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Biomedical subjects

I Katoh

Publications and source records attributed to I Katoh.

At least 55 records · Page 3Linked to original sources

[Experience in surgical management for active aortic valve endocarditis with periannular abscess--outcome of abscess cavity after patch closure].

Two patients with active aortic valve endocarditis and periannular abscess underwent surgical management. Both patients had bicuspid aortic valves. Involvement of the aortic annulus with the formation of the periannular abscess was found at one third circumference in the aortic annulus and extended to the sinuses of Valsalva. In one patient the periannular abscess ranged from the right side of the ostia of a left coronary artery to the right commissural region, and in another patient it existed at the left commissural region. the ostia of coronary arteries were separated from the inflammatory and necrotic tissue in both patients. The wall of periannular abscess could not be totally excised. Instead, debridement and transaortic patch closure of the abscess cavity were performed. In the former patient, partial resection of the aneurysmal wall of the abscess was performed and the remaining aortic wall was approximated with extra-luminal sutures supported by Teflon felt pledgets. However, in the latter patient, the plication of the abscess wall could not be performed. Prosthetic mechanical valve was implanted at the paraannular position by utilizing the patch. In the former patient it took a month and a half until the disappearance of the inflammatory reaction, and the echo free space could not be detected at the same place of the abscess cavity by the two-dimensional echocardiogram since early postoperative period. However, in the latter patient it took three months until the disappearance, and the echo free space had been existing at the same place for thirteen months after the operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Abscess↗

Changes in plasma dopamine-beta-hydroxylase activity during the perioperative period of cardiac surgery: an index of sympathetic nerve activity.

To evaluate the usefulness of plasma dopamine-beta-hydroxylase (DBH) activity as an index of sympathetic nerve activity during cardiac operations, we examined the serial changes in plasma DBH activity, in relation to the plasma noradrenaline (NA) level and hemodynamic parameters, in patients who underwent cardiac surgery. The plasma DBH activity decreased significantly after cardiopulmonary bypass, and remained low during dopamine (DA) infusion until 72 h after the operation. However, recovery of the hemodynamic parameters, being the mean arterial pressure, heart rate and cardiac index, was seen as early as 1-3 h postoperatively. It was therefore assumed that the plasma DBH activity takes a long time to recover after an operation. The time-course changes in the plasma NA level were quite different from the changes in DBH activity, with an apparent negative correlation being observed between them. Thus, there is a possibility that exogenously administered DA, as well as increased plasma NA, might inhibit DBH activity during cardiac surgery. Moreover, since catecholamines are often administered upon completion of cardiac surgery, measurement of the plasma catecholamine level would be inappropriate for evaluating real sympathetic nerve activity. From the results of this study, it is surmised that measurement of the plasma DBH activity could be useful for estimating the intrinsic sympathetic nerve activity of patients who have undergone cardiac surgery.

Adult↗

Bovine leukemia virus RNA sequences involved in dimerization and specific gag protein binding: close relation to the packaging sites of avian, murine, and human retroviruses.

In vitro detection of a specific complex of the bovine leukemia virus (BLV) MA(p15) protein and the 5'-terminal RNA dimer led to the hypothesis that the NH2-terminal domain of retrovirus gag protein precursor is involved in the selective viral RNA packaging mechanism. Here we describe mapping of the BLV RNA for dimer-forming and MA(p15)-binding abilities by a simple cDNA probing method followed by mutation analyses with the reactive U5-5' gag RNA. The RNA dimerization is mediated by the region harboring U5, the primer binding site (PBS), and the 30 bases immediately downstream of PBS. This conclusion is supported by computer-assisted RNA secondary-structure analysis which predicted a multibranched stem-loop folding throughout the dimer region determined. Another region from PBS to the 5'-terminal 60 residues of the gag gene, partially overlapping the dimer region, likely provides essential elements for the MA(p15) binding reaction, although the presence of either the 3' or 5' neighboring sequences increases the complex-forming efficiency significantly, and each of the substructures predicted within the core region has, if any, only very weak affinity to MA(p15). These in vitro characterizations of the BLV RNA may reflect general features of the specific protein-RNA interaction in the packaging events of various retroviruses. 5'-terminal folded structures of retroviral RNA molecules and their biological activities are discussed.

Base Sequence↗

Abnormal signal averaged ECG after surgical repair of tetralogy of Fallot--a combined analysis in the time and frequency domain.

