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Biomedical subjects

T Iwabuchi

Publications and source records attributed to T Iwabuchi.

At least 109 records · Page 6Linked to original sources
PubMed1984

[Two cases of primary intracranial malignant lymphoma].

Two cases of primary intracranial malignant lymphoma are reported. Case 1 was a 65-year-old female who was operated on for a left frontoparietal tumor in 1966 at our hospital, and the tumor was diagnosed as reticulum cell sarcoma histologically. Irradiation was also done. Thereafter, she had had no serious trouble except for slight right hemiparesis. In March of 1982, right hemiparesis became worse and disturbance of consciousness also appeared. CT scan and left carotid angiogram revealed a left fronto-temporoparietal tumor. Subtotal removal of the tumor was performed on the 1st of April. The tumor was diagnosed as malignant lymphoma, of large cell type. Chemotherapy was started postoperatively and marked decrease of enhanced area was observed in the CT scan taken on the 9th of July. But the patient showed melena and was diagnosed as having rectal adenocarcinoma histologically by biopsied specimen. Case 2 was a 48-year-old male who had been suffering from left facial palsy and vertigo since August, 1981. Those symptoms gradually progressed. On the 4th of December, he was admitted to our clinic. On admission, neurologically, multiple cranial nerve involvement was noticed such as of the IIIrd, IVth, Vth and VIth nerves bilaterally, and the VIIth, IXth, Xth and XIth cranial nerves on the left side. Right hemihypalgesia, thermohypesthesia, dysmetria, dysdiadochokinesis, and cerebellar taxia were also seen. CT scan and left vertebral angiogram revealed a tumor in the pons and IVth ventricle. On December 8th, suboccipital craniectomy was performed, but almost all of the tumor seemed growing under the floor of the IVth ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1984

[Gangliocytoma of the pineal body. A case report and general review].

A case of pineal gangliocytoma in a 51 year-old man is presented. He was admitted to the hospital on February 2, 1982, with complaints of headache, nuchal pain, blurred vision, nausea and vomiting of three years' duration. Neurological examination did not show any neurological deficits but bilateral choked disc. Preoperative CT scan disclosed a sharp by circumscribed high density lesion in the pineal region with moderate hydrocephalus. Preoperative 99m Tc-DTPA brain scan revealed a warm activity in the pineal region, and changes of its activity were only little in the course of time. Preoperative Amipaque ventriculogram showed dilation of the lateral ventricles and a shadow of the tumor bulging into the posterior half of the distended third ventricle. A diagnosis of tumor of the pineal region was made and removal of the tumor was performed by biparieto-occipital interhemispheric approach in "sea lion" position. The tumor was a dark reddish solid mass which replaced the pineal body and extended under the cerebellar tentorium. The patient made an uneventful recovery without any neurological deficits. By light microscopy, the neoplasm was composed mostly of mature and immature ganglion cells and small round cells with moderate cellularity and multiform cytologic features. Ganglion cells with large nuclei and prominent nucleoli had characteristic Nissl substance in various amounts. Oligodendrocytes and astrocytes appeared around the tumor but did not show neoplastic growth. GFAP stain did not show glial component in the tumor. According these findings, the tumor was diagnosed as gangliocytoma originated from the pineal body, and this was the first case in Japan.

Brain Neoplasms↗
PubMed1983

Comparative efficacy of antiherpes drugs against various strains of varicella-zoster virus.

Twenty antiherpes compounds were compared for their inhibitory activities against five laboratory strains and five clinical isolates of varicella-zoster virus (VZV) in human embryo fibroblast cultures. E-5-(2-bromovinyl)-1-beta-D-arabinofuranosyluracil (BVaraU), E-5-(2-iodovinyl)-2'-deoxyuridine (IVDU), and E-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) were the most effective. The average values of the 50% inhibitory dose (ID50) for VZV replication were 0.0013, 0.0015, and 0.0024 micrograms/ml, respectively. 1-beta-D-Arabinofuranosyladenine and 9-(2-hydroxyethoxymethyl)guanine were 1.2 and 3.4 times less effective than 5-iodo-2'-deoxyuridine (IDU). The selectivity indexes (ratio of ID50 for host-cell DNA synthesis to ID50 for VZV replication) of BVaraU, IVDU, and BVDU were between 41,000 and 67,000, whereas those of cytosine arabinoside, IDU, and 5-bromo-2'-deoxyuridine were less than 1.1. BVaraU, IVDU, and BVDU were the most potent and the most selective inhibitors of VZV activity. A deoxythymidine kinase deficient mutant of VZV was resistant to most of the compounds tested at concentrations up to 36,000 times greater than the average ID50 for strains that were not deficient.

Antiviral Agents↗
PubMed1983

Changes of the auditory system after cerebellopontine angle manipulations.

The current tendency in acoustic neuroma surgery to attempt the preservation of hearing function and the problem of accidental hearing loss caused by microsurgical neurovascular decompression operations for hemifacial spasm or trigeminal neuralgia prompted us to study the exact surgical vulnerability of the auditory system. The surgical procedures for operation on the cerebellopontine angle of dogs were carried out according to the sequence of the posterior fossa transmeatal operation for acoustic neuroma. The operation was tentatively divided into three stages: (a) craniectomy and dural opening, (b) cerebellar retraction, and (c) identification of the cochlear nerve in the unroofed internal auditory canal (IAC). The postoperative behavior of the auditory system was evaluated electrocochleographically (EcochG) and histologically. Overzealous retraction of the cerebellar hemisphere caused transient disturbance of the EcochG pattern. Mechanical stretching of both the cochlear nerve and the internal auditory artery may cause a disturbance in the synchronized discharge of the cochlear neurons. Various manipulations at the porus acusticus internus or the IAC (such as pinching the nerve with forceps or electrocoagulation) produced thoroughly distorted EcochG patterns. From the histological findings, the main causative factor for these labyrinthine damages was considered to be vascular insufficiency. The current need for neurosurgical operations to preserve hearing is discussed in the light of these findings.

