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Biomedical subjects

K Momma

Publications and source records attributed to K Momma.

At least 73 records · Page 4Linked to original sources
PubMed1997

Effect of acidosis on contraction, intracellular pH, and calcium in the newborn and adult rabbit aorta.

This study investigated the effect of acidosis on intracellular pH (pHi), intracellular calcium concentration ([Ca]i), and vascular contraction in the aorta of the newborn and adult rabbit. Isometric tension, pHi, and [Ca]i were measured in an isolated ring preparation. After the vascular contraction was induced with 50mM KC1, the effect of respiratory acidosis produced by elevation of PCO2 was studied. Respiratory acidosis caused a transient depression followed by a recovery of contractile tension. The decrease in developed tension was greater in the newborn than in the adult. The decrease in pHi during acidosis was similar in the two age groups. [Ca]i increased during acidosis and the increase was greater in the newborn than in the adult. These data show that the vasorelaxant effect of acidosis in the newborn aorta is greater than that in the adult aorta. The greater vasodilation in the newborn cannot be explained by the difference in pHi or [Ca]i.

Acidosis, Respiratory↗
PubMed1997

Small left coronary arteries after arterial switch operation for complete transposition.

BACKGROUND: Myocardial perfusion is not completely normal and ventricular function is depressed in some patients after the arterial switch operation. The basic mechanism has not yet been defined totally. METHODS: The diameters of the right, left main trunk, anterior descending, and circumflex coronary arteries were measured by computer-assisted densitometry at 8 to 86 months (mean, 47.5 months) after the arterial switch operation in 86 patients. RESULTS: The Z scores, compared with control, were +2.0 +/- 0.3, -1.8 +/- 0.3, and -1.5 +/- 0.3 for the right, left anterior descending, and circumflex coronary arteries, respectively. The Z score for the total cross-sectional area of the three vessels was -1.5 +/- 0.3. These parameters did not correlate with left ventricular ejection fraction. CONCLUSIONS: At the midterm follow-up after the arterial switch operation for complete transposition of the great arteries, the left coronary arteries are small. A careful follow-up study is mandatory to clarify the clinical significance of this finding.

Absorptiometry, Photon↗
PubMed1997

Truncus arteriosus communis associated with chromosome 22q11 deletion.

OBJECTIVES: The purpose of this study was to clarify characteristics of truncus arteriosus communis associated with chromosome 22q11 deletion (del 22q11). BACKGROUND: DiGeorge syndrome and conotruncal anomaly face syndrome are associated with del 22q11 (hemizygosity). In 30% of cases, truncus arteriosus communis is associated with the deletion. METHODS: Fifteen consecutive patients with truncus arteriosus communis were checked for 22q11 with fluorescent in situ hybridization using an N25 probe (Oncor). Cardiovascular anomalies were studied with cardiac catheterization, cineangiography and echocardiography. RESULTS: Five patients had del 22q11. Two had a rare type of truncus arteriosus: type A3 of Van Praagh and Van Praagh with major aortopulmonary collateral arteries and pulmonary ostial stenosis. The other three had type A1 truncus arteriosus and pulmonary artery stenosis. One of them had major aortopulmonary collateral arteries. Ten patients with truncus arteriosus had no del 22q11. The types of truncus arteriosus in these 10 patients were type A1 in 7, type A2 in 2 and type A3 with closed ductus in 1. None of nine patients with type 1 or type 2 truncus arteriosus had pulmonary stenosis. CONCLUSIONS: In truncus arteriosus communis, the rare type A3 with major aortopulmonary collateral arteries and pulmonary ostial stenosis and type A1 with pulmonary artery stenosis are associated with del 22q11.

Abnormalities, Multiple↗
PubMed1997

Preliminary clinical study on gastric ulcer scars and ulcer relapses after Helicobacter pylori eradication therapy.

To determine the effect of Helicobacter pylori eradication on the healing of gastric ulcers, endoscopic examinations of gastric ulcer scars and ulcer relapse after eradication therapies or antisecretory therapy were carried out in 24 H. pylori-positive patients with recurrent gastric ulcers located in the gastric angle. Sixteen patients were initially treated with 2-week triple eradication therapy. Subsequently, seven of eight noneradicated cases were retreated with triple therapy, which included metronidazole. Eight patients received antisecretory monotherapy. Endoscopic examinations were performed at 4 weeks and 6 months after the treatments. Gastric ulcer scars were classified endoscopically into three types: Sa, a central depression surrounded by a coarse pattern: Sb, a coarse regenerated pattern; and Sc, a fine pattern indicating matured scar of high quality. Transformations of the scar patterns and ulcer relapse were assessed in 19 patients who showed an ulcer scar at 4 weeks after initial therapy. Thirteen cases in which H. pylori was successfully eradicated, either after initial or re-eradication therapies, mainly showed Sc scars and had no ulcer relapse. Sa scar was mainly observed during H. pylori-positive conditions. Transformation from the Sa to the Sc was observed after successful re-eradication. Ulcer relapses occurred in three patients who showed Sa scar after antisecretory therapy. Although a random study would be needed to obtain a definite conclusion, we suspect that the H. pylori-negative condition after eradication therapies may result in good ulcer healing and may subsequently reduce ulcer relapse.

