Biomedical subjects

H Kurosawa

Publications and source records attributed to H Kurosawa.

At least 19 recordsLinked to original sources

PubMed1995

Total cavopulmonary connection without the use of prosthetic material: technical considerations and hemodynamic consequences.

Total cavopulmonary connection with use of an autogenous intraatrial tunnel to create a straight tube between the inferior vena cava and the pulmonary artery was attempted in several types of cardiac anomaly in eight consecutive candidates for the Fontan operation. A small right atrium with an extraordinary location of the inferior vena cava and a short superior vena cava prevented the use of this procedure in two cases. By preserving the crista terminalis and the sinus node and its arteries we prevented the development of postoperative atrial arrhythmias in the short follow-up period, and the P trigger-signal averaged P waves were not different from those of other cardiac anomalies. The proximal stump of the superior vena cava was not incised in any case to enlarge the anastomosis, even when size mismatch between the superior and inferior venae cavae existed, as in a case of bilateral superior venae cavae. Stretching the vessels by approximately 150% was possible and permitted an adequate anastomosis. Cavopulmonary connections via the intraatrial tunnel ensured smooth, nonturbulent, somewhat pulsatile flow without a pressure gradient. We concluded that the creation of an autogenous intraatrial tunnel was possible in many cases without serious complications and that this procedure has potential benefit for the pulmonary circulation in the aspect of pulsatility.

Adult↗

PubMed1995

Mucociliary function in the mouse measured in explanted lung tissue.

To develop a method for the study of mucociliary clearance in small-caliber airways, we investigated ciliary function in an in vitro lung tissue culture technique in mice. Lungs were excised from 45 anesthetized mice [weight 30.9 +/- 6.2 (SD) g] and inflated with 2% liquid agarose at 37 degrees C via the trachea. After cooling to 4 degrees C, the lungs were cut into 0.5- to 1.0-mm thick slices and cultured overnight. Ciliary beat frequency (CBF) was measured in airways cut in cross section using a computerized image processing system. In some experiments, charcoal particle transport (PT) in tangentially cut airways was also measured. Airway diameter ranged from 0.3 to 0.8 mm. In this preparation CBF was stable over a 3-h period and unaffected by minor pH changes. Both CBF and PT exhibited a linear dependency on temperature. CBF and PT were significantly correlated with each other. CBF at 37 degrees C (18.7 +/- 2.93 Hz) was almost twofold higher than values at 22 degrees C (9.74 +/- 3.11 Hz). Isoproterenol increased CBF in a dose-dependent fashion (50% effective concentration of 10(-6.75) M); the effect of isoproterenol could be blocked by propranolol. Administration of forskolin (10 microM) also increased both CBF and PT significantly. These findings demonstrate the feasibility of measuring the major aspects of mucociliary clearance in this system. This approach holds promise as a technique suitable to the investigation of both the small airways of humans and other large animals as well as of airways in murine genetic models of respiratory disease.

Animals↗

PubMed1995

[New configuration of right ventricular dynamic cardiomyoplasty by latissimus dorsi for hypoplastic right ventricle].

UNLABELLED: The purpose of this experimental study is to evaluate the efficacy of linear-type right ventricular (RV) dynamic cardiomyoplasty in a setting of patch enlargement model for hypoplastic RV. In 6 puppies (6-8 kg), under a cardiopulmonary bypass (CPB), RV free wall and septal traveculation were resected and replaced with large pericardial patch, simulating RV patch enlargement of hypoplastic RV. A pedicled left LD, anchored to 3rd rib, wrapped onto the RV patch in parallel to RV long axis, while LD fixed to only RV diaphragma surface without wrapping LV surface. After the termination of CPB, LD flap was synchronously paced at 1:1 ratio with cardiac beat with a trained-pulse stimuli (10-25 Hz). RV performance was tested by RV function curve (RVSWI vs CVP) and RV pressure-volume relationship (ESPVR) assessed by conductance catheter. RESULTS: LD graft stimuration showed significant augmentation of PAP (145 +/- 21%), PA flow (152 +/- 21%) and AP (128 +/- 23%) at CVP of 10 mmHg. RV function curve and ESPVR confirmed dramatical augmentation of RV performance by graft stimulation, which was identical to preoperative normal RV function even at the low CVP range. CONCLUSIONS: Linear LD myoplasty after patch enlargement of RV may viable surgical option for hypoplastic RV.

Animals↗

PubMed1994

Preproenkephalin gene expression in the rat cerebral cortex during chronic tracheal stenosis.

