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Biomedical subjects

D Saito

Publications and source records attributed to D Saito.

At least 127 records · Page 7Linked to original sources
PubMed1988

[The influence of sodium thiosulfate on the antitumor effect of cisplatin in human gastric cancer cell lines].

It is well known that the sodium thiosulfate (STS) decrease not only the nephrotoxicity which is a dose limiting factor of cisplatin (CDDP) chemotherapy but also its antitumor activity. Therefore, we examined the antitumor effect of CDDP in the human gastric cancer cell lines under various concentrations of STS. The cell lines used were KATO-III, MKN 28, MKN 45 and MKN 74. The consistency of STS in relation to CDDP (2.0 ng/ml) was 25-250 fold-molar ratio. The chemosensitivity of CDDP was positive in the 3 cell lines, KATO-III, MKN 28 and KATO-III in order. When STS was used with 50 fold-molar ratio in KATO-III and MKN 28 and 100 fold in MKN 45, a CDDP colony inhibition rate of more than 80% was maintained. This results suggest that the antitumor effect of CDDP will not be suppressed not so much when the low dose of STS was used in CDDP with STS chemotherapy, even though used through the same route of administration and simultaneously.

Cell Line↗
PubMed1988

[Atrial septal aneurysm: a report of three cases].

Three cases of isolated atrial septal aneurysm are reported. Case 1: A 66-year-old man visited our hospital for detailed examination and evaluation of premature ventricular contractions and left ventricular hypertrophy previously detected. Echocardiography revealed an atrial septal aneurysm protruding into the left atrium in the early systolic phase and into the right atrium during the mid-systolic to diastolic phase. Subxiphoid M-mode echocardiography showed triphasic movement of the wall of the atrial septal aneurysm toward the left atrium during the end-diastolic to systolic phase, which was enhanced during inspiration. No abnormalities were found by Doppler echocardiography. Cardiac catheterization revealed normal intracardiac pressures and oxygen saturations, but a right arteriogram revealed a defect in the right atrium. Case 2: A five-month-old male infant was referred to our hospital for detailed examination and evaluation of a heart murmur. Echocardiography revealed an atrial septal aneurysm in which a part of the interatrial septum protruded into the right atrium. Case 3: A one-day-old female infant was admitted to our hospital for detailed cardiac examination. Echocardiography revealed that the entire interatrial septum protruded into the right atrium. In Cases 2 and 3 the morphology of the aneurysms did not show cyclic or respiratory change. These two cases had no other abnormalities on echocardiography or Doppler echocardiography. The mechanism of the wall movement in Case 1 seemed to be attributed to differences in pressures between the right and left atria and in properties of the aneurysmal walls. Enhancement of the protrusion of the aneurysmal wall toward the left atrium during inspiration was considered due to inspiratory increase of right atrial pressure.

Aged↗
PubMed1988

A case of anomalous origin of the right coronary artery from the pulmonary trunk: imaging of abnormal flow by Doppler color flow mapping.

An asymptomatic 48-year-old woman was admitted to our hospital for evaluation of a precordial continuous murmur. The chest radiograph showed a normal cardiac silhouette. The resting electrocardiogram showed incomplete right bundle branch block. A multistage, graded treadmill exercise test did not affect the ST-T segment. A thallium-201 myocardial perfusion scan with a multistage ergometer exercise test showed no distinct perfusion defect. A two-dimensional echocardiogram disclosed a dilated left coronary artery arising from the left sinus of Valsalva, and a dilated right coronary artery crossing the aorta anteriorly to the pulmonary trunk. Real-time two-dimensional Doppler echocardiography of the same region showed an abnormal jet coming from the right coronary artery into the pulmonary trunk during diastole. A continuous wave Doppler flow study in the pulmonary trunk revealed a high-speed, disturbed flow which began in mid-systole, and continued during diastole. These findings were compatible with anomalous origin of the right coronary artery from the pulmonary trunk. An aortogram confirmed the diagnosis.

