras gene or in microsatellite instability. Genetic changes were then examined in small parts of serrated adenomas, such as the upper or lower parts of crypts, to determine the extent of gene mutations by using a microdissection technique. Exon 15 of the APC gene and the DCC gene, in addition to the p53 and Ki-ras genes and microsatellite instability, were analysed. Identical mutations of the p53 gene were found in both invasive adenocarcinomas and adjacent serrated adenomas by direct sequencing, suggesting single clonal origins for those lesions. Mutations of the APC gene and microsatellite instability were heterogeneous in some lesions. No loss of heterozygosity (LOH) of the DCC gene was found. These findings suggest that mutations of the p53 gene are the most characteristic genetic alterations in serrated adenomas, as a relatively early event in a multistep carcinogenic pathway of this type of colorectal lesion, that might be distinct from the ordinary adenoma-carcinoma sequence or from carcinogenesis via mutations of mismatch repair genes.

Effect of adenosine triphosphate on human coronary circulation

We investigated in humans the effects of adenosine triphosphate (ATP), administered by intracoronary bolus (4-16 microg) or intravenous infusion (25-200 microg/kg/min), on coronary and systemic hemodynamics and electrocardiogram (ECG) variables. All patients had normal epicardial coronary arteries. The maximal coronary blood flow velocity (CBFV) was determined with intracoronary bolus of papaverine. A 12 microg bolus of ATP (n=12) caused maximal coronary hyperemia similar to that caused by papaverine. Intracoronary boluses caused a small brief decrease in arterial pressure but no significant changes in HR or ECG variables. Intravenous infusion of ATP at 150 microg/kg/min (n=15) caused a decrease in the coronary resistance index similar to that caused by papaverine, but the rate of increase in CBFV by ATP was smaller than that caused by papaverine. No patients had a significant change in ECG variables, but some patients (40%) had a serious decrease in arterial pressure. These studies suggest that maximal coronary vasodilation can be achieved safely with intracoronary ATP administration and that intravenous infusions at 150 microg/kg/min cause near-maximal coronary hyperemia in most patients.

Significance of vessel count and vascular endothelial growth factor in human esophageal carcinomas

The purpose of this study was to determine the angiogenic profile of human esophageal carcinomas. The expression of vascular endothelial growth factor (VEGF) was examined in 6 esophageal carcinoma cell lines and 119 human esophageal carcinoma tissues by Northern blot analysis and immunohistochemistry, respectively. Immunohistochemistry using antibodies against CD34 (endothelial cell specific) was carried out on archival specimens, and microvessels were quantitated by counting vessels in a x200 field in the most vascular area of the tumor. All of the cell lines constitutively expressed VEGF mRNA at various levels. A total of 71 of 119 (59.7%) tumors showed intense VEGF immunoreactivity in the cytoplasm of cancer cells. Vessel count was significantly higher in the VEGF-positive tumors than it was in the VEGF-negative tumors. VEGF expression correlated with the depth of tumor invasion, tumor stage, venous invasion, and lymphatic invasion. The survival rate of patients with high vessel density in the tumor was significantly worse than that of patients with low vessel density in the tumor. There was a tendency for poorer prognosis in the group with VEGF-positive tumors compared with that of the group with VEGF-negative tumors. Overall, these results suggest that VEGF is associated with tumor progression by stimulating angiogenesis in human esophageal carcinoma.

Expression of vascular endothelial growth factor in human gallbladder lesions

The purpose of this study was to examine whether vascular endothelial growth factor (VEGF) regulates angiogenesis in human gallbladder carcinomas. We examined the expression of VEGF in 131 gallbladder lesions by immunohistochemistry and in situ mRNA hybridization technique. VEGF immunoreactivity was detected in 100% (9/9) of hyperplasias, 75% (3/4) of adenomas and 91% (107/118) of carcinomas. In gallbladder carcinoma tissues, VEGF mRNA level directly correlated with its protein level. VEGF expression in the neoplasms significantly correlated with vascularization, but not prognostic parameters. These findings suggest that VEGF is commonly expressed in human gallbladder carcinomas and may contribute to neovascularization during carcinogenesis.

Helicobacter pylori infection and gastric neoplasia: correlations with histological gastritis and tumor histology

OBJECTIVE

Several authors have reported an association between Helicobacter pylori (H. pylori) and gastric carcinoma, but the data are conflicting. Atrophic gastritis and intestinal metaplasia (IM) have also been linked to gastric carcinoma, especially the intestinal tumor type. We investigated the relationship between H. pylori infection, gastric neoplasms, and histological gastritis.

METHODS

A total of 105 patients with gastric carcinoma, 36 patients with gastric adenoma, and 105 age- and sex-matched control subjects were examined for H. pylori infection and histological gastritis. H. pylori status was evaluated by Giemsa staining and IgG serology. Mucosal inflammation, atrophy, and IM were evaluated in biopsy specimens from antrum and corpus.

