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Biomedical subjects

H Komai

Publications and source records attributed to H Komai.

At least 19 recordsLinked to original sources
PubMed2002

Plasma hepatocyte growth factor levels after open heart surgery for congenital heart disease.

BACKGROUND: Hepatocyte growth factor (HGF) is a polypeptide which acts protectively against endothelial cell dysfunction. A high plasma level of HGF is shown when the endothelium is injured. We measured plasma HGF levels during and after open heart operations for congenital heart disease, to elucidate its involvement with endothelial cell injury. METHODS EXPERIMENTAL DESIGN: prospective study. SETTING: perioperative setting. PATIENTS: 18 children electively operated upon for congenital heart disease using CPB. RESULTS: Plasma HGF levels (ng/ml) before cardiopulmonary bypass (CPB) were 0.36+/-0.07 in 10 children (S-group) who were older and with simpler diseases, and 0.48+/-0.12 in 8 children (C-group) who were younger and with relatively complex diseases. HGF levels significantly increased after CPB, and gradually decreased thereafter. Plasma HGF levels 3 and 6 hours after CPB were significantly greater in the C-group than in the S-group (1.13+/-0.12 vs 1.68+/-0.1 6 3 hours after, and 1.09+/-0.19 vs 2.35+/-0,43 6 hours after; p<0.05 for both). There were significant positive correlations between HGF levels 6 hours after CPB and the duration of the CPB, the aortic crossclamping time, and plasma thrombomodulin levels just after CPB in all patients (p<0.05 for all). CONCLUSIONS: This data suggests that increased HGF levels are associated with endothelial cell injury induced by CPB, and that the increases are much greater in younger patients with complex anomalies.

Biomarkers↗
PubMed2001

Right atrial rupture in blunt chest trauma.

The mortality rate from cardiac rupture by blunt chest injury is high. Here, we report a case of 27-year-old male who suffered a right atrial rupture by blunt chest injury and was successfully treated. The hemodynamics were stabilized by pericardiocentesis with a 5F Pigtail catheter for cardiac tamponade and rapid fluid transfusion. Then the right atrial rupture was repaired without a cardiopulmonary bypass. The postoperative course was uneventful, and the patient was discharged on the 14th postoperative day.

Adult↗
PubMed2001

Midterm results after ventricular septation for double-inlet left ventricle in early infancy.

We performed ventricular septation for a 40-day-old boy with double-inlet left ventricle and discordant ventriculoarterial connection but without pulmonary stenosis. Postoperative cardiac function is satisfactory, with no evidence of pulmonary hypertension or subaortic stenosis. Nine years after the operation, the patient has an active life, is free from symptoms, and requires no medication. He may be the first patient to survive ventricular septation for double-inlet left ventricle in early infancy.

Angiography↗
PubMed2001

Local anesthetic inhibition of voltage-activated potassium currents in rat dorsal root ganglion neurons.

BACKGROUND: Local anesthetic actions on the K+ channels of dorsal root ganglion (DRG) and dorsal horn neurons may modulate sensory blockade during neuraxial anesthesia. In dorsal horn neurons, local anesthetics are known to inhibit transient but not sustained K+ currents. The authors characterized the effects of local anesthetics on K+ currents of isolated DRG neurons. METHODS: The effects of lidocaine, bupivacaine, and tetracaine on K+ currents in isolated rat DRG neurons were measured with use of a whole cell patch clamp method. The currents measured were fast-inactivating transient current (I(Af)), slow-inactivating transient current (I(As)), and noninactivating sustained current (I(Kn)). RESULTS: One group of cells (type 1) expressed I(Af) and I(Kn). The other group (type 2) expressed I(As) and I(Kn). The diameter of type 2 cells was smaller than that of type 1 cells. Lidocaine and bupivacaine inhibited all three K+ currents. Tetracaine inhibited I(As) and I(Kn) but not I(Af) For bupivacaine, the concentration for half-maximal inhibition (IC50) of I(Kn) in type 2 cells was lower than that for I(Kn) in type 1 cells (57 vs. 121 microM). Similar results were obtained for tetracaine (0.6 vs. 1.9 mM) and for lidocaine (2.2 vs. 5.1 mM). CONCLUSIONS: Local anesthetics inhibited both transient and sustained K+ currents in DRG neurons. Because K+ current inhibition is known to potentiate local anesthetic-induced impulse inhibition, the lower IC50 for I(Kn) of small type 2 cells may reflect preferential inhibition of impulses in nociceptive neurons. The overall modulatory actions of local anesthetics probably are determined by their differential effects on presynaptic (DRG) and postsynaptic (dorsal horn neurons) K+ currents.

