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Biomedical subjects

K Ninomiya

Publications and source records attributed to K Ninomiya.

At least 73 records · Page 4Linked to original sources

[Borderline values of laboratory data in patients with hyperlipidemia].

In Japanese, serum cholesterol levels have been increasing. This seems to be due to changes in life style, mainly the increase in dietary fat. Epidemiologic studies in the United States and Europe have shown that patients with hypercholesterolemia have a high risk of ischemic heart disease. Some guidelines for the management of hyperlipidemia have been developed in the United States, Europe, and Japan. The National Cholesterol Education Program (NECP) in the United States divides serum cholesterol level into three grades (desirable: below 200 mg/dl, borderline: between 200 mg/dl and 240 mg/dl, hypercholesterolemia: over 240 mg/dl). Borderline serum cholesterol is also a risk, especially in people complicated by other risk factor(s). As most borderline serum cholesterol seems to be due to polygenic hypercholesterolemia, an attempt to change the diet should be the first recommendation for treatment.

Cholesterol↗

[An experimental study on transcoronary chemical ablation: comparison of ventricular tachyarrhythmias induced by chemical ablation according to different chemical materials].

The purpose of this study was to compare heart rate, appearance rate and duration of ventricular tachycardia (VT) by transcoronary chemical ablation using 95% ethanol and 1% aethoxysclerol respectively. After the balloon which was guided to the left or right coronary artery with PTCA technique in anesthetized dogs was inflated, chemical ablation was performed using ethanol (n = 5) or aethoxysclerol (n = 5). These chemicals were administered at 0.05 ml/sec with total dose of 0.50-1.50 ml. A quadripolar electrode catheter was used to record the intracardiac electrogram. VT occurred in all dogs (100%) after the administration of both ethanol and aethoxysclerol. In one dog using ethanol, VT developed into ventricular fibrillation, resulting in death. In dogs using aethoxysclerol, the heart rate and duration of VT were significantly lower and shorter than in those using ethanol (p < 0.05). There were no significant differences determined histologically in the ablated lesions caused by these different chemicals. We conclude that the severity of VT induced in all subjects by chemical ablation is different according to the materials applied, and that aethoxysclerol seems to be safer in comparison with ethanol.

Animals↗

[The influence of repetitive delivery of radiofrequency current in catheter ablation].

The single delivery of radiofrequency current to the cardiac tissue can produce discrete small and shallow area of homogeneous coagulation necrosis. Little is known, however, concerning the influence of repetitive deliveries of radiofrequency current to the identical site of the ventricular myocardium. Therefore, in animal experiments using 8 dogs, we investigated the influences of those applications on the ventricular myocardium from the histological and electrocardiographical aspects. The used frequencies of radiofrequency current were 13.56 MHz (RF-50), 520 kHz (Hatt 200 S) and 500 kHz (LL-50). Released power was 25 Watts in current and 20 seconds in duration. The innings of application were 10, 20 and 30 times per one ablation session. The depth of ablated lesion became greater as the applied innings increased in any generator of radiofrequency current. The ablated lesion by the delivery over 20 times reached from the ventricular endocardium to the epicardium. In contrast, surface area produced by repetitive application was determined by the size and length of the tip of electrode catheter. T wave inversion and isolated premature ventricular contraction on electrocardiogram were observed only during repetitive radiofrequency energy application. Thus, since the repetitive delivery of radiofrequency energy to the identical myocardium caused the deep ablated lesion reached to the epicardium, caution should be taken against myocardial perforation in a clinical setting. However, this application could be useful for the ablation of deeper lesion responsible for ventricular tachycardia.

Animals↗

A familial case of hereditary angioneurotic edema in Japan.

A 53-year-old man was admitted with impairment of breathing following laryngeal edema. Serum levels of CH50 (22 U/ml), C4 (3 mg/dl), C1-INH protein (10.6 mg/dl) and C1-INH activity (LT 25%) were low. Complement study of the patient's family members revealed that he was one of 5 patients in 3 generations with hereditary angioneurotic edema (HANE). Administration of the androgen derivatives Danazol (600 mg/day) and Oxymetholone (30 mg/day) effectively increased serum levels of C1-INH activity and C4. Though eruption and hepatic dysfunction attributable to administration of the drugs appeared, these side effects improved after withdrawal of the drugs. Subsequently, the treatment with Danazol at a low dose (100 mg/day) was resumed, and the patient has had no episodes of edema for the past 3 years. Regarding the familial cases of HANE, fewer than 20 have been reported in Japan.

Angioedema↗

[An experimental study of determining the appropriate frequency of radiofrequency catheter ablation in vitro and in vivo for ventricular tachycardias].

