Biomedical subjects

H Orita

Publications and source records attributed to H Orita.

At least 73 records · Page 4Linked to original sources

PubMed1993

A cardiac myocyte culture system as an in vitro experimental model for the evaluation of hypothermic preservation.

In cardiac transplantation, the donor heart is exposed to severe hypothermic and ischemic conditions. The purpose of the present study was to evaluate the functional and biochemical effects on cardiac myocytes cultured under hypothermic conditions. Cardiac myocytes were isolated from neonatal rat ventricles and cultured for 4 days, then incubated (1.5 x 10(6) myocytes/culture flask) for 24 h in media at 4, 10, 15, 20, and 37 degrees C. In addition, myocytes were incubated at 4 degrees C for 6, 12, 18, 24, 36, and 48 h. After each incubation, creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) were measured and the myocytes then cultured for an additional 24 h at 37 degrees C to evaluate the recovery of the myocyte beating rate. The recovery ratio of the myocyte beating rate following 24 h of varying temperature incubations was complete for the 10, 15, 20, and 37 degrees C groups, although it was markedly decreased in the 4 degrees C group, at 25.1% of the control; taken as the beating rate prior to hypothermic incubation. The release of CPK and LDH in the 4 degrees C group showed a three-fold increase compared to the other four groups, with a CPK of 147.2 mIU/flask and a LDH of 487.5 mIU/flask. The recovery of the beating rate for varying time incubations at 4 degrees C was complete for the 6- and 12-h groups, but decreased significantly in the other four groups, being 59.0% at 18 h, 28.2% at 24 h, 16.3% at 36 h, and 0% at 48 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

In vitro evaluation of diltiazem on hypothermic injury to immature myocytes.

The purpose of the present study was to evaluate the functional and biochemical effects of diltiazem (DTZ) on cardiac myocytes incubated under hypothermic conditions. Cardiac myocytes were isolated from neonatal rat ventricles and cultured for 4 days with MCDB 107 medium. Then, myocytes (12.5 x 10(5) myocytes/flask) were incubated at 4 degrees C for 24 hours in media with or without DTZ at concentrations of 0 M (group C), 10(-7) M (Group D1), 10(-6) M (group D2), 10(-5) M (group D3), or 10(-4) M (group D4). After 24 hours at 4 degrees C, CPK and LDH were measured. The myocytes were then cultured for 24 hours at 37 degrees C to evaluate the recovery of the myocyte beating rate. In group C (n = 7), the recovery ratio of the myocyte beating rate was 29.9% of control (beating rate prior to hypothermic incubation). Groups D1 and D2 (n = 7 each) had approximately the same recovery ratios as group C (24.0% and 24.7%, respectively); however, groups D3 and D4 (n = 7 each) showed no beating rate recovery. Release of CPK and LDH in group C was 112.3 mIU/flask and 457.4 mIU/flask, respectively. Groups D1 and D2 showed no significant differences in both enzymes compared to group C. However, the levels of CPK were significantly higher in group D4 (203.3, p < 0.05), and LDH levels were significantly higher in groups D3 and D4 (669.3, p < 0.05; 883.4, p < 0.02). In conclusion, DTZ showed no protective effects on hypothermic injury to immature cardiac myocytes; moreover, it accelerated cellular injury at the concentrations of 10(-5) and 10(-4) M both functionally and biochemically. Therefore, diltiazem may not be suitable for cardiac preservation during the neonatal period.

Animals↗

PubMed1993

Modulation of cardiac myocyte beating rate and hypertrophy by cardiac fibroblasts isolated from neonatal rat ventricle.