Coronary Vessel Anomalies↗
PubMed1988

[Indications and problems of endoscopic treatment for gastrointestinal tract cancers, with special reference to early gastric cancer].

We carried out a clinicopathologic and endoscopic investigation of the relationship between the presence/absence of lymph node or distant metastasis and several crucial factors using resected specimens of early gastric cancer, and concluded that endoscopic treatment was indicated for four types of early gastric cancer: 1) type IIa less than 2 cm in size, 2) focal cancer, 3) so called "gastritis-like" early cancer less than 2 cm in size and 4) polypoid type with mucosal involvement. Up to now, cases of early gastric cancer have been treated by polypectomy, strip biopsy and laser endoscopy. Residual cancer cells were found in 10 out of 20 resected cases. In 2 out of 54 cases followed up for more than one year without any surgical treatment, cancer cells were discovered by biopsy. The effectiveness rate was estimated to be 84% (62/74). Endoscopic treatment was able to provide high efficiency for early gastric cancer of the above types. Causes of ineffectiveness were a lesion more than 2 cm in size, vertical invasion of the lesion into the submucosa and the location of a lesion in a difficult area such as the prepylorus or the cardia.

Aged↗
PubMed1987

The daily profile of ventricular premature beats in the patients with ischemic heart disease.

To clarify factors affecting the prevalence of ventricular premature contraction (VPC) in patients with stable ischemic heart disease, daily profiles of VPC prevalence were studied in 92 patients using continuous 24-hour electrocardiographic recordings. VPCs in patient groups with effort angina and inferior infarction showed similar daily profiles. However, a significant relationship between VPC prevalence and heart rate was observed in inferior infarction group, while patients with resting angina exhibited another relationship between the two parameters. Higher prevalence rate of VPCs in the early morning in patients with resting angina suggested the contribution of cardiac autonomic nerve activity to the increased frequency of VPCs, while constant frequency of VPCs during the day in anterior infarction group provided no influences on heart rate, effort, and autonomic nerve activity on the VPC prevalence. Age, sex, left ventricular ejection fraction, and nitrates and diltiazem used for the treatment of angina pectoris did not affect the daily profile of VPC prevalence in any patient groups. These results indicated that the clinical and pathophysiological differences of ischemic heart disease, even in stable patients, showed the different distribution of VPC prevalence within a day which is due, in part, to the varied activities of cardiac autonomic nerves.

Aged↗
PubMed1987

The effect of cardiac sympathetic nerve stimulation on the right ventricle in canine heart.

The change in coronary hemodynamics during right or left cardiac sympathetic nerve stimulation was studied in anesthetized open chest dogs. No difference in the increasing rate of mean coronary blood flow between right coronary artery (RCA) and left anterior descending coronary artery (LAD) was observed. However the increasing rate of right ventricular systolic pressure X heart rate (RVSP X HR) was greater than that of left ventricle (LV). With phentolamine injection, cardiac sympathetic nerve stimulation showed similar changes as the controls. Beta-stimulation by isoproterenol infusion did not cause different effects on the increasing rate of coronary blood flow between RCA and LAD. These results showed that cardiac sympathetic nerve stimulation increased the double product of the right ventricle (RV) more than that of the LV and the increase was not affected by phentolamine. Moreover, cardiac sympathetic nerve stimulation, either the right or the left, caused the greater effects on the RV compared to the LV mainly through beta-adrenoceptors, and that the response of the RV to increase in oxygen demand was possibly, in part, different from that of the LV.

Animals↗
PubMed1987

A case of pancreatic cancer with liver metastasis which responded to chemotherapy.

