The effects of chymase on matrix metalloproteinase-2 activation in neointimal hyperplasia after balloon injury in dogs.

Chymase is known to generate angiotensin II in the vascular wall. In this study we investigated a novel role for chymase other than angiotensin II production in vascular proliferation after balloon injury. Chymase promoted the migration of vascular smooth muscle cells in the matrix-coated invasion chambers and activated promatrix metalloproteinase-2 obtained from the culture medium of vascular smooth muscle cells. Two weeks after balloon injury, significant neointimal formation was found in dog carotid arteries. After injury, active matrix metalloproteinase-2 was increased in parallel with the augmentation of chymase activity that was seen in the proliferating region of the vascular wall. The oral administration of NK3201 (1 mg/kg per day), a chymase inhibitor, prevented neointimal formation and significantly suppressed both active matrix metalloproteinase-2 and chymase activities 2 weeks after injury. These results suggest that chymase inhibitors can prevent the development of intimal hyperplasia via the inhibition of matrix metalloproteinase-2 activation in balloon-injured arteries.     

Ischemic stroke in infancy,childhood, and adolescence

The authors studied 34 patients with juvenile ischemic cerebrovascular disease over a 15-year period. Of the 34 patients, 23 had intracranial occlusions attributed to cerebral thrombosis or embolism and 11 had occlusions resulting from moyamoya disease. Clinicopathological features were evaluated in the 23 cases with ischemic stroke, but not those with moyamoya disease. The cause of the arterial occlusion remained undetermined in 11 patients and was found to be an embolism based on congenital heart disease in 8, on trauma in 3, and on infection in 1. Cerebral angiography was performed in 21 patients. Of these, 17 had stenoses or occlusions corresponding to their symptoms. CT scans were performed in 10 patients; the lesion in question showed no stenosis or occlusion with cerebral angiography. With regard to prognosis, patients with unknown etiology had good outcomes compared with those with congenital heart disease. With respect to acute infantile hemiplegia, 10 patients had convulsive seizures and 4 had a history of an earlier infection. Angiography and CT scans in patients with congenital heart disease demonstrated arterial occlusive sites in the middle cerebral artery region. Three patients had abscesses after their ischemic lesions.     

Exponential hyperbolic sine function fitting of heart rate response to constant load exercise

We attempted to fit heart rate (HR) changes induced by constant exercise loads of different intensities to an exponential hyperbolic sine curve by the least-squares method, and we compared the results with the fitting of the changes to exponential curves. Seven healthy male volunteers performed three different intensities of constant-load exercise on a bicycle ergometer. The exponential hyperbolic sine function adequately fitted the HR responses induced by all three different intensities of loads: low (30 W: correlation coefficient, r = 0.68 +/- 0.13, mean +/- SD), moderate (75 W: r = 0.93 +/- 0.07) and high (125 W: r = 0.97 +/- 0.02). The first-order exponential curve fitted only the moderate load response. Although the second-order exponential equation fitted the HR response for both the moderate and high loads, the equation did not fit the low-load response (r = 0.43 +/- 0.26). In low-load exercise, the sum of the power of the residuals for the exponential hyperbolic sine curve fitting was significantly smaller than that for the first- or second-order exponential curve fitting. In conclusion, the exponential hyperbolic sine function is useful for quantitative analyses of the HR response to exercise loads of various intensities.     

Histological study on healing of cryocautery-induced rat gastric ulcer treated with T-593]

The effect of T-593, a novel anti-ulcer agent, on the healing of cryocautery-induced rat gastric ulcer was investigated histologically in comparison with that of famotidine. Seven days after ulceration, T-593 (30 mg/kg) or famotidine (30 mg/kg) was orally administered twice daily for 8 weeks. Two, 4 and 8 weeks after the start of administration, the ulcer size was measured by a stereoscopic microscope, and the gastric mucosa was observed histologically. The thickness of the regenerated mucosa, the density and the arrangement of gastric glands, the degree of inflammatory-cell infiltration in the submucosal tissue and the number of microvessels in the submucosal tissue were quantified. In macroscopical evaluation, T-593 and famotidine significantly accelerated ulcer healing, and the time courses of the ulcer index were similar in both cases. In histological evaluation of healed ulcers, T-593 normalized the thickness of regenerated mucosa and reduced the degree of inflammatory-cell infiltration and the number of microvessels in the submucosal tissue, while famotidine had no effect. In conclusion, T-593 possesses accelerating effects not only on the restoration of regenerated mucosa but also on the maturation of submucosal tissue. Therefore, T-593 improves the quality of ulcer healing.     