To evaluate whether the endogenous opioid system is activated in the higher brain centre while a chronic resistance to airflow, we examined changes of mRNAs for preproenkephalin (PPE)-A, which is a precursor of enkephalin, and for 70 kD heat shock protein (HSP70) in the cerebral cortex of rat brain during chronic tracheal stenosis. Northern blot revealed that PPE-A mRNA was induced at 3 days of airway stenosis. In situ hybridization revealed that PPE-A mRNA was gradually induced in frontal cortex. The significant induction of PPE-A mRNA was observed at 3 and 7 days. However, no significant induction of HSP70 gene was observed. These results suggest that the endogenous opioid system may be at work as an important compensatory mechanism to reduce the respiratory sensation during chronic respiratory stress.

Animals↗

PubMed1994

Effect of clentiazem (TA-3090) with posttreatment on neurologic and histologic disorders of stroke-prone spontaneously hypertensive rats with history of stroke.

After stroke-prone spontaneously hypertensive rats (SHRSP) received a salt-loaded diet to accelerate onset of stroke, the therapeutic effect of clentiazem, a benzothiazepine Ca antagonist, on neurologic and histologic disorders was examined. Treatment with clentiazem (3, 15, and 30 mg/kg) orally twice daily (b.i.d.) for 28 days after the occurrence of stroke reduced neurologic symptoms and histologic changes of brain and kidney in a dose-dependent manner. Acute treatment with clentiazem (15 mg/kg, b.i.d.) administered immediately after stroke for 1 week not only almost completely abolished neurologic symptoms during treatment, but partially improved them even after treatment. Subacute treatment with clentiazem starting 10 days after stroke and continuing for 18 days also suppressed the neurologic signs. Both acute and subacute treatment improved cerebral histology. These results suggest that clentiazem treatment in the acute and subacute phases of stroke is beneficial.

Administration, Oral↗

PubMed1992

Leukemia inhibitory factor/differentiation-stimulating factor (LIF/D-factor): regulation of its production and possible roles in bone metabolism.

Leukemia inhibitory factor/differentiation-stimulating factor (LIF/D-factor), expression of its mRNA, and possible roles in bone metabolism were studied in murine primary and clonal osteoblast-like cells. Local bone-resorbing factors such as IL-1, TNF alpha, and LPS strongly induced expression of LIF/D-factor mRNA in both clonal MC3T3-E1 cells and primary osteoblast-like cells. Neither parathyroid hormone nor 1 alpha,25-dihydroxyvitamin D3 stimulated expression of LIF/D-factor mRNA. LIF/D-factor per se did not stimulate expression of its own mRNA. Appreciable amounts of LIF/D-factor were detected in synovial fluids from rheumatoid arthritis (RA) patients but not in those with osteoarthritis (OA). Simultaneous treatment with LIF/D-factor, IL-1, and IL-6 at the concentrations found in synovial fluids from RA patients greatly enhanced bone resorption, though these cytokines did not stimulate bone resorption when separately applied. This suggests that LIF/D-factor produced by osteoblasts is in concert with other bone-resorbing cytokines such as IL-1 and IL-6 involved in the bone resorption seen in the joints of RA patients. LIF/D-factor specifically bound to MC3T3-E1 cells with an apparent dissociation constant of 161 pM and 1,100 binding sites/cell. LIF/D-factor dose-dependently suppressed incorporation of [3H]thymidine into MC3T3-E1 cells. In addition, it potentiated the alkaline phosphatase activity induced by retinoic acid, though LIF/D-factor alone had no effect on enzyme activity. These results suggest that LIF/D-factor is involved in not only osteoclastic bone resorption but also osteoblast differentiation in conjugation with other osteotropic factors.

Acid Phosphatase↗

PubMed1992

Histological and biochemical analysis of the fibrous tissue induced by implantation of synthetic ligament (Dacron): an experimental study in a rat model.

We conducted a comparative study to evaluate the quality and true nature of the fibrous tissue formed around synthetic grafts when used in ligament replacement. In one group of Lewis rats, a patellar ligament was replaced with a Dacron prosthesis; the comparison group received a tail tendon isograft. Two-, 4-, 8-, 12-, and 24-week comparisons showed histological and biochemical changes in the Dacron group alone that were consistent with foreign-body reaction. Specifically, the Dacron group showed infiltration by large numbers of macrophages and foreign-body, multinucleated giant cells. In addition, the capsule of fibrous tissue that developed around the Dacron ligaments was characterized by lower collagen solubility, a higher content of noncollagenous protein, and a higher proportion of type III collagen than that comprising the isografted tendons. The results of this study call into question the suitability of synthetics for ligament replacement.