PURPOSE: The clinical significance of abnormal signal averaged ECG (SA-ECG) determined by time and frequency domain analyses was assessed in tetralogy of Fallot patients after surgical repair, and the methods of analysis were compared. MATERIALS AND METHODS: SA-ECG was performed in 42 patients (mean age, 9.4 years) after radical surgical repair of tetralogy of Fallot, and in 11 preoperative patients (mean age, 2.6 years). Abnormal SA-ECGs were defined by time domain analysis (vector magnitude method) and frequency domain analysis (fast Fourier transformation). RESULTS: Abnormal SA-ECGs were recognized in 10 postoperative, patients (3 by time domain and 9 by frequency domain, analysis), but in none of the preoperative patients. Three patients with abnormal SA-ECGs had nonsustained ventricular tachycardia, 5 others had premature ventricular contractions, and the remaining 2 had no ventricular tachyarrhythmias documented by 24 h Holter monitoring. Patients with abnormal SA-ECGs more commonly had ST-T segment depression on standard ECG during exercise (8/10 versus 8/32, p < 0.001), a history of resection of a hypertrophic septoparietal muscle band (8/10 versus 2/32, p < 0.001) and histologically documented myocardial fibrosis at radical surgical repair (9/10 versus 5/19, p < 0.002). CONCLUSION: A Combination of time and frequency domain analyses was necessary to detect abnormal SA-ECGs in postoperative patients because of ventricular conduction disturbance. This technique might increase our ability to identify patients at risk of ventricular tachyarrhythmia, or those with underlying myocardial abnormalities.

Adolescent↗

Balloon pulmonary valvuloplasty for infants with severe tetralogy of Fallot.

Balloon pulmonary valvuloplasty was performed in 3 infants with severe tetralogy of Fallot at days 24, 54 and 86 because of progressive hypoxemia. In two patients, the balloon catheter (4 cm long, 5-8 mm diameter) could not pass through the pulmonary valve. This necessitated a smaller balloon and required a two-step procedure. Initially, a coronary artery balloon (2 cm long, 3.5 mm diameter) was used. Following balloon valvuloplasty, arterial oxygen saturation increased from 63 to 83% in case 1, from 69 to 85% in case 2 and 63 to 86% in case 3. Immediate postvalvuloplasty right ventricular cineangiography revealed that the maximal opening diameter of the pulmonary valve leaflets increased from 1-2 mm to 3-4 mm in cases 1 and 3, and from 2-3 mm to 4-5 mm in case 2. No significant complications occurred. Echocardiographic follow-up data showed that the diameter of the right ventricular outflow tract and pulmonary arteries increased with age. The present results show that the pulmonary valvuloplasty is an effective procedure for relief of pulmonary valve stenosis in tetralogy of Fallot and to improve oxygenation and growth of the pulmonary arteries and right ventricular outflow tract without the need of an immediate aortopulmonary shunt.

Cardiac Catheterization↗

Reduction in arm swelling and changes in protein components of lymphedema fluid after intraarterial injection of autologous lymphocytes.

The intraarterial arm injection of freshly isolated autologous lymphocytes to a patient with upper extremity secondary lymphedema brought about a rapid and remarkable reduction in arm swelling. The protein components in the edema fluid were analyzed by two-dimensional electrophoresis before and after lymphocyte injection. We observed the appearance of a novel protein spot, with an isoelectric point of 6.5, in an electropherogram as early as 30 minutes after the lymphocyte injection. Immunoblotting using antibody against human total serum proteins suggested that the novel protein was not derived from the serum. Because incubation in vitro of the lymphedema fluid with the isolated lymphocytes produced a new protein spot, corresponding to the novel protein observed in vivo, we suspect that the novel protein originated from limited hydrolysis of a unique protein present in the arm edema fluid. Significance of the novel protein and the role of limited proteolysis after lymphocyte injection in the management of lymphedema are examined.

Electrophoresis, Gel, Two-Dimensional↗

[A case of pseudoaneurysm of the thoracic aorta with Behçet's disease].

A 54-year-old female with incomplete type of Behçet's disease was operated on because of impending rupture of the thoracic aneurysm. There was a saccular pseudoaneurysm below the left subclavian artery, and a punched out lesion of the aorta was recognized. The defect of the aortic wall was closed with a PTFE patch. Before and after the operation, we have given prednisolone. The postoperative course was uneventful. Two years later, there was no recurrence of pseudoaneurysm near the PTFE patch. In many reports, aneurysms of Behçet's disease are saccular pseudoaneurysms, and have high incidence of complications about anastomosis postoperatively. We need a further follow-up about this patient.