Anti-Bacterial Agents↗
PubMed1997

Current treatment of brain abscess in patients with congenital cyanotic heart disease.

OBJECTIVE: The goal of this study was to define clearly the role of management in patients with cyanotic heart disease and brain abscesses by evaluating retrospectively the factors influencing poor outcome in these patients. METHODS: This study included 62 patients with cyanotic heart disease and brain abscesses diagnosed in the computed tomography era. Basic characteristic parameters (number, size, location, computed tomographic classification and organism type of abscess, convulsion, type of cyanotic heart disease, age distribution, immunocompromised status, pretreatment neurological state, and intraventricular rupture of brain abscess [IVROBA]) and therapeutic parameters (type of antibiotics and duration of administration, steroid medication and therapeutic modalities, aspiration with or without cerebrospinal fluid drainage, total extirpation after aspiration, or primary extirpation and medical treatment) were evaluated as independent predictors of poor outcome (totally disabled state or death) by using univariate and multivariate logistic regression analysis. We also statistically estimated the possible causes of IVROBA and the multiplicity of brain abscess. RESULTS: Although there were no statistically significant correlations between patients with good and poor outcomes in regard to other basic characteristic and therapeutic parameters, patients with poor outcomes were older (P < 0.02), more frequently had IVROBA (P < 0.005), and had a higher frequency of neurological deterioration (P < 0.01) than those with good outcomes. Multiple logistic regression analysis predicted that poor outcome increased the relative risk of IVROBA by a factor of 18.9 (odds rate, 18.9; 95% confidence interval, 1.7-211.6; P < 0.02). More patients with multiple abscesses had positive immunocompromised states than those with single abscesses (P < 0.01). Deep-located abscesses also more frequently had IVROBA (P < 0.005) and abscesses located in the parieto-occipital region ruptured into the occipital horn of the lateral ventricle in a short period (P < 0.02). CONCLUSIONS: Our findings suggest that IVROBA strongly influences poor outcome in patients with cyanotic heart disease. The key to decreasing poor outcomes may be the prevention and management of IVROBA. To reduce operative and anesthetic risk in these patients, abscesses should be managed by less invasive aspiration methods guided by computed tomography. Abscesses larger than 2 cm in diameter, in deep-located or parieto-occipital regions, should be aspirated immediately and repeatedly, mainly using computed tomography-guided methods to decrease intracranial pressure and avoid IVROBA. IVROBA should be aggressively treated by aspiration methods for the abscess coupled with the appropriate intravenous and intrathecal administration of antibiotics while evaluating intracranial pressure pathophysiology.

Adolescent↗
PubMed1997

OKT3 therapy for transfusion-associated graft-versus-host disease in a neonate.

Transfusion-associated graft-versus-host disease (TA-GVHD) is a fatal side effect of blood transfusion. The present study describes a case of TA-GVHD in a neonate treated with anti-CD3 monoclonal antibody (OKT3). The patient died of systemic bacterial infection. However, it is suggested that OKT3 suppressed the graft-versus-host reaction due to the improvement in the clinical signs and a change in the human leucocyte antigen (HLA) type on the surface of circulating lymphocytes. A relatively large dose of OKT3 together with steroid pulse therapy and cyclosporin A may be required for the control of TA-GVHD in neonates.

Bacterial Infections↗
PubMed1997

Developmental changes in the contractile system of the mesenteric small artery of rabbit.

