Search PubMed⌕ Search

Biomedical subjects

T Okuno

Publications and source records attributed to T Okuno.

At least 289 records · Page 16Linked to original sources
PubMed1988

Partial labyrinthectomy with argon laser.

Ablation of the saccule and the utricle using an argon laser was carried out in monkeys. After stapedectomy, the saccular macula and the utricular macula were irradiated through the oval window. Animals were sacrificed on 0 days, 10 days, 14 days, and 10 weeks after irradiation. The sensory cells of the saccular macula were detached from the supporting cells at the impact point. The otolith, the saccular wall, and the connective tissue of the saccular macula just beneath the supporting cells were intact. Two weeks after irradiation, sensory cells had disappeared, and the number of nerve fibers was reduced. Ten weeks after the irradiation (1.0 w x 0.5 s x 3 spots), two-thirds of the saccular macula had degenerated, and its surface was covered by a cuboidal cell layer. The number of nerve fibers was reduced. The ganglion cells of the inferior vestibular nerve had degenerated and the cells were smaller than the superior vestibular nerve. Two weeks after irradiation of the utricle, not only sensory cells and supporting cells but also the basement membrane of the utricular macula, connective tissue, and nerve fibers had degenerated and disappeared. Degeneration was extremely localized.

Animals↗
PubMed1988

[A case of carotid superior cerebellar artery anastomosis associated with bilateral hypoplasia of the internal carotid artery represented as the rupture of posterior cerebral artery-posterior communicating artery aneurysm].

A rare case of a variant type of the persistent primitive trigeminal artery associated with bilateral hypoplasia of the internal carotid artery was reported. Left common carotid arteriography revealed a thin left internal carotid artery terminated at the ophthalmic artery. Right common carotid arteriography showed that a narrow internal carotid artery gave off several fine vessels to the cavernous portion, and terminated at the right superior cerebellar artery via the prominent persistent primitive trigeminal artery (PTA). Supraclinoid portions of the bilateral internal carotid arteries were not able to be found. Eventually the entire cerebral hemisphere was supplied by the vertebrobasilar system via the posterior communicating artery. The narrowed supraclinoid portion of the left internal carotid artery was confirmed by surgery of the left posterior cerebellar artery-posterior communicating artery aneurysm. This case may provide an important suggestion about the mechanism of the persistence of the primitive trigeminal artery. In an embryo, at the stage of 5-6mm embryo in size, the posterior communicating artery begins to develop and then PTAs begin to dwindle. If the C1- or C2- portion of the internal carotid artery is gradually occluded, the forebrain, which has to be supplied by the internal carotid system, must be supplied retrogradely by the basilar system via the posterior communicating artery. At this stage, however, the vertebral artery has not developed enough to supply the entire central nervous system. Therefore, the PTA can not regress and this results in the postnatal persistence of the primitive trigeminal artery.

Adult↗
PubMed1988

Cholestatic liver disease in a 20-yr-old woman with histiocytosis X.

A 20-yr-old woman with known diabetes insipidus complained of high fever and jaundice. Liver specimens biopsied under peritoneoscopy showed proliferating histiocytic or foamy cells in periportal areas. Immunocytochemical investigation demonstrated the presence of S-100 protein, but the absence of lysozyme in their histiocytic cells, and ultrastructural study revealed Birbeck granules in them. Vinblastine therapy reduced jaundice and high fever, and diabetes insipidus was controlled. Clinical, immunohistological, and cytological features suggested Letter-Siwe disease with jaundice, which responded well to treatment.

Adult↗
PubMed1988

[Usefulness of CT angiography for demonstrating cerebral aneurysms].

We report the usefulness of computed cerebral angiotomography (CT angiography) for demonstrating cerebral aneurysm and the clinical significance of CT angiography for ruptured cerebral aneurysm. Our modified method of CT angiography was easy and less time-consuming. Fifteen seconds after starting a single bolus injection, 1 ml/kg/25 seconds via cubital vein, of contrast medium (60% urograffin), 5 serial 5 mm thick-CT slices were scanned in every 6.5 seconds including 2 seconds of interval, beginning from an axial level 20 mm above the orbitomeatal line and ending at a level 40 mm. A total of 103 patients were examined in this report, consisting of 70 unruptured asymptomatic, 8 unruptured symptomatic (oculomotor nerve palsy) and 25 subarachnoid hemorrhage (SAH). Seven unruptured aneurysms in 4 asymptomatic cases, 2 unruptured aneurysms in 2 symptomatic cases 27 aneurysms in 24 SAH cases were suspected by CT angiography. Of these 36 aneurysms suspected by CT angiography 32 aneurysms were confirmed by cerebral angiography. The detection rate of CT angiography in this report was 89%, higher than those of previous reports. Thirteen aneurysms were located at internal carotid-posterior communicating artery (ICPC) junction. 11 at anterior communicating artery (Acom), 7 at middle cerebral artery (MCA). CT angiography showed a false positive findings in 4 cases, which were all located at Acom. Four aneurysms were not detected in CT angiography, which were all located at MCA and were very small (2-3 mm) in diameter. There were no deteriorated cases during and after CT angiography. We suggest that CT angiography is a useful and safe method for predicting the location of not only unruptured but ruptured aneurysms.

