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Biomedical subjects

S Fukuchi

Publications and source records attributed to S Fukuchi.

At least 109 records · Page 6Linked to original sources
PubMed1989

[New selection criterion for Fontan procedure: pulmonary artery clamping test and pulmonary vascular resistance in increased pulmonary blood flow].

A new selection criterion for Fontan procedure, pulmonary artery clamping test (PACT) was developed and employed in 13 candidates for Fontan procedure. PACT was aimed to evaluate the response of pulmonary vascular bed to increased pulmonary blood flow and calculate the pulmonary vascular resistance in the increased pulmonary blood flow as a selection criterion for Fontan procedure, preoperatively. After a median sternotomy incision, an electromagnetic flow meter was employed for measuring the pulmonary blood flow (Qp) on the pulmonary trunk. By clamping the left pulmonary artery and the right pulmonary artery, right pulmonary vascular resistance and the left pulmonary resistance in the pulmonary blood flow of Qp were calculated respectively. By means of electrical analogue, right and left lungs were simulated as resistors in parallel. And the equivalent pulmonary vascular resistance Rpc was calculated as the predicted pulmonary vascular resistance in the increased pulmonary blood flow of two times Qp. Fontan procedure was performed in 9 cases with a Rpc of less than 3 unit.m2 with a successful result and no death. Postoperative cardiac index ranged from 2.6 to 3.7 L/min.m2 with a mean of 2.8 L/min.m2. Postoperative pulmonary vascular resistance ranged from 1.6 to 3.2 unit.m2. Postoperative cardiac index was correlated with postoperative pulmonary vascular resistance. And postoperative pulmonary vascular resistance was well correlated with equivalent pulmonary vascular resistance but was not correlated with preoperative pulmonary vascular resistance measured by Fick's method at the preoperative catheterization. In Fontan procedure, the pulmonary blood flow frequently increases to a certain degree postoperatively. And pulmonary vascular resistance is not a static resistance, but a dynamic resistance. Hence, in discussing a pulmonary vascular resistance as a selection criterion for Fontan procedure, the pulmonary blood flow in which the pulmonary vascular resistance stand should be taken into account. Equivalent pulmonary vascular resistance Qpc is a theoretical selection criterion for Fontan procedure and well reflects the postoperative pulmonary vascular resistance. Fontan procedure can be successfully performed with a Rpc of less than 3 unit.m2.

Adolescent↗
PubMed1989

[A case of mitral valve replacement with autologous pulmonic valve in congenital mitral stenosis].

A one-year-old infant with congenital mitral stenosis and pulmonary hypertension underwent by mitral valve replacement with his pulmonic valve autograft and pulmonary tract reconstruction with heterogeneous pericardial conduit. His postoperative hemodynamics data showed that left atrial pressure decreased and pulmonary hypertension continued. Echocardiography showed that the implanted autograft functioned properly. On the seventh postoperative day, he died of pulmonary hypertension. In case with congenital mitral stenosis with the small mitral annulus and the small left ventricular cavity, it is difficult to perform mitral valve replacement by commercially available mechanical or tissue valves. Because these valves are not suitable for the small mitral annulus. The mitral valve replacement with pulmonic valve autograft is recommended in such a case with the congenital mitral stenosis.

Female↗
PubMed1989

[The results of surgical treatment of total anomalous pulmonary venous return in neonates].

By the time, the results of surgical treatment for total anomalous pulmonary venous return have been unsatisfactory. From 1981, we changed a surgical procedure fro Gersony-Malm procedure to the posterior approach method, and a surgical technique from the deep hypothermia and the circulatory arrest to the moderate hypothermia and the pump perfusion. Consequently, the results of surgical treatment was improved. From 1981 to 1987, 18 neonates with total anomalous pulmonary venous return underwent corrective operations in our institute. This diagnosis was decided by echocardiography without cardiac catheterization, because the preoperative status of these neonates were poor. Under the cardiopulmonary bypass, we performed the posterior approach method for type I and III, the cut-back method and Van Praagh procedure for II and IV without aortic clamping. According to the posterior approach method, the atrial septal defect was closed through the left atrial incision and the left atrium was anastomosed to the common pulmonary trunk during ventricular fibrillation. The incision was limited within the common pulmonary trunk or the vertical vein and was not extended into the pulmonary veins. According to cut-back method and Van Praagh procedure, the coronary sinus was closed internally so as to avoid the postoperative conduction disturbance. There were four hospital deaths (22.2%). The causes of deaths were pulmonary hypertension in two, low cardiac output in one, and intracranial bleeding in one. From the results of our institution, we concluded that the primary factors determining the outcome were the condition of the patients prior to repair and the severity of pulmonary hypertension.