This study investigated developmental changes in the contractile system of the mesenteric small arteries of the rabbit. Arteries about 1 mm in length and 100-250 microns in internal diameter were dissected out from the mesenteric bed of the fetus (29 d of gestation), newborn (3-5 d old), and adult rabbit. Vascular contraction was induced by high KCl concentration, and contractile force was measured using a tension transducer. The sensitivity of vascular contraction to high KCl was similar in the three age groups. To determine the role of Ca influx across the sarcolemma in vascular contraction, the vasorelaxant effect of diltiazem was studied in the artery precontracted with high KCl concentration. The vasorelaxant effect of diltiazem in the fetus and newborn was less than in the adult. To estimate the size of the intracellular Ca pool, caffeine-induced and noradrenaline-induced contraction were measured in the Ca- and Na-free solution. In the fetus and newborn, both the caffeine-induced contraction and noradrenaline-induced contraction were greater than in the adult. The ultrastructural study showed that the endoplasmic reticulum was abundant in the fetus and newborn, and it was scarce in the adult. These data indicate that the dependency of vascular contraction on Ca influx across the sarcolemma increases and the intracellular Ca store decreases with development in the mesenteric resistance arteries.

Aging↗
PubMed1997

Developmental changes in the effect of acidosis on contraction, intracellular pH, and calcium in the rabbit mesenteric small artery.

The purpose of the present study was to determine developmental changes in the effect of respiratory acidosis on vascular smooth muscle contraction. Vessel diameter, intracellular pH (pHi), and calcium concentration ([Ca]i) were measured in a cannulated preparation of the small mesenteric artery of newborn and adult rabbits. In the artery precontracted by high KCl, acidosis caused a vasorelaxation both in the newborn and the adult; the vasorelaxation was greater in the newborn than in the adult. The fura-2 fluorescence ratio, an indicator of [Ca]i, decreased transiently during acidosis and the decrease was similar in the two age groups. In the artery precontracted by norepinephrine, acidosis caused a transient vasoconstriction in the adult and a vasorelaxation in the newborn. In these vessels, the fura-2 fluorescence ratio increased transiently during acidosis; the increase was similar in the two groups. Upon induction of acidosis, pHi fell rapidly in the artery precontracted by norepinephrine or high KCl, and the depression of pHi was similar in the two groups. In the skinned smooth muscle preparation, a tension-[Ca] relationship curve at pH 7.1 was not significantly different from that at pH 6.8 in the adult. In the newborn, the tension-[Ca] curve at pH 6.8 was shifted to the right, compared with that at pH 7.1. These data suggest that the vasorelaxant effect of respiratory acidosis in the premature vessel is greater than in the adult. The greater vasorelaxation in the newborn cannot be explained by the age-related difference in pHi or [Ca]i during acidosis. The greater sensitivity of myofibrils to low pHi in the newborn may, at least in part, be responsible for the greater vasorelaxation in this age group.

Acidosis, Respiratory↗
PubMed1997

Balloon angioplasty for aortic coarctation--report of a questionnaire survey by the Japanese Pediatric Interventional Cardiology Committee.

The aim of this study was to analyze the results of a questionnaire survey regarding acute and late effects of balloon angioplasty for aortic coarctation in Japan. Considerable controversy still exists regarding the effectiveness and safety of balloon angioplasty in native coarctation. Moreover, little information about this mode of treatment is available from Japan. A questionnaire was sent to 55 Japanese institutions with pediatric cardiology units. A total of 208 patients from 35 institutions were reported and analyzed for indications for balloon angioplasty, acute and late results, and complications. Balloon angioplasty was performed in 56 patients with native coarctation (group I) and in 152 patients with postoperative recoarctation (group II). In group I, the pressure gradient across the coarcted site decreased significantly from 34 +/- 19 to 16 +/- 21 mmHg (p < 0.001), and the diameter of the coarcted site increased significantly from 3.7 +/- 1.7 to 6.0 +/- 2.5 mm (p < 0.001). In group II the pressure gradient significantly decreased from 41 +/- 20 to 15 +/- 15 mmHg (p < 0.001) and the diameter of the coarcted site significantly increased from 4.2 +/- 2.2 to 6.8 +/- 3.1 mm (p < 0.001). The restenosis rate was significantly higher in group I (19/41, 46%) than in group II (25/139, 18%) (p = 0.0006). Redilation was successfully performed in 27 of 29 of the patients with restenosis. Major complications included femoral pulse loss, transient bradycardia, and arrhythmia. No patient died of a cardiac event related to the procedure. The significant risk factors for late restenosis included type of coarctation, age under 4 months, balloon size used, pressure gradient and coarctation diameter before the procedure. Balloon angioplasty is a suitable treatment for aortic coarctation in both native coarctation and postoperative recoarctation. Restenosis was significant after initial balloon angioplasty in native coarctation but redilation was effective in most cases. The most significant risk group for restenosis is young children with native coarctation.