Aortic Aneurysm, Thoracic↗

[Cardioprotective effect of cromakalim, a K+ channel opener, on isolated globally ischemic and reperfused rat hearts].

Examination was made of cardioprotective effect related to the ATP-sensitive K+ (KATP) channel on isolated globally ischemic reperfused rat hearts using cromakalim, a putative ATP-sensitive K+ channel opener. The hearts were subjected to 20 min Langendorff perfusion with Krebs Henseleit Bicarbonate Buffer (KHBB) (70 cmH2O, 37 degrees C), followed by 30 min ischemia at 36 degrees C, and 30 min reperfusion with KHBB, with (cromakalim group) or without (control group) pretreatment by 10 microM cromakalim added to KHBB for 5 min prior to ischemia. Before ischemia, no significant change in heart rate (HR), left ventricular developed pressure (LVDP) or coronary flow (CF) by 10 microM cromakalim could be detected. The two groups were the same in CF during reperfusion, but recovery of HR and LVDP significantly improved in the cromakalim group. Creatine kinase (CK) leakage in the cromakalim group was significantly less than in the control group during reperfusion. Cromakalim is thus shown to reduce the myocardial injury during ischemia and reperfusion. Intracellular Ca2+ content of the cromakalim group appeared lower than that of the control group at 30 min of reperfusion. At 5-30 min of reperfusion, in the cromakalim group, intracellular Ca2+ storage was prevented, leading to a good recovery of cardiac function, while in the control group, intracellular Ca2+ increased and recovery of cardiac function was poor. After pretreatment with 10 microM cromakalim, intracellular K+ content of the cromakalim group was significantly lower than in the control group before ischemia. At 5 min of reperfusion, intracellular K+ content of the cromakalim group was slightly less than that of the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Deconjugating activity for sulfoconjugated dopamine in homogenates of organs from dogs.

To clarify the possibility that sulfoconjugated dopamine (DA) may play a physiological role by being converted to active free DA, we examined the deconjugating activity in homogenates of organs from dogs. Each tissue homogenate was incubated with sulfoconjugated DA, and the deconjugating activity of the organs was compared. The kidney and liver exhibited the highest deconjugating activities. In contrast, the intestine and heart showed lower arylsulfatase activities, and almost no activity was found in the brain or skeletal muscle. Moreover, in the heart, the deconjugating activity for sulfoconjugated DA was higher in the atrium than the ventricle. These results indicate that sulfoconjugated DA is converted to active free DA in homogenates of organs from dogs and that the deconjugating activity varies between different parts of an organ. Sulfoconjugated DA must be looked upon as a possible precursor or reservoir for the production of active free DA.

Animals↗

Changes in plasma free and sulfoconjugated catecholamines before and after acute physical exercise: experimental and clinical studies.

To elucidate whether sulfoconjugated catecholamines in plasma, especially dopamine, serve as a source of free catecholamines, we examined the change in afterload on the deconjugating activity of catecholamines in isolated Langendorff perfused rat hearts. Dopamine-sulfate was administered under ordinary or high-work-load conditions. Free dopamine in the effluent was increased by the high-work-load of the hearts, whereas conjugated dopamine showed an apparent decrease. These results indicate the possibility that deconjugation of sulfoconjugated catecholamines is accelerated by a high-work-load. To obtain further evidence in humans, we also examined the changes in the plasma levels of free and sulfoconjugated catecholamines in healthy volunteers before and after marathon running. Free dopamine increased 1.99-fold from the baseline value after exercise, whereas conjugated dopamine decreased by 12%. Similarly, the plasma levels of free noradrenaline and adrenaline increased after exercise to 2.45- and 1.51-fold their respective baseline values, while conjugated noradrenaline and adrenaline both decreased. These clinical results, as well as those of the experimental studies, suggest that the increase in plasma free catecholamines after exercise is due not only to increased release from the sympathoadrenal system but also to accelerated conversion from sulfoconjugated catecholamines in the plasma.

Adolescent↗

In vitro accurate transcription from the cap site of bovine leukemia virus (BLV) dependent on the BLV-infected cell nuclear lysate.