Cardiopulmonary Bypass↗
PubMed1989

[Modified Fontan procedure on 106 cases: indication and surgical results].

Since 1974, we have performed modified Fontan procedure on 106 patients, ranging in ages from 1 to 32 years, consisting of 44 cases of tricuspid atresia (TA), 21 with univentricular heart (UVH) of right ventricular type, 18 with UVH of left ventricular type, for which ventricular partition was unfeasible, and 23 with various complex anomalies. Hospital mortality rates for TA and other complex anomalies were 11.4 and 11.3%, respectively. Surgical results have markedly improved recently. Since 1986, 50 cases underwent Fontan procedure with 3 hospital deaths (6.0%). Late death occurred in 4 cases in a mean follow-up period of 49 months. Regarding the indication for operation, majority of patients had 2 to 3 parameters which were out of 10 criteria for Fontan procedure. Regurgitation of atrioventricular valve was repaired by annuloplasty in 19 patients underwent Fontan procedure and 17 survived. Abnormal systemic venous connection was seen in 11 cases and all survived. Association of total anomalous pulmonary venous connection is still a difficult problem and 2 of 5 cases died. Fontan procedure was performed in 8 patients following palliative right ventricular outflow reconstruction for poor development of pulmonary artery and 7 survived. Cumulative mortality rate for the entire series was relatively well at 15.1%.

Adolescent↗
PubMed1988

[Effects of o,p'-DDD on pituitary-gonadal function in patients with Cushing's disease].

O,p'-DDD has a cytotoxic action and inhibits the cholesterol side chain cleavage enzyme, 11 beta-hydroxylase, 3 beta-hydroxysteroid dehydrogenase coupled with delta 5 to 4 isomerase and 21-hydroxylase of the adrenal cells. However, the effects of o,p'-DDD on gonadal steroidogenesis are still unknown. In the present study, the effects of o,p'-DDD on Plasma cortisol, pregnenolone, 17 alpha-hydroxypregnenolone (17-OH-pregnenolone), progesterone, 17 alpha-hydroxyprogesterone (17-OH-progesterone), 11-deoxycorticosterone (DOC), corticosterone, dehydroepiandrosterone (DHEA), delta 4-androstenedione (androstenedione), estradiol, and LH and FSH were investigated in 3 patients with Cushing's disease before and after the administration of o,p'-DDD. The results are presented here. In Case 1 (18 yr old female) who had had secondary amenorrhea for 2 years, the plasma levels of cortisol, pregnenolone, 17-OH-pregnenolone, DHEA, androstenedione, testosterone, estradiol and corticosterone were elevated. The basal levels of plasma LH and FSH and the responses of both gonadotropins were lower than those of women with eumenorrhea. The plasma levels of progesterone, DHEA and testosterone decreased to normal 2 months after the beginning of the administration of o,p'-DDD. She restored menstrual cycles ranging from 40 to 50 days 3 months after the administration of o,p'-DDD, but with anovulatory bleeding. She showed a biphasic body temperature pattern with plasma progesterone and estradiol levels indicating corpus luteum formation 11 months after the start of the treatment, when plasma cortisol as well as progesterone and androgen were reduced to normal. The basal levels of FSH and LH and responses of these gonadotropins were slightly improved at that time. The plasma levels of cortisol, DHEA and androstenedione were high in Case 2 (38 yr old male) and Case 3 (45 yr old male), whereas plasma testosterone level was normal in Case 2 and low in Case 3. The plasma levels of these 3 steroids were normalized 28 days after the beginning of the o,p'-DDD administration. These results suggest that o,p'-DDD does not interfere with gonadal steroidogenesis in Cushing's disease.

