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Biomedical subjects

K Fukui

Publications and source records attributed to K Fukui.

At least 379 records · Page 21Linked to original sources
PubMed1986

Biosynthesis of porcine kidney D-amino acid oxidase.

The biosynthesis of a porcine kidney peroxisomal enzyme, D-amino acid oxidase (EC 1.4.3.3., DAO), was investigated. Pig kidney mRNA as well as free and membrane-bound polysomes were used to investigate in vitro protein synthesis using a rabbit reticulocyte lysate. mRNA and free polysomes, but not membrane-bound polysomes, directed the synthesis of DAO. To examine the in vivo synthesis of the enzyme, a pig kidney cell line (LLC-PK1) was biosynthetically labelled. Both the in vitro and in vivo synthesized DAO had the same molecular weight, 38,000, as that of the purified enzyme. These results indicate strongly that DAO is synthesized on free ribosomes and transferred to the interior of peroxisomes without any proteolytic modification.

Animals↗
PubMed1986

Vasoactive intestinal peptide- and peptide histidine isoleucine amide-like immunoreactivity colocalize with vasopressin-like immunoreactivity in the canine hypothalamo-neurohypophysial neuronal system.

The distribution of vasoactive intestinal peptide (VIP) and peptide histidine isoleucine amide (PHI) was investigated in the canine hypothalamus by immunocytochemistry. VIP- and PHI-like immunoreactive neurons were detected in the magnocellular supraoptic and paraventricular nucleus. These magnocellular VIP- and PHI-producing neurons coexist with vasopressin-like immunoreactivity and send axons to the median eminence and neurohypophysis. These findings may serve as an anatomical basis for studying the function of VIP and PHI on pituitary hormone secretion.

Animals↗
PubMed1986

Further confirmation of heterogeneity of the rat striatum: different mosaic patterns of dopamine fibers after administration of methamphetamine or reserpine.

Heterogeneity of adult rat neostriatum has been studied by fluorescence histochemistry. The distribution of dopamine nerve fibers and terminals, known normally to be homogeneous, tended to become heterogeneous after administration of methamphetamine or reserpine. Both drugs caused mosaic formations of fluorescent dopamine axons and terminals, though a minor difference was present in the pattern of distribution. The results indicate that the striatum possesses at least two types of dopamine nerve terminals, sensitive and relatively insensitive for the two catecholamine depletors.

Animals↗
PubMed1986

Suppression of immunoglobulin synthesis by activated B cells in chronic active liver diseases and primary biliary cirrhosis.

We investigated the suppressor function of peripheral blood B cells from patients with chronic active liver diseases (CALD) and primary biliary cirrhosis (PBC). Suppressor cells were generated by preincubation of B cells with protein A, and suppressive effects were evaluated by inhibition of pokeweed mitogen-induced immunoglobulin (Ig) synthesis of normal peripheral blood lymphocytes (PBL) in second-set cultures. The mean percent suppressions for IgG and IgM synthesis of 12 HBsAg-negative patients with CALD, who were not on prednisone therapy, were lower (p less than 0.01, respectively) than those of controls. B cells from 6 HBsAg-positive patients with CALD also showed less suppression of IgG and IgM synthesis (p less than 0.01, respectively). Moreover the suppression for IgG and IgM in 7 patients with PBC were decreased (p less than 0.01, respectively). There was an inverse correlation between serum gammaglobulin level and percent suppression for IgG synthesis by protein A-activated B cells of patients with CALD (r = -0.50, p less than 0.05). Further studies demonstrated that protein A-activated B cells were capable of activating the suppressor function of T cells, which could then act to inhibit further B cell differentiation. These results suggest an aberrance of a feedback mechanism that is likely to regulate Ig synthesis in patients with CALD and PBC.

Adult↗
PubMed1986

Radiologic demonstration of Caroli's disease: a case report.

Since the first report by Caroli et al., there have been several reports dealing with Caroli's disease or multiple communicating cysts of the biliary tree. Recently, the usefulness of computed tomography, endoscopic retrograde cholangiopancreatography, ultrasonography, and radionuclide scintigraphy have been emphasized for evaluation of this condition. This report describes a case of Caroli's disease and emphasizes the value of ultrasonography in the evaluation of this condition.

Bile Duct Diseases↗
PubMed1986

Screening and treatment of unruptured cerebral aneurysms.