Adolescent↗
PubMed1997

Coil occlusion for patent ductus arteriosus in Japan.

We surveyed Japanese experience of coil occlusion of patent ductus arteriosus up to 30 September 1996 by sending questionnaires to 175 hospitals. Thirty-four hospitals reported outcome data for 231 procedures in 218 patients. Successful implantation was achieved in 94% and acute complete closure of the ductus occurred in 71% of those in whom implantation of the coil was successful. Of the latter, 83% reported late complete closure. When those patients who underwent reocclusion for residual shunt are included, 89% attained complete closure. No life-threatening complications have occurred so far. Late reopening was reported in 3 cases. Although the angiographic type of ductus was significantly related to successful implantation (p < 0.01), there was no significant correlation with complete occlusion. Ductuses with a minimum diameter greater than 3 mm had a decreased chance of successful implantation, whereas those less than 2 mm had a greater incidence of complete closure.

Child↗
PubMed1996

Growth of the neopulmonary valve annulus after arterial switch operation in transposition of the great arteries.

BACKGROUND: It is known that supravalvular pulmonary artery stenosis can occur in patients with d-transposition of the great arteries (TGA) after arterial switch operation (ASO). However, little is known about the growth of the neopulmonary valve annulus after the ASO. This study investigated the growth potential of the neopulmonary (old aortic) valve annulus. METHODS AND RESULTS: Annular diameters of the old aortic and neopulmonary valve were measured from cineangiograms in patients who underwent cardiac catheterizations both before and > 1 year after the ASO. Of 71 patients, 13 (18%) had either a small annulus (< 70% of the expected normal value) or no significant growth of the neopulmonary annulus after the ASO, and 4 (6%) had a pressure gradient of > 30 mm Hg across the valve. The small annulus or no growth of the neopulmonary valve was more frequent in patients with a history of pulmonary artery banding. After the ASO, the valve diameter in patients with a ventricular septal defect was 80 +/- 15% of normal (n = 24), and the value was significantly less than in patients with an intact ventricular septum (91 +/- 11%, n = 47). In all patients with an intact ventricular septum who underwent the one-stage ASO, the valve diameters before and after the ASO were within normal limits, and a significant increase in the pulmonary valve annulus was observed. CONCLUSIONS: These data indicate that not only supravalvular pulmonary stenosis but also pulmonary valvular stenosis due to a small annulus can occur in TGA, especially in patients with a history of pulmonary artery banding and in patients with ventricular septal defect.

Humans↗
PubMed1996

Cardiac anomalies associated with a chromosome 22q11 deletion in patients with conotruncal anomaly face syndrome.

Among 114 cardiac patients with conotruncal anomaly face syndrome and DiGeorge syndrome, 100 patients were found to have a chromosome 22q11 deletion. Those with the deletion included 73 patients with tetralogy of Fallot, 12 with ventricular septal defect, 5 with aortic arch anomalies without intracardiac anomaly, 4 with interrupted aortic arch, 2 with double-outlet right ventricle, 2 with truncus arteriosus, 1 with complete transposition, and 1 with atrial septal defect.

Child, Preschool↗
PubMed1996

Molecular cytogenetic diagnosis of Williams syndrome.

Williams syndrome (WS) is characterized by distinct facial changes, growth deficiency, mental retardation, and congenital heart defect (particularly supravalvular aortic stenosis), associated at times with infantile hypercalcemia. Molecular genetic studies have indicated that hemizygosity at the elastin locus (7q11.23) causes WS. The purpose of this study was to confirm that this regional deletion, involving the elastin locus, is the cause of WS in Japan, and to clarify the correlation between the phenotype and the elastin locus. Thirty-two patients with WS and thirty of their relatives were examined by fluorescent in situ hybridization (FISH), using the WS chromosome region (WSCR) probe. All patients had cardiovascular disease (100%), 30 had typical WS facial changes (94%), 31 had mental retardation or developmental delay (97%), 16 were small-for-date at birth (50%), 14 had short stature (44%), and 13 had dental anomalies (41%). No relatives showed any manifestation of WS. Hemizygosity for a region of 7q11.23, involving the elastin locus, was found in all WS patients, but was not found in the 30 relatives.

Adolescent↗
PubMed1996

Effect of acidosis on contraction, intracellular pH and calcium in the rabbit mesenteric small artery.

