Biomedical subjects

R Oka

Publications and source records attributed to R Oka.

33 records · Page 2Linked to original sources

PubMed1993

Health problems among Vietnamese refugees resettled in Japan.

A medical examination of 932 Vietnamese refugees was conducted within 1 month of their resettlement in Japan between 1989 and 1991. A variety of abnormalities were detected, including parasitic disease (78% prevalence), anemia (12%), HBsAg positive state (14%), liver dysfunction (10%), hypertension (0.8%), active pulmonary tuberculosis (2%) and syphilis (0.7%). These rates were still as high as the prevalence in previous studies of earlier immigrants from Vietnam. The high frequency of infectious diseases in recent Vietnamese refugees compared with the Japanese community leads to a recommendation for continuing medical examinations and treatment for new Vietnamese refugees.

Adolescent↗

PubMed1991

Disposition of single-dose intravenous and oral aspirin in children.

We described the pharmacokinetics of acetylsalicylic acid and salicylic acid in 5 children with prior Kawasaki disease receiving buffered aspirin tablets or intravenous aspirin DL-lysine. Oral aspirin is characterized by its longer mean residence time in the body (MRT), an indicator for duration of exposure, than intravenous aspirin (1.18 vs. 0.37 h). The apparent elimination half-life (t1/2) of acetylsalicylic acid was also longer after oral than after intravenous administration of aspirin (40 vs. 17 min). The mean absorption time was calculated to be as long as 0.8 h. In contrast, the two modes of administration gave virtually identical results regarding MRT of salicylic acid proper and its t1/2. After oral administration of aspirin, 51% of the dose is absorbed intact as acetylsalicylic acid while 23% is converted to salicylic acid presystemically, indicating that 74% of aspirin is actually absorbed. Our data suggest that an equivalent intravenous aspirin dose to achieve the same salicylic acid concentration is about 70% of the oral dose. However, the area under the curve of acetylsalicylic acid itself, a more potent cyclooxygenase inhibitor than salicylic acid, would be about 1.5 times higher than that following oral administration. The clinical consequences of this exposure difference remain uncertain.

Absorption↗

PubMed1991

Impaired skeletal muscle function in patients with congestive heart failure. Relationship to systemic exercise performance.

In patients with congestive heart failure (CHF), the poor relationship between systemic exercise performance and cardiac function, together with morphologic and metabolic abnormalities in skeletal muscle, raises the possibility that skeletal muscle function may be impaired and limit systemic exercise performance. We assessed strength and endurance of the knee extensors during static and dynamic exercise in 16 patients with Class I-IV CHF and eight age-matched sedentary controls and related these measurements to systemic exercise performance. To assess skeletal muscle function independent of peripheral blood flow, endurance was repeated under ischemic conditions. Strength was not significantly different in the two groups. Dynamic endurance, quantified as the decline in peak torque during 15 successive isokinetic knee extensions, was significantly reduced in the patients compared to controls during aerobic (peak torque 65 vs. 86% of initial for exercise at 90 deg/s and 60 vs. 85% for exercise at 180 deg/s; P less than 0.002 for both), and during ischemic exercise (56 vs. 76% of initial torque; P less than 0.01). Static endurance, defined as the time required for force during a sustained maximal voluntary contraction to decline to 60% of maximal, was reduced in the patients compared to controls (40 +/- 14 vs. 77 +/- 29 s; P less than 0.02). There were highly significant relationships between systemic exercise performance and skeletal muscle endurance at 90 and 180 deg/s in the patients with CHF (r = 0.90 and 0.66, respectively). These findings indicate that skeletal muscle endurance is impaired in patients with CHF, that this abnormality is in part independent of limb blood flow, and that these changes may be important determinants of systemic exercise performance.

Adult↗

PubMed1991

[Variance of signal-averaged electrocardiographic parameters with age in normal children].

The high-frequency components of the surface QRS was analyzed quantitatively in 87 normal infants and children. The subjects were categorized in 4 groups by age; Group A: one day (n = 27), Group B: 1-5 years (n = 20), Group C: 6-10 years (n = 20), Group D: 11-15 years (n = 20), and the results were compared among the 4 groups. Signal-averaging and high-pass, bidirectional and digital filtering were used for analysis. The total duration of the QRS, the duration of the low-amplitude signals (< 40 microV) in the terminal portion of the QRS (U 40), the amplitude of the signals in the QRS (RMS; QRS) and the amplitude of the last 40 msec of the QRS (RMS 40) were measured at high-pass filter frequency settings of 25, 40, 60 and 100 Hz. Statistical analysis was performed with the unpaired t-test. Differences were considered significant if p < 0.05. The results were as follows: 1. At all filters, the durations of the QRS and U 40 were longer in the order of Groups A < B < C < D, and the amplitude of the RMS; QRS and RM 40 were greater in the order of Groups D < C < B < A. 2. There were significant differences in the QRS between the groups at all filters. 3. There were significant differences in U 40 between the groups except between Groups B and C at 25-Hz filter, but at 40-, 60-, 100-Hz filters, there were no significant differences among Groups B, C and D.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1989

Digoxin clearance and serum beta-2-microglobulin in neonates.