The cell-free transcriptional system initiating from the cap site in bovine leukemia virus (BLV) LTR by RNA polymerase II was constructed. The transcription was completely dependent on the template DNA and the nuclear lysate isolated from BLV-infected bat lung cells (TB1Lu). The relative transcriptional rates estimated using several deletion mutants around the promoter sequence in BLV LTR as templates closely corresponded to that obtained by transient expression assay in cultured cells using these plasmids and tax-producing plasmid. The partial purification of the factor(s) involving to the transcriptional activation from the nuclear lysate suggested that the factor(s) was different from tax and rex, the regulatory factors encoded on viral genome. The transcription from the caps site of adenovirus E3 was also stimulated in the presence of the nuclear lysate from BLV-infected cells.

Animals↗

Direct effect of thyroid hormone on left ventricular myocardial relaxation.

The left ventricular diastolic indices of the hyperthyroid (HTH) patients without cardiac disease (n = 31) were compared with those of the normal controls (NC) (n = 49) using echocardiography. The HTH group had a significantly shorter IIa-mitral valve opening time (IIa-MVO), and a significantly larger maximum descending rate of the left ventricular posterior wall (maxPWDR), peak E and peak A than the NC group. IIa-MVO, maxPWDR, peak E and E/A showed significant simple correlation with T3 in the HTH group. To elucidate spurious correlation among these indices and T3, partial correlation analysis among these indices and its influencing factors were calculated. IIa-MVO, maxPWDR and peak E showed significant partial correlation coefficients with T3, but peak E had a lesser partial correlation with T3 than with age and left ventricular end-diastolic volume. Fourteen of the hyperthyroid patients were reexamined after antithyroid treatment. Their diastolic indices were found to be normalized compared with pre-treatment values and showed no significant difference with those of NC group. Augmented myocardial relaxation in patients with hyperthyroidism correlated with the thyroid hormone level, and IIa-MVO and maxPWDR were more effective indices of left ventricular myocardial relaxation than peak E and E/A in hyperthyroidism.

Adult↗

Clinical significance of late potentials in patients after intracardiac operation for congenital heart disease.

The aim of this study was to evaluate the late potentials (LPs) in postoperative patients with congenital heart disease (CHD) and to study the association with the clinical characteristics in the postoperative patients with LPs. Signal averaged electrocardiogram (SA-ECG) was recorded in 119 postoperative patients aged 4 to 23 years and compared with those in age matched 49 healthy volunteers with and without right bundle branch block. Based on control data, criterias of LP were defined and altered in the presence of bundle branch block. Abnormal SA-ECGs were not detected in the patients with non-cyanotic CHD. However, abnormal and borderline SA-ECGs were recognized in 5 (12%) of 42 patients after intracardiac operation for tetralogy of Fallot and 3 (30%) of 9 patients after Rastelli's operation. The patients with abnormal and borderline SA-ECGs were significantly older at the time of operation, and had more frequent ventricular arrhythmias (7/8: 3/111, p less than 0.01) and depression of the ST-T segment on ECG (7/8: 11/111, p less than 0.01), compared with the normal SA-ECG group. Abnormal SA-ECGs including those of borderline patients were 50% sensitive and 96% specific for documented ventricular arrhythmias. However, there was no association between abnormalities of SA-ECGs and cardiomegaly on chest X-ray or left ventricular ejection fraction on echocardiogram. These results indicate that prolonged exposure to hypoxia may be the main cause of the primary role in the development of LPs. And late surgical intervention may result in histological background for the development of LPs.

Action Potentials↗

Intraarterial lymphocyte-injection therapy for lymphedema of the leg: an examination using indium-111 oxine labeled autologous lymphocytes.

A 58-year-old female patient with lymphedema of the left leg was treated by repeated intraarterial lymphocyte-injection therapy. To elucidate whether the injected lymphocytes act at the affected site of the leg, we examined the distribution of the In-111 oxine labeled lymphocytes injected into the proximal artery to the affected leg in comparison with the distribution in the other, healthy, leg. The radioactivity of the affected leg was almost two times higher than that of the healthy leg during the first 30 min after injection, and it remained higher even after 24 hours. The circumference of the affected leg of the patient decreased steadily during her hospital stay. These results, together with the clinical findings, suggest that some of the intraarterially-injected lymphocytes remained in the affected leg at least 24 hours and might play some role in reducing the volume of lymphedematous fluid.

Blood Component Transfusion↗

[A case report of Lucas-Schmidt IIA type Cor triatriatum in neonate].