RESULTS

H. pylori seroprevalence was higher in patients with gastric carcinoma (98 of 105, 93%) and adenoma (34 of 36, 94%) than in control subjects (82 of 105, 71%, p < 0.05). H. pylori was more prevalent in patients with noncardia (OR, 5.67; 95% CI, 2.25-14.44) than cardia (OR, 5.20; 95% CI, 0.65-41.68) tumors. Histologic types and tumor stage (early; OR, 6.60; 95% CI, 2.23-19.69, advanced; OR, 4.27; 95% CI, 1.21-15.03) showed no difference in H. pylori prevalence. Atrophy and IM scores were higher in patients with the intestinal- but not diffuse-type of carcinoma and adenoma than in H. pylori-positive control subjects. Smoking was associated with gastric carcinoma (OR, 3.05; 95% CI, 1.58-5.93) but not alcohol or coffee use, blood group A, or a family history of gastric cancer.

CONCLUSIONS

Our results confirm a strong association between H. pylori and gastric carcinoma and adenoma. The intestinal-type gastric carcinoma is associated with atrophic gastritis and IM.

Abnormal platelet Ca2+ handling accompanied by increased cytosolic free Mg2+ in essential hypertension

To test the hypothesis that abnormal platelet Ca2+ handling in essential hypertension results from cellular Mg2+ deficiency, cytosolic free Mg2+ concentration ([Mg2+]i) and Ca2+ metabolism were studied in mag-fura 2 and fura 2-loaded platelets from 30 essential hypertensive patients and 30 sex- and age-matched normotensive controls. Basal cytosolic free Ca2+ concentration ([Ca2+]i) and intracellular Ca2+ discharge capacity were higher in hypertensives than in normotensives (22 +/- 5 vs. 18 +/- 5 nM, P < 0.05; 743 +/- 250 vs. 624 +/- 144 nM, P < 0.05, respectively). The thrombin (0. 03-1.0 U/ml)-evoked [Ca2+]i response was also enhanced in platelets from hypertensives in both the absence and presence of extracellular Ca2+. However, basal [Mg2+]i was higher in hypertensives than in normotensives (437 +/- 110 vs. 353 +/- 85 microM, P < 0.05), whereas serum Mg2+ was similar in the two groups. These results oppose the Mg2+ deficiency hypothesis in platelets in essential hypertension.

Correlation of ratio of serum pepsinogen I and II with prevalence of gastric cancer and adenoma in Japanese subjects

OBJECTIVE

Gastric cancer (GC) and adenoma (GA) are reported to be related to atrophic gastritis, in which the serum pepsinogen (PG) I level and the PGI/PGII ratio (I/II ratio) are reduced. To verify that the finding of a low PG level increases the risk for GC and GA, we investigated the correlation between low PG levels and the prevalence of GC and GA in individuals.

METHODS

The 2,039 subjects (734 Japanese men, mean age 68.5 yr, and 1,305 women, mean age 66.7 yr), selected from among 10,996 local residents who underwent health check-ups based on reductions in their serum PG levels, underwent upper gastrointestinal endoscopy.

RESULTS

Gastrointestinal endoscopy detected 21 GCs and 15 GAs. The prevalence of GC was higher than that in the residents without low serum PG. The percentage of early stage of GC (90%) was significantly higher than that of GC detected in unscreened residents (56.9%). The prevalence of GC in men was closely and significantly correlated with the I/II ratio (r = 0.935, p = 0.0063), whereas there was less correlation with age (r = 0.842, p = 0.0734). The prevalence of GA was also closely and significantly correlated with the I/II ratio in men (r = 0.881, p = 0.0203), but not with age (r = 0.163, p = 0.7928). In women the prevalence of GC (r = 0.744, p = 0.090) and GA (r = 0.678, p = 0.1392) did not correlate as strongly with the I/II ratio, although the highest prevalence was seen in the group with the lowest I/II ratio.

CONCLUSION

Our study verified that a low I/II ratio signifies a high risk for GC and GA and that measuring serum PG levels can be used as a screening method for GC and GA.

Combined expression of HLA-DR antigen and proliferating cell nuclear antigen correlate with colorectal cancer prognosis

HLA-DR antigen expression and the proliferating cell nuclear antigen labeling index (PCNA-LI) were examined immmunohistochemically in 59 surgically resected advanced colorectal cancers to clarify the clinicopathologic significance of the HLA-DR antigen. HLA-DR antigen expression was detected in 33 (56%) of the 59 lesions, which showed less frequent liver metastasis than lesions without HLA-DR antigen expression (40 vs. 68%; p < 0.05). Five-year survival rates of patients with and without HLA-DR antigen expression were 50 and 19%, respectively. Lesions combining HLA-DR antigen expression and a relatively low PCNA-LI had the best prognosis. These results indicate that HLA-DR antigen expression, particularly combined with a low PCNA-LI, is an important outcome predictor in colorectal cancer.