Anesthetics, Local↗
PubMed2000

Ductal aneurysm of adult patients.

A ductal aneurysm is very rarely diagnosed in adults. We experienced 2 cases of adult ductal aneurysm. Both cases developed hoarseness and computed tomographic scanning demonstrated a typical 'triple star sign' at the aortopulmonary window level. They underwent surgical repair with successful results. During the same period, we experienced 38 operations for true thoracic aneurysm. The ductus origin was found in 5.2% of these patients. The ductal aneurysm may no longer be considered a 'rare' vascular disease with more careful diagnostic procedure.

Aged↗
PubMed2000

Autologous blood donation with recombinant human erythropoietin for abdominal aortic aneurysm surgery.

We evaluated the efficacy of autologous blood donation using recombinant human erythropoietin for elective abdominal aortic aneurysm (AAA) surgery regarding postoperative recovery. Twenty-five AAA patients who completed surgery without receiving a homologous blood transfusion were divided into two groups, consisting of a control group (n = 12) who did not bank any autologous blood, and a donation group (n = 13) who did bank more than 800 ml of autologous blood with the use of erythropoietin. The hematocrit (Ht) level of the control group decreased from 41.1% +/- 1.2% before the operation to 36.2% +/- 0.9% just afterwards (P > 0.01). In the donation group, however, the Ht did not change significantly during either the donation period or the perioperative period. The postoperative period before oral food intake and natural defecation were both significantly shorter in the donation group than in the control group. The first day of mobilization was also earlier in the donation group. In conclusion, autologous blood donation using erythropoietin for AAA surgery is therefore considered to promote the early recovery of patients.

Aged↗
PubMed1999

Interaction of bupivacaine and tetracaine with the sarcoplasmic reticulum Ca2+ release channel of skeletal and cardiac muscles.

BACKGROUND: Although various local anesthetics can cause histologic damage to skeletal muscle when injected intramuscularly, bupivacaine appears to have an exceptionally high rate of myotoxicity. Research has suggested that an effect of bupivacaine on sarcoplasmic reticulum Ca2+ release is involved in its myotoxicity, but direct evidence is lacking. Furthermore, it is not known whether the toxicity depends on the unique chemical characteristics of bupivacaine and whether the toxicity is found only in skeletal muscle. METHODS: The authors studied the effects of bupivacaine and the similarly lipid-soluble local anesthetic, tetracaine, on the Ca2+ release channel-ryanodine receptor of sarcoplasmic reticulum in swine skeletal and cardiac muscle. [3H]Ryanodine binding was used to measure the activity of the Ca2+ release channel-ryanodine receptors in microsomes of both muscles. RESULTS: Bupivacaine enhanced (by two times at 5 mM) and inhibited (66% inhibition at 10 mM) [3H]ryanodine binding to skeletal muscle microsomes. In contrast, only inhibitory effects were observed with cardiac microsomes (about 3 mM for half-maximal inhibition). Tetracaine, which inhibits [3H]ryanodine binding to skeletal muscle microsomes, also inhibited [3H]ryanodine binding to cardiac muscle microsomes (half-maximal inhibition at 99 microM). CONCLUSIONS: Bupivacaine's ability to enhance Ca2+ release channel-ryanodine receptor activity of skeletal muscle sarcoplasmic reticulum most likely contributes to the myotoxicity of this local anesthetic. Thus, the pronounced myotoxicity of bupivacaine may be the result of this specific effect on Ca2+ release channel-ryanodine receptor superimposed on a nonspecific action on lipid bilayers to increase the Ca2+ permeability of sarcoplasmic reticulum membranes, an effect shared by all local anesthetics. The specific action of tetracaine to inhibit Ca2+ release channel-ryanodine receptor activity may in part counterbalance the nonspecific action, resulting in moderate myotoxicity.