We evaluated the in vitro modulation of cardiac myocyte beating rate and growth hypertrophy in the presence or absence of cardiac fibroblasts. Cardiac myocytes and fibroblasts were isolated from neonatal rat ventricles, and cultures of either myocytes alone or of myocytes in co-culture with fibroblasts were established and observed for 21 days. The beating rate in control myocytes increased rapidly, reached peak values on day 5 (266.2 +/- 58.2 beat/min), and then decreased by day 21. The beating rate of myocytes which were co-cultured with fibroblasts in group 2-1 (2-1 ratio of myocytes to fibroblasts, 6.0 x 10(5) total cells/well) was significantly lower than that in control myocytes, and showed a decreased peak value on day 7 (135.1 +/- 46.4). The beating rate in group 1-1 was significantly less than that of group 2-1, with a peak value on day 7 (85.9 +/- 24.9). Group 1-2 myocytes did not show a beating rate increase. Myocyte hypertrophy was measured after three days of culture. The surface area of myocytes which had been co-cultured with fibroblasts was significantly increased, as compared to that of control myocytes. In addition, myocyte surface area increased with increasing numbers of fibroblasts (mean myocyte surface areas in group 2-1, 1-1 and 1-2 were 143 +/- 21, 163 +/- 33, 206 +/- 38% of control, respectively). In conclusion, suppression of the myocyte beating rate and acceleration of myocyte hypertrophy are characteristic expressions of myocyte differentiation and growth during the neonatal period The present results suggest that fibroblasts play an important role in controlling myocyte development.

Animals↗

PubMed1993

[Post operative embolism and left atrial enlargement in the old-aged ASD (atrial septal defect) patients].

As the operation risk of ASD is little today, the unexpected postoperative complication such as embolism is a miserable concern. We experienced two cases of embolism, which were cerebral infarction, in old-aged patients after ASD correction. It has been reported that low cardiac function, atrial fibrillation and foreign body in the left atrium should be risk factors of the embolism after ASD correction. However, blood stasis in the left atrium due to its enlargement may be an essential risk factor of the embolism. Accordingly we evaluated the left atrial volume in 87 ASD patients without complicated cardiac disorder. There was a significant correlation between the age (X) and left atrial volume index (Y). (Y = 16.5 + 1.1X, r = 0.668, p < 0.001). Left atrial volume index in our two cases of cerebral infarction indicated 171.7, 190.8 ml/m2 respectively. The former case had sinus rhythm and its defect was directly closed, and the latter had atrial fibrillation and its defect was closed with teflon patch. In addition pulmonary artery pressure and cardiothoracic ratio correlated with left atrial volume index significantly. Although some investigators reported that pulmonary hypertension and cardiomegaly were the risk factors of embolism, the left atrial enlargement by aging was thought to be the main risk factor. Thus, we concluded that anticoagulant therapy was necessary for the ASD patients with marked left atrial enlargement.

Aged↗

PubMed1993

[In vitro evaluation of prostaglandin I2 analogue on hypothermic injury to immature myocytes].

We evaluated the functional and biochemical effects of prostaglandin I2 analogue (PGI-A) on cardiac myocytes incubated under hypothermic conditions. Myocytes were isolated from neonatal rat ventricles and cultured for 4 days. Then, myocytes (12.5 x 10(5) myocytes/flask) were incubated at 4 degrees C for 24 hrs in media with PGI-A as follows; O M PGI-A (group C: control), 10(-9) M (group P1), 10(-8) M (group P2), 10(-7) M (group P3), 10(-6) M (group P4). After hypothermic incubation, CPK and LDH were measured. The myocytes were then cultured for 24 hrs at 37 degrees C to evaluate the recovery of myocyte beating rate. For the beating rate, group P2 showed significantly increased recovery compared to the control (P2: 47.9, p < 0.025, C:18.1 percent of control; ie, beating rate prior to hypothermic incubation). The release of CPK and LDH was significantly suppressed in group P2 compared to the control (P2:57.7, p < 0.05, 275.1, p < 0.025; C:96.8 mIU/flask, 439.6 mIU/flask, respectively). In conclusion, prostaglandin I2 has direct cytoprotective characteristics for immature myocytes that may be suitable for cardiac preservation.

