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Biomedical subjects

N Aoyagi

Publications and source records attributed to N Aoyagi.

At least 73 records · Page 4Linked to original sources
PubMed1985

[Traumatic delayed intracerebral hematoma--clinical aspects].

In order to seek the occasion and the management of traumatic delayed intracerebral hematoma, we selected 17 cases (4.2%) of traumatic delayed intracerebral hematoma (secondary lesion) from 401 cases of head injury, and compared them with other 11 acute traumatic intracranial multiple lesion (immediate lesion). The age ranged from 15 to 78 (except for a newborn hit on the cranium by his mother) and the average was 49 in secondary lesion and 58 in immediate lesion. Sex distribution, 15 males and 2 females in secondary lesion, and 10 males and 1 female in immediate lesion. Though both lesions were supposed to be resulted from almost same severe loads, secondary lesion took worse prognosis than the other: misery outcome (poor and fatal) of secondary lesion was 59% and that of immediate lesion 27%. Of 8 hypertensive cases who were all fatal, 7 were of secondary lesion. Secondary lesion could be expected in only 59% (10/17) by the initial X-CT performed 5.4 +/- 6.2 hr. after trauma. The predicted secondary lesion were classified into three types: salt and pepper like high density lesion (Lanksh's II type), low density lesion (Lanksh's I type) and isodensity mass lesion. The shortest interval between injury and the X-CT detection of secondary lesions was 10 hours and the longest interval was 69 hours (40 hours mean) in conservatively treated patients. In operated patients, the shortest and longest intervals were 8 and 84 hours, respectively (33 hours mean, except for one case who was not examined for 10 days after operation).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

[Study of ruptured intracranial aneurysms with intracerebral hematomas--with special reference to operative indication].

We reviewed 40 cases of intracranial ruptured aneurysm with intracerebral hematoma (An-ICH) and compared those with 177 cases of intracranial single ruptured aneurysm causing only subarachnoid hemorrhage (An-SAH). An-ICH accounted 11.6% of the intracranial aneurysm, ruptured at the mean age of 54 years, and occurred equally in both sexes. The localization of An-ICH was 50% in the middle cerebral artery (MC), 43% in the anterior cerebral artery (AC) and 8% in the internal carotid arterial region. Forty percent of An-ICH were treated conservatively and the outcome was very misery (no useful life and 94% was poor or dead). Sixty percent of An-ICH were treated surgically (neck-clipping and removal of the hematoma) and the outcome was poor (17% useful life and 46% poor and dead). Especially in MC aneurysm, operability was 85% and post-operative useful life was 12% and post-operative poor or dead was 53%. In AC aneurysm, operability was 35% and post-operative useful life was 33% and poor or dead was 33%. These miserable results raised a question of operative indication for An-ICH. The five clinical indices (decerebration, hypertension greater than or equal to 200 mmHg, Hunt-Hess grade V, anisocoria in AC, severe shift of midline structure on X-CT) were selected, because any patients who presented with even only one of them became fatal or vegetative state regardless of conservative or surgical treatment. Assuming them as the non-operative standards, operability decreased in 35% MC, 29% AC, useful life outcome came up to 20% MC, 40% AC, and misery outcome came down to 20% MC, 20% AC.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Bioavailability of indomethacin capsules in humans. (I): Bioavailability and effects of gastric acidity.

The bioavailabilities of five indomethacin capsules, two commercial and three experimental products, were studied in ten human subjects. The bioavailabilities of the products increased in proportion to their in vitro dissolution rates, although one of the commercial products provided a relatively lower bioavailability than was expected. Comparison of the bioavailabilities between high and low gastric acidity humans revealed that the serum levels of the drug during the absorption phase following oral administration of all the indomethacin products, except for one commercial product, were higher in the low acidity subjects than in the high acidity subjects. Also, the mean peak serum level of the most rapidly dissolving product was 1.6 times higher in the low acidity subjects than in the high acidity ones. These gastric acidity effects indicated enhanced dissolution of indomethacin from the capsules in the stomach of low acidity humans.

Adult↗
PubMed1985

Bioavailability of indomethacin capsules in humans (II): correlation with dissolution rate.

