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Biomedical subjects

M Nakazawa

Publications and source records attributed to M Nakazawa.

At least 253 records · Page 14Linked to original sources

Ventricular function after anatomic repair in patients with atrioventricular discordance.

Since June 1989, 18 patients with atrioventricular discordant anomalies under 15 years of age underwent anatomic correction, or double switch operation, with 2 hospital deaths (11%). Ages ranged from 1 year 4 months to 12 years (mean 7.2 years) and body weights ranged from 7.1 to 32.5 kg (mean 20.1 kg) at operation. Visceral situs was solitus in 12 and inversus in 6. Ventriculoarterial connection was discordant in 4 and double-outlet in 14. All had associated congenital cardiac anomalies consisting of ventricular septal defect in 17, atrial septal defect in 9, pulmonary atresia in 10, pulmonary stenosis in 6, systemic tricuspid regurgitation in 9, mitral regurgitation in 6, bilateral superior venae cavae in 6, patent ductus arteriosus in 6, Wolff-Parkinson-White syndrome in 2, and congenital atrioventricular block in 1. Previous palliation had been performed 19 times in 11 patients including systemic-pulmonary shunts in 10 patients and pulmonary banding in 1 patient. Anatomic correction consisted in the Mustard procedure in 12 or the Senning procedure in 6 at the atrial level and in external conduit repair in 14, arterial switch operations in 3, or direct anastomosis between the pulmonary artery and right ventricle in 1 at the ventriculoarterial level. The arterial switch operation was indicated in patients with a normal pulmonary valve, and external conduit repair was indicated for patients with pulmonic stenosis or atresia. Anatomic right ventricular end-diastolic volume showed significant reduction from 122.2% +/- 46.3% of normal to 78.8% +/- 24.0%, mainly owing to unloading of the ventricle after the operation (p < 0.0003). Right ventricular ejection fraction remained unchanged (56% +/- 8% to 56% +/- 6%). Anatomic left ventricular end-diastolic volume and left ventricular ejection fraction remained unchanged before and after the operation: volume 134.6% +/- 50.0% of normal to 127.3% +/- 32.8% and ejection fraction from 61% +/- 8% to 56% +/- 8%. Cardiac index averaged 3.1 +/- 0.5 L/min per square meter after the operation. The double switch operation is best indicated in patients with atrioventricular discordance associated with systemic tricuspid regurgitation and/or with poor systemic right ventricular function.

Cardiac Output↗

[Differential reactivities of three kinds of carbon dioxide absorbents with sevoflurane].

The differential reactivities of three kinds of carbon dioxide absorbents, Soda lime, Soda lime A, and Baralyme with sevoflurane were investigated. Sevoflurane was made to react with each carbon dioxide absorbents in a glass vial or in a closed system under administration of carbon dioxide. Glass vials were kept at 55 degrees C and 70 degrees C, and three kinds of carbon dioxide absorbents were compared regarding their reactivity under each temperature. In a closed system, we also monitored the temperature of glass container which was filled with each carbon dioxide absorbent. In a glass vial, the highest reactivity of sevoflurane was found with Baralyme. Although Soda lime A decomposed sevoflurane less than Baralyme or Soda lime in glass vial, the highest reactivity of sevoflurane in a closed system was found with Soda lime A. On the other hand, Soda lime A increased the temperature of glass container most. As increasing temperature tends to promote reaction, the possibility that the high temperature of the glass container contributes to the reactivity of sevoflurane with carbon dioxide absorbents exists. These results suggest that the highest reactivity of Soda lime A with sevoflurane was caused by the highest temperature of glass container although its chemical composition makes it most reactive with sevoflurane than the others.

Calcium Compounds↗

Primary gastric T-cell lymphoma. Morphological and immunohistochemical studies of two cases.

Primary T-cell lymphoma of the stomach is very rare. We report two cases of primary gastric T-cell lymphoma, one of which had a morphological appearance and a phenotype that were similar to those of node-based peripheral T-cell lymphoma. The other case was related to human T-cell lymphotropic virus type I and displayed a feature of lymphoma cell pleomorphism. The lymphoma cells were both positive for Ki-1/CD30.

Blotting, Southern↗

Adenoid cystic carcinoma with morphological diversities--report of a case and discussion of the morphologic and immunohistochemical features.

