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Biomedical subjects

A Naito

Publications and source records attributed to A Naito.

At least 145 records · Page 8Linked to original sources
PubMed1989

A multichannel FES system for the restoration of motor functions in high spinal cord injury patients: a respiration-controlled system for multijoint upper extremity.

A multichannel functional electrical stimulation (FES) system for the restoration of quadriplegic upper extremity function is described. The system is composed of a personal computer NEC PC-8801mkII, peripheral electronic circuits, CRT display and respiratory sensors for volitional control by the patient, and percutaneous electrodes. A C4 quadriplegic patient could drink canned tea by herself by using this FES system. Distinct features of the system are as follows: 1) Versatile volitional control was realized by controlling the memory allocation of the stored stimulation data by voluntary respiratory signals. 2) Sophisticated fine control of the fingers, wrists, and elbow was realized by creating the multichannel stimulation data from recorded myoelectric activities of normal subjects during movements of the upper limb.

Arm↗
PubMed1987

Molecular cloning of the closed circular provirus of human T cell leukaemia virus type I: a new open reading frame in the gag-pol region.

A DNA clone of human T cell leukaemia virus type I (HTLV-I) was isolated from extrachromosomal closed circular copies in chronically infected promyelocytic leukaemia HL60 cells. The new HTLV-I isolate had an intact reading frame in the gag-pol region which could encode protein of 234 amino acids. This open reading frame has not been observed in previous HTLV-I isolates, although similar open reading frames have been reported in the corresponding locations in the related bovine leukaemia virus and HTLV type II. We consider that this open reading frame codes for the virus-encoded protease, on the basis of the homology of the predicted amino acid sequence with those of previously identified retrovirus proteases.

Amino Acid Sequence↗
PubMed1986

Serum CA 19-9 concentrations and computed tomography findings in patients with pancreatic carcinoma.

Carbohydrate antigen (CA) 19-9 is a new tumor marker, defined by a monoclonal antibody. Serum CA 19-9 concentrations and computed tomography (CT) findings were studied in 55 patients with histologically proven adenocarcinoma, and in 22 patients with chronic pancreatitis. CA 19-9 was useful in 83% of cases for the differential diagnosis between pancreatic carcinoma and chronic pancreatitis, and serum CA 19-9 levels in pancreatic carcinoma were highly related to the size of tumors. Serum CA 19-9 levels greater than 37 U/ml were seen in patients with a tumor of less than 3 cm, 3 to 5 cm, and greater than 5 cm in diameter 13% (1/8), 90% (19/21), and 92% (24/26) of cases, respectively. Tumor location, however, was unrelated to serum CA 19-9 value. These results indicated that the measurement of serum CA 19-9 concentrations would be useful in most, if not all, cases for the differential diagnosis between pancreatic carcinoma and chronic pancreatitis, and for the evaluation of tumor burden in patients with pancreatic carcinoma.

Antigens, Neoplasm↗
PubMed1986

A functional study of a case of glucagonoma exhibiting typical glucagonoma syndrome.

A 46-year-old man had a 7-year history of severe rash, which was then diagnosed as necrolytic migratory erythema. He had a weight loss of 6 kg, abnormal glucose tolerance test findings, anemia, glossitis, hair loss, and hypoproteinemia. Plasma amino acids levels were significantly decreased, and the fasting plasma glucagon (IRG) level was high at 5000 to 8000 pg/ml. Circulating IRG significantly increased after oral glucose loading, meal ingestion, and arginine infusion, and decreased with somatostatin infusion and insulin-induced hypoglycemia. No other gut or pancreatic hormone levels in plasma were elevated. Plasma IRG was eluted by gel-filtration, mainly in the position of true glucagon (MW 3500) by antiserum 30K. The rash was markedly improved after infusion of amino acids. Computerized tomography (CT) scan and celiac angiography revealed a large pancreatic tumor with multiple liver and lymph node metastases. The pancreatic tumor was totally resected, and was identified as glucagonoma by immunohistochemical technique. Since the plasma IRG levels remained high after surgery, the patient received dimethyltriazenoimidazole carboxamide therapy. After several courses of this treatment, plasma IRG levels decreased to 1000 to 2000 pg/ml, and the hepatic metastases were remarkably diminished in size.

Adenoma, Islet Cell↗
PubMed1986

Oxidation of 1,5-anhydro-D-glucitol to 1,5-anhydro-D-fructose catalyzed by an enzyme from bacterial membranes.

Bacteria which grow on 1,5-anhydro-D-glucitol (AG) were isolated from soil. One such strain showing the highest AG-assimilating activity was further characterized and identified as a new strain of the Pseudomonas family (named Pseudomonas sp. NK-85001). A subcellular membranous fraction obtained from this strain catalyzed the oxidation of AG to 1,5-anhydro-D-fructose. This oxidation reaction consumed molecular oxygen as the terminal electron acceptor. The AG-oxidizing activity was further purified after solubilization. The AG oxidation catalyzed by this solubilized enzyme utilized molecular oxygen only in the presence of an electron mediator such as 2,6-dichlorophenolindophenol or phenazine methosulfate. Thus, the enzyme was suggested to be a dehydrogenase rather than an oxidase. The solubilized enzyme preparation also showed a strict substrate specificity. The observed specificity indicated that application of the enzyme for AG assay in clinical samples might be possible.

