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Biomedical subjects

K Sawatari

Publications and source records attributed to K Sawatari.

At least 19 recordsLinked to original sources
PubMed2001

Relationships between chemical structures and mutagenicity: a preliminary survey for a database of mutagenicity test results of new work place chemicals.

A database of mutagenicity test results of new chemicals has been developed. Based on the amendment of the Industrial Safety and Health Law (ISHL) in 1979, manufacturers and importers in Japan are required to register any new work place chemicals with bacterial mutagenicity test results. At present more than ten thousand substances have been examined. We have surveyed correlations between 44 substructures and mutagenicity in 2,857 ISHL data as well as in 1,207 National Toxicology Program data as a preliminary analysis. The percentages of the mutagenic compounds were calculated. High percentages were found for electrophilic reagents such as epoxides (63%), aromatic nitro compounds (49%) and primary alkyl monohalides (46%). 71% of peroxides was found to be mutagenic. The results suggest that several types of reactions such as nucleophilic substitution reaction, nitrenium cation reaction and radical reaction are included in the process of the mutagenic alterations of DNA.

Databases, Factual↗
PubMed2000

[An imported case of primary pulmonary coccidioidomycosis].

Coccidioides immitis is a causative agent of coccidioidomycosis, which is one of the most dreadful mycosis because of its infectious and pathogenic nature. The endemic areas are in the southwestern parts of the United States and other semi-arid regions throughout the Western Hemisphere. During the early 1990s, the incidence of coccidioidomycosis in California increased dramatically, resulting in recognition for this mycosis as a reemerging infectious disease in the United States. The patients included a large number of non-informed visitors from non-endemic countries. Our report is on an imported case of primary pulmonary coccidioidomycosis. A 35-year-old Japanese male, after living in the United States for nine months, suffered from a combination of headache and fever. He was given a serological examination, and a chest radiograph in Phoenix, Arizona in the United States and was diagnosed as coccidioidomycosis. A daily dosage of 400 mg of fluconazole was administered and he returned to Japan. His headache and skin rash persisted and he was admitted to our hospital to evaluate the severity of his disease. There were no fungi cultured from neither bronchoalveolar nor cerebrospinal fluid and he was discharged. The patient had been treated with fluconazole and his symptoms, high-resolution CT and serological antibody titer were monitored. After 18 months, his clinical and radiological evolution was favorable and his serological IgM titer was below its sensitivity medication was stopped and there were no relapses.

Adult↗
PubMed1998

[A study of virulence factors produced by MRSA strains isolated from blood samples].

Toxic shock syndrome toxin-1 (TSST-1) and enterotoxins are important virulence factors produced by Staphylococcus aureus. It is reported that these toxins are associated with septic shock and toxic shock syndrome. We investigated the toxin production and coagulase types of 701 MRSA strains isolated in Sasebo City General Hospital between 1994 and 1996 TSST-1 or/and enterotoxins were detected in 67% of all MRSA strains, and those were detected in 88% of MRSA strains isolated from blood samples. 45% of all MRSA strains produced both TSST-1 and enterotoxin C, and 70% of MRSA strains obtained from blood produced those toxins. Frequency of TSST-1 or/and enterotoxin production by MRSA strains isolated from blood samples was significantly higher than that by MRSA strains isolated from urine and pharynx (p < 0.05), and frequency of both TSST-1 and enterotoxin C production by MRSA isolates from blood was significantly higher than that by MRSA strains isolated from pharyngeal sample (p < 0.05). This study indicated that investigation of virulence factors produced by MRSA might give the useful information on prevention and treatment of MRSA infection.

Bacteremia↗
PubMed1997

Lung lesions induced by intratracheal instillation of nickel fumes and nickeloxide powder in rats.

Acute and subacute lung toxicity of nickel fumes was examined by single and repeated intratracheal instillation of nickel fumes and Ni2O3 and NiO powders in the rat. LD50 of nickel fumes was estimated as 38.2 mg/kg body weight (b.w.) according to the method of Litchfield and Wilcoxon. Body weight gain was retarded as in the order of a single dose of 13.0 mg Ni2O3/kg > 14.3 mg nickel fumes/kg > 1.4 mg Ni2O3/kg > 13.0 mg NiO/kg b.w. compared to controls. The histopathological changes in the lungs of the 14.3 mg nickel fumes/kg-dosed rats were milder than those induced by administration of 13.0 mg Ni2O3/kg but severer than those induced by administration of 1.4 mg Ni2O3/kg b.w. A single administration of NiO powder did not produce any histopathological effects on the lungs. The repeated administration of nickel fumes produced persistent edema and proteinosis in the alveoli. The nickel fumes, which were chemically composed of 97% of NiO and 3% of Ni2O3, were very fine particles about 5-10 nm in diameter, partly aggregated into larger particles and spherical particles about 0.6 micron in diameter. Solubility in distilled water and saline was in the order of nickel fumes > Ni2O3 powder > > NiO powder. It was suggested that a toxic Ni2O3 component and very fine particles of nickel fumes are involved in the acute lung toxicity of nickel fumes. The epithelial injury induced by reactive oxygen and hydroxy radicals, which would be produced during the process of conversion of Ni(III) to Ni(II) and phagocytosis of nickel fumes by macrophages and polymorphonuclear cells, are presumed to be involved in the pathogenesis of nickel fumes-induced lung lesion.