A case of adenoid cystic carcinoma (ACC) with polymorphous features and an unknown differential diagnosis was presented. It appeared, without any pain, in the right maxillary sinus of a 47 year-old man. A variety of histopathological patterns were found, including glandular, cribriform, tubular and solid ones. However, the typical features of ACC, such as cribriform pattern associated with pseudocyst and tubular formations were rather scarce. A single cell strand appearance, so-called "Indian file arrangement", and papillary cystic formation were also noted, which are often associated with polymorphous low-grade adenocarcinoma (PLGA). Immunohistochemistries of EMA, CEA and musclespecific actin showed also similar staining patterns to those of PLGA in some areas. Our case could not be regarded as PLGA; but this case with features of PLGA as well as those of ACC might suggest an entity of transitional type between ACC and PLGA.

Adenocarcinoma↗

Ischemic changes in myocardial ionic contents of the isolated perfused rat hearts as studied by NMR.

Using 31P-, 23Na- and 39K-NMR, we assessed ischemic changes in high energy phosphates and ion contents of isolated perfused rat hearts continuously and systematically. To discriminate intra- and extracellular Na+, a shift reagent (Dy(TTHA)3-) was used in 23Na-NMR study. In 39K-NMR study, the extracellular K+ signal was suppressed by inversion recovery pulse sequence in order to obtain intracellular K+ signal without using shift reagents. During the early period of ischemia, increases in intracellular Na+ and inorganic phosphate (Pi) were observed in addition to the well-documented decreases in creatine phosphate and ATP and a fall of intracellular pH, suggesting an augmented operation of Na(+)-H+ exchange triggered by a fall of the intracellular pH resulted from breakdown of ATP. At around 15 min of ischemia, a second larger increase in intracellular Na+ and a decrease in intracellular K+ were observed in association with a second increase in Pi. This was accompanied by an abrupt rise of the ventricular end-diastolic pressure. As there was a depletion of ATP at this time, the increase in intracellular Na+ and associated decrease in intracellular K+ may be explained by inhibition of the Na(+)-K+ ATPase due to the depletion of ATP. A longer observation with 31P-NMR revealed a second phosphate peak (at lower magnetic field to ordinary Pi peak) which increased its intensity as ischemic time lengthened. The pH of this 2nd peak changed in parallel with the changes in pH of the bathing solution, indicating the appearance of a compartment whose hydrogen concentration is in equilibrium with that of the external compartment. Thus, the peak could be used as an index of irreversible membrane damage of the myocardium.

Adenosine Triphosphate↗

The prognostic significance of DNA ploidy for neuroblastoma.

Flow cytometric DNA analysis was performed on 45 neuroblastomas in order to evaluate the prognostic significance of DNA ploidy. The DNA ploidy was diploid in 14 and aneuploid in 31 neuroblastomas and did not correlate with the conventional prognostic variables such as age, Evans' stage, or the primary site of the tumor. The survival of 31 patients with aneuploid tumors was comparable to that of 14 patients with diploid tumors. On the other hand, DNA aneuploidy was associated with a decreased long-term survival in 21 patients older than 24 months of age at the time of operation, and in 27 patients with advanced disease at Evans' stage III or IV. These results suggest that more intensive and longer-term postoperative chemotherapy is necessary for neuroblastoma patients older than 24 months of age, or for those with advanced disease if they have aneuploid tumors.

Age Factors↗

Right aortic arch with aberrant retroesophageal innominate artery: a report of 2 cases and review of the literature.

We describe two patients of right aortic arch associated with aberrant retroesophageal innominate artery. One case was associated with tetralogy of Fallot and a tortuous left common carotid artery originating from the retroesophageal innominate artery. Tetralogy of Fallot associated with this kind of aortic arch anomaly has never before been reported. The other case was associated with a perimembranous ventricular septal defect. Symptoms such as dyspnea, dysphagia and recurrent respiratory infection due to the compression by the vascular anomaly were not noted in these two cases. The morphological findings are indicative of a double aortic arch with an interruption of the left arch proximal to the common carotid artery.

Aorta, Thoracic↗

Balloon angioplasty for postoperative pulmonary artery stenosis in transposition of the great arteries.

