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Biomedical subjects

Y Imai

Publications and source records attributed to Y Imai.

At least 721 records · Page 40Linked to original sources
PubMed1993

Growth potentiating activity of endogenous production of interleukin-1 and tumor necrosis factor alpha in blast cells of acute myeloblastic leukemia.

For the optimal growth of clonogenic cells in acute myeloblastic leukemia (AML), several cytokines such as tumor necrosis factor alpha (TNF-alpha), interleukin-1 (IL-1) and IL-6 are required in addition to colony-stimulating factor (CSF), which may be produced by blast cells themselves. In the present study, we addressed the potential role of endogenous production of TNF-alpha and/or IL-1 in the in vitro growth of AML clonogenic cells supported by IL-3. Addition of a specific neutralizing antibody against TNF-alpha (anti-TNF-alpha) to the culture significantly reduced the growth-stimulating effect of IL-3 on the cells in 11 of 14 patients. Simultaneous addition of anti-IL-1 alpha and anti-IL-1 beta also partly affected the growth, although to a much lesser extent when compared to the effect observed with anti-TNF-alpha. In 3 patients, the growth-stimulating effect of IL-3 was completely abrogated by anti-TNF-alpha or a combination of all three antibodies. Constitutive TNF-alpha transcript was observed in 5 patients and TNF-alpha protein was present in culture supernatant. Following in vitro culture, a transient but profound increase in c-fos, c-jun, TNF-alpha and IL-1 beta mRNA levels was observed. Anti-TNF-alpha inhibited the accumulation of TNF-alpha transcript, suggesting that membrane-integrated TNF-alpha may be partly responsible for the induction of TNF-alpha mRNA. It seems likely that the accumulation of these genes occurs through a protein kinase C-independent signaling pathway.

Antibodies↗
PubMed1993

[Evaluation of home blood pressure measurement by a correlation study between home blood pressure and ambulatory blood pressure].

To evaluate the self-measurement of blood pressure at home, a comparative study was performed among home (Home BP), ambulatory (24-hour BP) and office blood pressure in essential hypertensive patients. In all patients, Home BP was self measured by themselves twice a day for a month. 24-hour BP was measured once during the period of self-Home BP measurement. Office BP was measured twice a month. The average of Office BP (147/92 mmHg) and Home BP (145/89 mmHg) were higher than the average of 24 hour BP (131/82 mg). For systolic BP, about two weeks self-measurement of BP at home just after waking elicited a very high correlation between home and average 24-hour BP (r = 0.82), whereas for diastolic BP the r value was moderate (r = 0.61). In patients (n = 22) treated with antihypertensives, furthermore, the correlation coefficient between home and 24-hour BP for systolic BP reached 0.89, which is higher than in all patients (n = 28). The average value of BP measured just after waking at home elicited a higher correlation with the average value of 24-hour BP compared with that measured before going to bed. The results suggest that in essential hypertensive patients who are treated with antihypertensives, to measure BP just after waking for about two weeks at home could help clinicians to evaluate and predict the value of average 24-hour BP.

Adult↗
PubMed1993

LFA-1 expression on exocrine glands as a potential novel marker of malignant disease.