Aerosols↗
PubMed1996

[Invasive pulmonary aspergillosis caused by aspiration of polluted water after nearly drowning].

A 21-year-old male nearly drowned in a reservoir by a traffic accident and he aspirated a large mount of polluted water containing Aspergillus fumigatus. On admission to our hospital, he was alert but cyanotic. Chest rentogenograms showed scatter infiltrative shadows in bilateral lung fields. We administered methylpredonizolon and antimicrobial agents immediately because of respiratory failure which was rapidly progressing. During the following six days, infiltrative shadows diminished but multiple nodular shadows in both lung fields appeared. The diagnosis of pulmonary aspergillosis was confirmed by serological and microbiological studies. Intravenous amphotericin B and oral itraconazol were administrated, and clinical improvement was observed.

Adult↗
PubMed1995

Surgical management of tricuspid malinsertion in the Rastelli operation: conal flap method.

From June 1986 to May 1994, 25 patients underwent the Rastelli operation for complete transposition of the great arteries with ventricular septal defect and pulmonary stenosis or atresia. Fourteen patients whose tricuspid valve chordae were normal underwent the conventional Rastelli procedure (conventional group), whereas 11 patients who had tricuspid malinsertion into the infundibular septum underwent the Rastelli operation concomitant with mobilization of the infundibular septal flap, with the tricuspid valve chordae, to the right ventricular side of the intraventricular conduit (conal flap method) (conal flap group). In relation to the mobilization of the tricuspid valve chordae, right heart function and tricuspid regurgitation were compared between the two groups. There was one early death after the conventional Rastelli procedure and no early death after the Rastelli operation with a conal flap. There was one late death in the conventional group and two late deaths in the conal flap group. The mean follow-up was 50.8 +/- 5.1 months in the conventional group and 54.9 +/- 7.5 months in the conal flap group (p = 0.43). Reoperation was necessary for 1 patient in the conal flap group during follow-up. At the most recent follow-up, all patients in both groups were in New York Heart Association functional class I. Tricuspid regurgitation was estimated from the echocardiograms. Mild to moderate regurgitation was noted in 6 patients in the conventional group and 8 in the conal flap group. However, postoperative right heart catheterization data did not show any significant differences.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Multiple↗
PubMed1994

[A case of MRSA sepsis treated by the sequential combination therapy netilmycin and minocycline].

A sixteen year old female was feverish from June 12, 1993. Methicillin-resistant Staphylococcus aureus was isolated from the blood, the diagnosis of MRSA sepsis was established. Vancomycin (2 g/day) was administered for eighteen days, but MRSA was not eradicated in the blood culture. Then she was administered a combination therapy of arbekacin (200 mg/day) and imipenem/cilastain (1 g/day) for seven days, but MRSA in the blood was cultured continuously. The sequential combination therapy of netilmycin (200 mg/day) and minocycline (200 mg/day) was started, MRSA was eradicated from the blood culture after four days. The sequential combination therapy netilmycin and minocycline was seemed to be effective for MRSA infection.

Adolescent↗
PubMed1994

[A case of brain abscess associated with enterococcal endocarditis].

Enterococcal infections involving the central nervous system are uncommon clinical entities. A 74-year-old male was admitted to our hospital on November 3, 1991 for high fever. Nuchal rigidity was observed at neurological examination. All four blood cultures yielded E. faecalis. The MIC value of ABPC against the isolated E. faecalis was 0.25 microgram/ml. Vegetation on the mitral valve and mitral regurgitation were revealed by an echocardiogram. Enhanced CT scan showed low density area with ring enhancement in the right basal ganglia and a CSF examination suggested bacterial meningitis. He became better after ABPC 8 g/day was intravenously administered. Then the vegetation on the mitral valve and the brain abscess disappeared. He was discharged with no complications. We reported a rare case of brain abscess associated with enterococcal endocarditis.

Aged↗
PubMed1994

Prediction of quality of life at long-term follow-up after Fontan operation by scoring risk factors.

