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Biomedical subjects

S Kaku

Publications and source records attributed to S Kaku.

103 records · Page 6Linked to original sources
PubMedDate not supplied

Determination of nitrite by high-performance liquid chromatography system with electrochemical detector: measurement of nitric oxide synthase activity in rat cerebellum cytosol.

A simple and sensitive assay method for NO synthase activity is described. Using glassy carbon as electrode and 30% methanol solution with 10 mM NH4Cl as mobile phase, NO2- can be measured without disturbing ECD-detectable substance in NO synthase assay mixture. The NO2- production in the assay mixture of rat cerebellum: NO synthase increased with protein and in a time-dependent manner. The Km value for the substrate, L-arginine, was 1.25 microM. The enzyme activity was inhibited in a concentration-dependent manner by a NO synthase inhibitor, NNA. The Ki value for NNA was 0.166 +/- 0.060 microM. This ECD-HPLC method for determining NO synthase activity has advantages compared with the diazo-coupling method of the Greiss reagent and the isotopic method in which the conversion of the substrate, [14C]L-arginine, to the product, [14C]L-citrulline is measured; it is simple, sensitive and is convenient for studying the NO synthase activity with various compounds as the substrate.

Amino Acid Oxidoreductases↗
PubMedDate not supplied

Epidemiological findings and evaluation of the amount of organochlorine pesticides in human blood plasma in Japan.

Epidemiological and experimental studies were carried out in order to evaluate the significance of the amount of organochlorine pesticides in biological specimens. The amount of beta-BHC, DDT and DDE was determined and compared in human plasma samples taken from several different socio-economic groups. The residue pesticides thus determined reflected the difference in the amount of pesticides used for agricultural purposes in respective areas. The highest value of beta-BHC was found among the people of some groups who had taken more fat-rich animal proteins than the people in other groups. It was also noteworthy that the amount of beta-BHC has decreased in the females in the population who have experienced pregnancy more than one time. The animal experiment also showed the effect of pregnancy on the elimination or decomposition of the pesticides in the biological milieu.

Adolescent↗
PubMedDate not supplied

Cerebral B-cell lymphoma following treatment for Tolosa-Hunt syndrome.

We herein report a unique case of cerebral lymphoma which occurred after lymphocytic neuritis of cranial nerves causing Tolosa-Hunt syndrome and demonstrate the histological difference between these two diseases. A 70-year-old woman developed a sensory disturbance in the first and third divisions of the left trigeminal nerve and a left ocular movement disturbance five years before death. Although she was clinically diagnosed to have a schwannoma in the left cavernous sinus, a histologic examination verified a diffuse infiltration of T lymphocytes in the left trigeminal ganglion. Corticosteroid therapy was effective. Thereafter she demonstrated a disturbance of consciousness and dysphasia four years after surgery. A T1-weighted magnetic resonance image (MRI) disclosed high intensity lesions in both the basal ganglia and corpus callosum. She also showed progressive spastic paralysis. At autopsy a diagnosis of primary intracranial B-cell lymphoma was made. Although there was no invasion of the lymphoma cells into the left trigeminal nerves, a mild inflammatory infiltration of T cells still remained.

Aged↗
PubMedDate not supplied

Percutaneous occlusion of patent foramen ovale in patients with paradoxical embolism.

INTRODUCTION: A patent foramen ovale can be found in about one quarter of adults and in a small percentage it is a wide opening and may be associated with aneurysmal formation. The association between a wide patent foramen ovale and paradoxical embolism is well established. In such cases percutaneous closure is indicated, as an alternative to life-long anticoagulant therapy or surgery. Percutaneous closure is an attractive technique and is more advantageous than other methods. METHODOLOGY: We describe the first cases of percutaneous occlusion of patent foramen ovale performed in Portugal, using the Amplatzer PFO occluder, in three female patients with documented cerebrovascular accidents due to paradoxical embolism. We also analyze the rationale for using this technique in such patients and its preliminary results. RESULTS: All three patients submitted to percutaneous occlusion of patent foramen ovale had a similar history of ischemic cerebrovascular accident. Transesophageal echocardiography showed a wide-open foramen ovale ranging from 9 to 12 mm, with spontaneous right-to-left shunt in all patients, and one of them also had an aneurysmal formation. Total procedure time ranged from 30 to 55 minutes and fluoroscopic time from 9 to 12 minutes. There were no complications and during the short follow up all patients are asymptomatic and free of recurrent events. CONCLUSIONS: Percutaneous closure of patent foramen ovale is a safe and promising technique in the prevention of recurrent systemic thromboembolism in appropriately selected patients. Prospective studies comparing antithrombotic therapy or surgery with percutaneous closure should clarify its efficacy and therapeutic value.