A case of pancreatic cancer with liver metastasis is reported, in which chemotherapy had a marked effect, with the responses clearly documented. The patient was a 59-year-old male who experienced epigastric pain in February 1985, upper gastrointestinal X-ray examination revealing extragastric compression by the pancreas. He visited the National Cancer Center Hospital, Tokyo, in April 1985 and the diagnosis of pancreatic cancer with liver metastasis was made using the imaging procedures of ultrasonography, computed tomograph scanning and endoscopic retrograde cholangiopancreatography as well as by biochemical and serological tests. At the time a 5 cm tumor was palpable in the middle upper abdomen. The patient was treated with Cis-diaminedichloro platinum, tegafur, and 5-fluorouracil, successively, and the abdominal tumor gradually diminished, finally becoming impalpable. The response was evaluated as one of partial responses (PR) by ultrasonography, and the improvement substantiated by computed tomography and tumor markers.

Cisplatin↗
PubMed1986

Effect of proximal and distal coronary pressure change on the resistance of stenotic coronary segment.

While dynamic changes in the resistance of stenotic coronary segments were recently proposed by several investigators, the mechanisms of these changes are obscure. This study was conducted to correlate changes in coronary pressure distal to the stenosis to dynamic changes in the stenosis resistance in the canine heart. Coronary pressure distal to the stenosis was raised by either proximal aortic pressure elevation or intracoronary blood infusion distal to the stenosis. The pressure rise resulted in a significant fall in the stenosis resistance. Distal coronary pressure drop induced by phlebotomy or removal of blood from the distal coronary bed caused the reverse effects on resistance. Linear regression analysis revealed a close relationship between changes in distal coronary pressure (delta DCP) and those in resistance of the stenotic coronary segment (delta RL) represented by the following equation; delta RL (dyne X cm-5 X sec X 10(-3)) = 0.50 X [delta DCP (mmHg)]-6.0 X 10(-2), r = 0.86, p less than 0.01. The results suggest that dynamic changes in stenosis resistance appear largely to be a function of the pressure changes distal to the stenosis.

Animals↗
PubMed1986

Hemodynamic effects of labetalol in the dog. Comparative study in the anesthetized open-chest dog and in the conscious dog.

Hemodynamic effects of labetalol, an alpha- and beta-adrenoceptor blocking drug, were investigated in the conscious dog and in the anesthetized open-chest dog. In the conscious dog, intravenous injection of labetalol, in a dose of 0.5 mg/kg, decreased the total peripheral resistance by approximately 20% (P less than 0.01) in association with falls in blood pressure and heart rate. The total peripheral resistance of the anesthetized open-chest dog was not affected by labetalol in the presence of the same extent of blood pressure fall as results of the conscious dog. In contrast, agents which have beta-adrenoceptor blocking effect alone provided substantial elevation of the total peripheral resistance in the anesthetized dog. These results indicate that the different responses of the resistance to labetalol probably result from the vascular alpha-adrenoceptor blocking action, and also show that in the conscious state alpha-adrenoceptor blocking action of labetalol is enhanced in comparison with the effect in the anesthetized open-chest dog.

Adrenergic beta-Antagonists↗
PubMed1986

Cardiac hypertrophy in hypertrophic cardiomyopathy and hypertension evaluated by echocardiography and body surface isopotential mapping.

To elucidate the useful indices for differentiating cardiac hypertrophy due to essential hypertension (EH) from that due to hypertrophic cardiomyopathy (HCM), we examined standard 12-lead ECGs, chest radiographs and echocardiograms (Echo) in 66 EH and 46 HCM cases. Body surface isopotential mappings (MAPs) were recorded in 16 cases of EH and 18 of HCM. The thickness of the interventricular septum (IVST) and the IVST/PWT ratio (PWT = the thickness of the posterior wall) were greater and left ventricular diastolic diameter (LVDd) was smaller in the HCM group than in the EH group. The septal activation time (SAT), the time interval during which the maximum positive potential moves from the mid-sternal line or the left sternal border to the left mid-clavicular line in the QRS complex, correlated directly with the IVST (r = 0.55, p less than 0.005) and the IVST/PWT ratio (r = 0.61, p less than 0.005). When the SAT was longer than 30 msec, the IVST was over 25 mm and the IVST/PWT ratio was over 2.0, all cases belonged to the HCM category. When subjects were limited to patients with IVST less than 25 mm, the SAT of the HCM group was significantly greater than that of the EH group. These data suggest that the SAT may reflect the etiological differences between the septal hypertrophy of the EH group and that of the HCM group, and that these parameters of MAPs may be helpful to distinguish cardiac hypertrophy due to EH from that due to HCM.