Many factors will determine the quality of life at long-term follow-up after the Fontan operation. We tried to predict the long-term outcome of modified Fontan operation based on the combined assessment of various preoperative data. The preoperative condition was evaluated by a scoring system in which multilevel scores (from zero to 8 points) were given to a total of 14 morphological and physiological factors according to the contribution of each factor to mortality. The major factors were the association of the extracardiac total anomalous pulmonary venous connection, pulmonary arterial vascular resistance, mean pulmonary arterial pressure, PA index, ejection fraction of the main ventricle, and creatinine clearance. Points for each factor were determined according to surgical mortality, with zero points indicating no increased risk. The total score, i.e., the sum of the points for each item, in each patient was analyzed in relation to the patient's quality of life over a long-term follow-up, as evaluated by questionnaires. Twenty-six of 29 patients with scores of 5 or less showed normal or almost normal life long after the operation, whereas 5 of 10 with higher scores had restricted physical and daily activity. In conclusion, good preoperative condition predicts a good quality of life long after the Fontan operation. In addition, the concept of taking into account all possible risk factors as a comprehensive indicator may be useful in predicting long-term results.

Adolescent↗
PubMed1994

Speciation of vanadium(IV) and vanadium(V) using ion-exchange chromatography and ICP-AES.

A speciation method for vanadium(IV) and vanadium(V) is presented that uses a combination of HPLC and ICP-AES. In this method, 1 mM HNO3 solution and 100 mM HNO3 solution were applied in sequence as eluent. A vanadium(IV) and vanadium(V) mixture was injected into a HPLC anion-exchange column; and vanadium(IV) cation was then eluted by 1 mM HNO3, while vanadium(V) oxoacid anion was trapped on the column. After this separation, vanadium(V) was eluted as a cation from the column by 100 mM HNO3. Vanadium was detected by ICP-AES. In this separation, about 15% of vanadium(V) interfered with vanadium(IV), and trace vanadium(IV) interfered with vanadium(V). This interference could be estimated by simple calculation based on standard observations, and the speciation of vanadium(IV) and vanadium(V) was performed. The lower determination limit was 1 microgram/mL, which is insufficient to speciate vanadium sampled by conventional sampling methods in a working environment. However, impurity of the other valent vanadium species in a vanadium(V) reagent can be determined by the present method, which should be valuable in precisely assessing the toxicities of vanadium species.

Chromatography, High Pressure Liquid↗
PubMed1994

[Left ventricular characteristics after Jatene operation for transposition of the great arteries with intact ventricular septum--comparative study of neonatal primary and two stage repairs].

Left ventricular characteristics in late postoperative period after the arterial switch operation (ASO) was evaluated in fifty-nine patients with transposition of the great arteries and intact ventricular septum. They included 22 neonates who underwent a neonatal ASO (Group I) and 37 patients who underwent a two-stage ASO (Group II). Group II was subdivided into two groups according to the presence or absence of aortic regurgitation in the late postoperative period as group IIa (aortic regurgitation [-], 22 patients) and group IIb (aortic regurgitation [+], 15 patients). Age at ASO ranged from 4 to 27 days (average 12.7 days) in the group I, 5 to 43 months (average 12.7 months) in the group IIa, and 4 to 54 months (average 16.3 months) in the group IIb. Postoperative follow-up period ranged from 8 to 68 months (average 25.0 months) in the group I, 12 to 74 months (average 59.0 months) in the group IIa, and 19 to 66 months (average 48.5 months) in the group IIb. Left ventricular end-diastolic volume was significantly smaller in the group I (123 +/- 19% of normal) than the group IIa (146 +/- 38 of normal) and the group IIa (183 +/- 53% of normal). And left ventricular ejection fraction was significantly higher in the group I (67 +/- 5%) than the group IIa (62 +/- 11%) and the group IIb (58 +/- 8%). Left ventricular normalized mass was significantly smaller in the group I (85 +/- 11% of normal) than the group IIa (113 +/- 14% of normal) and the group IIb (130 +/- 9% of normal).(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1994

[Reoperations of extracardiac valved conduit for congenital cardiac defects].

Fifteen of 223 patients who have had extracardiac conduit repair at the Heart Institute of Japan from January, 1970, to April, 1991, have required conduits replacement because of conduit obstruction or infection. The main causes of obstruction were degeneration of the prosthetic valve and proliferative pseudo-intima in the conduit. The interval between initial conduit repair and conduit replacement was 2.2 to 18.3 years (mean 10.5 +/- 4.4). The average pressure gradient through the conduit decreased from 74.7 +/- 42.0 mmHg preoperatively to 12.3 +/- 7.1 mmHg postoperatively (p < 0.05). There was no early and late death. We concluded that xeno-pericardial roll conduits were superior to others and that conduit replacement procedure following the extracardiac conduit repair was safe and effective.

Adolescent↗
PubMed1994

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↗
PubMed1994

[The youngest case of isolated interruption of the aortic arch without associated cardiac anomalies].