The lymphocyte function associated antigen 1 has been found only on leukocytes and lymphoid tissues; however, the expression of lymphocyte function associated antigen 1 on nonhematopoietic cells has not been reported previously. In this study, immunohistochemical expression of lymphocyte function associated antigen 1 was examined on various tissues from 35 patients with malignant diseases and 36 patients with benign diseases including benign tumors. The expression of lymphocyte function associated antigen 1 was found on various exocrine tissues (eg, gastric glands, bronchial epithelium, alveolar epithelium, duodenal glands, bile ducts, pancreatic acini, and salivary glands) uninvolved by tumor in patients with malignant diseases. Localization of lymphocyte function associated antigen 1 was limited to the exocrine glands and differed from tissue-infiltrating leukocytes. The expression of lymphocyte function associated antigen 1 on exocrine tissues was confirmed in all 35 cases of malignant diseases that were examined. These included a wide spectrum of carcinomas and hematopoietic tumors. In contrast, none of the 36 cases with benign diseases examined expressed lymphocyte function associated antigen 1 on their exocrine glands. These results indicate a strong correlation between lymphocyte function associated antigen 1 expression on exocrine glands and malignant disease. The expression of lymphocyte function associated antigen 1 on nonhematopoietic cells was further confirmed in nonhematopoietic cell lines. Two of 19 nonhematopoietic cell lines (MKN45 and PANC-1; exocrine gland cell lines) examined expressed lymphocyte function associated antigen 1 on both cell surface and cytoplasm. These results suggested that immunohistochemically defined lymphocyte function associated antigen 1 molecules on nontumorous exocrine gland cells are a potential marker for the presence of malignant diseases.

Antibodies, Monoclonal↗
PubMed1993

[The limits for modified Fontan operations with AV valve regurgitation--the effect of AV valve regurgitation on the Fontan operation for single ventricle].

We performed a modified Fontan operation on 14 patients of single ventricle with AV valve regurgitation (single right ventricle: SRV 8, single left ventricle: SLV 6) until 1990. During the same period, 41 patients of single ventricle without AV valve regurgitation underwent the modified Fontan operation. To evaluate the effect of AV valve regurgitation on the Fontan operation, operative mortality, ventricular and pulmonary functions were compared between two groups. No significant differences were observed in operative mortality (7% vs 12%). There were also no significant differences of post-operative cardiac index (mean 2.6 L/min/m2 vs 2.6 L/min/m2), pulmonary vascular resistance (mean 2.3 U.m2 vs 2.2 U.m2) and preoperative ejection fraction (mean 54% vs 62%) between two groups. Therefore, the hemodynamic status of single ventricle following the Fontan operation remained almost unchanged irrespective of the presence of AV valve regurgitation. This suggested that AV valve regurgitation was not itself a contraindication of the Fontan operation, if the correct indices and time for operation were selected.

Heart Atria↗
PubMed1993

[Successful two-staged Jatene operation for severe right ventricular dysfunction and tricuspid regurgitation after Senning operation--a case report].

We report a seven-year-old boy who underwent a successful Jatene procedure seven years after Senning procedure. The modified Senning operation was performed for the treatment of transposition of the great arteries with intact ventricular septum at three years of age. However, he gradually showed the progressive right ventricular failure with tricuspid regurgitation after operation. When he was referred to our hospital, he was in severe right ventricular failure and showed massive tricuspid regurgitation simultaneously with the moderate degree of left ventricular failure. Staged pulmonary artery banding was applied to prepare the left ventricle for Jatene procedure in spite of the presence of left ventricular failure. The systolic pressure ratio of left ventricle to right ventricle was elevated to 0.91 by this banding although the left ventricular ejection fraction decreased from 43% to 30%. And Jatene procedure was successfully performed after three months of preparation period. Catheterization study after Jatene procedure revealed improved right and left ventricular functions with decrease of tricuspid regurgitation. We conclude that the Jatene procedure should be an ideal alternative in patient with right ventricular failure and/or tricuspid regurgitation after an atrial switch operation; the left ventricle could be prepared by an effective pulmonary banding in most instances.

Child↗
PubMed1993

[Measurement of cardiac output by Doppler echocardiography: clinical validation in pediatric patients after open heart surgery].