Expression of vascular endothelial growth factor in human gastric carcinomas

Vascular endothelial growth factor (VEGF), also known as vascular permeability factor, is a secreted protein which may play a pivotal role in tumor-associated microvascular angiogenesis and hyperpermeability. The expression of mRNA for VEGF was examined in eight gastric carcinoma cell lines and 30 gastric carcinoma tissues as well as corresponding normal mucosa. All the cell lines expressed VEGF mRNA at various levels that correlated well with the amounts of VEGF secreted into the condition medium. The expression of VEGF mRNA by TMK-1 cells was increased by the treatment of epidermal growth factor (EGF) or interleukin-1alpha (IL-1alpha), whereas it was decreased by the treatment of interferon-beta (IFN-beta). In gastric carcinoma tissues, the level of VEGF mRNA in primary tumors was higher than that in the corresponding normal mucosas in six (46%) of 13 well-differentiated adenocarcinomas and in two (12%) of 17 poorly differentiated adenocarcinomas, respectively. Vessel counts in well-differentiated adenocarcinomas had a tendency to be higher than those in poorly differentiated adenocarcinomas. In well-differentiated adenocarcinomas, the levels of VEGF mRNA expression tended to be higher in carcinomas of advanced stage than in early stage carcinomas. Both in situ mRNA hybridization and immunohistochemistry demonstrated the presence of VEGF expression within the tumor cells. These results suggest that VEGF may confer angiogenesis and progression of human gastric carcinomas, especially of the well-differentiated type.

Angiotensin-converting enzyme inhibition, but not calcium antagonism, improves a response of the renal vasculature to L-arginine in patients with essential hypertension

Endothelial function has been shown to be impaired in patients with essential hypertension. The purpose of the present study was to determine whether antihypertensive drug therapy improves impaired endothelium-dependent renal vasorelaxation in essential hypertensive patients without atherosclerosis. We evaluated the effects of intravenous infusion of L-arginine (500 mg/kg given over 30 minutes) on systemic and renal hemodynamics in 27 patients with mild to moderate essential hypertension who were randomly assigned to treatment with either the angiotensin-converting enzyme inhibitor imidapril or the calcium antagonist amlodipine for 12 weeks in a double-blind fashion. After the 12 weeks, the decrease in blood pressure was similar in the imidapril (n=14) and amlodipine (n=13) groups. The increase in renal plasma flow was also similar in both groups. L-Arginine-induced renovascular relaxation was increased by imidapril (renal plasma flow, 9.6+/-5.1% to 14.4+/-7.4%; renal vascular resistance, -10.4+/-8.1% to -16.7+/-9.2%, P<0.05, respectively) but not by amlodipine. Urinary excretion of nitrite/nitrate in response to L-arginine was significantly increased by imidapril (90+/-29% to 134+/-63%, P<0.05) but remained unchanged by amlodipine. These findings suggest that angiotensin-converting enzyme inhibition improves the impaired endothelium-dependent renovascular relaxation in patients with essential hypertension due to the increase in nitric oxide production and that the reduction in blood pressure with a calcium antagonist does not play a major role in the potentiation of L-arginine/nitric oxide-mediated effects.

Immunoreactive MUC1 expression at the deepest invasive portion correlates with prognosis of colorectal cancer