The purpose of this study was to examine the appropriate frequency of radiofrequency catheter ablation (RFA) for ventricular tachycardia. Radiofrequency energy generated by a device in which the frequency could be changed, was delivered from an electrode catheter with an electrode tip-width of 4 mm. RFA was performed for 10 seconds with 20W (50V x 0.4A) using 7 different frequencies from 10 to 500 kHz on ventricular myocardium in vitro and in anesthetized dogs. The ablated lesion was significantly larger with RFA of 200-300 kHz in both surface area and depth (p less than 0.05). The appearance of ventricular arrhythmia during RFA increased as the frequency decreased, and one dog applied with RFA of 100 kHz had spontaneous ventricular fibrillation resulting in death. All dogs with frequency less than 100 kHz had a muscle cramp during RFA. We conclude that appropriate frequency seems to be 200-300 kHz to obtain a large ablated lesion, and a frequency higher than 300 kHz seems suitable to avoid arrhythmia. We also conclude that a frequency under 100 kHz should not be used.

Animals↗

[Is radiofrequency catheter ablation available for treatment of ventricular tachycardias?--Effects of sequential unipolar applications using multiple electrode catheter].

The purpose of this study was to examine the effects of radiofrequency energy delivered to the canine endocardium in sequential unipolar applications using multipolar electrode catheter for treatment of ventricular tachycardias. Radiofrequency energy generated by the newly designed device (500 kHz) was delivered to the ventricular myocardium by a quadripolar electrode catheter. The device could indicate output and voltage and could calculate myocardial impedance. In order to determine the power of the ablation in vivo, sequential unipolar application was performed with various output in vitro. A continuous endocardial ablation was achieved with output beyond 15 W and with duration of 5 sec per one pole. According to our measurement, the myocardial impedance in vivo was about three times as large as that in vitro. Therefore, minimal output of 45 W in vivo was applied in the same manner in vitro, which resulted in continuous belt-shaped endocardial ablated lesion. Ventricular stimuli after sequential unipolar applications did not induce ventricular tachycardia in any of the dogs. We conclude that radiofrequency sequential unipolar application using the newly designed device produces a large ablated area and may be suitable for ablation of the foci of ventricular tachycardias.

Animals↗

[Coronary collateral vessels during the early period of acute myocardial infarction: their development].

The aim of this study was to investigate the incidence and development of coronary collateral circulations in patients with acute myocardial infarction (AMI). We categorized 165 patients with persistent 100% occlusion of the infarct-related artery into 6 groups according to the time from the onset of AMI to angiography. Group I consisted of 55 patients evaluated within 6 hours after the onset of AMI; Group II, 28 patients, between 6 and 12 hours after the onset; Group III, 12 patients, between 12 and 24 hours after the onset; Group IV, 11 patients, between 2 and 13 days after infarction; Group V, 46 patients, between 14 and 44 days after infarction; and Group VI, 13 patients, more than 45 days after infarction. Collateral vessels were applied a numerical score between 0 and 3 according to the degree of opacification of the native vessel distal to the occlusion. In 58%, 79%, 67%, 73%, 89%, and 92%, patients of Groups I to VI had evidence of collateral vessels, respectively. Well-developed collaterals were observed in 24% of Group I compared with 50%, 58%, 55%, 73% and 69% of patients in Groups II to VI, respectively. The mean coronary collateral scores were 0.9 +/- 0.1, 1.4 +/- 0.2, 1.4 +/- 0.3, 1.6 +/- 0.4, 2.0 +/- 0.2 and 2.2 +/- 0.3 for Groups I to VI, respectively. Patients with preinfarction angina had more well-developed collateral circulations than did patients without it, however, there was no significant correlation between the duration of previous angina and extent of coronary collaterals.

Adult↗

[An experimental study on the alteration of myocardial tissue by radiofrequency catheter ablation: differences according to the frequency and the device].

To evaluate the alteration of myocardial tissue by radiofrequency (RF) catheter ablation according to differences of the frequency and the device, we applied RF catheter ablation to canine right ventricular myocardium in vitro. The devices delivering RF energy were LL-49(0. 49MHz, fixed voltage mode), RA-50 (13.56MHz, fixed watt mode) and HAT200 (0.52MHz, fixed watt mode with the capability of temperature adjustment). After RF catheter ablation were performed with a unipolar electrode catheter at various output under the same condition of contact, the ablated lesions by each device were compared. Histologically, we recognized coagulation layer with the necrosis of endocardium and the dissociation of myocardium in each experiment. The degree and the size of ablation layer was significantly larger in lower frequency delivery (p less than 0.05) and was significantly smaller by using the device with temperature adjustment as compared with the others (p less than 0.05). It was suggested that the alteration of myocardial tissue ablated with RF energy differ according to the frequency and the mode of output adjustment of the device.

Animals↗

[Clinical evaluation of sultamicillin in lower respiratory tract infections].