Aged↗
PubMed1987

Single central maxillary incisor and holoprosencephaly.

A holoprosencephalic child was born to a mother with a single central maxillary incisor. The infant had a median cleft lip, a flat nose with a single nostril, hypotelorism, and normal chromosomes. The head was brachycephalic and small, and computed tomography (CT) of the brain showed semilobar holoprosencephaly. The mother had mild hypotelorism but no anosmia, and her brain CT was normal. She was of normal intelligence and stature. Other relatives did not have single central maxillary incisors, hypotelorism, or oral clefts. Whether the mother's anomaly was a new mutation or had been inherited is unknown. We show the significance of a single central maxillary incisor as an indicator or potential holoprosencephaly in the next generation, even if other relatives are apparently normal.

Abnormalities, Multiple↗
PubMed1987

Chronic active hepatitis with histological features of primary biliary cirrhosis.

A 51-year-old woman was evaluated because of Raynaud's phenomenon, Sjögren's syndrome, and general malaise. There was neither skin itching nor jaundice. Endoscopic retrograde cholangiopancreatography showed a normal extrahepatic as well as intrahepatic biliary tree. Serum GOT and GPT fluctuated with episodes of marked increases. The alkaline phosphatase was slightly increased and total cholesterol was normal. There were marked increases of IgG and IgM. AMA was positive at a titer of 1:320, which was measured by an indirect immunofluorescence method. PBC-specific AMA (anti-M2) was positive, but mixed-form AMA (anti-M4) negative. An LE-cell test, ASMA, ANA, and anti-DNA antibody were all positive on several repeated tests. A wedge liver biopsy tissue showed mixed features of PBC and CAH. A diagnosis of CAH was made on the basis of the clinical, serological, and morphologic findings. The patient responded well to prednisolone treatment with prominent improvement of her symptoms and liver function tests. Subsequently, AMA fell to undetectable levels by indirect immunofluorescence method.

Antibodies↗
PubMed1987

Biological significance of AFP-positive cells in rat livers with hyperplastic nodules induced by 3'-Me-DAB; combined immunocytochemical and radioautographical studies.

We investigated alpha-fetoprotein (AFP)-positive cells in 3'-Me-DAB hepatocarcinogenesis. In the early stage of 3'-Me-DAB hepatocarcinogenesis immunoreaction of AFP was detected in proliferating cholangiolar "oval" cells and in the late stage, AFP-positive cells, differing from oval cells, were detected in clusters in rat liver with hyperplastic nodules. The clusters of AFP-positive cells were morphologically classified into two different types of foci and one type of nodule. The combined techniques of immunocytochemistry and ratioautography revealed that AFP-positive foci and nodule had more 3H-thymidine labeling index than did areas without AFP-positive cells in liver with hyperplastic nodules; also one type of AFP-positive foci had a higher labeling index than the other type and in AFP-positive nodules there was active cell proliferation; but AFP-positive foci or nodules had less 3H-thymidine labeling than AFP-positive hepatoma cells. These findings suggested that AFP-positive foci and nodule had different biological significance in development of hepatocellular carcinoma and that AFP-positive foci with higher labeling index and AFP-positive nodule should be surveyed as preneoplastic population.

Animals↗
PubMed1987

Change in salt appetite due to rehydration level in rats.

Thermally dehydrated rats were given a choice of tap water and saline (0.9% or 1.8% NaCl), and the change in the salinity of their choice during rehydration was measured up to 15 hr. The rats consumed more water than saline for about 2 hr after the start of fluid replacement (about 55 mEq/l), while they consumed more saline than tap water (about 120 mEq/l) thereafter. Urine output and urinary Na output were only about 20% of their intake during the initial 4 hr of rehydration, while after 4 hr the output became almost equal with the intake. The change in salt intake occurred when about 90% of Na loss and 60% of fluid loss was regained. The results indicate that rats choose dilute salt solution to lower plasma osmolality during the initial period of the rehydration and then regain body fluid isotonically. Urine volume and urinary Na output increased only after volume repletion. Thus, osmoregulation with salt appetite has priority over fluid volume regulation in restitution from thermal dehydration.