This study sought to examine the relationship between MUC1 expression at the deepest invasive portion, invasive/metastatic potential, and prognosis of colorectal cancer in relation to cellular proliferation. MUC1 expression was detected immunohistochemically using KL-6 antibody (anti-MUC1 monoclonal antibody) in 100 surgically resected specimens of advanced colorectal cancer. Distinct staining of the luminal surfaces, defined as positive immunoreactive (IR)-MUC1 expression, was seen in more than 30% of the tumor cells at the deepest invasive portion. The proliferating cell nuclear antigen labeling index (PCNA-LI) was also examined in the same areas. IR-MUC1 expression was detected in 71 (71%) of 100 lesions. Lesions with lymphatic or venous invasion showed a significantly higher incidence of IR-MUC1 expression than those without lymphatic or venous invasion (80 vs. 42% and 82 vs. 61%, respectively). Lesions with lymph node metastasis showed a significantly higher incidence of IR-MUC1 expression than those without lymph node metastasis (88 vs. 53%). Lesions with liver metastasis showed a significantly higher incidence of IR-MUC1 expression than those without liver metastasis (92 vs. 59%). Dukes' stage was also significantly correlated with IR-MUC1 expression. The incidence of IR-MUC1 expression did not significantly differ with regard to histologic subclassification and depth of invasion. There was no significant correlation between IR-MUC1 expression and the PCNA-LI. IR-MUC1 expression at the deepest invasive portion revealed a significant correlation with prognosis; furthermore, in patients with better differentiated lesions, in those with lesions confined to muscularis propria or subserosa (subadventitial) invasion, in those with Dukes' B and C, or in those undergoing curative resection, IR-MUC1 expression significantly correlated with prognosis. Patients with high PCNA-LI lesions showed a significantly poorer prognosis than those with low PCNA-LI lesions. Only in patients undergoing curative resection, patients with IR-MUC1-positive and high PCNA-LI lesions showed a significantly poorer prognosis than those with IR-MUC1-negative and low PCNA-LI lesions. The significant risk factors in the order of poorer prognosis in patients undergoing curative resection by the multivariate analysis were the histologic grade (moderately-poorly, poorly or mucinous adenocarcinomas), IR-MUC1 expression, and lymph node metastasis. These results indicate that IR-MUC1 expression is an important predictor of the metastatic potential and the prognosis of colorectal cancer, independent of histologic grade, depth of invasion or cellular proliferative activity. Combined analysis of IR-MUC1 and histologic grade, and combined expression of IR-MUC1 and PCNA at the deepest invasive portion are especially useful in predicting colorectal cancer prognosis.

Quantitative assessment of comparative potencies of cholesterol-crystal-promoting factors: relation to mechanistic characterization

The crystallization of cholesterol is affected by various factors in bile. The present study evaluated the relative importance of cholesterol-nucleation-promoting factors and partially characterized the mechanisms of their action. Model biles with an identical relative composition of cholesterol, egg-yolk phosphatidylcholine and taurocholate, except for replacing phosphatidylcholine (5-20%) with dilinoleoyl-phosphatidylcholine or taurocholate (10-30%) with taurodeoxycholate. Cholesterol crystallization was quantitatively assessed spectrophotometrically and morphologically estimated by the laser-scattering diffraction analyser and video-enhanced microscopy in the absence and presence of concanavalin A-binding glycoprotein isolated from human bile. In a series of experiments, lipid distribution among particulate species was determined after isolation by FPLC. In all experiments, cholesterol crystallization was dose-dependently enhanced with a rank order of: concanavalin A-binding glycoprotein > dilinoleoyl - phosphatidyl choline> taurodeoxycholate. No morphological alteration was evident for vesicles and crystals, but the cholesterol/phospholipid ratio in vesicles was increased significantly by replacement with dilinoleoyl-phosphatidylcholine and excess cholesterol. A high proportion of relatively hydrophilic phosphatidylcholine species such as dilinoleoyl-phosphatidylcholine and excess cholesterol in bile cause a redistribution of cholesterol to increase a vesicular cholesterol/phospholipid ratio, eventually promoting cholesterol crystallization, whereas concanavalin A-binding glycoprotein acts via differing mechanisms.

Effect of 17beta-estradiol on inhibition of platelet aggregation in vitro is mediated by an increase in NO synthesis

The low prevalence of coronary heart disease in premenopausal women and its increase after menopause are well established. Although estrogen is thought to play a role in protecting the vasculature, the mechanism has not been fully clarified. The contribution of platelets to atherosclerotic cardiovascular diseases is well recognized. The present study focused on the still-controversial effect of estrogen on platelet function. We investigated the in vitro effects of estrogen on human platelets, including their aggregation, Ca2+ metabolism, the synthesis of cyclic nucleotides, and NO (nitrite/nitrate) synthesis after stimulation with thrombin or ADP. Pretreatment of platelets with 17beta-estradiol reduced the platelet aggregation induced by thrombin or ADP, whereas 17alpha-estradiol had no effect. 17Beta-estradiol accelerated the recovery of [Ca2+]i after the agonist-induced peak and reduced the area under the curve of accumulated platelet [Ca2+]i but did not alter the baseline [Ca2+]i, Ca2+ influx induced by thrombin or ADP, the release of Ca2+ from internal stores, or the size of internal Ca2+ stores. Pretreatment of platelets with 17beta-estradiol had no effect on the intracellular concentration of cAMP but increased that of cGMP in agonist-stimulated platelets. Additionally, 17beta-estradiol increased the platelet concentration of nitrite/nitrate in a dose-dependent manner. These effects of 17beta-estradiol on platelet aggregation, Ca2+ metabolism, and NO synthesis were abolished by exposure to N(G)-monomethyl-L-arginine, an NO synthesis inhibitor. These results suggest that 17beta-estradiol plays an important role in inhibiting platelet aggregation by promoting Ca2+ extrusion or reuptake activity that is dependent on the production of cGMP by increasing NO synthesis.