Anesthetics, Local↗
PubMed1999

[A case report of successful mitral valve replacement for congenital mitral stenosis associated with coarctation of the aorta and ventricular septal defect].

A 5-month-old infant with coarctation of the aorta, ventricular septal defect and mitral stenosis known as "Shone's anomaly" is presented. He underwent the repair of coarctation of the aorta by means of the extended aortic arch anastomosis and banding of the pulmonary trunk at 1 month of age and the patch closure of ventricular septal defect and debanding of the pulmonary trunk at 3 months of age in our institution. About 2 months after second surgery, he had been admitted to our institution due to developing tachypnea and he needed the support of mechanical ventilation. The chest X-ray showed pulmonary congestion and the echocardiography revealed only one papillary muscle of mitral valve and pressure gradient about 30 mmHg through mitral valve. Mitral stenosis due to parachute mitral valve was suspected and he was subjected to an emergent surgery. Initially we performed mitral valve repair for parachute mitral valve but echocardiography during the surgery revealed moderate grade of mitral regurgitation and a hemodynamics was not satisfactory. Eventually mitral valve replacement was successfully done with Carbo-Medics mechanical valve (19 mm in diameter) in the position of left atrial wall because his mitral annulus was so small as 10 mm in diameter. The postoperative course was uneventful and the patient has been doing well.

Aortic Coarctation↗
PubMed1998

Successful operative treatment for acute triple-barreled aortic dissection in a patient with Marfan's syndrome: report of a case.

Triple-barreled aortic dissection is a rare form of aortic dissection associated with high mortality. We report herein the case of a 41-year-old woman with Marfan's syndrome who developed acute triple-barreled aortic dissection from a Stanford type B dissecting aneurysm. Successful graft replacement of the proximal third of the descending thoracic aorta was subsequently performed. To the best of our knowledge, this is the first case of successful operative treatment for an acute triple-barreled aortic dissection ever to be reported.

Adult↗
PubMed1998

[Evaluation of the growth of a new pulmonary trunk after the reconstruction of right ventricular outflow tract without using an external conduit].

To evaluate the growth of a pulmonary trunk reconstructed without an extracardiac conduit, the hemodynamics and diameter of a new pulmonary trunk were measured in 5 patients from the right ventriculogram and MRI at postoperative follow-up periods. There were tetralogy of Fallot with pulmonary atresia in two patients, tetralogy of Fallot with single coronary in one, truncus arteriosus type I in one and transposition of the great arteries with ventricular septal defect and pulmonary stenosis in one. The age at operation ranged from 26 days to 4.5 years. The posterior wall continuity of the right ventricle and pulmonary artery was established by the direct pulmonary-right ventricular anastomosis in three patients and by the interposition of the left atrial appendage in two. Postoperative follow-up periods ranged from 2 years and 6 months to 3 years and 10 months (median: 2 years and 11 months). In four of them, the postoperative right ventricular to aortic or left ventricular systolic pressure ratios were less than 0.4 without any significant systolic pressure gradients between pulmonary artery and right ventricle. In these four patients, the diameters of the reconstructed pulmonary trunks grew from 10-18 mm to 18-21 mm postoperatively. These diameters were more than 100% of normal values. In the remaining patient with tetralogy of Fallot and single coronary artery, the obstruction of the new pulmonary trunk by a bulged left atrial appendage, which was used as the posterior wall, was observed on the right ventricular outflow tract reconstruction without an extracardiac conduit has growth potential in the future.