Thirty outpatients with unruptured cerebral aneurysms screened by computed angiotomography have been analysed and followed up in our clinic since 1979. Seventeen were men and the age range was 41 to 74 years old (mean 57.7 years). Patients had no or only mild neurological symptoms, such as headache, sensorimotor or speech impairment and others, which were scarcely related to the unruptured aneurysms themselves. It is important to realize that these first aneurysms which remain unruptured, have a primary significance to the individual in the protective aspect of an initial subarachnoid haemorrhage. Operation was successfully performed in fifteen patients. Transient aggravation of previous diseases, e.g. cerebral infarction, occurred in three after operation. Follow-up studies of fifteen patients without operation revealed no change in eight and some worsening or death due to other or previous diseases in six. One died of aneurysmal rupture in the 5th month after its detection. Because of the low operative risk, we advocate the operative treatment of unruptured aneurysms, following careful selection of the indicated patients.

Adult↗
PubMed1986

The initial phosphate burst in ATP hydrolysis by myosin and subfragment-1 as studied by a modified malachite green method for determination of inorganic phosphate.

The Malachite Green method for determination of inorganic phosphate (Pi) (Itaya K. & Ui, M. (1966) Clin. Chim. Acta 14, 361-366) was modified to measure Pi in the range of 0.2-15 nmol per ml of ATPase reaction mixture. An ATPase reaction mixture is quenched with an equal volume of 0.6 M PCA; the supernatant after centrifugation is mixed with an equal volume of the Malachite Green/molybdate reagent containing 2 g of sodium molybdate, 0.3 g of Malachite Green and 0.5 g of Triton X-100 or Sterox SE in 1 liter of 0.7 M HCl, and the absorbance at 650 nm is then measured after a 35-40 min incubation at 25 degrees C. Owing to the high sensitivity and simplicity of the modified method, the slow time course of myosin ATP hydrolysis in the presence of Mg2+ and the size of initial phosphate burst can be determined accurately using relatively low concentrations of native myosin and its subfragment-1. The phosphate burst size varied with changes in pH, ionic strength, and temperature. A typical value was 0.8-0.9 mol per site in 0.1 M KCl, 10 mM MgCl2, pH 8.0 at 25 degrees C for fresh enzyme preparations.

Adenosine Triphosphatases↗
PubMed1986

Actinobacillus (Haemophilus) actinomycetemcomitans in periodontal disease.

Actinobacillus (Haemophilus) actinomycetemcomitans is a facultatively anaerobic, gram-negative coccobacillus which is a possible etiological agent in juvenile periodontitis (JP). In this study, bacterial flora, especially the occurrence of A. actinomycetemcomitans, in the periodontal pockets of one juvenile with gingivitis (G), one JP patients, five rapidly progressive periodontitis (RP) patients and one adult periodontitis(AP) patient, and one adult with healthy periodontium was investigated using a blood agar medium and a selective medium for A. actinomycetemcomitans. Eight hundred and sixty-five bacteria were isolated from the periodontal pockets, examined for their gram-stain, cell morphologies, relations to O2 and CO2 and catalase reaction, and divided into 21 groups on the basis of these characters. Among the isolates, 604 isolates were further characterized biochemically and identified. A. actinomycetemcomitans was found as 0.2% of the flora of a site in the JP patient, as 9% of the flora of a site in the G patient, and as 19% and 1%, respectively, of the flora of a site in the two RP patients. However, the organism was not detected in another lesion site of the JP patient. In our JP and RP patients, Fusobacterium, Wolinella, Streptococcus, and obligately anaerobic, gram-positive cocci were frequently found at high levels. The bacterial flora of the G and AP patients were more heterogeneous and included Bacteroides at relatively high proportions. These results indicate that A. actinomycetemcomitans is not always associated with JP but occurred in some patients with RP and G.

Adolescent↗
PubMed1986

Monoclonal antibody to Streptococcus mutans type e cell wall polysaccharide antigen.

A monoclonal antibody against the polysaccharide antigen of Streptococcus mutans serotype e was prepared. It was found that beta-methyl-D-glucopyranoside and cellobiose markedly inhibited the precipitin reaction, whereas maltose showed no inhibition. The beta-glucosyl moiety of the type e polysaccharide seems to be the predominant antigenic determinant of the antigen.

Animals↗
PubMed1986

Effects of ouabain on autoregulation of renal blood flow in dogs.

Effects of ouabain on the autoregulation of renal blood flow (RBF) and renin release were examined in filtering and nonfiltering kidneys of anesthetized dogs. Autoregulation of RBF was observed in both kidneys; however, autoregulation in the nonfiltering kidney was comparatively less efficient. These findings indicate that both the myogenic mechanism via a sensor element in the afferent arteriole, a so-called baroreceptor, and the tubuloglomerular feedback mechanism via the macula densa are essential for complete autoregulation. In both the control and nonfiltering kidney, intrarenal arterial infusion of ouabain abolished the autoregulation of RBF and glomerular filtration rate, with no change in the renal vascular sensitivity to vasoactive substances or in renin release induced by pressure reduction. Since various vasoactive drugs elicited a normal vascular response, it appears that the site of action of ouabain was not the vascular contractile elements; at least, an impairment of autoregulation during ouabain infusion was apparently not due to a defect in these elements. These results suggest the possible existence of another mediator, a sensor element in the afferent arteriole that is affected by ouabain. Ouabain may abolish the autoregulation of RBF and renin release via a modification of this baroreceptor in the afferent arteriole as well as through inhibition of the macula densa.