A combination therapy with simvastatin and ursodeoxycholic acid is more effective for cholesterol gallstone dissolution than is ursodeoxycholic acid monotherapy

Inhibitors of 3-hydroxy,3-methylglutaryl coenzyme A (HMG-CoA) reductase have been reported to decrease the cholesterol saturation index (CSI) in duodenal bile in humans and to prevent formation of cholesterol gallstones in animal studies. We performed a prospective study to evaluate the role of HMG-CoA reductase inhibitors as gallstone-dissolving agents. Fifty patients with radiolucent gallstones in a gallbladder opacifying at drip infusion cholecystography were treated with either 10 mg/day simvastatin plus 600 mg/day ursodeoxycholic acid (group 1, n=26) or 600 mg/day ursodeoxycholic acid alone (group 2, n=24) for 12 months. The ratio of solitary to multiple gallstone cases was 21:29. Plasma lipid levels were assessed and ultrasonographic examination of the gallbladder was performed at baseline and at 3-month intervals during treatment. Duodenal bile sampling was performed in five patients in each group at baseline and after 12 months of treatment. Plasma cholesterol decreased significantly in group 1 but not in group 2. In solitary gallstone cases, no significant difference in dissolution rates was observed between groups 1 (3 of 9, 33%) and 2 (4 of 12, 33%). In contrast, the dissolution rate in multiple gallstone cases was significantly higher in group 1 (12 of 17, 71%) than in group 2 (3 of 12, 25%) (p < 0.01). Bile cholesterol saturation index was significantly decreased (p < 0.01) but did not significantly differ between the two groups. These results suggest that combination therapy with simvastatin and ursodeoxycholic acid is more effective for cholesterol gallstone dissolution than ursodeoxycholic acid monotherapy in patients with multiple gallstones.

DD genotype of the angiotensin I-converting enzyme gene is a risk factor for early onset of essential hypertension in Japanese patients

Although angiotensin-converting enzyme (ACE) plays an important role in blood pressure regulation, no relationship between the insertion/deletion (I/D) polymorphism of the ACE gene and essential hypertension has been observed. However, as the pathogenesis and genetic background of essential hypertension are heterogeneous, we investigated whether the ACE gene is a marker of subgroups of patients with essential hypertension. A group of 178 patients with essential hypertension (90 men/88 women; 53 +/- 13 years of age, mean age +/- SD ) and 101 normotensive control subjects (54 men/47 women; 51 +/- 14 years of age, mean age +/- SD ) were included in the study. The allele frequencies of the two groups were similar. There were no differences in age, blood pressure, retinopathy grade, presence of proteinuria, or resting plasma renin activity (PRA) among the hypertensive patients with the II, ID, and DD genotypes. However, the age of onset of hypertension of patients with the DD genotype was lower (p < 20.05) and their left ventricular mass index was higher (p < 2 0.05) than those in patients with the non-DD genotype. These data suggest that the I/D polymorphism of the ACE gene is associated with an early onset of hypertension and left ventricular hypertrophy in Japanese patients with essential hypertension.

Pepsinogen secretion: coupling of exocytosis visualized by video microscopy and [Ca2+]i in single cells

Conventional in vitro studies of pepsinogen secretion have measured secretion into the bulk medium and have demonstrated the critical role of Ca2+ in the process. The present study was undertaken to obtain further details of the process of secretion and its relation to Ca2+ changes over very short time periods. The relation between Ca2+ mobilization and exocytosis in an isolated individual peptic cell of the bullfrog was investigated by a method to measure both intracellular Ca2+ ([Ca2+]i), using a fluorescent Ca2+ indicator, fura 2, and exocytosis from single cells using a video microscope analyzing system. Bombesin (3.2 x 10(-7) M) and bethanechol (3.2 x 10(-4) M) caused a rapid increase in [Ca2+]i (initial peak) and a corresponding high frequency of initial exocytosis. After the initial peak, [Ca2+]i was maintained at a somewhat elevated level over the baseline (sustained phase), with a corresponding low frequency of exocytosis. Both the sustained phase of elevated [Ca2+]i and the related exocytosis were eliminated by the depletion of extracellular Ca2+. Low concentrations of bombesin (3.2 x 10(-10) M) and bethanechol (3.2 x 10(-7) M) caused sustained low-amplitude Ca2+ oscillations with correspondingly low frequencies but also caused sustained exocytosis. These data show that 1) cellular response differs between high and low concentrations of stimulus, 2) there is a close relation between [Ca2+]i and exocytosis, 3) exocytosis follows elevation of [Ca2+]i by 14-45 s (n = 6), and 4) there is a significant positive correlation between the peak [Ca2+]i and the number of exocytoses.