Adolescent↗
PubMed1988

Antihypertensive efficacy and safety of urapidil, alone or in combination with beta-blockers, in patients with phaeochromocytoma.

The clinical efficacy and safety of urapidil, used alone or in conjunction with beta-blockers, were evaluated in 14 patients with phaeochromocytoma. Following a 1-week placebo run-in period, the patients were treated with sustained-release capsules of urapidil, initially 30 mg twice a day, followed by dose adjustment within 30-270 mg (mean +/- s.d. 144 +/- 73) per day for 7-29 days (21 +/- 8 days). In six patients, beta-blockers were added to control associated tachycardia. Blood pressure and pulse rate were successfully controlled in 11/14 patients (78.6%) during the therapy. Both the frequency and the severity of hypertensive paroxysms were clearly reduced in 7/8 patients, who showed frequent paroxysms of hypertension during placebo treatment. A variety of subjective symptoms observed in 13 patients during placebo treatment improved during drug therapy in nine patients (69.2%). Side effects occurred in five patients but were minor and well tolerated except in one patient, who was withdrawn from urapidil monotherapy due to facial oedema and finger stiffness which persisted even after reducing the daily dose from 306 to 270 mg. Overall, in terms of antihypertensive effectiveness, improvement in subjective symptoms and the safety profile, urapidil was considered very useful in four patients (28.6%), useful in six (42.9%), slightly useful in three and useless in one. Urapidil therefore appears to be a worthwhile agent in the treatment of patients with phaeochromocytoma.

Adrenal Gland Neoplasms↗
PubMed1987

[Effects of dopamine and synthetic atrial natriuretic polypeptide on the release of norepinephrine and epinephrine from the adrenal medulla of rats].

We evaluated the effects of dopamine (DA) and synthetic atrial natriuretic polypeptide (ANP) on the release of catecholamines (CA) from the adrenal medulla. Adrenal glands of male Wistar rats were superfused with Ringer's solution saturated with 95%, O2, 5% CO2 by the use of a continuous flow incubation system, and norepinephrine (NE) and epinephrine (E) concentrations in the perfusate were continuously measured by high pressure liquid chromatography with fluorescent reaction. And the effects of DA and ANP on the CA release were evaluated. Next the effects of metoclopramide (MC), dopamine (D2) antagonist, and glucagon were added in the Ringer's solution, and the changes of NE and E in the perfusate were determined. Basal secretion of NE and E were 0.02-0.04 ng/mg.wet weight/min and 0.05-0.1 ng/mg.wet weight/min, respectively. DA remarkably decreased both NE and E release, and the suppressive effect was dependent on DA concentration in the perfusate. MC clearly raised NE and E release as well as glucagon. The increasing effect of MC was perfectly suppressed by 10(-4) M of DA. But the effect of glucagon was not blocked by the same dose of DA. Alpha rANP (10(-5)M) slightly decreased the releases of NE and E from adrenal medulla, and the magnitude of the effect of rANP was smaller than that of DA. MC significantly increased NE and E release even when the adrenal gland was superfused with Ringer's solution containing 10(-5)M of rANP. These data suggest that the release of CA from adrenal medulla may be regulated by DA, and that the receptors specifically binding to DA may exist in adrenal medulla as well as sympathetic presynaps. We concluded that DA (but not ANP) may play an important role in controlling (suppressing) the activity of sympathoadrenomedullary system.

Adrenal Medulla↗
PubMed1987

Congenital 17 alpha-hydroxylase deficiency: a clinicopathologic study.

The histopathologic features of the adrenal glands in three cases of congenital 17 alpha-hydroxylase deficiency are described in relation to clinical and endocrine findings. Diffuse or nodular adrenocortical hyperplasia, particularly in the zonae fasciculata and reticularis, was observed in all cases examined. The hyperplastic adrenal cortices were composed of cells with morphologic features of hypercorticism and hyperstimulation. Myelolipomatous lesions were detected in two cases. These morphologic findings were consistent with excessive adrenocorticotropic hormone secretion in this disorder. In all the cases examined, the plasma aldosterone concentration was within normal limits, and plasma renin activity was suppressed prior to dexamethasone treatment. Morphologically, however, hyperplasia of the cells with abundant mitochondria and smooth endoplasmic reticulum seemed to involve the zona glomerulosa. Nonencapsulated nests of hypertrophied cortical cells in periadrenal tissue were remarkable in one case. From these morphologic findings, we postulated hyperfunction of the zona glomerulosa as well as involvement of corticosteroids from the zona glomerulosa in the pathophysiology of this disorder.

