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Biomedical subjects

M Kitamura

Publications and source records attributed to M Kitamura.

At least 289 records · Page 16Linked to original sources
PubMed1995

Long-term results of coronary artery bypass grafting in elderly Japanese patients.

BACKGROUND: This study was undertaken to examine long-term results of coronary artery bypass grafting in elderly Japanese patients. METHODS: Of 1,425 coronary artery bypass grafting patients over the last 13 years, 137 patients were 70 or more years old and 1,288 were less than 70 years old. Mean number of distal anastomoses was similar in both groups. Postoperative survival and event-free proportion were estimated by the Kaplan-Meier actuarial method and compared among the groups by Cox-Mantel statistical analysis. RESULTS: Operative mortality and the incidence of late cardiac death after coronary artery bypass grafting were equivalent between the elderly and younger groups, although the rates of left main trunk disease, acute myocardial infarction, and emergency operation in the elderly group were significantly higher than those in the younger group. Coronary artery bypass grafting in elderly patients had a relatively high hospital mortality and more late noncardiac deaths, but the incidence of postoperative cardiac intervention in elderly patients was lower than that in younger patients. CONCLUSIONS: These results suggest that coronary artery bypass grafting for elderly patients is encouraged as well as is that for younger patients in a representative Japanese population.

Actuarial Analysis↗
PubMed1995

Left ventricular function on exercise after surgical treatment of small aortic annuli.

To evaluate left ventricular function during exercise after aortic annular enlargement 15 patients with either aortic (group I, n = 8) or aortomitral (group II, n = 7) annuloplasty for small aortic annuli and eight patients (group III) with standard valve replacement for aortic stenosis without small aortic annuli received gated cardiac pool imagining by technetium-99m-labelled red blood cells at rest and during exercise at a mean of 23 months after operation. Left ventricular ejection fraction, preload requitable stroke work and stroke power index (preload requitable stroke work/systolic ejection period) were measured. Compared with resting values, left ventricular performance and stroke work rate on exercise after aortic annular enlargements increased significantly, as did those after standard aortic valve replacement. These results suggest that aortic annular enlargement can be indicated for surgical treatment of valvular heart diseases associated with small aortic annuli.

Adult↗
PubMed1995

Medium-term results after surgery for aortic arch aneurysm with hypothermic cerebral perfusion.

We have used two techniques of hypothermic cerebral perfusion (CP) for the surgical treatment of aortic arch aneurysm in the last 10 years. Between March 1985 and December 1993, 83 patients underwent surgery for aortic arch aneurysm. Fifty-one cases had aortic dissection (AD) in the transverse arch and/or its branches, and 32 cases showed true aneurysm (TA) of the aortic arch. In those 83 patients, 37 cases received antegrade CP and 46 cases underwent retrograde CP. Surgical results were compared among the groups by Kaplan-Meier actuarial method and Cox-Mantel statistical analysis. The early mortality after surgery for aortic arch aneurysm was 11.8% in the AD group and 21.9% in the TA group. The early mortality was 21.6% with antegrade CP and 10.9% with retrograde CP. The 6-year actuarial survival rate was 71.7% in the TA group and 67.1% in the AD group. In the AD group, the 3-year survival rate was 93.9% with retrograde CP and 61.1% with antegrade CP (P < 0.005). In the TA group, the 3-year survival rate was similar for antegrade CP (73.3%) and retrograde CP (69.2%). These results suggest that current surgical results of aortic arch aneurysm with hypothermic CP are acceptable and the retrograde CP technique might be recommended, especially for surgery of aortic arch aneurysm with AD.

Actuarial Analysis↗
PubMed1995

Transfer of a mutated gene encoding active transforming growth factor-beta 1 suppresses mitogenesis and IL-1 response in the glomerulus.

Using in vivo gene transfer, we examined the anti-inflammatory potential of transforming growth factor-beta 1 (TGF-beta 1) in the renal glomerulus. TGF-beta 1 cDNA, modified to allow for secretion of the active form of TGF-beta 1, was introduced into cultured rat mesangial cells. The responses of the established transfectants were examined in culture. In vitro, the transduced mesangial cells showed a reduced mitogenic response to fetal calf serum and were insensitive to induction of matrix metalloproteinase-9 (MMP-9) by the proinflammatory cytokine IL-1 beta. To examine whether glomeruli which express active TGF-beta 1 in vivo are insensitive to these same stimuli, TGF-beta transfectants were transferred into normal rat glomeruli via renal artery injection. After 24 hours, isolated glomeruli containing transfectants exhibited TGF-beta bioactivity, a reduced mitogenic response, and repressed expression of MMP-9 in response to IL-1 beta. We further examined the responses of these chimeric glomeruli to an in vivo mitogenic stimulus by transferring TGF-beta transfectants into glomeruli of kidneys one day after the induction of anti-Thy-1 nephritis. The mitogenic activity of isolated glomeruli was examined four days after the cell injection. Compared to unmodified or mock cell-containing glomeruli, the in vivo mitogenic activity of glomeruli containing TGF-beta transfectants was significantly repressed. Furthermore, cellular outgrowth from nephritic glomeruli expressing active TGF-beta 1 was also suppressed ex vivo compared to controls. These data indicate that TGF-beta 1 inhibits mitogenesis and IL-1 response of the glomerulus and may, in part, act as a potential early suppressor of glomerular inflammation.