Animals↗

PubMed1993

[A case of treatment of the Paget-Schroetter syndrome with PTA and Gianturco' expandable metallic stent].

We report a effective management of the Paget-Schroetter syndrome. A 23-year-old man was seen with a complaint of arm swelling and venous engorgement of the left arm. A first-rib resection was performed through a infraclavicular approach with removal of compressive elements including scalenus anterior and subclavius muscles. He became asymptomatic. But 2 months later, recurrent symptoms developed and venograms demonstrated the presence of restenosis of the subclavian vein with extensive collaterals. To relieve symptoms a percutaneous transluminal angioplasty (PTA) and a insertion and placement of the Gianturco's expandable metallic stents was carried out for the remaining stenosis of the subclavicular vein and a residual compression. Venograms, 7 months after operation, showed widely the patent subclavian vein. Trans-infraclavicular approach allowed exposure of the stenotic or obstructed segments of the subclavian vein. The PTA and stenting, especially after removal of compressive elements or during chronic phase, was a very useful and effective procedure for the treatment of the Paget-Schroetter syndrome.

Adult↗

PubMed1993

[Suppurative mediastinitis after open heart surgery: in comparison between infants-children and adults].

Among 361 consecutive patients who underwent open surgery from Jan. 1987 to Sept. 1991, risk factors and clinical courses were analyzed retrospectively in comparison between infants-children and adults. Seven mediastinitis (4.0%) occurred in 173 adult patients (20 to 75 y/o, mean: 54.4 y/o) and were not associated with age, sex, type of disease, and duration of operation or cardiopulmonary bypass. Postoperative mediastinitis significantly increased in the patients with low output syndrome (LOS) determined as use of IABP and/or assistant circulations (p < 0.001) and reexploration for bleeding or tamponase was associated with an increased risk for mediastinitis (p < 0.01). Five mediastinitis (2.7%) occurred in 188 infants and children (0 to 17 y/o, mean: 4.2 y/o). All patients involved with mediastinitis were less than 12 month old (2.6 +/- 3.3 month). None of the other factors was associated with an increased risk for this complication. Bacterial cultures of exudate were positive in 11 of 12 patients, and identified as MRSA in 10 and Staphylococcus epidermidis in one. In the seven of adult patients, two developed sepsis and four died with other organic failures or mediastinal bleeding. All five of infants healed after postoperative 33 to 145 days. The immature state of immune response might associate with postoperative mediastinitis in infants, whether LOS may be important in the immune suppression by surgical stress in adults, and the prognosis of mediastinitis might be effected by prolonged depression of postoperative cardiac function in adult patients.

Adolescent↗

PubMed1993

[Experimental procedure for evaluation of myocardial protection using cultured cardiac myocyte--functional and biochemical effects of hypothermic preservation].

The purpose of the present study was to evaluate the functional and biochemical effects on cardiac myocytes cultured under hypothermic conditions. Cardiac myocytes were isolated from neonatal rat ventricles by collagenase dispersion and cultured for 4 days with MCDB 107 medium containing 2% FCS. Thereafter, the myocytes (12.5 x 10(5) myocytes/culture flask) were incubated at 4 degrees C for 6, 12, 18, 24, 36 or 48 hours. After each incubation, CPK and LDH were measured. The myocytes were then cultured for additional 24 hours at 37 degrees C to evaluate the recovery of myocyte beating rate. The recovery ratio of myocyte beating rate was well maintained at 6 and 12 hours (94.5, 103.4 percent of control: ie, beating rate prior to hypothermic incubation, respectively). Thereafter, the recovery ratio significantly decreased at 18 hours (58.4 percent, p < 0.05), and reached null levels at 48 hours. Release of CPK and LDH increased significantly at 18 hours (CPK: 131.8 mIU/flask, p < 0.05; LDH: 356.0 mIU/flask, p < 0.05), and showed a marked increase at 48 hours (CPK: 961.3, LDH: 1729.5). In addition, the CPK and LDH levels did not significantly increased at 37 degrees C for 48 hours compared to those for 6 hours (6 hours: 7.95, 193.7; 48 hours: 13.5, 199.4, respectively). In summery, 4 degrees C hypothermia induced the myocyte injury both functionally and biochemically, which increased with an increasing incubation time. In addition, it was suggested that an optimal temperature in hypothermic preservation might be 10 degrees C. Thus, this cell-culture system may provide a useful and simple method for in vitro evaluation of hypothermic preservation.