OBJECTIVES: This study was designed to assess the success rate and determinants of success or failure of balloon angioplasty for postoperative pulmonary stenosis in patients with transposition of the great arteries. BACKGROUND: Previous reports have suggested that pulmonary stenosis that develops after the arterial switch operation is not likely to be dilated. METHODS: Twenty-eight patients with transposition of the great arteries underwent 39 balloon angioplasty procedures after the arterial switch operation. The mean age at dilation was 4.5 +/- 2.2 years (range 0.7 to 9.8), and the interval between operation and balloon dilation was 3.6 +/- 1.8 years. The criterion of successful dilation was a > or = 50% increase in predilation diameter or a > or = 50% decrease in predilation pressure gradient. If the right ventricular/aortic pressure ratio decreased by > or = 0.2, so that the ratio became < 0.68, reoperation was thought to be not indicated. RESULTS: The success rate of balloon angioplasty for pulmonary artery stenosis was 51% (20 of 39 dilations). The mean age at dilation in the group with successful dilation (3.6 years) was significantly younger than that in the group with unsuccessful dilation (5.4 years). The interval between operation and dilation in the successful dilation group (2.4 years) was significantly less than that in the unsuccessful dilation group (4.6 years). In 13 patients who underwent balloon angioplasty < 3.5 years after operation, balloon dilation was successful in 92%. The balloon/artery ratio was significantly greater in the successful than in the unsuccessful dilation group. A right ventricular/aortic pressure ratio > or = 0.68 was observed in 20 patients, and reoperation was not indicated in 10 patients (50%). There was no death, but one pulmonary artery rupture that did not require surgical intervention occurred. Aneurysmal dilation of the pulmonary artery was observed in three patients. CONCLUSIONS: These data indicate that although the success rate of balloon angioplasty for pulmonary artery stenosis after the arterial switch operation is low (approximately 50%), balloon angioplasty can be the first therapeutic choice owing to the low complication rate and the potential benefit of the procedure. The success rate can be high if angioplasty is performed < 3.5 years after operation and a balloon of adequate size is used.

Age Factors↗

Huge facial nerve neuroma: a case report.

A case of huge facial nerve neuroma was reported. The patient was a 59-year-old woman who had 5 years' history of right facial paralysis. A CT study with contrast medium showed extensive destruction of the right temporal bone including the semicircular canals, and with protrusion of the tumor into the cerebello-pontine angle. CT findings with contrast enhancement and MRI suggested a neuroma and its origin. The operation confirmed that the tumor arose from the vertical portion of the facial nerve. Previous papers dealing with this kind of tumor were reviewed to delineate clinical characteristics for diagnosis and treatment of facial nerve neuroma.

Ear, Inner↗

Effects of spiraprilat, an angiotensin-converting enzyme inhibitor, on anesthetized dogs in a new model of acute left ventricular failure.

Spiraprilat, a new angiotensin-converting enzyme (ACE) inhibitor, was compared with enalaprilat for its ability to improve left ventricular (LV) function and metabolism in anesthetized open-chest dogs with a new model of acute LV failure (ALVF) induced by embolization of the left coronary artery with 50 microns plastic microspheres followed by intravenous (i.v.) infusion of methoxamine. With this procedure, LV end-diastolic pressure (LVEDP) increased from 4.2 +/- 0.7 to 12.8 +/- 1.3 mm Hg and remained at approximately 12 mm Hg throughout the experiment. Cardiac output (CO) decreased from 1.25 +/- 0.12 to 0.79 +/- 0.06 and 0.55 +/- 0.02 L/min at 30 and 90 min after methoxamine infusion, respectively. LVdP/dtmax and dP/dt/P decreased, while total peripheral resistance (TPR) increased. These hemodynamic changes indicated establishment of stable ALVF of a moderate degree. Moreover, decreases in myocardial lactate consumption and contents of creatine phosphate in the myocardium indicated the existence of moderate ischemia. The new ACE inhibitor, spiraprilat, as well as enalaprilat (30 micrograms/kg i.v.) effectively decreased mean aortic pressure (30%), LVEDP (20%), and TPR (30%) and increased stroke volume (SV) CO, and dP/dt/P. Both agents decreased myocardial oxygen consumption (20%) and caused a significant increase in myocardial creatine phosphate contents. These data indicate that the beneficial effects of both inhibitors extended not only to LV function but also to myocardial energy metabolism in ALVF.

Adenosine Triphosphate↗

HTLV-I, HIV-I, and hepatitis B and C viruses in Western Province, Papua New Guinea: a serological survey.