Animals↗

PubMed1992

An anatomical study of a new method for enlargement of narrowed aortic annulus: intra-arterial aorto-infundibuloplasty.

A new procedure "intraarterial aorto-infundibuloplasty" for the narrowed aortic annulus is described. Aortic valve replacement is performed through an aorto-pulmonary and infundibular septal incision which is eventually enlarged by a single patch, i.e., a two-dimensional patch instead of a three-dimensional patch as in Konno's procedure. An anatomical study showed that a prosthetic valve three sizes larger than the natural annular diameter could be implanted and the natural annular diameter was increased by as much as 42%.

Animals↗

PubMed1992

The effect of exercise on anterior knee laxity in female basketball players.

To study the effect of physical activities on the anterior laxity of the knee joint, the anterior knee laxity of female semi-professional basketball players was measured during a typical day. The participants worked in the office in the morning, and practiced in the afternoon, which included a 60 minute warm-up, followed by a 150 minute game style practice. The laxity was measured six times in one day at different activity levels. The anterior knee laxity did not change during sedentary work in the morning, but increased significantly with game style practice. After 1 1/2 hours the increased anterior knee laxity had not recovered completely. However, after five hours it had recovered completely.

Adult↗

PubMed1992

11;13 translocation in acute nonlymphocytic leukemia.

In this paper, we report on a 9-year-old girl with acute nonlymphocytic leukemia (FAB-M5) with a rare chromosome abnormality, t(11;23)(q21;p11). Peripheral blood showed Hb 7.5 g/dl, WBC 3,600 cells/microliters (10% blasts), and platelet count 110 x 10(3) cells/microliters. The bone marrow aspirates showed normal cellularity with 36.7% blasts. On morphological characteristics, micromegakaryocytes were observed, and on chromosome examination the karyotype was shown to be 46,XX,t(11;13)(q21;p11) in all metaphases.

Bone Marrow↗

PubMed1992

Alteration of pulmonary blood flow in tetralogy of Fallot: pre- and postoperative study with macroaggregates of 99mTc-labeled human serum albumin.

The pulmonary blood distribution was examined in 17 patients with tetralogy of Fallot (TOF) pre and postoperatively with macroaggregates of 99mTc-labeled human serum albumin. Most of the patients with TOF demonstrated an abnormal preoperative distribution pattern. The abnormalities included not only an unbalanced distribution between the right and left lungs but also a maldistribution of peripheral vessels in each lung. The Right/Left lung counts ratio and Pulmonary Peripheral Index (calculated in order to express the severity of peripheral maldistribution) correlated neither to the diameter nor the cross-sectional area of either right or left pulmonary arteries which were measured angiographically. Postoperatively, the pulmonary blood was shunted toward the developed side of the lung which further contributed to maldistribution of blood flow and unbalanced pulmonary growth. Since the patients with an unbalanced pulmonary blood distribution demonstrated a higher right ventricular pressure one year after the operation, a palliative operation facilitating the growth of the underdeveloped side of the lung might be considered as an effective procedure to precede intracardiac repair.

Child↗

PubMed1992

Acute hemodynamic effects of the active metabolite of imidapril, (4S)-3-((2S)-2-[N-((1S)-1-carboxy-3-phenyl-propyl)amino]propionyl)-1- methyl-2-oxoimidazolidine-4-carboxylic acid, and enalaprilat in anesthetized dogs.

The hemodynamic effects of imidapril, a novel nonsulfhydryl angiotensin-converting enzyme inhibitor, were examined in anesthetized dogs by the intravenous injection of its active metabolite 6366A ((4S)-3-((2S)-2-[N-((1S)-1-carboxy-3- phenylpropyl)amino]propionyl)-1-methyl-2-oxoimidazolidine-4-carboxylic acid, CAS 89371-44-8) and were compared to those of enalaprilat. 6366A (1-100 micrograms/kg) reduced the blood pressure and total peripheral resistance in a dose-dependent manner, while causing no marked changes in heart rate, LV dp/dtmax, and pulmonary arterial pressure. The cardiac output and stroke volume were slightly increased. Blood flow in the common carotid artery, the vertebral artery, and the femoral artery was reduced or tended to decrease, while the superior mesenteric arterial blood flow was increased. These effects were similar to those of enalaprilat. 6366A did not inhibit the pressor response of angiotensin II, but markedly inhibited that of angiotensin I, and the effects of 6366A on regional blood flow were opposite to those of angiotensin II. Thus, 6366A appears to produce its hemodynamic effects by angiotensin converting enzyme inhibition, as does enalaprilat. 6366A also tended to decrease myocardial oxygen consumption. These results suggested that the hemodynamic effects of imidapril on the heart and on regional blood flow are similar to those of enalapril.