Animals↗

PubMed1993

[Palliative management of left atrioventricular valve atresia with normal aortic valve].

We present three cases of the left atrioventricular valve atresia (LAVVA) with normal aortic valve. All cases showed [S,D,D] and had concordant AV connection. First case had two functional ventricles with multiple VSD and ventriculo-arterial connection was normal. Interatrial communication was maintained through ASD and the infant underwent pulmonary arterial banding (PAB). Four years later, the patient underwent Blalock-Hanlon (B-H) procedure for an inadequate ASD. Second case showed the univentricular heart of right ventricle with double outlet. In this case, PFO was restrictive and the infant underwent B-H procedure. Ten days after initial palliation, patient underwent PAB. Third case showed the univentricular heart of left ventricle and transposed great arteries. This patient had also the coarctation of the aorta. B-H procedure, PAB and subclavian flap aortoplasty were performed simultaneously by bilateral thoracotomy. All patients have done well, with normal growth and development at the time of their last outpatient evaluation at 10 year, 9 months and 9 months after surgery respectively.

Aortic Valve↗

PubMed1993

[A depression of respiratory function following the cardiopulmonary bypass in infants and children].

Fourty-one patients (2-44 month old) underwent the closure of ventricular septal defect using moderate-hypothermic cardiopulmonary bypass (CPB). The respiratory index (RI) were monitored after CPB, as functional parameters of oxygenation capacity. At 15 min after CPB, there was the increased level in RI (2.22 +/- 0.45; normal value: 0.1-0.37). Thereafter, RI gradually decreased by 90 min after CPB (1.22 +/- 0.19), and again increased reaching peak levels by 12 hrs after ICU-entry (2.56 +/- 0.64). The patients who exceed 1.00 at 15 min after CPB (RI-15) remained higher levels in RI compared to less than 1.00 and had the prolonged controlled ventilation. The RI-15 correlated with pulmonary-systemic flow ratio (Qp/Qs) and pulmonary-left ventricular pressure ratio (PA/LV). There was no significant correlation between RI-15 and CPB factors including CPB time, dilution rate, rectal temperature, flow and perfusion pressure. These results suggest that pulmonary dysfunction following the CPB may not be simply occurred by CPB but also involved by preoperative conditions. An increased pulmonary blood flow might be one of important and predictive factor for the depression of oxygenation following the cardiac surgery in infants and children.

Cardiopulmonary Bypass↗

PubMed1993

[A blind point of vent catheter: air aspiration].

We experienced a case of saphenous vein air embolism after coronary artery bypass graft, in which case we used vent catheter kept in the left atrium. Though it was considered that air bubbles were never aspirated through vent catheter, we speculated that the origin of air bubbles must be the vent catheter. And we made an experiment on the motion of air in the vent catheter using a model of left heart composed with soft reserver (atrium) and pulsatile pump (ventricle). When the pulsatile pump was arrest, the air bubbles were never aspirated from the vent catheter to the soft reserver even if we vented with strong negative pressure. But, when the pulsatile pump was in motion and the left atrium was vented with some negative pressure, some leaks of air bubbles were recognized. So we must pay much more attention to the degree of venting when the heart is in motion. Sometimes we use overpressure safety valve composed with vent catheter, but measured left atrial pressure showed that decreased left atrial pressure was only 2 mmHg. So its use should be restricted in the patients with good ventricular function.

