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Biomedical subjects

R Kamimura

Publications and source records attributed to R Kamimura.

At least 19 recordsLinked to original sources
PubMed2001

Pulmonary atherosclerosis and pulmonary arterial pressure in cholesterol-fed New Zealand white rabbits.

The lung produces many vasoactive substances originating from its vascular endothelium and plays an important part in various pathose. The present study was carried out to clarify pulmonary atherosclerosis and pulmonary arterial pressure, and to elucidate a part of the pulmonary pathosis in cholesterol-fed rabbits. Atherosclerosis was induced by feeding the animals a cholesterol-rich diet. When the rabbits were fed the cholesterol-enriched diets for 15 weeks, the grade of the atherosclerosis was severer than in 8W-feeding rabbits. The lesions of 8W-feeding rabbits were mainly composed of foam cells and fibrous components, whereas in 15W-feeding rabbits, the aggregation of foam cells beneath the endothelium of the vessel was infiltrating the media and severe stenose of the lumen was observed. In the entire pulmonary arterial system, the severe obstructive vascular lesions were localized and not diffused. The pulmonary arterial pressures of the rabbits increased slightly with time and the mean pressures were 11.3+/-0.9 (control group), 11.8+/-1.0 (8W group) and 13.7+/-1.5 mmHg (15W group) respectively. A significant difference existed in the mean pressure between the control group and 15W-feeding group, but there were no significant differences in the systolic and diastolic pressures among the three groups. In conclusion, we could induce pulmonary atherosclerosis in rabbits by feeding them a hyper-cholesterol diet but not overt pulmonary hypertension.

Animals↗
PubMed2001

Arteriosclerosis in the influx and intravisceral arteries of the liver, kidney and lung of WHHL rabbits.

We performed a histopathological investigation on arteriosclerotic development in the influx and intravisceral arteries of the liver, kidney and lung of male WHHL rabbits. In the influx arteries of these organs, we observed severe atherosclerotic vascular lesions with high-grade luminal stenosis. In the intravisceral arteries of the liver and kidney, no arteriosclerotic lesions were observed. However, in the intrapulmonary arteries, we recognized severe atherosclerotic vascular changes with high-grade stenosis or total obstruction of the lumen in some middle to large sized pulmonary arteries. These observations indicate that the development of arteriosclerosis in parenchymatous organs differs, and that some organs are predisposed to arteriosclerosis formation.

Animals↗
PubMed2000

Surgical management of early stage central (hilar) and peripheral nonsmall cell lung carcinoma.

BACKGROUND: To the authors' knowledge, the definitions of early lung carcinoma used in Japan are not yet approved internationally. In the current study the diagnostic methods, pathology, and results of the surgical treatment of early hilar and peripheral nonsmall cell lung carcinoma cases defined by Japanese criteria are presented. METHODS: Between 1977 and 1998, 43 patients with early hilar lung carcinoma were encountered. These patients constituted 14.5% of 200 hilar lung carcinoma patients who underwent resection during the same period. Between 1973 and 1998, there were 174 early peripheral lung carcinomas, which comprised 14.8% of 1173 peripheral lung carcinoma patients who underwent resection during the same period. RESULTS: The 5-year and 10-year survival rates of the early hilar lung carcinoma were 100% and 96.9%, respectively. The majority of the patients underwent bronchoplastic surgery, such as sleeve lobectomy and parenchymal-sparing surgery including seven sleeve segmentectomies and two second carinal resections. The effectiveness of the parenchymal-sparing resections was assessed by the conventional pulmonary function test as well as perfusion and ventilation scanning. There were 174 cases of peripheral early lung carcinoma among the 218 cases of peripheral lung carcinoma with tumor dimensions of < or = 2 cm. The cell types were 142 (81.6%) cases of adenocarcinoma, 18 (10.3%) cases of squamous cell carcinoma, and 14 (8%) cases of other cell types. These 174 patients comprised 14.8% of 1173 patients with peripheral nonsmall cell lung carcinoma who underwent surgery during the same period. The 5-year and 10-year survival rates for adenocarcinoma were 89.6% and 86.8%, respectively. The 5-year and 10-year survival rates for other cell types were both 71.8%. The overall 5-year and 10-year survival rates were 86.8% and 84.6%, respectively. CONCLUSIONS: Early lung carcinoma in both the hilar and peripheral regions, is curable if it is properly diagnosed and treated.

Aged↗
PubMed1999

Growth induction of rat primary hepatocytes using antisense oligonucleotides.