The association between antral G and D cells and mucosal inflammation, atrophy, and Helicobacter pylori infection in subjects with normal mucosa, chronic gastritis, and duodenal ulcer

OBJECTIVE

The aim of this study was to clarify the mechanism of inappropriate hypergastrinemia in Helicobacter pylori (H. pylori)-infected subjects.

METHODS

We measured fasting serum gastrin (SG) concentrations, and investigated immunohistochemically G and D cell numbers in 47 subjects with normal mucosa, 24 subjects with chronic gastritis, and 24 subjects with duodenal ulcer (DU). The degree of inflammation and atrophy were classified into four categories based on criteria established in the Sydney System: none, mild, moderate, and severe. Avidin-biotin complex methods were used to identify G and D cells, which were counted per unit square (0.25 mm2) in five random fields from each of two well-oriented antral and fundic biopsies. SG concentrations were measured by radioimmunoassay.

RESULTS

The G cell number was not significantly different between 24 subjects with H. pylori-associated gastritis and those with DU. However, the number of antral D cells was significantly lower and the G/D cell ratio was significantly higher in subjects with DU than in those with H. pylori-associated gastritis (p < 0.01), although the degree of inflammation and atrophy in the antrum and H. pylori status were similar between the two groups. The mean fasting SG concentration was higher in subjects with DU than in those with H. pylori-associated gastritis, but the difference was not statistically significant.

CONCLUSIONS

Our results demonstrate that a marked decrease in antral D cell number with a high G/D cell ratio may contribute to hypergastrinemia and the pathogenesis of DU.

Effects of cerivastatin sodium, a new HMG-CoA reductase inhibitor, on biliary lipid metabolism in patients with hypercholesterolemia

The use of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors has become common in the treatment of hypercholesterolemia. The present uncontrolled study was undertaken to determine the effect of cerivastatin sodium (BAY w 6228), a new HMG-CoA reductase inhibitor, on biliary lipid levels in patients with hypercholesterolemia. Twenty-one hypercholesterolemic patients (World Health Organization type IIa = 16 patients; type IIb = 5 patients) received placebo during a 4- to 6-week observation period, after which they received cerivastatin sodium 0.2 mg/d for 12 weeks. Fasting blood samples were drawn for the measurement of serum lipid levels early in the morning before the start of treatment and once a month for each of the 12 weeks of cerivastatin sodium treatment. Gallbladder bile samples were aspirated with a duodenal tube by cerulein stimulation to assess bile lithogenicity. Serum total cholesterol levels decreased markedly after 12 weeks. However, no significant difference was found in the molar percentage composition of biliary lipids (e.g., cholesterol, phospholipids, and total bile acids) or in individual biliary bile acids. Consequently, no significant change in bile cholesterol saturation index was found. The index values before and after 12 weeks of treatment were 0.81 +/- 0.38 and 0.80 +/- 0.47, respectively, whereas when patients were grouped by type of hypercholesterolemia, there was a tendency toward decreased lithogenicity in patients with type IIb but not type IIa hypercholesterolemia. We concluded that cerivastatin sodium was an effective cholesterol-lowering drug that did not appear to worsen biliary lipid metabolism and that may decrease lithogenicity in patients with type IIb hypercholesterolemia.

[Telomere length and telomerase activity in hepatocellular carcinoma]

Telomerase activity and terminal restriction fragment (TRF) length were examined in hepatocellular carcinoma (HCC). Telomerase activity was assayed by telomeric repeat amplification protocol (TRAP) connected with an internal telomerase assay standard (ITAS). The incidence of strong telomerase activity (highly variable level compared with the activity of non-cancerous liver tissue) was 79% in well, 84% in moderately, and 100% in poorly differentiated HCC, while 0% in non-cancerous liver tissues. The incidence of TRF length alteration (reduction or elongation) was 53% in HCC. The incidence of TRF alteration was significantly higher in HCC exceeding 3 cm in diameter, moderately or poorly differentiated in histology. Telomerase activity was not associated with TRF length alteration in HCC. In conclusion, strong telomerase activity and TRF length alteration increased with HCC tumor progressions.

Bile salt hydrophobicity modulates subselection of biliary lecithin species in rats depleted of bile salt pool

Although bile salts play an important role in the secretion of biliary lipid, little is known about the relationship between bile salt hydrophobicity and the selection of lecithin species to be secreted into bile. We therefore investigated whether bile salts modulate the selection of biliary lecithin subspecies. Rats that were depleted of the bile salt pool were infused with taurocholate (50, 100, 200, and 400 nmol/min/100 g body weight), taurochenodeoxycholate (25, 50, 100, and 200 nmol/min/100 g body weight), tauroursodeoxycholate (100, 200, 400, and 800 nmol/min/100 g body weight), or taurobetamuricholate (100, 200, 400, and 800 nmol/min/100 g body weight). Bile was collected to analyze bile flow, bile acid output, cholesterol levels, and lecithin levels. The hydrophobic-hydrophilic balance of the bile salts and biliary lecithin species was assessed by determining the retention times during reverse-phase high-performance liquid chromatography. Biliary lecithin secretion rates correlated with the hydrophobicity index of the biliary bile salts administered. Thus, biliary lecithin hydrophobicity increased with increasing bile salt hydrophobicity, whereas the molar cholesterol-lecithin ratio in the bile decreased. In conclusion, bile salt hydrophobicity regulates the selection of biliary lecithin subspecies during biliary secretion and thereby modulates, at least in part, bile cholesterol metastability. Thus, bile salt hydrophobicity accounts for the physicochemical conditions determining bile lipid metastability.