Catheterization, Central Venous↗

PubMed1992

Prophylactic lymph node dissection in patients with advanced gastric cancer promotes increased survival time.

BACKGROUND: There is no consensus of opinion regarding the efficacy of lymph node dissection. METHODS: Data were analyzed from 452 patients with advanced gastric cancer who underwent curative resection in the Department of Surgery II, Kyushu University Hospital, between 1970 and 1985, with special reference to the lymph node metastasis. RESULTS: Metastatic lesions were evident in the dissected lymph nodes of 300 of 452 (66.4%) patients. Survival time for patients without lymph node metastasis was longer than for those with it (P less than 0.01). In patients without lymph node metastasis, the tumor was smaller, serosal invasion was less prominent, tumor growth was less infiltrating, and the tumor stage was, therefore, less advanced. Lymphatic involvement was found in 38.9% of the patients with no evidence of lymph node metastasis. CONCLUSIONS: Because the postoperative mortality rate is low in patients with lymph node dissection, the authors advocate prophylactic lymph node dissection to prevent a recurrence.

Aged↗

PubMed1992

Signet ring cell carcinoma of the stomach.

Between 1965 and 1985, 51 of 1500 patients (3.4%) with gastric cancer who had gastric resection had signet ring cell gastric cancer. Patients with this form of cancer tended to be younger and female; the tumors were smaller and involved the stomach body, serosal invasion was less prominent, and lymph node metastases were less likely to be present. Early mucosal and submucosal cancer was present in 54.9% of the patients with the signet ring cell and in 24.6% with other types of gastric cancer. In 15.7% of patients with signet ring cell cancer, a noncurative resection was performed. The 5-year survival rate was 74.5% for patients with signet ring cell cancer and 52.4% for those with other types of gastric cancer (P less than 0.01). In patients with signet ring cell gastric cancer, the lesion is less extensive; thus, these patients probably can expect a longer survival time.

Adenocarcinoma, Mucinous↗

PubMed1992

Predictors of lymph node metastasis in early gastric cancer.

Data were analysed on 396 patients with early gastric cancer who underwent resection in this department; special reference was made to lymph node metastasis. Metastases were present in the dissected lymph nodes of 47 patients (11.9 per cent). The survival rate for patients with metastasis to lymph nodes was lower than for those without such metastasis (P less than 0.05). Lymph node metastasis was associated with larger tumour, a higher incidence of submucosal invasion, a higher rate of lymphatic vessel involvement, an advanced stage of disease and a non-curative resection rate of 6.4 per cent. Multivariate analysis showed that the independent risk factors for lymph node metastasis in patients with early gastric cancer were large tumour size, lymphatic vessel involvement and invasion into the submucosal layer. In patients with these risk factors, lymph node dissection and postoperative adjuvant therapy should be performed in an attempt to prevent recurrence in the form of lymph node metastasis.

Female↗

PubMed1992

Quality of life after gastrectomy in patients with carcinoma of the stomach.

One hundred and fifty patients without recurrence of disease after R2 gastrectomy for carcinoma of the stomach were interviewed to determine their quality of life after surgery. Patients ate less and weighed less but most appeared to be well adjusted and had an optimistic attitude regarding their physical state. There was no evidence of a diminished quality of life in those who had undergone distal partial gastrectomy. These patients had a higher overall food tolerance, body-weight and performance status compared with those treated by total gastrectomy. Considering the satisfactory outcome and the sustained quality of life, radical R2 gastrectomy may be the treatment of choice for carcinoma of the stomach.

Body Weight↗

PubMed1992

The hemostatic effect of deacetylated chitin membrane on peritoneal injury in rabbit model.