A five-month-old girl was admitted to our institute because of the systolic blood pressure gradient of 42 mmHg between upper and lower extremities. Cineangiography revealed that the brachiocephalic artery originated from ascending aorta, while the left subclavian and left vertebral arteries took their origin from the descending aorta. However, the left common carotid artery was not visualized either on the angiogram or on the digital subtraction angiogram. No other associated cardiovascular anomalies, such as patent ductus or ventricular septal defect, were found. Therefore the diagnosis of isolated interruption of the aortic arch (IAA) Celoria-Patton type C, was made. As the heart failure gradually progressed, the aortic arch reconstruction with a extended polytetrafluoroethylene graft of 10 mm in diameter under extracorporeal circulation utilizing separate ascending aortic cannulation were performed. Her postoperative course was uneventful. The majority of cases with IAA associated with cardiac anomalies require surgical intervention in the neonatal period or in infancy. However, clinical course of isolated IAA generally resembles to that of the post ductal coarctation of the aorta, and most of the isolated interruption is diagnosed in adulthood. The infant is the youngest case with isolated IAA undergone aortic arch reconstruction with success ever reported in the literature.

Aorta, Thoracic↗
PubMed1994

[Anomalous origin of the right pulmonary artery from the ascending aorta: a report of eight cases].

We report eight cases with anomalous origin of the right pulmonary artery from ascending aorta. The ages at operation ranged from five days to fifteen years (average two years and seven months) with the body weights ranging from 1,610 g to 47.5 kg. Two patients underwent a surgical intervention in infancy; one of them with the body weight of 1,610 g was the smallest case previously reported in Japan. Associated cardiothoracic anomalies were patent ductus arteriosus (PDA) in five patients, atrial septal defect (ASD), PDA with ASD, tetralogy of Fallot with absent pulmonary valve in each one patient. Preoperative systolic pressure of pulmonary trunk were varied 83 to 115 mmHg (mean 94.7 mmHg). The continuity between pulmonary trunk and detached right central pulmonary artery was restored by a direct side-to-end anastomosis either behind (anatomical route) or in front of (non-anatomical route) the ascending aorta in all but one patient. There were one operative death and one hospital death. Postoperative pulmonary pressure was lower in patients with anatomical route than in patients with non-anatomical route. We conclude that successful surgical repair can be achieved by a direct anastomosis between abnormal detached central pulmonary artery and pulmonary trunk behind the ascending aorta even in infancy or early in childhood.

Adolescent↗
PubMed1994

[Reoperation after surgical repair of atrioventricular canal defect].

Among 114 survivors who underwent total repair of atrioventricular canal defect between 1981 and 1993, 19 patients underwent reoperation for the occurrence and progression of mitral valve insufficiency (18 patients), thrombosed prosthetic valve (1 patient), and subaortic stenosis (4 patients) on one or two occasions after operation. There were 7 males and 12 females with ages at reoperation ranging from 3 months to 13.8 years (mean, 3.8 years), and was no operative but one late death. At reoperation, reparative procedures involving the readjustment of previously repaired mitral cleft and annuloplasty were successfully achieved in 6 patients who had no additional abnormalities of subvalvar apparatus. Twelve patients, who were associated with additional valvar and subvalvar lesions, needed a prosthetic valve replacement. We emphasized that surgical technique based on precise knowledge of each individual mitral and submitral anatomy is indispensable to achieve good surgical results. When the anatomy involves submitral abnormalities, careful postoperative follow-up should be recommended to take measures of the progression of mitral valve regurgitation.

Adolescent↗
PubMed1993

[Pre and postoperative left ventricular volume and function in infants and children with total anomalous pulmonary venous return].

From January, 1989, to December, 1991, 36 consecutive patients with total anomalous pulmonary venous return (TAPVR) underwent intracardiac repair (ICR) in our institute. We studied the relationship between the size of atrial septal defect (ASD), age and preoperative left ventricular end-diastolic diameter (LVEDD) in 28 patients with regression analysis. There was no statistical relationship between the size of ASD, age and LVEDD. We measured LVEDD, RV to LV pressure ratio (RVP/LVP) and LV fractional shortening (LVFS) using two dimensional echocardiography in 15 patients, prior to and following ICR. LVEDD increased from 1.16 +/- 0.40 cm to 1.62 +/- 0.28 cm immediately following ICR, and then increased to 1.79 +/- 0.34 cm one month following ICR again. LVFS decreased from 38% to 35% immediately following ICR but still remained within normal range (normal range 28-45%). RVP/LVP decreased from 1.0 to 0.69 immediately following ICR, and to 0.39 one month following ICR. We concluded that the decrease of preoperative LV end-diastolic volume in TAPVR was not due to the decrease of LV preload but to anterior deviation of the ventricular septum caused by high RV pressure. There was significant increase of LV volume immediately following ICR, but LVFS maintained in normal range. This study suggested that small LV volume in patients with TAPVR did not influence the surgical results.

Echocardiography↗