Bioprosthesis↗
PubMed1998

[Closed Brock operation for an infant case of double outlet right ventricle with pulmonary atresia].

One-month-old boy with double outlet right ventricle and pulmonary atresia was referred to us for surgical treatment. As he had a membranous obstruction of the pulmonary artery we chose closed Brock operation as an initial procedure. A 6.5 mm in diameter of Trocar was used to open the atretic valve. Postoperative course was uneventful and his oxygen saturation was maintained satisfactory. At the age of one year and nine months he underwent corrective surgery. The pulmonary valve was widely opened enough to perform the right ventricular outflow tract reconstruction with valvotomy and outflow patch. The boy got well and was followed in the outpatient clinic. Double outlet right ventricle with membranous pulmonary atresia is a rare combination and closed Brock operation is shown to be one of the most effective procedure for this type of anomaly.

Double Outlet Right Ventricle↗
PubMed1998

Surgical treatment of a cardiac papillary fibroelastoma developing from the chordae of the tricuspid valve: report of a case.

Papillary fibroelastoma is a rare, benign cardiac tumor that can cause multiple emboli. We report herein a case of papillary fibroelastoma developing from the chordae of the tricuspid valve which was detected by echocardiography and confirmed by surgical resection. To our knowledge, this is only the fifth documented case of a tricuspid valve papillary fibroelastoma detected by echocardiography in a living patient.

Adult↗
PubMed1998

The protective effect of a leucocyte removal filter on the lung in open-heart surgery for ventricular septal defect.

We elucidated the protective effect of a leucocyte removal filter on cardiopulmonary bypass (CPB)-induced lung dysfunction during open-heart surgery for ventricular septal defect (VSD). Forty-six VSD patients were divided into two groups: (a) a control group of 22 patients in whom the banked blood was used to prime the CPB circuit, and (b) a leucocyte removal group of 24 patients in whom a leucocyte removal filter was used for priming and every supplement of banked blood during and after the operation. The respiratory index immediately after the CPB was significantly lower in the leucocyte removal group than in the control group (2.23 +/- 0.22 vs 3.90 +/- 0.68; p < 0.05). The duration of stay in the intensive care unit was significantly shorter in the leucocyte removal group (3.0 +/- 0.4 vs 4.1 +/- 0.4 days; p < 0.05). These data suggest that the use of a leucocyte removal filter for blood added to the CPB prime or administered after CPB may have protective effects on lung function after open heart surgery for VSD patients.

Child↗
PubMed1998

Plasma adrenomedullin level after cardiopulmonary bypass.

Adrenomedullin is an intrinsic vasodilator which is metabolized mainly in the pulmonary circulation. We measured plasma levels of adrenomedullin in children with congenital cyanotic heart disease (CY group, n = 6), children with high pulmonary blood flow due to congenital heart disease (PH group, n = 8), and in adults with mitral valve disease (MV group, n = 7) before and 3 h after cardiopulmonary bypass (CPB). Before CPB, the adrenomedullin level was the highest in the MV group, possibly due to chronic heart failure. Three hours after CPB, the plasma adrenomedullin level (pg/ml) increased to 1712.7 +/- 498.4 in the CY group, 167.6 +/- 26.4 in the PH group, and 1404.3 +/- 313.7 in the MV group, the level in the PH group being significantly lower than the rest. In the PH group, there was statistically significant negative correlation between the mean pulmonary arterial pressure at the preoperative catheter study, and the adrenomedullin level 3 h after CPB. These results illustrate that the adrenomedullin level increased after CPB, but that the increase was less marked in the PH group, implying that where the pulmonary vasculature was damaged most, this results in increased vasoconstriction.

Adrenomedullin↗