Animals↗
PubMed1995

Resection margin for squamous cell carcinoma of the esophagus.

OBJECTIVE: The safe resection margin in esophagectomy for esophageal squamous cell carcinoma (SCC) was determined based on the extent of epithelial and subepithelial accessory lesions from the main lesions of esophageal SCC. BACKGROUND: There have been many reports on the high incidence of a positive resection margin for esophageal cancer. Although there were some studies on the relationships of the proximal clearance to postoperative local recurrence, no pathologic study on the resection margin has been reported. METHODS: Four hundred twenty specimens of a whole resected esophagus were examined histopathologically and the longitudinal length from the main lesion to the five types of accessory lesions was measured on microscopic slides. RESULTS: Contiguous intraepithelial carcinoma existed in 69 (46%) of 150 sites of main lesions restricted to the mucosa or submucosa and subepithelial lesions existed in 131 (54%) of 245 sites and 82 (55%) of 150 sites of main lesions invading an adventitia and into neighboring structures, respectively. The risk of a positive resection margin due to subepithelial lesions was below 5% at 10 mm in the main lesion, restricted to the submucosa or the muscularis propria, and at 30 mm in the main lesion, invading the adventitia in the potentially curative operation cases. CONCLUSION: These clearances of the resection margin, in which the risk of a positive resection margin is below 5%, are acceptable, although these clearances should only be accepted after the extent of epithelial accessory lesions is accurately determined by the Lugol's stain method.

Adult↗
PubMed1995

A gene encoding a cytochrome c oxidase-like protein is located closely to the cytochrome c-553 gene in the anaerobic bacterium, Desulfovibrio vulgaris (Miyazaki F).

The gene encoding cytochrome c-553 from Desulfovibrio vulgaris (Miyazaki F) was cloned using a synthetic oligodeoxyribonucleotide probe. The nucleotide sequence indicated that cytochrome c-553 was synthesized as a precursor protein with an NH2-terminal signal sequence of 23 residues. In the cloned DNA fragment, there are three other open reading frames whose products have 191, 157, 541 amino acid residues, respectively. The putative ORF-4 product is highly homologous with the cytochrome c oxidase subunit I from various organisms.

Amino Acid Sequence↗
PubMed1995

Soluble ICAM-1 as a regulator of nasal allergic reaction under natural allergen provocation.

BACKGROUND: Intercellular adhesion molecule-1 (ICAM-1) plays a key role in the early stage of the signal cascade leading to cellular extravasation and development of an inflammatory response. Recently, it has been reported that the soluble form of this adhesion molecule is present in human sera, possibly mediating biological actions. OBJECTIVE: The purpose of this study was to investigate levels of soluble ICAM-1 (sICAM-1) and its receptors in patients with allergic rhinitis, and to discuss sICAM-1's biological function. METHODS: The levels of sICAM-1 in sera and nasal epithelial lining fluids (ELF), the percentage of CD11a-positive lymphocytes in the peripheral blood, and scores of subjective symptoms from 14 patients with pollinosis (allergic group) were measured from pre- to post-season, results were compared with those from 10 non-allergic subjects (control group). RESULTS: The levels of sICAM-1 in sera and ELF were upregulated, and CD11a-positive lymphocytes were downregulated during the in-season in the allergic group. In addition, levels of sICAM-1 sera from the allergic group remained high during the post-season, when levels of other parameters (symptoms, blood eosinophil counts, sICAM-1 in ELF and CD11a-positive lymphocytes) had roughly returned to the initial pre-season levels. CONCLUSIONS: We demonstrate systemic and local upregulation of sICAM-1 and systemic downregulation of LFA-1 positive lymphocytes in patients with seasonal allergic rhinitis under natural allergen provocation, suggesting that sICAM-1 plays a role in regulating seasonal allergic inflammation.

Adult↗
PubMed1995

Development of an autoflow cruise control system for a centrifugal pump.