We examined growth control of adult and fetal hepatocytes by regulating the expression of cell-cycle-related proteins using antisense S-oligonucleotides to tumor suppressors retinoblastoma (RB) protein and p53, and cyclin-dependent kinase (CDK) inhibitors p21 and p27. The protein expression in both adult and fetal hepatocytes was significantly suppressed with the addition of corresponding antisense oligonucleotides at a concentration of 2.5 microM. For the evaluation of growth, 3H-thymidine incorporation and DNA content were measured and the results demonstrated that all the antisense oligonucleotides had growth-promoting effects and the promoting potential was equivalent or slightly greater than that with the addition of hepatocyte growth factor (HGF) (10 ng/ml). The growth-promoting effect of the antisense oligonucleotides was enhanced by HGF in both adult and fetal hepatocyte cultures, and the effects on hepatocyte growth were also observed in a suspension culture.

Journal Article↗
PubMed1999

Development of atherosclerotic lesions in cholesterol-loaded rabbits.

To examine both of the target vessels and the optimal time of their endothelial denudation to study vascular restenosis after balloon injury in cholesterol-loaded rabbits, we made 36 atherosclerotic rabbits by feeding a hypercholesterol diet, and histologically examined the onset time and the development of atherosclerosis. Atheromatous changes were observed first after the 5th week in the thoracic aorta from the start of the diet, and then extended to the abdominal aorta, coronary artery with time. The atherosclerotic lesions in the thoracic aorta and the proximal portion of the coronary artery showed high-grade concentric intimal thickening with luminal stenosis. The abdominal aortic lesion mildly progressed. In the renal, carotid and femoral arteries, in contrast, slight atheroscleromatous changes developed during the diet period. These results suggest that the thoracic and abdominal aortas and the coronary artery would be suitable as target vessels to study vascular restenosis after balloon injury, and the endothelial denudation of these vessels should be performed between the 8th and 15th week in this diet protocol for an accurate analysis.

Animals↗
PubMed1999

Salt water promotes hypertension in Dahl-S rats.

Hypertension was induced in Dahl-salt-sensitive (Dahl-S) rats by administering salt in drinking water. Control rats receiving tap water did not show a significant change in blood pressure or abnormalities in the kidney. Rats receiving 0.5% NaCl solution developed moderate hypertension and renal lesions. Rats receiving 1.0% NaCl solution showed prominent and increasing hypertension and severe renal damage. This method of salt administration should be simpler than administration in the diet as a means of promoting renal hypertension. The lower concentration salt water caused chronic mild hypertension in Dahl-S rats, and may serve as a useful model for progressive hypertension.

Animals↗
PubMed1999

Expression of cholesterol 7alpha-hydroxylase and delta(4)-3-ketosteroid 5beta-reductase genes in rat pancreatic hepatocyte-like cells.

Hepatocyte-like cells have been observed in the pancreas of the rat. We examined the bile acid biosynthetic function of these cells to determine whether they were real hepatocytes. This study investigated the existence of two liver-specific enzymes involved in bile acid biosynthesis (cholesterol 7alpha-hydroxylase and delta(4)-3-ketosteroid 5beta-reductase) in the hepatocyte-like cells. We could demonstrate cholesterol 7alpha-hydroxylase activity and its circadian rhythm in the hepatocyte-like cells. Northern blot analysis demonstrated the expression of messenger RNA for the 7alpha-hydroxylase and delta(4)-3-ketosteroid 5beta-reductase in the pancreatic hepatocyte-like cells. To measure the amount of the messenger RNA, we used the competitive polymerase chain reaction method for the 7alpha-hydroxylase. This quantitation revealed the existence of a circadian rhythm of cholesterol 7alpha-hydroxylase messenger RNA in the hepatocyte-like cells. These results indicated that bile acid biosynthesis was performed in the pancreatic hepatocyte-like cells as noted as in the liver parenchymal cells.

Animals↗
PubMed1997

Division of donor liver for successful split-liver transplantation in pigs.

Split Liver Transplantation (SLT) is an attractive method to solve the problem of a shortage of liver grafts. A through knowledge of the anatomy of the porcine liver vessels and bile duct is essential in performing the experimental SLT. This study was undertaken to decide the split line for successful SLT in pigs by examining the main branching patterns both vessels and bile duct in 30 porcine livers macroscopically and angiographically. The hepatic arterial branching patterns were divided into three types and bile duct patterns into two types. There was no exception in branching patterns of the portal vein and the hepatic vein. We conclude it is desirable that the donor liver should be divided into two grafts between the left medial lobe and quadrate lobe.

Animals↗
PubMed1996

Knowledge-based systems, artificial neural networks and pattern recognition: applications to biotechnological processes.

