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Biomedical subjects

F Nakagawa

Publications and source records attributed to F Nakagawa.

At least 73 records · Page 4Linked to original sources
PubMed1984

Terferol, an inhibitor of cyclic adenosine 3',5'-monophosphate phosphodiesterase. I. Isolation and characterization.

Terferol, a new inhibitor of cyclic adenosine 3',5'-monophosphate phosphodiesterase (EC 3.1.4.17, cAMP-PDE), was isolated from the cultured broth of Streptomyces showdoensis SANK 65080. It was found to have the molecular formula C19H16O3 and to possess inhibitory activity not only against cAMP-PDE but also against cyclic guanosine 3',5'-monophosphate phosphodiesterase (cGMP-PDE) from various rat tissues. The terferol concentration required for 50% inhibition of cAMP-PDE was 0.82 microM.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1983

Bioavailability of phenytoin on single and multiple oral doses of two dosage forms in normal subjects.

The extent and rate of absorption of phenytoin (PHT) from tablet and powder were studied in four healthy adult volunteers. It was demonstrated by urinary and fecal excretion that the almost all quantity of PHT in tablet was absorbed through the gastrointestinal tract, and the observed values of the estimated free concentration (Cest.f) estimated from mixed saliva concentration of PHT in the multiple dose were in fair agreement with the calculated values of that by using computer simulation in case of tablet. On the contrary, the variations were observed in Cest.f using therapeutic dose of PHT powder. The values of Cest.f at steady-state in tablet administration were higher than those in powder administration. The absorption ratio of PHT powder was low and variable, and decreased upon increase of dose. The ratio calculated from the Cest.f values of both dosage forms at steady-state were in good correspondence to the observed values of PHT excreted in feces.

Adult↗
PubMed1983

Clinical pharmacokinetics and diuretic effect of furosemide in plain tablet and retard capsule with normal subjects and cirrhotic patients.

The dissolution profiles of furosemide in various solutions were studied with plain tablet and retard capsule of furosemide. The rate constant and percent dissolution in retard capsule were lower than that in plain tablet. Clinical pharmacokinetics and diuretic effect of furosemide after oral administration of two dosage forms were also studied with 3 normal subjects and 3 cirrhotic patients. In normal subjects, the extent of furosemide absorption from retard capsule was 45% of plain tablet. The daily urine volume after oral administration of two dosage forms was comparable, however, quite different profiles were observed between these dosage forms. In patients, the extent of furosemide absorption in retard capsule was one half that of plain tablet. The dose of retard capsule was increased without adverse reactions, thus decreasing of ascites, which was not observed with plain tablet, was achieved with increasing urine volume.

Adult↗
PubMed1983

Comparison of bioavailability for phenytoin products prepared by wet granulation in normal subjects and epileptic patients.

A 20% phenytoin (PHT) plain mixture with excipients (20%PM) and three PHT products prepared by wet granulation, which are 20% fine granule (20%FG), 99% air-dried fine granule (99%FG-A) and 99% freeze-dried fine granule (99%FG-F), were prepared. The extents of PHT absorption from these products and the Aleviatin Fine Granules (97%FG) prepared with microcrystalline PHT powder were compared with those from commercially available PHT powder (Aleviatin) and tablet (Hydantol Tablet 25 mg), which are of the Pharmacopoeia of Japan grade, in healthy adult volunteers. In single dose study, the extents of PHT absorption from the powder, 20%PM, 20FG, 99%FG-A, 99%FG-F, 97%FG and tablet were 89.7, 92.2, 99.0, 96.7, 99.1, 99.1 and 99.3%, respectively. The property of almost complete absorption of PHT from the product was shown in the 20%FG, 99%FG-F and 97%FG similar to the tablet. In multiple dose study, the minimum and the average estimated free concentrations of PHT at steady-state for 99%FG-F and 97%FG were nearly equal to those for the tablet, and were higher than those for the powder. In epileptic patients, the plasma PHT concentrations were increased when dosage form was changed from the powder to 99%FG-F. However, the plasma PHT concentrations were scarcely altered when dosage form was changed from the tablet to 99%FG-F. The change in dosage forms from the tablet to 99%FG-F and 97%FG or opposite direction can be done without causing toxicity in epileptic patients, so long as these products are used at the same amounts as PHT.

Adolescent↗
PubMed1983

Appearance of intoxication in rats by intraperitoneal administration of clioquinol.