We compared the cardiac output obtained by pulsed Doppler echocardiography (COPW) with simultaneous thermodilution measurements (COTD) in 13 children for 33 times after open heart surgery. Good correlation (r = 0.84, slope = 1.15) of cardiac output was obtained when direct measurements of aortic diameter during operation were used in the calculations. Cardiac output was overestimated (r = 0.89, slope = 1.42) when 2 DE measurements of aortic diameter were used. Nineteen measurements of 8 VSD patients revealed good correlation (r = 0.89, slope 0.85) using direct measurement of aortic diameter, whereas 14 measurements of TOF patients showed somewhat overestimation of cardiac output (r = 0.90, slope = 1.31). In serial determinations, percent change change in COPW well correlated with COTD (r = 0.75, slope = 1.08). We conclude that accurate cardiac output can be obtained by pulsed Doppler echocardiography after pediatric cardiac surgery by measuring aortic diameter directly in operation room. Accuracy in percent change in cardiac output proved that COPW is useful especially in hemodynamically unstable patients after pediatric cardiac surgery.

Age Factors↗
PubMed1993

[A case report of pulmonary valve blood cyst].

A six-year-old boy with pulmonary stenosis was hospitalized in order to examine the cause of pulmonary stenosis. The right-ventriculography showed a large shadow defect in the right ventricular outflow tract. But the echocardiography showed the cystic tumor, which was covered with thin wall and had echo-free space in it, in the right ventricular outflow tract. We made a diagnosis of pulmonary blood cyst. After cardiopulmonary bypass was established, the main pulmonary artery was incised longitudinally. There were two blood cysts at the left pulmonary cusp which were 1.5 x 1.5 cm and 0.7 x 0.5 cm in size. The cysts were resected and the pulmonary cusp was plicated. Histologically, the wall of the cysts was consisted thick valvular tissues. No pulmonary valve pressure gradient was detected with the echocardiography following the operation.

Child↗
PubMed1993

[Biventricular repair with a modified Glenn shunt for the hypoplastic right ventricle].

Between 1982 and 1990, 14 patients with small right ventricle underwent biventricular repair with a modified Glenn shunt. The patients consisted of 8 cases of pulmonary atresia and intact ventricular septum, 2 with pulmonary stenosis and intact ventricular septum, 3 with tetralogy of Fallot, 1 with pulmonary atresia and straddling tricuspid valve. Nine patients had one or more prior preliminary palliative procedures. Repairs consisted of a modified Glenn shunt and closure of the intracardiac and extracardiac shunt, with right ventricular outflow reconstruction in 13, and pulmonary valvotomy in 1. In nine patients superior vena cava was not ligated. There was one operative death (7%). Preoperative RVEDV ranged from 19 to 70% of normal with a mean of 36.1% of normal. Preoperative pulmonary resistance ranged from 1.6 to 5.3 unit with a mean of 2.8 unit. Preoperative PA index ranged from 102 to 444 mm2/m2 with a mean of 234.3 mm2/m2. No patients died later. Follow-up 2 to 9 year after operation showed that 9 patients were in the New York Heart Association class I and 4 were in class II. Our experience shows that this procedure can be safely done for patients, who have hypoplastic right ventricle smaller than 40% of normal and are not candidate for Fontan procedure because of high pulmonary vascular resistance and inadequate size of pulmonary artery. In this procedure a modified Glenn shunt without ligation of SVC may effectively reduce the volume overload on the right ventricle.

Adolescent↗
PubMed1993

[Surgical treatment of double orifice mitral valve in atrioventricular septal defect].

Ten patients with double orifice mitral valve and atrioventricular septal defect (AVSD) were examined. There were four cases with incomplete type, three with intermediate type and three with complete type AVSD. All patients with incomplete type AVSD were doing well after the mitral cleft repair, Leaving the accessory orifice untouched. Various valve repair procedures and prosthetic valve replacement were performed in the patients with intermediate and complete types of AVSD with left-sided atrioventricular valve regurgitation. There were three operative deaths, which included one patient with the intermediate type and two with the complete type. All of them were one-month old babies and were operated on emergency. Their general operative findings were hypoplasia of the common atrioventricular valve leaflets, abnormal attachment of the chorda tendineae and papillary muscle dysplasia. These findings increased the difficulty of the valve plasty to control mitral regurgitation.

Child↗
PubMed1993

[Surgical repair in hearts with univentricular atrioventricular connection and subaortic stenosis].