Anesthesia↗

PubMed1992

Evidence of organ damage after cardiopulmonary bypass. The role of elastase and vasoactive mediators.

In this study the causes of organ damage after cardiopulmonary bypass were multifactorial. The concentration of the proteolytic enzyme elastase, which was released from activated granulocytes in the milieu of significantly reduced levels of alpha 1-protease inhibitor (p less than 0.01), increased during cardiopulmonary bypass (p less than 0.01). In addition, bypass initiated platelet aggregation, which both altered the eicosanoid metabolism and caused the level of thromboxane A2 to increase and surpass the level of prostaglandin I2. Because thromboxane A2 dominance subsided immediately after cardiopulmonary bypass, the effect of thromboxane A2 (vasoconstriction) on the development of organ damage may have been influential only during bypass. Both during and after bypass, the increase in endothelin excretion (p less than 0.01 to 0.05) was believed to induce a further vasoconstriction in the microvasculature. On completion of the cardiopulmonary bypass, the elevation of the lysosomal enzyme beta-glucuronidase, which is a sensitive indicator of cellular damage, was influenced by the concentrations of elastase (r = 0.8) and endothelin (r = 0.52). As evidenced by leuko-sequestration in the lung after cardiopulmonary bypass, the increase in the alveolar-arterial oxygen tension difference correlated with the elastase concentration (r = 0.68). Renal damage, which was detected by an increase in renal tubular enzymes (N-acetyl-beta-D-glucosaminidase and gamma-glutamyltranspeptidase) was affected by the endothelin (r = 0.68, 0.56) and elastase levels (r = 0.58, 0.68), respectively, but not by the ratio of thromboxane B2 to prostaglandin F1 alpha. The elastase level influenced the pulmonary vascular resistance (r = 0.56). However, neither the cardiac index nor the systemic and pulmonary vascular resistances were influenced by the endothelin level and the ratio of thromboxane B2 to prostaglandin F1 alpha.

Acetylglucosaminidase↗

PubMed1992

[Surgical correction of atrioventricular discordance--results and follow-up].

Between January 1977 and October 1991, 47 consecutive patients with atrioventricular discordance, ventriculoarterial discordance, and two ventricles underwent intracardiac repair at the Heart Institute of Japan. Their ages at operation ranged from 2 months to 21 years (average 9.2 years) and period of follow-up ranged from 1 month to 168 months (average 65.1 months). There were five basic anatomic types according to the associated anomalies, grouped into (1) situs solitus, ventriculoarterial (V-A) discordance or double-outlet right ventricle (DORV), ventricular septal defect (VSD) and pulmonary outflow tract obstruction (POTO) (31 patients); (2) situs solitus, V-A discordance and VSD (6 patients); (3) situs solitus, V-A discordance and tricuspid regurgitation (TR) (2 patients); (4) situs inversus, V-A discordance or DORV, VSA and POTO (7 patients); (5) situs inversus, V-A discordance and VSD (1 patient). TR was evident preoperatively in 13 patients (28% of 47 patients), one of whom had Ebstein's anomaly. The conventional operation, which consisted of closure of VSD (34 patients), posterolateral pulmonary outflow enlargement (2 patients), tricuspid valvuloplasty (2 patients), and tricuspid replacement (1 patient) using the anatomical right ventricle as the systemic ventricle, was performed in 35 patients (RV group). The anatomic correction (so-called "double switch operation"), the new alternative operation using the anatomical left ventricle as the systemic ventricle, was achieved in 12 patients (LV group). Anatomic correction consisted of Senning and RV-PA ECR in 3, Mustard and RV-PA ECR in 4, Senning and arterial switch in 2, and Mustard and arterial switch in 1 patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

[Assessment of long-term systemic ventricular function after the surgical repair in patients with atrioventricular discordance].