The investigation was undertaken to study the neurological symptoms in rats caused by maintaining high plasma concentration of about 30 nmol/ml or more, of clioquinol. Clioquinol suspension which was prepared using polysorbate 80 was administered intraperitoneally to rats and plasma and tissue concentrations were determined. On administration of clioquinol of 100 and 200 mg/kg, the mean plasma concentrations of clioquinol reached maximum values of 30 and 58 nmol/ml, respectively, after 0.5-1 h and thereafter decreased rapidly. With 400 mg/kg, however, plasma concentration reached maximum value of about 75 nmol/ml and fell slowly. By single and repeated administration of the suspension, clioquinol was distributed in the liver and kidney at a high concentration, and also in the nervous system. In experiments on appearance of neurotoxicity in rats by repeated administration of the suspension, all of 10 rats administered intraperitoneally with 100 mg/kg/d did not develop any neurological symptoms for about 30 d. On the other hand, one of 10 and 7 of 13 rats administered with 200 and 400 mg/kg/d, respectively, developed ataxia in the hind legs or all legs on the 3rd to the 12th day after starting administration. Pathologically, a slight change of the peripheral nerve, central chromatolysis of the anterior horn neuron and severe neuronal degeneration of the Ammon's horn were observed in the rats with ataxia.

Animals↗
PubMed1983

Intestinal absorption and metabolism of clioquinol in the rat.

Plasma concentrations of clioquinol and its metabolites after single or repeated oral administration of clioquinol, absorption region of clioquinol in gastrointestinal tract, and intestinal metabolism were studied in rats. Plasma concentrations of clioquinol after oral administration of four different doses (20, 100, 200 and 400 mg/kg) were lower than those of the two metabolites, clioquinol glucuronide and sulfate. Mean maximal plasma concentration of unchanged drug was in the range of 1-8 nmol/ml. Clioquinol was absorbed poorly from the stomach and fairly from the small intestine. Bile was an important route for excretion of clioquinol in rats. The mesenteric venous plasma from the closed intestinal loops of both jejunal and ileal regions was analyzed for clioquinol and the metabolites and it was found that clioquinol glucuronide was formed predominantly in both regions. From the results of the present studies, intestinal metabolism of clioquinol can be pointed out as a major factor for difficulty to cause clioquinol intoxication.

Animals↗
PubMed1983

An approach to a basilar aneurysm above the bifurcation of the internal carotid artery. Case report.

The authors report a case of a basilar artery aneurysm approached by the transsylvian route; the aneurysm was successfully clipped through the space distal to the carotid bifurcation and between the frontal and temporal lobes. This approach is useful when the internal carotid artery is short, sclerotic, and difficult to mobilize. Special care should be taken when retracting perforating arteries and the posterior communicating artery.

Basilar Artery↗
PubMed1982

Mortality study of patients with subarachnoid haemorrhage at University hospitals and their affiliated hospitals in Japan.

This study was undertaken to examine the differences in aneurysm statistics between University hospitals where subacute or chronic patients are primarily treated and University-affiliated hospitals where both acute and chronic cases are also admitted. In each hospital group, the transition of the statistics in the last decade was studied. The purpose of this study was also to see if any conclusion could be drawn regarding the surgical treatment of acute cases. The death rate for all aneurysm cases admitted is 8% at University hospitals, whilst that at affiliated hospitals is roughly 30% during the 1970s. The operative death rate at the University hospitals is 3%, whilst that at affiliated hospitals is 16% which improved at one affiliated hospital to 8% in the 1980-1981 period. Morbidity also improved in the latest series in the affiliated hospital. These improvements are considered to be de to the change of operative and postoperative policies for acute cases to: limited surgical indications for grade IV patients, extensive cisternal clot removal at the time of surgery, and oral administration of Ticlopidine, a new antiplatelet agent.

Hospitals, Special↗
PubMed1982

Fenestrated clips for unusual aneurysms of the carotid artery.

Twenty-four different kinds of fenestrated clips are introduced for the obliteration of unusual aneurysms. The clips were used for eight aneurysms of the internal carotid artery and 10 aneurysms of the vertebral artery. All but one of the aneurysms were successfully obliterated. Recommendations are made concerning the actual use of the clips.

Aged↗
PubMed1980

Optociliary veins associated with meningioma of the optic nerve sheath.

We report on the clinical symptoms and the course of a case that showed the typical findings of a meningioma of the optic nerve sheath, characterized by visual disturbances, progressive visual field defect, proptosis, secondary atrophy of the optic disc, and shunt vessels between retinal and choroidal circulation. The shunt vessel which was demonstrated in this case by fluorescein angiography is identified with the optociliary vein reported in the literature. Fluorograms also revealed peculiar vessels at the margin of the optic disc, which have not been described in association with this tumor. CT scanning and roentgenograms of the optic canal proved useful as diagnostic tools for this tumor. The tumor was removed through a frontotemporal craniotomy, preserving the optic nerve. The histopathological diagnosis was meningothelial meningioma.

Adult↗