Seven hundred and twenty-three serum samples from individuals in 13 Gidra-speaking villages in Western Province, Papua New Guinea were tested for evidence of infection with human T-lymphotropic virus type I (HTLV-I), human immunodeficiency virus type I (HIV-I), hepatitis B virus (HBV) and hepatitis C virus (HCV). No samples were positive for antibodies to HIV-I. Antibodies to HTLV-I were found in 13 samples (1.8%), HBV surface antigens (HBsAg) were found in 86 samples (11.9%), and antibodies to HCV were found in 30 samples (4.1%). Six (46.2%) of 13 HTLV-I positive samples were positive for HCV or HBsAg. The seropositive rate varied in different villages and the incidence of HTLV-I and HCV was higher in coastal and riverine areas than inland.

Female↗

Dissociation of specific and total IgE antibody responses following repeated low-level infections with Nippostrongylus brasiliensis in rats.

IgE, IgG and mast cell responses were studied in rats infected weekly with 10 larvae of Nippostrongylus brasiliensis (NB). Worm recovery at 8 weeks of repeated infections was six-fold greater than that of a single infection with 10 larvae, suggesting the accumulation of worms during the repeated infections. Total serum IgE was increased after 2 weeks of infection, and further increased after repeated infections: at 6 weeks of infection the level was four to six times higher than that after a single infection. Anti-NB IgG1 levels were also significantly higher after repeated infections than after a single infection. On the other hand, there was no significant difference in the level of anti-NB IgE between single and repeated infections, as determined by ELISA, as well as by passive cutaneous anaphylaxis (PCA) reaction. Mastocytosis was induced in the small intestine after both single and repeated infections, but the levels did not differ between the two. These results indicate that total IgE and specific IgG1 production are augmented by repeated helminth infections, but specific IgE and mast cell responses are not. This pattern of response may minimize the development of IgE-dependent hypersensitivity reactions with repeated helminth infections.

Animals↗

Visual outcome after vitrectomy for diabetic retinopathy. A five-year follow-up.

For 5 years after surgery we measured visual acuity in 56 eyes that had undergone pars plana vitrectomy for proliferative diabetic retinopathy. A total of 44.7% eyes maintained improved visual outcome, 19.6% had unchanged visual acuity, and 35.7% were considered failures, as compared to preoperative measurements. Visual results obtained from each patient's visual acuity measured at 3 months, 6 months, 1 year, and 3 years after surgery were statistically compared with that obtained from the visual acuity at 5 years using the chi 2 test. Results showed that visual results recorded at 3 months and 6 months were significantly different from that recorded at the 5-year follow-up (p < 0.02, respectively). We found a tendency for the visual acuity to change during the initial 6 months after surgery and to stabilize by 1 year. Further analysis showed that the initial instability was due to the presence of preoperative retinal detachment. Postoperative visual functions also worsened with complications such as postoperative retinal detachment, glaucoma, and cataract formation.

Adult↗

In vitro effects of the new calcium antagonist lacidipine.

The effects of lacidipine (LC), a new dihydropyridine calcium antagonist, were studied in comparison with those of nifedipine (NF) in isolated arteries of the dog (DG-AR) and isolated aorta (GP-AO), left and right atria (GP-LA, GP-RA) and ventricular papillary muscles (GP-PM) of the guinea pig. In DG-AR precontracted with high K+, LC and NF produced a concentration-dependent relaxation. The relaxant effect of LC was most potent in the basilar artery. The calcium antagonistic effects of LC was 8.7 and 2.1 times more potent than those of NF, in GP-AO and GP-LA, respectively. Thus, LC was about 4 times more selective towards vascular smooth muscles than NF. The negative chronotropic effects in GP-RA and the negative inotropic effect in GP-PM of NF were more pronounced than those of LC. NF was more potent in inhibiting the action potential of GP-PM than LC both in normal polarized and depolarized conditions. The effects of LC were long-lasting. These results suggest that LC is a potent, highly vascular-selective calcium antagonist with little cardiodepressant effects and as such may be suitable for the treatment of hypertension.

Animals↗

An occurrence of equine transport pneumonia caused by mixed infection with Pasteurella caballi, Streptococcus suis and Streptococcus zooepidemicus.

An acute death occurred in a racehorse with pneumonia after long-distance transportation in December, 1990. Pasteurella caballi, Streptococcus suis and Streptococcus zooepidemicus were isolated from the lung at high rate. Specific antigens of these bacteria were also demonstrated immunohistologically in the pneumonic lesion. These findings indicated that the disease is equine transport pneumonia caused by a mixed infection of the three bacterial species. This is the first report on the isolation of P. caballi and S. suis from a racehorse in Japan.

Animals↗