Adrenal Cortex Hormones↗
PubMed1987

Multiple forms of immunoreactive renin in human adrenocortical tumour tissue from patients with primary aldosteronism.

There is increasing evidence which suggests that the adrenal gland contains the renin-angiotensin cycle. The localization of renin has been reported to be mainly in the zona glomerulosa rather than the fasciculata medullary portion. In the present study we have investigated extracts from aldosteronomas (n = 3), which are believed to derive from the zona glomerulosa cells. In addition, we have attempted to characterize the biochemical properties of the adrenal renin. Sizable quantities of renin-like activity (32.0 +/- 7.7 ng of angiotensin I generated h-1 mg-1 of protein, mean +/- SEM) were detected in the extracts. This renin-like activity was inhibited by anti-renin antibody raised against pure renin (mean, 95% of the total renin-like activity), indicating that it was not due to the non-specific action of proteases such as cathepsin D. The optimum pH of the tissue renin-like enzyme was 6.0 for rat plasma substrate. Differences were found, however, in the molecular mass (36,000, 37,000, 44,000 and 48,000), binding to concanavalin A and isoelectric points (4.40, 4.68 and 5.00). These results confirm the existence of specific renin in aldosteronoma. Renin microheterogeneity could be evidence for local production of the enzyme.

Adrenal Cortex Neoplasms↗
PubMed1987

Active and inactive renin-like enzymes in the brain of spontaneously hypertensive rat.

Renin-like enzyme(s) in the brain of spontaneously hypertensive rat (SHR) were activated unequivocally by trypsin. The highest concentration of the active renin-like enzyme was localized in the hypothalamus (1.03 +/- 0.25 ng angiotensin I/mg of protein per h, mean +/- S.D.), followed by the striatum (0.51 +/- 0.21), thalamus (0.40 +/- 0.08), midbrain (0.33 +/- 0.04), medulla oblongata (0.25 +/- 0.01), cerebral cortex (0.21 +/- 0.03), and cerebellum (0.14 +/- 0.03), while the highest concentration of the inactive renin-like enzyme was localized in the hypothalamus (0.86 +/- 0.17), followed by the striatum (0.47 +/- 0.15), thalamus (0.32 +/- 0.09), cerebellum (0.29 +/- 0.04), midbrain (0.26 +/- 0.02), cerebral cortex (0.24 +/- 0.04), and medulla oblongata (0.10 +/- 0.03). The active renin-like activity in the thalamus of SHR was significantly lower than that of age- and sex-matched normotensive Wistar-Kyoto (WKY) rats. Furthermore, the inactive renin-like activity in the striatum, thalamus, cerebellum, midbrain, and medulla oblongata of SHR was significantly lower than that in the corresponding areas of WKY rats. Although the precise mechanisms underlying the conversion of inactive to active renin-like enzyme in the brain remain to be resolved, these results may offer a new aspect for the role of the brain renin-angiotensin system in the initiation and/or development of hypertension of SHR.

Animals↗
PubMed1987

Biochemical characterization of angiotensin-converting enzyme in human neuroblastoma tissue.

High activity of angiotensin-converting enzyme was demonstrated in human neuroblastoma tissue. This activity required the presence of chloride ion and was almost completely inhibited by a specific converting enzyme inhibitor captopril (10 nM), indicating that the activity measured is indeed angiotensin-converting enzyme. Furthermore, the biochemical features of the enzyme were closely similar to the well-known properties of human lung converting enzyme, such as molecular weight (290,000), optimum pH (8.0-8.5), the presence of glycoprotein residues, and dependence on chloride ion concentration. These results provide definitive evidence for the presence of true angiotensin-converting enzyme in human neuroblastoma tissue.

Angiotensin-Converting Enzyme Inhibitors↗