Between 1986 and 1990, fourteen patients with univentricular atrioventricular connection and subaortic stenosis underwent surgical treatment. The patients consisted of 7 cases of double inlet left ventricle, 4 with double inlet right ventricle, 3 with tricuspid atresia. The palliative operation was performed in 6 infants ranging in age from 17 days to 6 months. Four patients with mild subaortic stenosis underwent pulmonary artery banding, in two patients this was combined with repair of coarctation of the aorta. Two patients with severe subaortic stenosis underwent the Norwood operation. There were no operative deaths. One of two patients who underwent the Fontan operation 2 years after the Norwood operation died later. The definitive operation was performed in 8 children ranging in age from 4 to 11 years. Five of these 8 patients had previous pulmonary artery banding. Five children with double inlet left ventricle underwent septation combined with enlargement of bulboventricular foramen. Postoperatively all remained in sinus rhythm and had no pressure gradient between Aorta and left ventricle. A Fontan operation combined with a Damus operation was performed in 2 children, 1 of double inlet right ventricle and 1 of tricuspid atresia. In both cases, postoperative angiogram showed no pulmonary incompetence. One patient underwent enlargement of bulboventricular foramen after a Fontan operation. All survived later. Young infants and neonates with severe subaortic stenosis can survive by the Norwood operation. Infants with mild subaortic stenosis, although can survive by pulmonary artery banding, should be closely followed for the development of subaortic stenosis. For relief of subaortic stenosis, enlargement of bulboventricular foramen may be effective in septation.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Coarctation↗
PubMed1993

Anatomic correction of atrioventricular discordance.

Between June 1989 and September 1991, 11 patients underwent anatomic correction of atrioventricular discordance. Their ages at operation ranged from 1 to 11 years (mean 6.7 years) and their weights ranged from 7.1 to 31.8 kg (mean 19.1 kg). Atrial situs was solitus in nine and inversus in two patients. Ventriculoarterial connection was discordant in five and was double-outlet right ventricle in six patients. Associated congenital heart defects were seen in all patients, including 10 with ventricular septal defect, eight with atrial septal defect, nine with pulmonary stenosis or pulmonary atresia, seven with tricuspid regurgitation, and four with mitral regurgitation. Five patients had prior Blalock-Taussig shunts. One patient with an intact ventricular septum had repeated pulmonary banding. Anatomic correction consisted of the Senning and Rastelli procedures in three, the Mustard and Rastelli procedures in five, the Senning and arterial switch operations in two, and the Mustard and arterial switch operations in one patient. In addition, mitral valvuloplasty or valvular annuloplasty was performed in three patients. We did not encounter kinking or torsion of the translocated coronary arteries in our three patients with the arterial switch operation. There was one surgical death. The other patients pursued satisfactory postoperative courses (mean follow-up period of 12.6 months). We recommend that anatomic correction for atrioventricular discordance should be indicated, especially in patients with any sign of systemic right ventricular dysfunction.

Cardiac Surgical Procedures↗
PubMed1993

Evaluation of structural change in diffuse liver disease with frequency domain analysis of ultrasound.

To evaluate structural changes in diffuse liver disease, frequency domain analysis was applied to ultrasonic signals from the liver. We assumed that liver tissue is a collection of semiregularly arrayed small scatterers of ultrasound. We applied cepstral analysis to the ultrasonic waveforms and evaluated the periodicity of scalloping of the power spectrum caused by an interference effect among liver scatterers of a given spacing. Patients with liver conditions involving nonspecific change (n = 6), chronic hepatitis (n = 11), cirrhosis (n = 7) or fatty liver (n = 6) were examined. One hundred ultrasonic signals were obtained noninvasively with a 3.5-MHz transducer, and the space among scatterers was calculated for each signal using cepstrum analysis. Two statistical parameters, mode and kurtosis, were determined from the distribution of the space among scatterers for each patient; these parameters were compared with the histological findings in the liver. Space among scatterers kurtosis decreased with progress of liver fibrosis, and space among scatterers mode increased in cirrhosis. Neither space among scatterers kurtosis nor space among scatterers mode was affected by pathological fat in the liver. These results suggest that we can evaluate fibrotic changes in diffuse liver disease and that we can also noninvasively discriminate diffuse fibrotic liver disease from fatty liver.