[Telomerase activity in pancreatic juice for the preoperative diagnosis of pancreatic cancer]

Although many diagnostic challenges have been tried in pancreatic cancer, its prognosis still remains poor. One of the reason that it is difficult to diagnose using present diagnostic procedure in early stage of pancreatic cancer. Therefore, we tried new procedure using telomerase activity from pancreatic juice. In this study, telomerase was assayed by use of pancreatic duct cells obtained preoperatively from 32 cases with pancreatic duct abnormalities. Telomerase activity was undetectable in all 17 subjects with benign pancreatic diseases, whereas 13 (87%) of 15 subjects with pancreatic cancer had detectable telomerase activity. Interestingly, we also detected telomerase activity in the case of carcinoma in situ. If future studies confirm, the detection of telomerase activity of pancreatic duct cells may become an useful tool for diagnosis of pancreatic cancer, perhaps at early stages.

The establishment of a preoperative diagnosis of pancreatic carcinoma using cell specimens from pancreatic duct brushing with special attention to p53 mutations

BACKGROUND

Previously, the authors reported that 82% of cases of pancreatic carcinoma were positive for p53 in cytologic specimens obtained by selective endoscopic pancreatic duct brushing (SEPB). However, there was an extreme discrepancy between the authors' data of p53 overexpression using cytologic specimens and other reports using surgically resected specimens. In this study, the authors demonstrate that p53 positive cells precisely reflect its gene mutations, and also establish systematic procedures for the preoperative diagnosis of patients with pancreatic carcinoma.

METHODS

The authors examined 44 cases of pancreatic carcinoma, 30 cases of chronic pancreatitis, and 9 cases of papillary adenoma. In all cases, pathologic diagnosis was made by surgery or autopsy. The conventional cytology and p53 immunocytology were performed simultaneously in the cell specimens obtained by SEPB. In the cases immunostained for p53, DNA was extracted selectively from p53 immunostained cells using a light microscope. p53 mutations in exons 5 to 8 were examined by direct sequencing.

RESULTS

Forty of 44 pancreatic carcinomas (91%) were diagnosed correctly by the methods of conventional cytology associated with p53 immunocytology. p53 mutations were detected in 12 of 14 cases that were positive for p53 (86%). Four of six cases that were inoperable due to massive metastasis or invasion had the mutation at codon 273 (CGT to CAT) in exon 8.

CONCLUSIONS

These results suggest that p53 immunocytology reflects its gene mutations precisely, and that the point mutation at codon 273 (CGT to CAT) of p53 may play an important role in the invasive potential and metastasis of pancreatic carcinoma.

Ergonovine-induced alterations in coronary flow velocity preceding onset of occlusive spasm in patients without significant coronary artery stenoses

This study examined serial changes in coronary flow velocity to elucidate the dynamic change of coronary circulation during coronary spasm. Twenty patients with variant angina and 27 control patients were studied. Coronary flow velocity was monitored using a Doppler guidewire following intracoronary ergonovine administration. In the control group, diastolic flow velocity either did not change or increased slightly in response to ergonovine. However, in patients with variant angina, 2 patterns of flow velocity alterations were observed. In the first pattern, flow initially increased and then suddenly decreased (16 of 20 patients). In the second pattern, flow gradually decreased (3 of 20 patients). In the remaining patient, the coronary flow alteration could not be detected because of branch spasm. When abnormally high flow velocity was defined as a 100% increase in flow after ergonovine administration within 1 minute, and abnormally low flow velocity was defined as a 50% decrease in flow to diagnose variant angina, sensitivities of 35%, 75%, and 85% were noted if flow was measured 1.0, 2.0, and 3.0 minutes after ergonovine administration, respectively. These abnormal flow velocities were observed before ischemic ST changes appeared. In conclusion, in patients with variant angina, characteristic serial changes in coronary flow velocity occur before occlusive spasm. Variant angina may be diagnosed earlier by monitoring flow velocity rather than by monitoring for ischemic electrocardiographic changes.