Clinical efficacy and safety of sultamicillin (SBTPC) in patients with lower respiratory tract infections, mainly pneumonia and bronchitis, have been evaluated in a multicenter trial by 19 institutions in the Kyushu area during a period of 12 months from December 1988 to November 1989. 1. Clinical evaluation was made in 132 patients and efficacy rates of SBTPC were 80.0% (28/35) for pneumonia, 78.5% (73/93) for bronchitis and 100% for the remaining 1 patient with other respiratory tract infections. The overall efficacy rate was 79.1% (102/129). 2. Clinical efficacy rate of SBTPC for respiratory tract infections in patients with underlying diseases such as chronic bronchitis, old pulmonary tuberculosis etc., was 75.0% (60/80) which was not significantly different from the efficacy rate of 85.7% (42/49) in patients without underlying diseases. 3. Of 13 patients who failed to respond to previous antibiotic treatments, 8 (61.5%) were effectively treated with SBTPC. 4. Clinical efficacy rates against infections caused by single species of organisms were 90.9% (10/11) for Haemophilus influenzae, 100% (8/8) for Streptococcus viridans and 100% (3/3) for Staphylococcus aureus. The overall clinical efficacy rate in all cases of monomicrobial infections was 88.6% (31/35), in polymicrobial infection 45.5% (5/11) and the overall efficacy rate in cases in which causative bacteria were identified was 78.3% (35/46). 5. Adverse reactions occurred in 6.8% (9/132) of the patients. The symptoms included allergic reaction in 1 patient, gastrointestinal system disorders in 7 patients and general fatigability in 1 patient. As abnormalities in laboratory test values, elevations of A1-P, GOT, and GPT were observed in 3 patients during the study, but returned to normal after discontinuation of SBTPC administration. 6. SBTPC is a useful antibiotic in the treatment of lower respiratory tract infections under the current medical environment where resistant organisms which produce beta-lactamases have been increasing.

Adolescent↗

A case in which coronary spasms were induced by ergonovine provocation at the sites of coronary artery ectasia.

We experienced a patient in whom coronary spasms were induced by an ergonovine provocation test during coronary angiography at the sites of coronary artery ectasia. The patient was a 45-year-old male with chest pain at rest, which promptly disappeared when given sublingual nitroglycerin. Similar attacks occurred frequently even with the administration of drugs after admission, but no significant changes were observed in electrocardiography (ECG) during the attacks or by repeated Holter ECG. The results of exercise ECG and provocation tests such as Valsalva maneuver, hyperventilation, and cold pressor test were negative. Coronary angiography showed ectatic changes in the left coronary artery, and the coronary spasms were induced by ergonovine administration at the ectatic portion of the left anterior descending artery and left circumflex artery, and right coronary artery with chest symptoms similar to those observed during spontaneous attacks. However, there were no significant changes in ECG. This rare case suggests an involvement of spasms in the pathogenic mechanism of myocardial ischemia in coronary artery ectasia.

Coronary Angiography↗

Syntheses and platelet aggregation inhibitory and antithrombotic properties of [2-[(omega-aminoalkoxy)phenyl]ethyl]benzenes.

A series of [2-[(omega-aminoalkoxy)phenyl]ethyl]benzene derivatives were synthesized and evaluated for their ability to inhibit collagen-induced platelet aggregation in vitro and to protect experimental thrombosis in mice. The results showed that the compounds were in vitro inhibitors of collagen-induced platelet aggregation. Most of them were also effective in the mouse antithrombotic assay. The compounds were found to be potent antagonists to S2 serotonergic receptor, and good correlation (r = 0.85) between their S2 serotonergic receptor antagonism and their potency as platelet antiaggregatory drugs was observed. Among the compounds studied, mono[2-(dimethylamino)-1-[[2-[2-(3- methoxyphenyl)ethyl]phenoxy]methyl]ethyl] succinate hydrochloride (12b, MCI-9042) was selected for further pharmacological and toxicological evaluation.

Animals↗

A consideration of salt intake from foods based on the simultaneous measurement of sodium and chlorine by neutron activation analysis.

Ordinary hospital meals for adults were simultaneously measured for Na and Cl by neutron activation analysis (NAA). Results obtained are summarized as follows: 1. Daily Na intake was estimated to be 4 to 8 g, corresponding to 11 to 18 g of salt. Daily Cl intake was estimated to be 5 to 9 g, corresponding to 7 to 12 g of salt. Their ratio was 1.6. 2. The higher values of salt intake obtained by conversion from Na intake are attributable to food additives. 3. In rating Na content, which has been reported to affect blood pressure, on the basis of salt intake, attention must be given to the fact that salt content converted from Cl content is rated to be lower than that converted from Na content.

Chlorine↗

[Significance of residual coronary artery stenosis after reperfusion therapy in acute myocardial infarction].