Serial changes in N-isopropyl-p[125I]-iodoamphetamine in mouse lung observed with a confocal laser scanning microscope

Serial changes in N-isopropyl-p[125I]-iodoamphetamine (125I-IMP) in mouse lungs were observed with a confocal laser scanning microscope. Male mice were intravenously injected with 125I-IMP and subjected to autoradiographic procedures 20 minutes, and 3 and 24 hours after injection. Differential interference contrast (DIC) images and confocal images were obtained with a confocal laser scanning microscope, and superimposed images were evaluated. Large numbers of silver grains were observed in the interstitium, bronchioles, and alveolar sacs 20 minutes after the injection, and lamellar distribution of the grains was observed on the ciliary surface. The numbers of silver grains in the interstitium and bronchioles had decreased 3 hours after the injection of 125I-IMP, but the numbers of silver grains in the alveolar spaces had not. Although small numbers of silver grains remained in both the bronchioles and alveolar sacs 24 hours after the injection, most of them had washed out. Confocal laser scanning microscopy is considered to be a useful procedure for studying the distribution of radioisotopes by microautoradiography, because it allows clear autoradiographs to be obtained in which tissues and silver grains are perfectly matched and all silver grains are in focus.     

An autopsy case of desmoplastic malignant mesothelioma]

On November 15, 2000, a 60-year-old man was admitted to our hospital with progressive dyspnea and right chest pain. He had a 40-year history of occupational asbestos exposure, which began when he was 20 years old. On admission, his chest radiographs showed pleural effusion on the right side, and asbestos bodies were detected in his sputum. Neither a cytological examination of the pleural effusion nor a histological examination of the pleura by percutaneous pleural biopsy revealed malignant cells. In addition, we could not find any other cause for the pleural effusion (such as tuberculosis, collagen disease, or heart failure). In May 2001, the patient also developed pleural thickening and pain in the right hypochondrium, and he was readmitted to our hospital on May 21, 2001. On readmission, an enhanced abdominal CT showed multiple liver tumors, and percutaneous pleural and liver biopsies were performed. The histological findings in the pleura and liver specimens revealed hypocellular collagen tissues without malignant cells. Thus, we could not determine the main cause either of the pleural effusion or of the patient's disease. However, his condition rapidly deteriorated, and he died on August 12, 2001. At the autopsy, bilateral pleural thickening, predominantly on the right side, and invasion of the lungs were observed. The histological findings in the pleural and hepatic tissues revealed hypocellular collagen fibers with a striate pattern and areas of neoplastic spindle cells. He was diagnosed as having malignant desmoplastic mesothelioma with liver metastasis. Cases of malignant desmoplastic mesothelioma have rarely been reported in Japan.     

Telomere length in human liver diseases

Abstract: To determine the role of telomere-mediated gene stability in hepatocarcinogenesis, we examined the telomere length of human liver with or without chronic liver diseases and hepatocellular carcinomas (HCC). The mean telomere restriction fragment (TRF) length of normal liver (n=13), chronic hepatitis (n=11), liver cirrhosis (n=24) and HCC (n=24) was 7.8±0.2, 7.1±0.3, 6.4±0.2 and 5.2±0.2 kb, respectively (mean±standard error). TRF length decreased with a progression of chronic liver diseases and that in HCC was significantly shorter than that in other chronic liver diseases (p<0.05). The ratios of TRF length of HCC to that of corresponding surrounding liver of well differentiated (n=7), moderately differentiated (n=10) and poorly differentiated (n=4) HCCs were 0.83±0.06, 0.75±0.05 and 0.98±0.09, respectively. The ratio of poorly differentiated HCC was significantly higher than that of moderately differentiated HCC (p<0.05). A comparison between the size and telomere length ratio of moderately differentiated HCCs revealed a decrease of the ratio with size until it reached 50 mm in diameter. In contrast, the ratio increased as the size enlarged over 50 mm. These findings suggest that the gene stability of the liver cells mediated by the telomere is reduced as chronic liver disease progresses and that telomerase is activated in poorly differentiated HCC and moderately differentiated HCC over 50 mm in diameter.     

A case of duodenal carcinoid tumor accompanied by liver metastasis and lymph node metastases in a patient with von Recklinghausen disease

We report a case of duodenal carcinoid tumor accompanied by liver metastasis and lymph node metastases in a patient with von Recklinghausen disease. A 48-year-old woman with von Recklinghausen disease was referred to our hospital because of a submucosal tumor at the ampulla of Vater detected by upper gastrointestinal endoscopy. The lesion was diagnosed as a carcinoid tumor based on the pathology of the biopsy specimen. At operation, although there were liver metastasis on the surface of S3 the liver and regional lymph node metastases, we selected pancreatoduodenectomy with lymph node dissection and enucleation of the liver metastasis. The postoperative course was good and the woman was discharged on postoperative day 33. No recurrence has been seen at 24 months since surgery.