Animals↗
PubMed1986

Serum levels of coenzyme Q10 and lipids in patients during total parenteral nutrition.

Serum levels of coenzyme Q10 (CoQ10) as well as lipids were determined in patients during total parenteral nutrition (TPN). The mean CoQ10 levels (M +/- SD) were 0.77 +/- 0.30 microgram/ml for 108 normal subjects and 0.59 +/- 0.35 microgram/ml for 95 patients before TPN. The mean CoQ10 level of the patients decreased significantly to 0.35 +/- 0.23 microgram/ml one week after the start of TPN, and then remained almost unchanged during TPN for up to 6 weeks. When the patients receiving TPN (TPN patients) were grouped according to their clinical diagnoses, the mean CoQ10 level of patients with cancer was significantly lower than that of the other patients without cancer in 4 week therapy, but there was no difference in the levels between the patients with and without diseases of the gastrointestinal tract. Serum levels of total cholesterol (T-Chol) and esterified cholesterol in TPN patients also declined below their respective normal ranges, but not to the same extent in comparison to CoQ10. The levels of triglycerides (TG), phospholipids (PL), non-esterified fatty acids, low density lipoproteins, very low density lipoproteins, chylomicrons, and cholesterol in the high density lipoprotein fraction in serum of TPN patients were within their normal ranges. The levels of CoQ10 in TPN patients were correlative to those of T-Chol, TG, and PL, and decreased rapidly prior to the latter levels.

Adolescent↗
PubMed1986

The haemodynamic, renal and endocrine effects of alpha-human atrial natriuretic polypeptide in normotensive people and patients with essential hypertension.

Intravenous administration of a small dose of synthetic alpha-human atrial natriuretic polypeptide (alpha-hANP, 0.025 microgram/kg per min) decreased arterial pressure and total peripheral resistance to a similar extent in eight normotensive people and 11 untreated patients with essential hypertension. Cardiac output was slightly, but not significantly, increased in both groups. Urinary volume, urinary sodium excretion and glomerular filtration rate (GFR) were significantly increased only in the hypertensives. However, net tubular reabsorption of sodium was enhanced in the hypertensives. Haematocrit (Ht) was increased in both groups. Although plasma renin activity (PRA) did not change in either group, plasma aldosterone was significantly decreased in the groups, with a greater change in the normotensives. These findings indicate that the hypotensive effect of alpha-hANP is due to the dilatation of resistant vessels, and that an increase in GFR, probably brought about by the combination of an increase in vascular permeability (as suggested by the changes in Ht) and high arterial pressure, is one of the main factors leading to the diuresis and natriuresis induced by alpha-hANP.

Adult↗
PubMed1986

Automatic reregistration for correction of localized misregistration artifacts in digital subtraction angiography of the head and neck.

A new automatic computer program, to remove misregistration artifacts secondary to motions such as rotation, contraction and relaxation of the body, has been developed. This program is called automatic reregistration and consists of determination of distortion vectors of corresponding segments of the mask and live images by detection of the peak value of two-dimensional cross correlation, followed by obtaining distortion vectors of other pixels through interpolation. Shift of the coordinate of the distorted live image is subtracted. Clinical evaluation of this new program, in comparison with already developed remasking and manual reregistration, have proved that some misregistration artifacts, uncorrectable by the latter two methods, have been removed to some extent. The new program has proven to be clinically useful.

Angiography, Digital Subtraction↗
PubMed1986

Development of the new cerebral angio-CT technique and magnetic resonance angio-imaging.

Using dynamic scanning, multiple cerebral computed angiotomography scans were obtained after a single bolus injection of contrast medium. The following three different techniques and their clinical applications were investigated. 1) Overlapping scanning was applied to detect unruptured intracranial aneurysms. 2) Sequential scanning was mainly applied for larger lesions such as isodense chronic subdural hematomas. 3) Two-step contrast-enhanced scanning was useful for investigating the relationship between tumor and surrounding vessels. Cerebral magnetic resonance angio-imaging was recently investigated as a noninvasive procedure using spin-echo magnetic resonance imaging.

Cerebral Angiography↗