We evaluated the efficacy of reperfusion therapy in acute myocardial infarction in terms of postinfarction angina (PIA), reinfarction and coronary reocclusion. In 99 hospitalized patients with acute myocardial infarction within 6 hours after the onset of symptoms, 67 were treated using intracoronary thrombolysis (ICT) alone (Group T) and the remaining 32 using ICT followed by percutaneous transluminal coronary angioplasty (PTCA) (Group T + A). PTCA was performed for the arteries with high grade residual stenosis (TIMI grade 0, 1, 2) after ICT. Recatheterization was performed 28 +/- 12 days after hospitalization in 93% (62/67) of Group T and in all of Group T + A. There were no significant differences in age, sex, time interval from the onset to reperfusion, the extents of coronary artery disease and the Cohn grade of collaterals. However, anteroseptal infarction was more frequent in Group T than in Group T + A (p less than 0.05). Residual stenosis (diameter) at the end of intervention was 81 +/- 14% in Group T, and 48 +/- 15% in Group T + A, (p less than 0.01). Residual stenosis at recatheterization was 70 +/- 23% in Group T, and 55 +/- 22% in Group T + A (p less than NS). The incidence of PIA did not differ between the two groups (20.1% vs 6.2%). However, the incidence was higher in patients with residual stenosis of 70% or more than in those with residual stenosis of less than 70% (23.8% vs 2.9%, p less than 0.05). The incidence of reinfarction (re-elevation of CPK) did not differ between the two groups (7.4% in Group T, 6.2% in Group T + A); and neither did the incidence of coronary reocclusion at the time of recatheterization (14.5% vs 3.1%). We concluded that higher degree of residual stenosis at the end of intervention has a greater risk of PIA and reocclusion. Although differences were not statistically significant, the patients treated with ICT followed by PTCA seemed to have lower incidence of PIA and reocclusion compared with those treated with ICT alone, thus having better hospital prognosis.

Aged↗

[Clinical evaluation of sulbactam/cefoperazone in lower respiratory tract infections].

Clinical evaluation, safety and kinetics in serum of sulbactam/cefoperazone (SBT/CPZ) in patients with lower respiratory tract infections have been studied in a multicenter trial participated by 28 institutions in Kyushu area during a period of 13 months from March 1987 to March 1988. 1. Mean peak serum levels of SBT and CPZ in 35 patients up to 4 hours after intravenous infusion of 2 g of SBT/CPZ were 38.2 +/- 17.3 micrograms/ml for SBT and 104.3 +/- 31.4 micrograms/ml for CPZ. Serum half-lives of SBT and CPZ were 0.76 hour and 1.53 hours, respectively. These results were in similar ranges to those reported elsewhere for SBT/CPZ. 2. Serum half-lives of SBT and CPZ after intravenous infusion of 2 g of SBT/CPZ were not significantly prolonged in patients with moderate liver or kidney dysfunctions. 3. Clinical efficacy rates of SBT/CPZ in 217 patients were 93.1% (81/87) for pneumonia, 93.3% (14/15) for lung abscess, 78.9% (15/19) for acute exacerbation of chronic bronchitis, 57.1% (4/7) for diffuse panbronchiolitis, 72.4% (21/29), 74.4% (32/43) and 100% (9/9) for infections concurrent to bronchiectasis, chronic respiratory disease and pulmonary emphysema, respectively. Those were 50% (1/2) for bronchitis associated with lung cancer and 66.7% (4/6) for empyema. The overall efficacy rate was 83.4% (181/217). 4. Clinical efficacy rate of SBT/CPZ for pneumonia in patients with underlying diseases such as lung cancer, pulmonary tuberculosis and pneumoconiosis, etc, was 85.3% (29/34) and was not significantly different from the efficacy rate of 98.1% (52/53) in patients without these underlying diseases. 5. Of 30 patients who failed to respond of previous antibiotic treatments, 21 were effectively treated by SBT/CPZ. 6. Bacteriological eradication rates against Pseudomonas aeruginosa, Haemophilus influenzae and Streptococcus pneumoniae were 42.9% (9/21), 87.5% (14/16) and 100% (5/5), respectively. The overall eradication rate in all cases including polymicrobial infections was 72.8% (67/92). 7. The high levels of peak serum concentration of CPZ, and the difference between serum levels of SBT and of CPZ seemed to contribute to the high clinical efficacy. 8. Adverse reactions occurred in 2.8% (6/217) of the patients, and consisted primarily of rash and diarrhea. Laboratory abnormalities were observed in 8 patients during the study. These were elevations of S-GOT and S-GPT, and eosinophilia. 9. SBT/CPZ is a very useful drug in the treatment of lower respiratory tract infections as it has become available just in time when increase in resistant organisms to beta-lactams is notable.

Adult↗