Adult↗
PubMedDate not supplied

Effects of chronic treatment with caffeine on behaviour and related parameters in male and female mice.

The effects of chronic free access to caffeine (0.01% or 0.05%) in drinking water and subsequent withdrawal on spontaneous motor activity for 24 hours and some related parameters were examined in 8-week-old male and female ICR mice. In the males, the 0.01% group showed little response, but in the 0.05% group the activities in both light- and dark-phases and, consequently, in total increased and peaked on day 5 of treatment. The response gradually decreased on days 15 and 30 and reached the control level after 30 days of caffeine withdrawal. Meanwhile, in the females, the activity was stimulated by both 0.01% and 0.05% of caffeine, at the dark- and light-phases in the former and latter, respectively. The response peaked at 30 days and decreased near to the control level thereafter in both groups. Caffeine affected little the food intake; however, water intakes were higher and lower than the control in the 0.05% and 0.01% male groups, respectively, but the opposite was true in the females. Plasma component levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), cholesterol and glucose were higher than the control in the males and females treated with 0.05% of caffeine. The caffeine had little effect on the body weight change, organ weights and external appearance throughout the experiment. Thus, the sex- and dose-related differences in the responses to caffeine of spontaneous motor activity and related parameters were proved under physiological conditions.

Adrenal Glands↗
PubMedDate not supplied

[Endocarditis caused by Candida parapsilosis after total correction of tetralogy of Fallot. Medico-surgical treatment].

Three children with Candida Parapsilosis endocarditis after total surgical correction for Tetralogy of Fallot, are reported. Blood cultures became negative in one child with amphotericin-B and in the other two with Ketoconazole, before reoperation for septal patch replacement. Oral therapy with Ketoconazole continued for a total of 24 months, and during a mean follow-up of 36 months no side effects or reinfection occurred. Medical and surgical conjoined therapy, with surgical timing decided on clinical and laboratorial grounds, were important for good results and cure.

Candidiasis↗
PubMedDate not supplied

[Rheumatic cardiopathy in children. A comparative study in 2 consecutive 9-year periods].

The case rate of children observed with rheumatic carditis or rheumatic heart disease during two consecutive periods of nine years are compared. The first was from October 1969 to September 1978, with previously published data, and the present study from October 1978 to September 1987. During the second period there were 38 cases, 26 of which had the first attack in Portugal, with isolated carditis in 18 (69%), associated with polyarthritis in 5 (20%) and associated with chorea in 3 (11%). Isolated mitral insufficiency was the most frequent valve lesion (80%) and 84% of the children were in NYHA class I and II when first seen. Eighteen children were followed during an average of 2.7 years and there was good compliance of secondary prevention in 78% of them with improvement of the valve lesion. The 12 cases referred from the african countries of portuguese language were more severe, and studied separately. Comparing with the first 9 years period, the case rate of rheumatic carditis, per year decreased from 12.5 to 2.3, the mortality was reduced and the clinical presentation was different, with earlier detection, milder forms and better compliance to secondary prevention.

Child↗
PubMedDate not supplied

[Acute myocardial infarct in infants].

A retrospective study was made of 6 children, with nonsurgical-related acute myocardial infarction (AMI), between January 1987 and December 1994. The ratio for gender was 1 and mean age at AMI was 49 days, 4 cases being associated with congenital heart disease (Fallot's tetralogy, truncus arteriosus and DiGeorge syndrome, one case each, and anomalous origin of left coronary artery, 2 cases). Kawasaki disease and coronary embolisation from thrombosis of the renal vein occurred in the other 2 cases respectively. All developed congestive cardiac failure and cardiomegaly. In the ECG pathologic q waves with more than 35 msec occurred in all, and QT prolongation occurred in 3. Five children (83%) all with AMI in the anterior and lateral wall of the left ventricle died, death being related with cardiac mechanical failure and not with arrhythmias.

Clinical Enzyme Tests↗