The purpose of the present study was to determine the effect of various types of acidosis on vessel diameter, intracellular pH (pHi), and calcium concentration ([Ca2+]i) in a cannulated preparation of the mesenteric arteriole of the rabbit. The effect of acidosis on vessel contraction was also studied in the wire-mounted preparation. In the cannulated preparation, pre-contracted by noradrenaline, hypercapnia caused vasoconstriction and increases in [Ca2+]i. In the wire-mounted preparation pre-contracted by either noradrenaline or high KCl, hypercapnia caused a transient vasoconstriction. In contrast, in the cannulated preparation pre-contracted by high KCl, hypercapnia caused a transient vasorelaxation and decreases in [Ca2+]i. Intracellular acidosis, induced by a NH4Cl prepulse, caused vasoconstriction and increases in [Ca2+]i even in the cannulated preparation pre-contracted by high KCl. The decrease in pHi during hypercapnia was similar to that observed after NH4Cl withdrawal. These data suggest that: (1) the effect of acidosis on vascular tone and [Ca2+]i is different depending upon the type of preparation and the mode of pre-activation, and (2) [Ca2+]i may, at least partly, regulate vascular contraction and relaxation during acidosis.

Acidosis↗
PubMed1996

A congenitally "poor" pulmonary artery is a major reason for exclusion from Fontan operation.

We reviewed the clinical records of 185 patients who were possible candidates for Fontan operation. We did this to clarify whether all patients with suitable anomalies ultimately underwent a Fontan operation. Of the 152 patients with decreased pulmonary blood flow, 38 (26%) did not fulfill the criteria for Fontan operation, and 17 of the 33 patients (52%) with increased pulmonary blood flow (P < 0.01) were excluded as candidates. Of 48 non-candidate survivors, 19 had high pulmonary artery (PA) pressure or resistance and small PA (which we term "poor PA"), 17 had pulmonary hypertension, 6 had a markedly distorted PA, and 6 had severe ventricular dysfunction. A significant proportion of possible candidates with a suitable anomaly ultimately did not undergo a Fontan operation, because of "poor PA", a congenital condition that precluded Fontan operation.

Adolescent↗
PubMed1996

Tetralogy of Fallot with pulmonary atresia associated with chromosome 22q11 deletion.

OBJECTIVES: The purpose of this study was to clarify characteristics of tetralogy of Fallot and pulmonary atresia associated with chromosome 22q11 deletion. BACKGROUND: DiGeorge syndrome and conotruncal anomaly facies syndrome are associated with chromosome 22q11 deletion (hemizygosity). Associated cardiac anomalies include tetralogy of Fallot, truncus arteriosus and interrupted aortic arch. METHODS: Twenty-three patients with tetralogy of Fallot and pulmonary atresia were proved to have chromosome 22q11 deletion with fluorescent in situ hybridization using N25 probe (Oncor). Cardiovascular anomalies were compared with those in 26 patients with tetralogy of Fallot and pulmonary atresia without the deletion. Cardiovascular anomalies were studied with cardiac catheterization, cineangiography and echocardiography. RESULTS: In patients with 22q11 deletion, additional anomalies of the aortic arch, ductus arteriosus and pulmonary artery were more common as follows: right aortic arch (70% with deletion vs. 23% without deletion), high aortic arch reaching third rib (43% vs. 15%), aberrant left subclavian artery (35% vs. 0%), absent ductus arteriosus (83% vs. 46%), major aortopulmonary collateral arteries (91% vs. 50%), absent confluent central pulmonary arteries (48% vs. 4%). CONCLUSIONS: In patients with tetralogy of Fallot and pulmonary atresia, additional anomalies of the aortic arch, ductus arteriosus and pulmonary arteries are more common in patients with than in those without the 22q11 deletion.

Abnormalities, Multiple↗
PubMed1996

Hypertrophic cardiomyopathy in Noonan syndrome.

Noonan syndrome, a well-known multiple congenital anomalies syndrome, is frequently accompanied by cardiovascular diseases including hypertrophic cardiomyopathy (HCM). The incidence of HCM in Noonan syndrome is approximately 20-30% and one-third of cases reveal ventricular outflow obstruction. HCM in Noonan syndrome is occasionally associated with a congenital heart defect, whereas classic HCM seldom accompanies cardiac malformations. Asymmetric septal hypertrophy and symmetric septal hypertrophy (concentric hypertrophy) can be observed both in HCM with Noonan syndrome and in classic HCM, but apical hypertrophy has not been reported in Noonan syndrome yet, although it appears in classic HCM. Congestive heart failure is the major cause of death in patients with HCM in Noonan syndrome, but cases of sudden death have also been reported. The histopathologic findings of ventricular myocardial tissue in HCM with Noonan syndrome are similar to those in classic HCM.

Adolescent↗