Adult↗
PubMed1986

[Immunoreactive carcinoembryonic antigens in gastric juice collected during endoscopy--their usefulness in the diagnosis of gastric cancer].

In the 109 subjects adopted for study, 52 involving gastric cancer and 57 noncancerous gastric disease, immunoreactive CEA (GI-SEA) in the gastric juice collected during endoscopy was measured by enzyme immunoassay using polyclonal (P group) and monoclonal (M group) antibodies against CEA. The results are outlined below. The mean value and the positivity of GI-CEA was the highest in advanced gastric cancer, followed by early gastric cancer and noncancerous gastric disease, in that order, and a particularly significant difference (P less than 0.001) was noted (in both the P and M groups) between the former two and the latter. In the GI-CEA of gastric cancer, high positivity was manifested regardless of the histological type, though the average values show that, in the case of the P group, high positivity manifested itself in undifferentiated adenocarcinoma, while in the case of the M group, it applied to differentiated adenocarcinoma. Moreover, no correlation was found between the size of the lesion and the positivity, though even with small lesions of less than 2 cm, there was an indication of probable high positivity. The values recorded for the P and M groups showed a close correlation between the two, except for the GI-CEA value of the histological type. However, for the M group, the positivity and GI-CEA value both tended to be low. The above results suggest that measurement of GI-CEA is of great help in the diagnosis of gastric cancer and that the use of polyclonal antibodies is appropriate for screening and early diagnosis.

Carcinoembryonic Antigen↗
PubMed1985

Effect of adenosine deaminase inhibitors on myocardial reactive hyperaemia following brief coronary occlusions.

Effect of two agents of adenosine deaminase inhibitor, 8-azaguanine and adenine, on myocardial reactive hyperaemia was tested in the anaesthetised open-chest dog. Reactive hyperaemic flow response of the circumflex coronary artery was observed following 5, 10, 15, 20 and 30 s coronary occlusions before, during and after infusion of 8-azaguanine and adenine, which are known as adenosine deaminase inhibitors. Intracoronary infusion of 8-azaguanine and adenine caused the minimum increase in the baseline coronary flow. Both the nucleic acids shifted the dose response curve of adenosine to the left. 8-azaguanine enhanced volume response of flow at all occlusion intervals tested. The infused dose of adenine also intensified volume response of flow after 5, 15, 20 and 30 s occlusions. Fifteen minutes after termination of the nucleic acid infusions, the reactive hyperaemia returned towards control levels. The results suggest that 8-azaguanine and adenine enhance myocardial reactive hyperaemia possibly by inhibiting adenosine deaminase to degradate myocardial interstitial adenosine to inosine.

Adenine↗
PubMed1985

Intracoronary adenosine enhances myocardial reactive hyperemia after brief coronary occlusion.

Adenosine is a prime candidate for the role of mediator between myocardial metabolic state and coronary blood flow. However, there are few reports concerning the direct effects of exogenously added adenosine on coronary autoregulation. The present investigation in the open-chest dog studied the effects of a threshold dose of intracoronary adenosine infusion on reactive hyperemia following brief coronary occlusions. The infused dose did not increase nonocclusive flow by greater than 10%. Adenosine enhanced total hyperemic flow at all occlusions tested (5, 10, 15, 20, and 30 s). Aminophylline pretreatment reduced reactive hyperemia below the control level even in the presence of an intracoronary infusion of adenosine. Adenosine injected into the left atrium and intracoronarily infused papaverine did not affect hyperemic response to 5- and 15-s coronary occlusions. The results suggest that a minimum dose of exogenously added adenosine enhances myocardial reactive hyperemia, possibly by potentiating the effects of endogenous adenosine released during ischemia.