Cell Membrane↗
PubMed1986

Functional recovery of locomotive behavior in the adult spinal dog.

Complete transection of the midthoracic spinal cord was performed on adult female dogs. Development of reflexes and locomotive movements in the hindlimbs after spinal transection was investigated over several months. In the earlier stages after the surgery, dogs showed flaccid paralysis of the hindlimbs. Within several weeks, muscle tone of the hindlimbs was gradually increased accompanied by development of flexion reflex with after-discharge in addition to monosynaptic reflexes. Alternating stepping movement also began to develop. Afterward, extensor thrust and crossed extension reflex were observed. Standing behavior of the hindlimbs was found after enough development of the extensor thrust and correct placement of the pads of the toes. Steady development of stepping and standing caused forward locomotion using fore- and hindlimbs. This walking behavior of the hindlimbs was never inhibited by additional spinal cord transection. These findings indicate that the isolated spinal cord caudal to the transected site is responsible for the locomotive behavior of the hindlimbs in adult spinal dogs. Spinal automatism and development of responses induced by afferent inflow from outside the cord may help to explain such functional recovery of the paralyzed hindlimbs.

Animals↗
PubMed1985

Biological properties of griseolic acid, a cyclic AMP phosphodiesterase inhibitor with an adenine group.

Griseolic acid inhibited cAMP phosphodiesterase (PDE) at low concentrations, the I50 being of the order of 0.01-0.1 microM. Administration of griseolic acid to rats increased the cAMP level in liver and plasma several-fold. It increased glycogen degradation in mouse liver and stimulated lipolysis in isolated rat fat cells. Griseolic acid did not block the adenosine-elicited accumulation of cAMP in guinea pig brain slices. It had no effect on cAMP-dependent protein kinase from rat liver nor on the adenyl cyclase from rat brain.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1985

Ambulatory electrocardiograms obtained by Holter monitoring system in patients with permanent demand pacemakers.

Ventricular inhibited demand pacemakers (VVI) were implanted in 27 patients with complete A-V block and pacemaker arrhythmias were analyzed by Holter system ambulatory electrocardiograms and conventional electrocardiograms. With Holter ECG, 13 patients showed myopotential inhibition, 5 patients had sensing failure and premature ventricular contractions (PVC) were observed in all patients. On the contrary, myopotential inhibition and sensing failure were not detected by conventional ECG and the detection rate of PVC was only 30%. The transient recovery of A-V conduction was observed in 14 of 27 patients with Holter ECG, but was not detected by conventional ECG. The Holter system ambulatory electrocardiogram clearly demonstrated the complex cardiac arrhythmias. Therefore, it is useful for monitoring arrhythmias caused by VVI pacemakers.

Adult↗
PubMed1985

Griseolic acid, an inhibitor of cyclic adenosine 3',5'-monophosphate phosphodiesterase. II. The structure of griseolic acid.

Griseolic acid, a potent inhibitor of cyclic adenosine 3',5'-monophosphate phosphodiesterase, was isolated from the fermentation broth of Streptomyces griseoaurantiacus SANK 63479. Treatment of griseolic acid with HCl-MeOH gave adenine and pseudo-sugar. The structure of griseolic acid, adenine nucleoside type structure, was elucidated by chemical degradation and X-ray analysis, and was shown to be structure 1.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1985

Griseolic acid, an inhibitor of cyclic adenosine 3',5'-monophosphate phosphodiesterase. I. Taxonomy, isolation and characterization.

Griseolic acid, a potent inhibitor of cyclic adenosine 3',5'-monophosphate (cyclic AMP) phosphodiesterase (EC 3.1.4.17) was isolated from the cultured broth of Streptomyces griseoaurantiacus SANK 63479. Griseolic acid has an adenine moiety and two carboxyl groups and possesses the molecular formula C14H13N5O8. Griseolic acid inhibited cyclic AMP phosphodiesterase competitively with regard to cyclic AMP, the substrate and the resulting Ki value was 0.26 microM. Griseolic acid showed the most potent inhibitory effect on rat aorta cyclic AMP phosphodiesterase among the enzymes of several rat organs tested. The plasma level of cyclic AMP was increased when griseolic acid was subcutaneously injected rats.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1984

Homology is not required for recombination mediated by DNA gyrase of Escherichia coli.

We have previously shown that DNA gyrase of Escherichia coli can promote recombination between heterologous DNAs in a cell-free system (Ikeda et al. 1982). In the present paper, we have studied the nucleotide sequences of several recombination junctions of lambda-pBR322 recombinants and found that there were not more than three-basepair homologies between the parental DNAs in six combinations of the lambda and pBR322 recombination sites. Based on this and previous results, we concluded that homology was not required for the DNA gyrase-mediated recombination. Furthermore, the structures of the recombinant DNAs we have analyzed suggest the occurrence of multiple cross-overs in our in vitro system.

Bacteriophage lambda↗