In this study, we determined the effect of 80% deacetylated chitin (DAC-80) membrane on postsurgical bleeding after visceral and parietal peritoneal abrasion. Japanese white rabbits underwent a midline laparotomy followed either by a bilateral peritoneal sidewall abrasion (4 x 4 cm) or an abrasion of liver surface (3 x 2 cm). The injured surface was then covered with a 0.2 mm thick DAC-80 membrane. On postsurgical day 2, the rabbits were sacrificed and the amounts of postsurgical bleeding was determined by quantitating the number of red blood cells recovered in 50 ml peritoneal lavage fluid. The DAC-80 membrane was found to reduce postsurgical bleeding after the abrasion of liver surface (treated with DAC-80 membrane: 2.9 +/- 0.8; control: 24.6 +/- 5.9 x 10(8) cells/peritoneal cavity, P less than 0.005). This same hemostatic activity was not observed after application in the peritoneal sidewall abrasion model. We also measured plasminogen activator activity (PA) and urokinase inhibitory (PAI) activity in the spent culture media of macrophages recovered from the postsurgical peritoneal exudate. The DAC-80 membrane reduced the PA secretion from postsurgical macrophages after liver surface abrasion (treated with DAC-80: 2.8 +/- 0.7; control: 3.9 +/- 0.9 mPU/ml). The DAC-80 membrane also showed similar effects on PA secretion after peritoneal sidewall abrasion. No significant effects were found in the secretion of PAI by postsurgical macrophages in both surgical models. These findings suggest that the DAC-80 membrane may have hemostatic activity through the modulation of fibrinolytic activity of peritoneal exudative macrophages.

Adolescent↗

PubMed1992

A clinical study of postoperative infections following open-heart surgery: occurrence and microbiological findings in 782 cases.

A total 782 consecutive patients underwent open-heart surgery with CPB between January, 1979 and December, 1988, at the Yamagata University Hospital. We assessed the incidence of postoperative infections in relation to age, the duration of surgery and antibiotic prophylaxis, and examined the causative organisms, after which the types of infecting flora were compared between the 1st period, from 1979 to 1983 and the 2nd period, from 1984 to 1988. Postoperative infection occurred in 104 of the 782 patients (13.3 per cent); in the form of a wound infection in 41 (5.2 per cent), pneumonia in 33 (4.2 per cent), urinary tract infection in 9 (1.2 per cent), prosthetic valve endocarditis in 6 (0.8 per cent), and other infections in 15 (1.9 per cent). Patients aged under 12 months or over 60 years showed a higher incidence of infection, being 17.4 per cent and 19.2 per cent, respectively. Patients who underwent an operation of over 8 hours duration also had a significantly higher incidence compared to those whose operation time was less than 4 hours, being 32.9 per cent and 6.3 per cent, respectively (p less than 0.0001). There was no significant difference in the incidence of postoperative infection between patients given or not given preoperative prophylaxis. A total 123 species of organisms were isolated from the 104 patients, 52.8 per cent being gram-negative bacteria (GNB), and 43.9 per cent gram-positive bacteria (GPB), and a remarkable increase in the incidence of GPB was seen in the 2nd period compared to the 1st period from 31.7 per cent to 50.0 per cent.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

Clinicopathologic evaluation of recurrence in early gastric cancer.

Five hundred ninety-two patients with early gastric cancer underwent surgical resection from 1970 to 1986 in our hospital, and 13 died from a recurrence of their disease. A careful analysis of these 13 patients suggests that carcinomas which invaded to the submucosa tend to recur more often than those confined to the mucosa. Well differentiated and papillary adenocarcinomas characterized by protruded or elevated lesions tend to recur earlier than poorly differentiated or signet-ring cell carcinomas characterized by depressed or excavated lesions. However, both types recurred from hematogenous metastases, with the liver being the most common site. Therefore, the macroscopic and histological features presently used to characterize early gastric cancer do not provide sufficient information to accurately predict which patients are at most risk for recurrence.

Adenocarcinoma↗