Adenosine↗
PubMed1985

[Difference in clinical treatment between patients histologically diagnosed as group III by the old and new "group classifications" of gastric biopsy].

Since 1971, when the first draft of the "Group Classification", which classifies the atypism of histological structure in biopsy specimens of the stomach, was proposed by the Japanese Research Society For Gastric Cancer, this classification has come into wide use in Japan. It was, however, revised in 1983, and, according to the revised classification, group III was defined as general histological findings in which it is difficult to make a differentiation between benign and malignant by biopsy specimens. Consequently, the new group III includes, various borderline histologies, in addition to the old group III, which had been defined as the histological features corresponding to those observed in gastric adenoma in biopsy specimens. At the National Cancer Center Hospital, 13,909 gastric biopsies were performed during the period between 1973 and 1982. By retrospective review of these, histological findings in 247 lesions of 231 cases corresponded to group III by the old classification (adenomatous type) and in addition to these, 54 lesions of 54 cases to group III by the new classification (non-adenomatous type). We compared the endoscopic and pathological features between the two types, and the following results were obtained: The false-negative rate of malignancy in the non- adenomatous type (24%) was much higher than that in the adenomatous type (6%). The difference between the two may suggest that, with the adoption of the new group classification, clinical treatment of the patients with group III becomes more complicated due to the increase of the false-negative rate. Endoscopically, most (84%) of the lesions in the adenomatous type were seen as polypoid, while in the non-adenomatous type, depressed lesions were dominant (80%). And, endoscopic details of the polypoid or depressed appearances were mostly different between the two types. These nuances of endoscopic appearance between adenomatous and non-adenomatous types are applicable to decisions regarding, adequate clinical treatment for patients diagnosed as group III by the new "group classification." Good communication between the endoscopist and pathologist is indispensable.

Adenoma↗
PubMed1984

Effect of pacemaker sites on contractile forces of the local myocardium and blood flow in the major branches of the left coronary artery in anesthetized open-chest dogs.

Decreased cardiac performance during ventricular tachycardia or ventricular pacing has been ascribed to the lack of synchrony due to altered ventricular contraction. However, the direct effect of the pacemaking site on blood flow in the major coronary arterial branches and on regional contractile forces has not been adequately examined. In this investigation, twelve dogs were used to assess coronary flow in the left anterior descending (LAD) and circumflex coronary arteries (LCx) and the regional myocardial function in response to ectopic electrical pacing. The sites were the outflow tract of the right ventricle (RV pacing), the anterior left ventricular wall supplied by the LAD (LAD pacing), and the lateral wall perfused by the LCx (LCx pacing). Strain gauge arches were transmurally fixed to myocardial segments of the anterior and lateral walls of the left ventricle. The mechanical forces generated were measured while simultaneously recording blood flow in the LAD and LCx. RV pacing diminished developed-tension similarly in both areas. LAD flow was further decreased during anterior pacing as was the developed-tension in the LAD supplied area. A similar relationship was observed between LCx flow and developed-tension in the LCx area during lateral pacing. Compared to RV pacing, anterior pacing did not affect LCx flow and local myocardial force in the lateral wall of the left ventricle, and lateral pacing did not cause further changes in LAD flow and anterior myocardial function. The decrements in blood flow were closely related to decreased myocardial function (p less than 0.01). These findings indicate that ventricular pacing decreases ventricular performance with attenuated regional myocardial function at the pacing area, in addition to causing altered ventricular contraction sequence.

Animals↗