Chronic Disease↗
PubMed1993

[Definitive repair for double inlet ventricle and common atrio-ventricular valve].

From 1982 through 1990, 13 patients with double inlet ventricle and common atrio-ventricular valve underwent definitive cardiac surgery. Nine patients simultaneously had anomalous systemic venous connection and 4 had anomalous pulmonary venous connection. One patient with double inlet left ventricle underwent a successful partition of ventricle and atrio-ventricular valve. All other 12 patients underwent a Fontan operation, which utilized different techniques to deal with various forms of anomalous systemic and pulmonary venous connection. Four patients with common atrioventricular valve regurgitation underwent a Fontan operation combined with a concomitant circular annuloplasty of atrio-ventricular valve. In all 4 patients, the degree of regurgitation decreased postoperatively. There was one operative death (mortality 7.7%). Most of patients with double inlet ventricle and common atrio-ventricular valve now are considered to be suitable not for partition but for the Fontan operation. Because of the complexity of anatomic variables, however, the repair of anomalous systemic or pulmonary venous connections in conjunction with the Fontan operation requires an individualised plan in each patient to provide unobstructed systemic and pulmonary venous pathways. We think that a circular annuloplasty could effectively decrease the degree of atrio-ventricular valve regurgitation in most cases.

Adolescent↗
PubMed1992

Enhanced production of platelet-activating factor in stimulated rat leukocytes pretreated with triacsin C, A novel acyl-coA synthetase inhibitor.

Triacsin C, a product of Streptmyces sp. SK-1894, was previously reported as an inhibitor of long chain acyl-CoA synthetase. Pretreatment with triacsin C (500 nM) for 1h enhanced production of platelet-activating factor in rat neutrophils, followed by stimulation with A23187 or fMLP. Amount of lyso-PAF was also augumented. Triacsin C alone did not increase PAF content and did not modulate enzymatic activities of acytransferase, cholinephosphotransferase, acetylhydrolase, acetyltransferase or phospholipase A2. These results suggest that triacsin C might enhance supply of substrate for PAF synthesis, i.e. accumulation of lyso-PAF by interfering reacylation pathway.

Acylation↗
PubMed1992

Cyclosporin A protects pancreatic islet cells from nitric oxide-dependent macrophage cytotoxicity.

It has been shown earlier in an in-vitro model of inflammatory islet cell death that activated macrophages lyse islet cells via the release of nitric oxide. Here we report that cyclosporin A suppresses macrophage cytotoxicity. Control experiments showed that the immunosuppressive drug does not improve the defences of islet cells against nitric oxide but inhibits the release of nitric oxide from LPS-stimulated macrophages. This property of cyclosporin A may contribute to the preservation of beta cell function seen in cyclosporin A-treated patients with recent onset type I diabetes.

Animals↗
PubMed1992

Generation of microglial cell lines by transfection with simian virus 40 large T gene.

Microglial cells, which were isolated from a primary culture of neonatal rat brain, were transfected with temperature-sensitive simian virus 40 (SV40) large T gene by the calcium phosphate precipitation method. Four weeks after transfection, several colonies were generated, and cloned cells were characterized. One of the cloned cells (RBM129) proliferated actively at 37 degrees C and the dividing rate was significantly decreased at 40.5 degrees C. The expression of large T antigen was detected by western blotting in cells incubated at both 37 degrees C and 40.5 degrees C. The cell line showed high activity of non-specific esterase, isolectin B4 binding and phagocytosis. Also the cells were stained by ED 1 monoclonal antibody. These results indicate that these cells were derived from rat brain microglia, and immortalized by large T gene.

Animals↗