The correlation between the dissolution rate and bioavailability in humans for five indomethacin capsules was investigated. The mean Cmax, Tmax and AUC24 of low gastric acidity in humans correlated well with the dissolution rate determined by the paddle method using a slow stirring rate. The Cmax of the high acidity subjects also correlated with the dissolution rates determined under mild conditions. However, the Tmax correlated with the dissolution rates determined under vigorous ones. The in vivo-in vitro correlation seems to have become complicated by an anomalous product whose dissolution was remarkably sensitive to environmental conditions. The correlation data also suggested that the deaggregation force on the adhesive agglomerate in human digestive tract might not be strong.

Biological Availability↗
PubMed1985

Bioavailability of indomethacin capsules in humans (III): Correlation with bioavailability in beagle dogs.

The bioavailabilities of five indomethacin capsules were studied in ten beagle dogs and correlations with the in vivo results in humans and dissolution rates were investigated. The difference in bioavailability between two commercial products was smaller in dogs than in humans, which seemed to be due to strong disintegration forces in dogs. The difference in the dissolution rate among the products was reflected less in the Tmax in dogs than in humans, and the Tmax was shorter in dogs which seems to be due to faster gastric emptying and passage of the drug through the absorption site in dogs. Gastric acidity effects on the indomethacin availability found in humans were not observed in dogs. The Cmax and Tmax correlated well with the in vitro dissolution rates, but AUC24 did not. The Cmax and Tmax in dogs also correlated with the corresponding parameters in humans, especially those in high gastric acidity humans, but AUC24 did not.

Animals↗
PubMed1985

[Clinical study of spinal intradural arachnoid cyst].

Spinal intradural arachnoid cysts (S-IAC) are rarely found and only 80 cases have been reported since 1915. We report two of them. A 68-year-old male had slowly progressive dull pain in both thighs for about 6 years prior to admission. Neurological examination and plain x-ray on admission showed no abnormality. Myodil myelography showed a S-IAC at T4 vertebral level. Surgical treatment of cyst wall excision resulted in success. The other case, a 39-year-old male suddenly noticed monoparesis and sensory disturbance of left leg in the morning. On admission were observed spastic monoparesis of the left leg, analgesia at right T2-3 cord segment and sensory disturbance (hypesthesia, dysesthesia, paresthesia) below T3-4 cord segment on the left side. Plain X-ray showed no abnormality. Myodil myelography revealed a S-IAC at T3-4 vertebral level. This patient was treated not surgically but conservatively because all neurological deficits but numbness in the left leg almost subsided after bed rest. The patient has experienced no neurological deterioration for five years since then. We also discuss the clinical feature, treatment and etiology of the S-IAC, by analyzing these 82 cases. There is a slight male preponderance. The age ranges between 3 and 66 years (mean 38 years). The duration from onset to admission is 2 days to 30 years. Sixty percent (48/80) of the cases were ill far longer than a year (mean 6.7 years). Of 82 cases, 83% suffered from motor disturbance, 70% had sensery disturbance, 62% local pain and 24% urinary with/without fecal disturbance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Analysis of 223 ruptured intracranial aneurysms with special reference to rerupture.

A review of 223 patients with ruptured intracranial aneurysms, including 46 with rerupture, showed that the operability rate was higher and the prognosis better in patients with one rupture. Rerupture cases with low Hunt--Hess grades (0--II) had no better prognosis than one-rupture cases of grade IV. The mean interval between first rupture and rerupture was 12 days. Aneurysms located in the vertebrobasilar system showed the highest rate of rerupture. Daughter and bled-shaped aneurysms had a greater tendency to rerupture. The incidence of rerupture was increased in patients with narrowly localized vasospasm and acute hydrocephalus. Time-course studies of factors of the coagulating and fibrinolytic system suggested their usefulness in predicting the occurrence of vasospasm, infarction, and rerupture and the prognosis of patients with ruptured intracranial aneurysms. Patients at high risk for rerupture of aneurysm should undergo early operation.

Adult↗
PubMed1984

Bioavailability of griseofulvin plain tablets in stomach-emptying controlled rabbits and the correlation with bioavailability in humans.