Recent years have witnessed the increasing application of artificial intelligence techniques, specifically, knowledge-based systems, artificial neural networks, and pattern recognition, to biotechnological processes. Although progress has been made in simple control applications, more work is needed to establish the advantages of these techniques for industrial process control, for diagnosis/monitoring, and to upgrade the information content of historical data.

Biotechnology↗
PubMed1996

Branching patterns in coronary artery and ischemic areas induced by coronary arterial occlusion in the CLAWN miniature pig.

This study of 28 CLAWN miniature pigs (male 17, female 11, mean weight 29 kg) was undertaken to investigate the coronary arterial branching patterns and the ischemic area induced by surgical occlusion of the left anterior descending artery (LAD) and change in the ischemic area over time. These results were compared with those in dogs, which have frequently been used in myocardial ischemic research. Regarding the coronary arterial branching pattern, there were fewer ventricular branches from the right and left coronary arteries than in dogs. The septal branches arose from only the LAD and the posterior descending artery (PD). The largest septal artery branched from the LAD. There were two types of septal artery branching patterns. In approximately 80% of the CLAWN miniature pigs, the PD arose from the right coronary artery (Right dominance). The peculiarity of the coronary arterial branching pattern in the CLAWN miniature pigs was more similar to human beings than to dogs. The ischemic area induced by occlusion at three-fifths distal section of the LAD was 12.1% to 22.6% (mean 17.1%) of the left ventricle. The ischemic area in all animals that died of global left ventricular malfunction and hemodynamic instability after LAD occlusion was more than 25% of the left ventricle.

Animals↗
PubMed1996

[Screening CT of the lungs: image quality compared with conventional CT].

More sensitive imaging methods may be required in the screening of early peripheral lung cancer. Among new radiologic techniques, helical volumetric computed tomography (CT) seems to be attractive. The image quality of helical CT with single breath-hold and low-dose technique (screening CT) was compared with conventional sequential CT in 12 patients to detect the pulmonary metastases. The screening CT protocol consisted of a 20 mm/sec table feed during a 20-second breath-hold at 40 mA, with reconstruction of images at 10 mm intervals. Conventional CT was performed with a 1-second scan time, 200 mA, and contiguous 10 mm-thick sections. In the evaluation of mediastinal vessels, bronchi and pulmonary nodules, screening CT showed high detectability images comparable to conventional CT. But subsegmental bronchi or small nodules overlapping pulmonary vessels were more difficult to visualize by screening CT because of image noise. The authors conclude that although further improvement is necessary, screening CT of the lung is an attractive new application of CT.

Aged↗
PubMed1995

Clinicopathological study of primary malignant tumors of the lung: an analysis of 993 tumors resected at the Kanazawa University Hospital between 1979-1993.

A retrospective study was conducted of 993 malignant tumors of the lung in 977 patients. The male-female sex ratio was 2.6:1. The age distribution of the males did not differ from that of the females and the overall mean age was 64.3 +/- 9.5 years (range, 13-85 years). Forty-three percent of the patients were in their seventh decade. The location was peripheral in 81% of the tumors and central in 19%. Of the central tumors, 85% were squamous cell (epidermoid) carcinoma (SCC), while 58% of the peripheral tumors were adenocarcinoma (ADENO). In males, 49% of all tumors were SCC and 36% ADENO, while in females 76% were ADENO. The incidence of positive lymph node metastasis increased in parallel with the pT status in both central and peripheral carcinomas. However, it was noted that, of peripheral lung carcinomas, no SCC with a diameter of 15 mm or less had lymph node metastasis, whereas 18.9% of the ADENO of this size were positive for lymph node metastasis. These results indicate that lymph node metastasis can occur even in small-sized peripheral ADENO less than 15 mm. Thus, early detection and surgery together with mediastinal lymph node dissection are necessary even for small-sized tumors to improve the prognosis in patients with peripheral ADENO of the lung.

Adolescent↗
PubMed1995

Clinical application of single dual-energy subtraction technique with digital storage-phosphor radiography.

We used a single-exposure dual-energy subtraction technique with a storage-phosphor computed radiography (CR) system to evaluate various pulmonary diseases. Clinical applications of this method have been studies at our institution. In our experience, the dual-energy subtraction technique provided better visualization of pulmonary nodules, tracheobronchial abnormalities, pulmonary vascular diseases, calcification in a nodule, and rib lesions than conventional CR images did. Single-exposure dual-energy subtraction images were obtained with a sandwich technique using two storage-phosphor imaging plates with a 1-mm-thick copper filter interleaved between the two. The front plate obtains a lower kilovoltage image, whereas the back plate obtains a higher kilovoltage image. We can visualize soft tissue and bone images as well as unsubtracted digital images by the subtraction process.