Long-term systemic ventricular function at rest and during supine bicycle exercise was studied in 12 patients with atrioventricular discordance (AVD group) using multigated radionuclide blood pool imaging. For comparison, similar measurements were made in eight children (control group). The mean age at the exercise test was 12.3 years in AVD group and was 14.8 years in the control group. In AVD group, ages at the operation ranged from three to 21 years (mean 12.3 years), and the exercise test was performed from one to 9.8 years after the operation (mean 5.3 years). The operative procedures in AVD group consisted of closure of the ventricular septal defect in 11 patients, extracardiac conduit between the left ventricle and the pulmonary artery in nine patients, postero-lateral left ventricular outflow reconstruction in two patients, tricuspid annuloplasty in one patient, and tricuspid valve replacement in one patient. Exercise tolerance of AVD group was less than that of the control group. Heart rate and blood pressure were significantly increased during exercise in both groups. In the control group, end-diastolic count index (EDCI) (= end-diastolic volume) remained unchanged and end-systolic count index (ESCI) (= end-systolic volume) decreased during exercise. In contrast, both EDCI and ESCI were decreased in AVD group. As a consequence, systemic right ventricular ejection fraction (RVEF) increased during exercise in the control group, but remained unchanged in AVD group. Although stroke count index (SCI) (= stroke volume index) did not increased during exercise in AVD group, output count index (OCI) (= cardiac index) increased with the increase of heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

[A case of acute A type aortic dissection with lower extremity ischemia--percutaneous fenestration of the aortic septum followed by ascending aortic graft replacement by open distal anastomosis and retrograde cerebral perfusion].

A 56-year-old woman with severe back pain and a cold, pulseless right extremity was admitted to our hospital. Angiogram revealed a type A aortic dissection extending from ascending aorta to the aortic bifurcation with no definite re-entry point. The false lumen gave origin to the right renal artery and the right external iliac artery was occluded. Therefore, a catheter was manipulated into the true lumen through a percutaneous right femoral artery approach, and was advanced into the false lumen through the right posterolateral wall of the dissecting aortic septum. Fenestration was then performed with fully dilated angioplasty balloon across the septum. Immediately after the procedure, the patient's symptoms improved. The day after the fenestration, replacement of the ascending aorta with 24 mm woven Dacron graft was followed under the deep hypothermia and the retrograde cerebral perfusion. The patient followed a satisfactory postoperative course and postoperative angiogram showed a complete closure of the entry at the ascending aorta and adequate revascularization of the right renal and external iliac arteries.

Acute Disease↗

PubMed1992

[Successful surgical treatment of coronary aneurysm following PTCA].

A case of 50-year-old man who developed coronary aneurysm at the initial PTCA site following dilatation was reported. The patient was suffered severe effort angina pectoris and admitted to our hospital. Coronary angiography revealed 99% stenosis in the right coronary artery (RCA), and the underwent balloon dilatation of the RCA lesion with 3.0 mm balloon catheter at 3 atm of pressure. PTCA provided sufficient coronary dilatation, however a small dissection remained. He was discharged from the hospital without any symptom. Two months after PTCA he was suffered from recurrent angina, and electrocardiographic exercise stress test was positive for ST segment depression in inferior wall. The repeat coronary angiography showed severe stenosis of the original lesion and aneurysm formation at the area of dissection which occurred during initial angioplasty. Coronary artery bypass surgery with a saphenous vein graft performed successfully.

Angioplasty, Balloon, Coronary↗

PubMed1992

[A case report--combined Jatene procedure and extended aortic arch reconstruction for the original Taussig-Bing malformation associated with hypoplastic aortic arch, subaortic stenosis and coarctation of the aorta].

A successful repair with combined Jatene procedure (Lecompte modification) and extended aortic arch reconstruction in a two-month-old boy with the original Taussig-Bing malformation, associated with hypoplastic aortic arch, subaortic stenosis and coarctation of the aorta was described. The ascending aorta was measuring 8 mm and the distal aortic arch was 4 mm in outer diameter. The interventricular rerouting was not feasible, because the infundibular septum was almost aligned to the interventricular septum. So that arterial switch operation was preferred. The primary interventricular foramen was enlarged by wedge resection and the secondary interventricular foramen was closed with a patch of preserved equire pericardium. An extensive patch angioplasty of entire aortic arch down to descending aorta was performed with a composite patch of Xenomedica (preserved equire pericardium) and Dacron velour. Hypertrophied muscle bundles were resected for relief of subaortic stenosis. Jatene procedure was then performed. During neo-pulmonary reconstruction, distal pulmonary orifice was shifted towards right to avoid kinking and compression on the coronary arteries. One stage correction consisting of Jatene procedure and extended aortic arch reconstruction was considered to be a procedure of choice in this type of complex anomalies.

Aorta, Thoracic↗