Animals↗
PubMed1987

Clorazepate therapy for intractable epilepsy.

Thirty-one epileptic patients with seizures refractory to conventional anticonvulsants were treated by adding clorazepate dipotassium to their regimen. Twelve cases showed improvement in seizure frequency, three of whom attained a seizure free state. Response to clorazepate was not related to the type of epilepsy, but patients with secondary generalized epilepsy tended to be less responsive than those with partial epilepsy. Among the various seizure types, generalized tonic-clonic seizures and simple partial seizures showed, although not significant, a tendency to be more responsive to clorazepate therapy than other seizure types, including complex partial seizures, atypical absence, atonic seizures, and tonic seizures. Drowsiness was the main adverse effect, of which 14 patients complained. Six patients were withdrawn from clorazepate because of drowsiness, but in the remaining 8 patients, this side effect disappeared within a week. The appearance of adverse effect was not related to the dose of clorazepate given. Clorazepate may be an effective secondary anticonvulsant in the treatment of intractable epilepsy.

Adolescent↗
PubMed1987

Langer-Giedion syndrome with del 8 (q24.13-q24.22).

An 8-year-old boy with the features of Langer-Giedion syndrome except for short stature is described. Chromosome analysis using high resolution G-banding techniques revealed an interstitial deletion of the long arm of chromosome 8:46,XY,del(8)(q24.13-q24.22).

Child↗
PubMed1987

Changes in blood volume and plasma sodium concentration after water intake in rats.

Changes in blood volume (BV) and Na+ concentration of plasma ([Na+]) were measured continuously during recovery from thermal dehydration in rats. At least 5 days prior to the experiments rats were cannulated into both the jugular vein and the descending aorta. After thermal dehydration (DBT: 36 degrees C, RH: 20%) amounting to approximately 6% of body wt, catheters were connected to a system for continuous monitoring of BV and [Na+]. Water was made available and water intake, BV, and [Na+] were recorded at 30-s intervals for 4 h. The rats took 2-3 ml of water/100 g of body wt in the first 10 min and then drank 1 ml at 30- to 60-min intervals to reach equilibrium in 2-3 h. The relations between water intake and delta BV and between delta[Na+] were analyzed for 2 h after the start of water supply. BV was unchanged until 18.9 +/- 3.6 min after access to water, whereas [Na+] started to decrease after 3.6 +/- 0.6 min. The retention ratio of ingested fluid in the vascular space was 20.8 +/- 2.8%, and the decrease of [Na+] was 1.5 +/- 0.2 meq X l-1 X ml ingested fluid-1 X 100 g body wt-1. These results indicate that drinking causes the change of [Na+] more rapidly than that of blood volume.

Animals↗
PubMed1987

A case of hyperbilirubinemia during treatment with chenodeoxycholic acid.

This is a report of a 27-year-old female with hyperbilirubinemia during treatment with chenodeoxycholic acid (CDCA) for the resolution of gallstones. After CDCA administration, serum bilirubin increased markedly without an apparent obstruction of bile ducts. The histological findings of the liver were compatible with toxic liver injury. Bile acids analysis, however, did not reveal the increment of lithocholic acid, toxic metabolite of CDCA in the serum and the hepatic tissue. The bile acids sulfation and the 6 alpha-hydroxylation of CDCA were also normal. Her jaundice disappeared quickly after discontinuation of CDCA. Presumably, in this case, the stagnation of bile acids in the liver caused by choledochal sands facilitated the toxic effect of CDCA on the damaged hepatocytes.

Adult↗
PubMed1987

Microangioarchitecture of the feline spinal cord. Three-dimensional observation of blood vessel corrosion casts by scanning electron microscopy.

The microangioarchitecture of corrosion casts of the cat spinal cord was studied by scanning electron microscopy. On the ventral surface of the spinal cord, the anterior spinal artery and the anterior spinal vein ran parallel along the anterior median fissure. Many central arteries branching from the anterior spinal artery coursed in a wavelike manner in the anterior median fissure. The number of central arteries was lowest in the thoracic spinal cord. Central arteries at some spinal cord levels revealed well-developed anastomoses with other central arteries in the anterior median fissure. These well-developed anastomotic central arteries were frequently observed in the thoracic spinal cord, in which the number of central arteries was lowest. On the dorsal surface of the spinal cord, the posterior spinal vein ran longitudinally at the midline and was drained by circumferential veins and posterior central veins. This vein formed a characteristic anastomotic plexus. Small arterioles (20 microns in diameter) in the spinal parenchyma revealed a ring-like compression at the branching site.

Animals↗