Comparison of the effect of bezafibrate on improvement of atherogenic lipoproteins in Japanese familial combined hyperlipidemic patients with or without impaired glucose tolerance

The effect of bezafibrate on plasma lipoproteins was investigated in Japanese familial combined hyperlipidemic patients with or without an impaired glucose tolerance accompanied by a low-density lipoprotein subclass, with the major gradient gel peak at a particle diameter of less than 25.5 nm. Bezafibrate treatment at a dose of 400 mg/d for 12 weeks produced an antiatherogenic effect on lipoprotein profiles, as reflected by a decrease in plasma triglyceride levels, an increase in plasma high-density lipoprotein-cholesterol levels, induction of the large-size subclass of low-density lipoprotein, and disappearance of intermediate-density lipoproteins. The plasma total and low-density lipoprotein-cholesterol-lowering effect of bezafibrate was significant in patients without impaired glucose tolerance but was not significant in patients with impaired glucose tolerance. Bezafibrate increased lipoprotein lipase activity and decreased the activity of cholesteryl ester transfer protein, both in patients with or without impaired glucose tolerance. There was no difference in the distribution of signal peptide insertion/deletion or Xbal polymorphisms of the apolipoprotein B gene in patients with or without impaired glucose tolerance. Mechanisms other than lipoprotein lipase, cholesteryl ester transfer protein activities, and an apolipoprotein B gene polymorphism may be responsible for the resistance to lowering of plasma total and low-density lipoprotein cholesterol levels with bezafibrate treatment in familial combined hyperlipidemic patients with impaired glucose tolerance.

Structural characteristics of Koch's triangle in patients with atrioventricular node reentrant tachycardia

The aim of this study is to investigate whether patients with atrioventricular node reentrant tachycardia (AVNRT) present different structural characteristics of Koch's triangle from patients with atrioventricular (AV) reentrant tachycardia and other control patients. Fifty-eight patients with arrhythmia or chest pain underwent selective coronary sinus angiography so that the diameter of the coronary sinus could be measured. The patients with arrhythmia also underwent electrophysiological study and measurement of the height of Koch's triangle. Patients with AVNRT had large coronary sinus ostial diameters compared with patients with AV reentrant tachycardia and those with chest pain (13.6 +/- 2.2 mm vs. 10.6 +/- 2.7 mm [p < 0.005] and 10.0 +/- 2.1 mm [p < 0.002], respectively), while there were no differences in distal diameter. The ostial diameter in patients with dual AV node pathways but noninducible AVNRT (11.8 +/- 1.5 mm) tended to be smaller than that in patients with AVNRT. No differences in the height of Koch's triangle and electrophysiological characteristics, including AV node properties, were found among the study groups. In conclusion, an increased size of the coronary sinus ostium (the base of Koch's triangle) is a structural characteristic in patients with AVNRT and may be the substrate needed for the appearance of AVNRT.

Probucol inhibits neointimal formation in carotid arteries of normocholesterolemic rabbits and the proliferation of cultured rabbit vascular smooth muscle cells

The proliferation of vascular smooth muscle cells (VSMCs) plays an important role in the formation of atherosclerotic lesions and restenosis after angioplasty. It has been suggested that probucol inhibits VSMCs proliferation, but this effect has not been directly demonstrated. In this study we investigated the effect of probucol on neointimal formation after balloon injury in normocholesterolemic rabbits and examined whether probucol could inhibit the proliferation of rabbit cultured VSMC stimulated by fetal bovine serum (FBS). Probucol inhibited the formation of neointima by about 63% 2 weeks after balloon injury. Probucol inhibited the increase in the number of cultured VSMCs and bromodeoxyuridine (BrdU) incorporation stimulated by 10% FBS in a dose-dependent manner. Also, 10% FBS stimulated the activities of mitogen-activated protein kinase (MAP kinase) and protein kinase C (PKC) in cultured VSMCs. Probucol inhibited these activities in a dose-dependent fashion. These results suggest that probucol may inhibit neointimal formation after balloon injury in normocholesterolemic rabbits by preventing the proliferation of VSMCs via inactivation of MAP kinase and PKC.

Living related partial liver transplantation for primary biliary cirrhosis--a case report

An adult living related partial liver transplantation was performed on a 49 year old female with terminal hepatic failure due to primary biliary cirrhosis (PBC). The donor was her 53 year-old sister. A sufficient volume of graft tissue was obtained, which comprised 1.5% of the body weight of the recipient. The recipient had an excellent recovery without any major complications, and was discharged 35 days after the operation. At 15 months after the operation, the patient has shown no signs of rejection while using FK506 and prednisolone as immunosuppressants. The progression of symptomatic PBC can be predicted, and the timing of the transplantation can be easily determined. In addition, the results of liver transplantation for PBC are good. Therefore, adult living related partial liver transplantation is an excellent treatment for primary biliary cirrhosis.