To improve the ease of driving a centrifugal pump that is afterload dependent, we have developed an automatic flow control system for the Terumo Capiox centrifugal pump system. This system consists of an autoflow cruise control system with a safety cutoff. The Capiox Pump Console 3000 was controlled by a personal computer through a serial communication line. In the usual manual mode, the motor speed knob works as a pump speed control, and in the autoflow mode, the same knob works as a blood flow rate control. After selecting and obtaining the desired flow rate, the mode was changed from manual to autoflow mode. In the autoflow mode, the computer compares the desired flow rate with the actual flow measured by an ultrasonic Doppler flowmeter and adjusts the motor rotational speed accordingly. During both in vivo and in vitro testing, this autoflow mode was able to return the changed flow that was disrupted by either clamping and declamping of the tubing or by the bolus injection of a vasomotor drug to the selected flow rate within 10 s without any significant fluctuation. In conclusion, the newly developed computer controlled autoflow system was able to produce a reliable and effective flow regulation for a centrifugal pump.

Animals↗
PubMed1995

Current strategy for severe heart failure with mechanical circulatory support.

In the last 10 years, 37 patients received assisted circulation or a ventricular assist device after open-heart operations at the Heart Institute of Japan. After cardiovascular surgery, 12 patients underwent venoarterial bypass (VAB), 13 had biventricular bypass (BVB), 8 had left ventricular bypass (LVB), and the remaining 4 received a left ventricular assist device (LVAD). Weaning and discharge rates of the patients by type of circulatory supports were 41.7 and 25.0% with VAB, 69.3 and 46.2% with BVB, 87.5 and 37.5% with LVB, 75.0 and 50.0% with LVAD, and 44.4 and 11.1% with PCPS, respectively. Concerning complications of postcardiotomy circulatory support, hemorrhage and ventricular arrhythmia postcardiotomy circulatory support, hemorrhage, and ventricular arrhythmia (immature weaning) decreased with low-heparinized isolated left ventricular supports (i.e., LVB, LVAD). However, profound biventricular failure, infection, and multiple organ failure remain as possible complications with any type of assisted circulation. These results suggest that early application of circulatory support and appropriate selection of the mode of support and devices used are important for successful circulatory support.

Adult↗
PubMed1995

Endotoxin-induced hydrogen peroxide production in intact pulmonary circulation of rat.

Although the importance of free oxygen radical has been reported in acute lung injury, the direct evidence in vivo model was lacking. We report a new method, which for the first time allows direct detection of hydrogen peroxide in the intact rat pulmonary microcirculation. We used the computer image-analyzing system and 2',7'-dichlorofluorescin diacetate for the marker of hydrogen peroxide production in vivo. A rat sepsis model was produced by continuous infusion of endotoxin for 30, 60, and 120 min. Hydrogen peroxide production in the pulmonary microcirculation of the sepsis rat was higher than in the control rat at each time point (p < 0.01) and increased time-dependently (p < 0.01). Catalase (5,000 U/kg) almost completely inhibited the hydrogen peroxide production in the sepsis rat (p < 0.01). In high-power view, hydrogen peroxide was detected in granulocytes that adhered to the capillaries and endothelial cells that were adjoining adherent granulocytes. These observations suggest that hydrogen peroxide in the endothelium was diffused from granulocytes. In this study, we demonstrated direct evidence of hydrogen peroxide production from adherent granulocytes in intact rat lung treated with endotoxin. We conclude that endotoxin causes the granulocyte adhesion and oxidative stress to the endothelium due to adherent granulocytes within 30 min in the pulmonary microcirculation.

Animals↗
PubMed1995

[Analysis of tracheostomy for patients after thoracic esophageal cancer resection].

Tracheostomy is an available method for respiratory management, but a consensus has not been reached with regard to the significance of postoperative respiratory management. So, we analyzed postoperative tracheostomy patients of esophageal cancer and clarified its significance. We analyzed 26 patients from among 85 who underwent resection for thoracic esophageal cancer between April 1989 and December 1992. We divided them into 3 groups according to the indications of tracheostomy, group I: cases with postoperative pulmonary complications (n: 17), group II: cases of prophylaxis against pulmonary complications (n: 5) and group III: cases with dyspnea deriving from postoperative recurrent nerve palsy (n: 4). Tracheostomy was most often performed between 3 and 4 POD in group I, up to 1 POD in group II and from 5 POD to 7 POD in group III. Long-term respiratory support was needed in 13 cases in group I and 2 cases in group II. The rate of tracheostomy was higher in the case who had postoperative recurrent nerve palsy and received preoperative chemoradiotherapy. All cases excluding a case of MOF had a good clinical course after tracheostomy. We were able to clarify the significance of tracheostomy by dividing tracheostomy patients into 3 groups according to the indications for the procedure. It was concluded that tracheostomy is a very useful technique in the respiratory management of resected thoracic esophageal cancer patients.

Dyspnea↗
PubMed1995

[Resection of the posterior mediastinal gastric tube used in reconstruction after radical surgery for esophageal cancer--case reports].