Bioavailability after giving oral doses of 62.5 mg griseofulvin tablets having different dissolution rates to stomach-emptying controlled rabbits, was estimated and compared with that in humans receiving 125 mg dose of the same griseofulvin preparations. The relative differences in Cmax and AUC infinity between the product with the highest availability and others tended to be greater in rabbits than in humans. The in vivo parameters correlated well between the two species. However, power analysis indicated a larger variability of Cmax in rabbits than in other species (dogs, minipigs and humans). Water volume (5 and 50 ml) coadministered with the drug did not significantly influence the bioavailability. The rabbits which were not given food after oral dosing with griseofulvin exhibited a lower Cmax than those which were fed immediately after dosing. The bioavailability of an ultramicronized formulation in rabbits was higher after the postprandial dose than after the preprandial dose. Food intake just after the drug administration seems to be an important factor for controlling the passage rate of the drug through the gastrointestinal tract in stomach-emptying controlled rabbits.

Animals↗
PubMed1984

Development and evaluation of a new peroral test agent GA-test for assessment of gastric acidity.

A new peroral test capsule, GA-Test, containing riboflavin (5 mg) granules coated with polyvinylacetal diethylaminoacetate (AEA) for assessing gastric acidity without intubation was developed and evaluated for usefulness. GA-Test is based on the tracing in the urine of riboflavin, which is released in the stomach only in the presence of acidic fluid and is absorbed. Due to the film coating, riboflavin released very quickly at a pH of less than 5, and not at all at a pH of greater than 6. GA-Test gave a significant correlation, quantitatively, with peroral Gastrotest in assessing acidity, a non-intubation method which had been marketed in Japan prior to 1980. GA-Test results allowed division of the subjects into two groups i.e., subjects having low (hypo- or anacidity) gastric acidity and those having high (normal or hyperacidity) gastric acidity, GA-Test results agreed well with results of intubation (around 91.4%; 32 out of 35 cases) and were easily reproduced during the evaluation.

Adult↗
PubMed1984

Bioavailability of griseofulvin from plain tablets in Göttingen minipigs and the correlation with bioavailability in humans.

Intravenous administration of 125 mg of griseofulvin to G ottingen minipigs showed biexponential elimination of the drug from plasma, in which the half lives of the initial and terminal phases were 0.2-0.6 h and 4.3-6.6 h, respectively. The bioavailability of four griseofulvin tablets used in a human bioavailability study was investigated in the pigs and compared with the human results. The differences of Cmax and AUC between the standard product and the others were smaller in the pig than in humans, however, the correlations of Cmax and AUC between humans and minipigs were high for the four products. The differences of Tmax among the products were small, and the Tmax of the standard product was large in the pigs compared with that in humans. In addition, delayed onset of drug absorption was observed in some of the pigs. The findings suggest slow gastric emptying of the drug in the pigs. The statistically small powers for the in vivo parameters observed in the pig, seem to indicate variable absorption of the drug in the animal.

Administration, Oral↗
PubMed1984

Effect of food on bioavailability of nalidixic acid from uncoated tablets having different dissolution rates.

The effect of food on the bioavailability of two single lots of commercial tablets and one trial tablet of nalidixic acid, varying widely in drug dissolution characteristics, was determined in healthy male subjects after oral administration. Four subjects received, in a crossover fashion, a single 250 mg dose in an uncoated tablet during periods of fasting and non-fasting. Significant differences in Cmax, Tmax and AUC0-8 were observed between the tablet having the fastest dissolution rate and the other tablets tested, when administered postprandially. Both Cmax and AUC0-8 were significantly increased after administration of the two tablets exhibiting the poorer dissolution characteristics to the non-fasting subjects. However, food was not observed to affect any of the bioavailability parameters after postprandial administration of the tablet exhibiting the fastest dissolution rate. The improvement of bioavailability of the two tablets exhibiting the poorer dissolution by food intake was ascribable to enhanced dissolution of nalidixic acid resulting from vigorous mixing and agitation in the digestive tract. It was concluded that the effect of food on the bioavailability of nalidixic acid from uncoated tablets varies with formulation factors, especially with dissolution characteristics.

Adult↗
PubMed1984

Use of PKM-MULTI program for fitting discontinuous absorption profiles using a microcomputer.

The programs for the pharmacokinetic models with discontinuous absorption, written in BASIC, were connected to MULTI, which had been proposed for nonlinear least squares for a microcomputer by Yamaoka et al. Using this program (designated as PKM-MULTI), the same data sets previously calculated by HFCM, FITSI2 and NONLIN were fitted and the finally obtained estimates were in close agreement with those obtained previously. The plasma data of nalidixic acid were also fitted to the pharmacokinetic model with discontinuous absorption, which were suggested to be more valid compared with one compartment model with continuous absorption.

Biological Availability↗