Bronchial Diseases↗
PubMed1995

Fine structure of the parotid gland in tree shrew (Tupaia glis).

The parotid glands of Tupaia glis were examined by light and transmission electron microscopy. The acinar cells were seromucous in nature, and contained many acidophilic granules with strong affinity for periodic acid-Schiff (PAS) and weak affinity for alcian blue (AB). These granules consisted of a fine granular matrix of moderate density in which a denser corpuscles or semilunar materials were present. Intercalated duct cells had a few fine vesicles, vacuoles and very few dense granules in the apical region. In occasional epithelial cells, acidophilic, PAS-positive and AB-negative bodies with moderate density were observed in the supranuclear region. The striated ducts consisted of columnar light and dark cells containing round or small ovoid granules of moderate density and did not show the granular duct as seen in the parotid glands of kobe mole and tenrec which are placed in the order insectivora.

Alcian Blue↗
PubMed1994

[Dual-energy subtraction technique with FCR: clinical application for diagnosis of pulmonary vascular diseases].

The use of dual-energy techniques has already proved to be beneficial in nodule detection and characterization of the calcification in nodules. Other clinical applications, in which simplification of the background might lead to improved results, should be investigated. We evaluated the image quality of pulmonary vessels in the dual-energy techniques with FCR. In visualization of the pulmonary vessels of normal patients, dual-energy soft tissue images were equal or inferior to the original unsubtracted digital images because of increased noise. In the diagnosis of some pulmonary vascular diseases (e.g., Takayasu's arteritis), however, soft tissue images resulted in improved conspicuity of involved sites compared with the unsubtracted images.

Adult↗
PubMed1994

Simultaneous occurrence of lung adenocarcinoma and fibular osteosarcoma in a 13-year-old girl.

Bronchogenic cancer in the pediatric age group is extremely rare and less than 100 cases have been reported in the world literature. We report a 13-year-old girl with simultaneous occurrence of lung adenocarcinoma and osteosarcoma. The patient was admitted with lower leg pain, and an abnormal shadow in the right fibula was noted on X-ray examination. Further examination of the fibular lesion including tumor biopsy revealed an osteosarcoma. Following completion of the first course of preoperative chemotherapy, multiple lung shadows were found on chest X-ray films. After five courses of preoperative chemotherapy, however, all lung shadows except one in the right lower lobe disappeared. The fibular tumor was then resected. Postoperatively, an additional six courses of chemotherapy was given. However, the lung shadow in the right lower lobe was still present. Exploratory thoracotomy was performed. Pathologically, the lung tumor measured 0.8 cm in diameter with an ill-defined border, and histological examination revealed a well differentiated papillary adenocarcinoma. To our knowledge, only a few cases of pediatric lung cancers have been reported to be associated with congenital cystic malformation of the lung. However, this combination of pediatric lung adenocarcinoma and osteosarcoma has not been previously reported.

Adenocarcinoma, Papillary↗
PubMed1994

Simultaneous detection of intercellular adhesion molecule-1 (CD54) and carcinoembryonic antigen in lung adenocarcinoma.

Simultaneous detection of intercellular adhesion molecules-1 (ICAM-1) and carcinoembryonic antigen (CEA) was investigated in AMeX (Acetone, Methyl benzoate and Xylene)-fixed, paraffin-embedded tumor sections of 24 adenocarcinomas of the lung, using the avidin-biotin-peroxidase complex (ABC) method. Distinct expression of both ICAM-1 and CEA was found in tumor cells in all cases. The staining pattern of these two antigens was quite similar and was mainly affected by the tumor grade. In well-differentiated adenocarcinoma, uniformly positive staining was demonstrated predominantly along the apical surfaces of the tumor cell nests, and to a lesser degree on the lateral cell surface and in the cytoplasm with apical concentration, but no positive staining was found on the basal cell surfaces. In poorly differentiated adenocarcinoma, positive staining was found along the entire cell surface and in the cell cytoplasm without any apical concentration, and the staining intensity varied from region to region in the same tumor cell and from cell to cell within the same tumor cell nest. In moderately differentiated adenocarcinoma, the staining pattern was intermediate between those of well and poorly differentiated adenocarcinoma with some degree of apical concentration. The expression pattern of ICAM-1 or CEA on tumor cells did not correlate well with stromal inflammatory cell infiltration. These results indicate that the expression pattern of CEA and ICAM-1 is an inherent characteristic of tumor cells, and that their abnormal expression may play an important role in the physiological behavior of tumor cells because the polarity of their expression is lost in parallel with histological tumor grades.

Adenocarcinoma↗