Lucas-Schmidt IIA type of Cor triatriatum has been rarely reported. Since it shows the same hemodynamics as Darling IIb type TAPVC, it is important as a emergent surgical case in early infancy. We reported a male neonate with IIA type Cor triatriatum. He was admitted to our hospital because of cyanosis and dyspnea since birth. The echocardiographic examinations revealed the accessory chamber behind the left atrium and atrial septal defect. The view from the right atrium revealed that there was no direct connection between the accessory chamber and the true left atrium, and we diagnosed it Lucas IIA type Cor triatriatum. The abnormal diaphragma was resected, and the atrial septum was corrected with a Xenomedica patch. The patient had an uneventful postoperative course, and was discharged on the 25th postoperative day.

Cor Triatriatum↗

[Changes in plasma sulfoconjugated catecholamines during perioperative period of cardiac operations--effect of continuous infusion of dopamine].

In order to clarify the physiological significance of sulfate conjugation of catecholamines and the effect of continuous dopamine infusion on the conjugate formation, we measured the plasma levels of free and sulfoconjugated catecholamines during the perioperative period of cardiac operations. The study group consisted of 12 adult patients who underwent cardiac operations. There were 13 study intervals starting from a day before each operation to 72 hours after each operation for the collection of blood specimen. The plasma levels of free and sulfoconjugated catecholamines were measured by radioenzymatic assay. The plasma levels of free dopamine did not show significant change by the induction of anesthesia, but they increased rapidly after the start of dopamine infusion to the level of 7654.9 +/- 731.7 pg/ml. Thereafter, the plasma free dopamine levels remained steady during the 24 hours after operation at 7516.7 pg/ml to 8449.2 pg/ml. On the other hand, the plasma levels of conjugated dopamine increased progressively by dopamine infusion during the 24 hours after operation. The plasma levels of free adrenaline increased significantly to the level of 1049.5 +/- 117.7 pg/ml by dopamine infusion, and lasted with plateau until the 24th hour after operation at the range of 1076.8 pg/ml to 1218.9 pg/ml. Conjugated adrenaline followed a similar pattern to that of conjugated dopamine, with a progressive increase due to the infusion of dopamine. In the case of noradrenaline, free noradrenaline started to increase at the time of cardiopulmonary bypass and showed a further increase by dopamine infusion during the first hour after operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Characterization of palytoxin-induced catecholamine secretion from cultured bovine adrenal chromaffin cells. Effects of Na(+)- and Ca(2+)-channel blockers.

The effect of palytoxin (PTX), a potent marine toxin, on catecholamine (CA) secretion from cultured bovine adrenal chromaffin cells was examined. PTX at concentrations of over 10(-10) M induced CA secretion concentration-dependently. About 40-50% of the total cellular CA was secreted during 20-min incubation with 3 x 10(-8) M PTX. PTX-induced CA secretion was dependent on both extracellular Na+ and Ca2+. PTX caused increases in [22Na](+)- and [45Ca](2+)-influxes into the cells. Increase in [22Na](+)-influx was observed at concentrations of over 10(-11) M PTX and was maximal at 10(-10) M PTX and then gradually decreased at higher concentrations that induced [45Ca](2+)-influx and CA secretion. On the other hand, increase in [45Ca](2+)-influx was observed at concentrations of over 10(-10) M PTX and increased with increase in concentration of PTX. This concentration-response curve for PTX-induced [45Ca](2+)-influx was similar to that for PTX-induced CA secretion. The CA secretion and [22Na](+)- and [45Ca](2+)-influxes induced by PTX were not affected by tetrodotoxin (TTX), but were significantly inhibited by quinidine and aprindine(mexiletine), antiarrythmic drugs known to block Na(+)-channels. Ca(2+)-channel blockers such as nifedipine, verapamil, Co2+, Cd2+, inhibited both CA secretion and [45Ca](2+)-influx induced by PTX. These results indicate that PTX-induced CA secretion is mediated by activation of Na(+)-dependent, TTX-insensitive voltage-dependent Ca(2+)-channels, and is inhibited by quinidine and aprindine through their inhibitory effects on the Na(+)- and Ca(2+)-influxes into the cells induced by PTX.

Acrylamides↗

New operative method for distal aortopulmonary septal defect.

A new technique is described for repairing distal aortopulmonary septal defect with aortic origin of the right pulmonary artery in a 26-day-old neonate. To prevent the narrowing of the proximal right pulmonary artery in the distal aortopulmonary septal defect caused by conventional intraluminal prosthetic patch reconstruction, rerouting of the right pulmonary artery using native aortic wall tissue without artificial material was performed. This method seems to be superior to the conventional method, especially during the neonatal period.

Anastomosis, Surgical↗