To find reliable indicators of digoxin clearance (CLdig) in the neonatal period, we investigated the linear correlation of CLdig and the reciprocal of CLdig (1/CLdig) with serum beta 2-microglobulin (S beta 2-MG), serum creatinine, blood urea nitrogen, age, and weight on 25 occasions in 21 neonates with congenital heart disease. The S beta 2-MG value showed a significantly closer correlation to 1/CLdig (r = 0.84, p less than 0.0001) than to the other values. The regression equation was (1/CLdig) = 0.15 X (s beta 2-MG) + 0.08. Creatinine and blood urea nitrogen values correlated less closely with 1/CLdig (r = 0.67 and 0.71, respectively). Age and weight had no significant linear correlation with CLdig and 1/CLdig. Determination of s beta 2-MG values allowed an estimate of CLdig by means of the regression equation between s beta 2-MG and 1/CLdig, and permitted a prediction of the required maintenance dose of digoxin. We conclude that s beta 2-MG is a good indicator of CLdig in neonates, and that the determination of s beta 2-MG values may facilitate the advance individualization of digoxin therapy in the neonatal period.

Blood Urea Nitrogen↗

PubMed1989

[Fanconi's anemia with squamous cell carcinoma--a case report and a review of literature].

A 39-year-old woman was admitted to our hospital complaining of hemosputum and right neck swelling. Pharyngography, neck CT scan and laryngoscopy revealed moderately differentiated squamous cell carcinoma of the right pyriform sinus. After series of examinations, it was found that she had pancytopenia, hypoplastic bone marrow, hyperpigmentation of the skin, cardiac anomaly, small stature, hypogonadism, chromosomal aberrations and consanguinity in her parents. These findings suggested that she was the congenital aplastic anemia, that is Fanconi's anemia, variant form. Although pepleomycin and corticosteroids were administrated for the treatment of squamous cell carcinoma and aplastic anemia, she died of cardiovascular shock due to massive hemorrhage. Flow cytometric analysis of squamous cell carcinoma showed an unusual aneuploidy DNA histogram. This is the first report on Fanconi's anemia with squamous cell carcinoma in Japan. It is said that chromosomal aberrations and impairment of DNA cross-links repair may play an important role developing of malignancy in Fanconi's anemia.

Adult↗

PubMed1984

A unique electrophoretic slow-moving glucose 6-phosphate dehydrogenase variant (G6PD Asahikawa) with a markedly acidic pH optimum.

A new glucose 6-phosphate dehydrogenase (G6PD) variant associated with chronic nonspherocytic hemolytic anemia was discovered in Japan. The patient showed hemolytic crises after upper respiratory infections. The enzyme activity was about 3.8% of the normal. The partially purified enzyme revealed slow anodal electrophoretic mobility, high Km NADP, marked thermal-instability, and increased affinity for a substrate analogue (deamino-NADP). A particular characteristic of this enzyme was a biphasic pH curve with a greatly increased activity at low pH values. From these results, this variant was clearly different from hitherto observed G6PD variants, and was designated G6PD Asahikawa.

Anemia, Hemolytic↗

PubMed1984

Evaluation of varicella vaccine in childhood leukemia. Observation over 6 years.

Since 1977, we have used a live attenuated varicella vaccine to immunize 10 children with acute leukemia. 8 patients had no adverse clinical reaction but 2 patients developed mild fever and papulovesicular rash after vaccination. All 9 tested children became seropositive after the vaccination. Also in all 3 children who were observed for more than 4 years, persistence of neutralizing antibody was detected. Most of the recipients were prevented from developing symptoms of varicella in spite of contact exposure. Two patients developed varicella when they were in severe immunosuppressive states but their symptoms were mild. None of the children developed herpes-zoster during the 6 year follow-up period. The results suggest that the varicella vaccine is effective in children with acute leukemia, and that long-term effectiveness can be expected.

Antibodies, Viral↗

PubMed1984

[A child with successfully treated posterior mediastinal endodermal sinus tumor].

A 15-month-old boy with posterior mediastinal endodermal sinus tumor is reported. The patient was admitted with recurrent hemothorax, and his serum alpha-fetoprotein level was 29,520 ng/ml. After removal of the posterior mediastinal tumor, VAC therapy (vincristine, actinomycin D, cyclophosphamide) was started. The chemotherapy was continued 18 months. The patient continues to do well with no sign of tumor and a normal alpha-fetoprotein level 53 months after the operation and 35 months after the completion of therapy. He is the youngest patient documented in the literature and successfully treated for mediastinal endodermal sinus tumor.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1982

Ultrasonographic diagnosis of uriniferous perirenal pseudocyst.

A child with a traumatic uriniferous perirenal pseudocyst was presented. The diagnosis was not made by routine radiological studies, but ultrasound examination demonstrated a perirenal fluid accumulation clearly. The usefulness of the ultrasound examination in the diagnosis of this condition was emphasized. The characteristic finding in ultrasonogram consists of a hydronephrotic kidney and its invagination into the echolucent mass. When perirenal cystic lesions are demonstrated by ultrasound, the junctional zone between the cyst and kidney should be carefully checked for signs of invagination of the kidney into the cyst.

Child, Preschool↗

PubMed1982

Changes in aerobic pharyngeal flora related to antibiotic use and the emergence of gram-negative bacilli.

Pharyngeal flora were evaluated semi-quantitatively by counting and differentiating the colonies growing on blood agar plates into four major bacterial groups. In children they consisted mainly of alpha-streptococci, followed by smaller portions of Neisseria, and of gram-positive organisms other than alpha-streptococci. Gram-negative bacilli did not occur under normal conditions. Oral ampicillin in a daily dose of 50 mg/kg caused suppression of the alpha-streptococci, and promoted emergence of gram-negative bacilli. Oral cephalexin in the same dose caused changes in the same direction, but less extensively than ampicillin . Parenteral aminoglycoside antibiotics in usual dosage did not change the pharyngeal flora. Differential counting of the growth is a simple and useful tool to evaluate the ecology of pharyngeal flora. It serves to monitor overgrowth of resistant organisms in the respiratory tract.

Administration, Oral↗

PubMed1981