Two patients are presented who underwent resection of a gastric tube placed in the posterior mediastinum during reconstruction following radical esophageal resection for esophageal cancer. The indications for gastric tube resection were bleeding from a peptic ulcer in one and gastric cancer in the other. Case 1: A 72-year-old man, who had undergone a thoracic esophagectomy 3.5 years prior to admission, presented with a chief complaint of hematemesis. The gastric tube was resected and replaced with an antethoracic, pedicled segment of left colon. Pathologic examination of the resected gastric tube revealed a penetrating peptic ulcer. Case 2: A 65-year-old man with esophageal cancer and early gastric cancer underwent thoracic esophagectomy with combined resection of the fundus and lesser curvature of the stomach. One year later, he was found to have a new early gastric cancer in the antrum. The distal portion of the gastric tube was resected and replaced with a pedicled jejunal graft. Of the 526 patients with esophageal cancer treated in our department from 1972 to 1993, peptic ulcers were evident in the gastric tube used to reconstruct the esophagus in only seven cases. The stomach was resected in only one of these patients. Similar patients requiring gastric tube resection have been reported. All six of these cases are reviewed. Cancer of the gastric tube developed in 3 of the 526 patients. Although 74 cases of gastric tube cancer have been reported in the Japanese literature, the patient presented here (case 2) is the first to undergo successful resection of the stomach from the posterior mediastinal position.

Aged↗
PubMed1995

[Flow competition of right gastroepiploic artery graft in coronary artery bypass surgery].

We evaluated the competitive flow between the right gastroepiploic artery (RGEA) and native coronary artery in coronary artery bypass surgery with respect to anastomosis in a retrograde fashion and the relationship of the degree of proximal stenosis with the flow dependency. The RGEA has been used in 157 patients and was anastomosed in a retrograde fashion in 22 patients. There was no significant difference between the retrograde anastomosis and the antegrade anastomosis on revascularization to the left anterior descending coronary artery in terms of diameter (2.0 +/- 0.5, 1.68 +/- 0.2 mm), flow (21.8 +/- 13.2, 24.5 +/- 19.4 ml/min), early patency (100%, 100%) and string sign (0%, 0%). We examined angiographically the relationship between the preoperative degree of proximal stenosis and postoperative pattern of flow dependency in the right coronary artery distal to the RGEA anastomosis in 98 patients. With a proximal stenosis of 75% (n = 19), RGEA occlusion was observed in two patients (11%), native coronary-dependent flow in four (21%), balanced flow in nine (47%) and RGEA-dependent flow in four (21%). With a proximal stenosis of 90% (n = 16), native-dependent flow was observed in one (6%), balanced flow in six (38%) and RGEA-dependent flow in nine (56%) patients. With a proximal stenosis of 99%-100% (n = 63), RGEA occlusion was observed in three (5%) and RGEA-dependent flow in sixty (95%) patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[A case of primary pulmonary hemangiopericytoma recurred locally 10 years after the first surgery].

Hemangiopericytoma is a rare tumor of vascular origin. This tumor has a malignant potential and often recurs or metastasize. A case of primary pulmonary hemangiopericytoma which recurred locally 10 years after the first surgery is presented. The histological appearance of the tumor had some findings of malignant potential in both of the primary and recurrent lesions. We discussed on malignant potential of this tumor in the number of mitotic figures, cellular atipia, and DNA ploidy pattern.

Female↗
PubMed1995

Extensive spreading carcinoma of the esophagus with invasion restricted to the submucosa.

OBJECTIVES: The aim of this study was to examine the clinicopathological features of extensive spreading type of squamous cell carcinoma (SCC) of the esophagus with invasion restricted to the submucosa. METHODS: Thirty-eight submucosal SCC were studied histopathologically, and five of these 38 submucosal SCC, which demonstrated an extensive spreading-type SCC in which the size of the SCC was over 5 cm in longitudinal length while extending entirely across the esophageal lumen in a circumferential spread, are described in detail. RESULTS: The extent of SCC depended mainly on the extent of intraepithelial carcinoma (IEC) and ranged from 50 to 135 mm in longitudinal length. IEC existed continuously in four cases, and multiple IEC existed separately in one case. An epithelium showing dysplasia was present in all cases, and the involvement of the glands and ducts by IEC was present in two cases. There was only one invasive part of SCC observed in one case, and three to 10 invasive parts of SCC were observed in the other four cases; various features of invasion, including an invasive SCC from the esophageal glands and ducts, were also present. CONCLUSIONS: The extensive spreading-type SCC of the esophagus, which was considered to result from the widespread or multiple carcinomatous changes of the esophageal epithelium, was found to not be as rare as generally thought. The multiple and various features of the invasive parts of SCC suggested the simultaneous development of a downward invasion of SCC at different areas in extensive IEC.

Adult↗