Action Potentials↗
PubMed1983

Dural sinus pressure as related to neurosurgical positions.

Taking advantage of the exposure of dural sinuses during craniotomies, we measured confluens sinuum pressure by direct catheterization. The influence of various surgical positions and of other factors on confluens sinuum pressure was studied. When the upper half of the body was raised, the confluens sinuum pressure decreased to reach zero at +25 degrees; when the angle was +90 degrees, a marked negative pressure of -12.7 +/- 3.0 cm H2O (mean +/- SD) was observed in adults. In children under 6 years of age, however, such negative pressure was not observed even at an angle of +90 degrees. The confluens sinuum pressure was 2.7 +/- 0.6 cm H2O with the patient in the reverse jackknife position (supine position with the upper and lower halves of the body elevated ca. 20 degrees), 3.0 +/- 0.8 in the sea lion position (prone position with the upper and lower halves of the body elevated ca. 20 degrees and with the neck hyperextended), 5.8 +/- 0.9 in the prone position, and 5.9 +/- 1.7 in the supine position. In the supine and the sitting positions, the confluens sinuum pressure was elevated well enough by jugular compression to prevent air embolism. Positive pressure respiration did not raise the confluens sinuum pressure. The pressure of the jugular bulb measured by percutaneous direct puncture did not always reflect the confluens sinuum pressure, probably because subcutaneous hematoma produced an effect similar to that of jugular compression.

Adolescent↗
PubMed1983

Role of multiple cerebral microthrombosis in symptomatic cerebral vasospasm: with a case report.

In our studies of the pathogenesis of cerebral vasospasm, we have been emphasizing that microthrombosis may play an important role in the induction of cerebral ischemic symptoms or cerebral infarction. In this report, multiple microthrombi are demonstrated histologically to be a major cause of cerebral infarction in the autopsied brain of a 63-year-old woman who died from typical cerebral vasospasm that occurred after the rupture of an anterior communicating artery aneurysm. We discuss the significance of thrombus formation and subarachnoid perivascular acidosis in vasospasm.

Cerebral Angiography↗
PubMed1983

[The significance of dural sinus pressure in neurological surgery-- correlation with surgical position].

A study was made of the significance of confluens sinus pressure in various surgical positions and of various factors influencing confluens sinus pressure. The following findings were obtained: Confluens sinus pressure in various positions was follows: Reverse jackknife position (supine position with upper and lower halves of the body elevated ca 20 degrees) 1.3 +/- 0.8 (Mean +/- SD) cmH2O Sea lion position (prone position with upper and lower halves of the body elevated ca 10 degrees with neck hyperextended) 2.7 +/- 0.6 cmH2O Prone position 5.8 +/- 0.9 cmH2O Supine position 5.9 +/- 1.7 cmH2O Right lateral position 6.9 +/- 0.7 cmH2O Left lateral position 9.6 +/- 1.2 cmH2O Since confluens sinus pressure is strongly affected by gravity, the determination point, the height of the right atrium, and the central venous pressure were referred to when measuring the surgical position. When the upper half of the body was raised (at angle ranging from--10 degrees to +90 degrees) confluens sinus pressure became zero in adults when the angle was +25 degrees or thereabouts. When the angle was +90 degrees, a marked negative pressure of -12.7 +/- 3.0 cmH2O, was observed, suggesting the danger of air embolism. In 4 children under 6 years of ago, however, negative pressure was not observed even at an angle of +90 degrees, although some changes due to different angles were noted. This suggests some specificity of dural sinus pressure. Intrathoracic negative pressure at inspiration, the contraction of skeletal muscles, and profuse hemorrhage, and sympathetic nervous strain were surmised as other factors influencing dural sinus pressure.

Adult↗
PubMed1983

[Formation of postoperative hematoma directly under a silastic dural substitute].

Several cases of spontaneous hematoma formation occurred under the Silastic dural substitute were reported with CT-scan and recraniotomy findings. In overall analysis, an incidence of the spontaneous hematoma formation was 35.1% in cases of artificial dural grafting with Silastic sheeting and none with autogenous temporal fascia. On CT-scan the hematoma showed localized high density area severely convex toward underlying brain. At recraniotomy, the hematoma consisted of massive clot presented locally beneath the dural substitute. As it depressed sharply underlying brain, it tends to having shown heavy clinical symptoms in comparison with a volume of clot. Neomembrane formed under the artificial graft seemed the most probable bleeding source.

Adult↗
PubMed1982

Histological change in permanently clipped or ligated cerebral arterial wall. Part I. An experimental study in dogs.

In this paper, we discuss the results of a study by light microscope of the effect of permanent clipping or ligation on the intracranial arteries of 38 operation dogs and 7 control dogs. The findings obtained are: 1. In the cerebral arterial circle, necrosis could easily result from ordinary clipping or ligation because of scarce vasa vasorum. 2. As for the incidence of necrosis, the greatest was found in the case of the Yaşargil clip after electric coagulation, next came the Yaşargil clip alone, next ligation, and last the silver clip. The degree of necrosis correlated with the duration of clipping in the cases treated with a spring type clip, and was influenced more by the closing strength at the time of application in the cases with non-spring type clips or ligation. 3. In some of the cases ligated for long duration, recanalization was caused by the passage of the ligature through the vessel wall, suggesting that ligation is not a certain procedure if it is applied alone. 4. The granulation tissue round the clip and ligature began to grow after one month. As for its degree, the most marked granulation was that caused by the silver clip, next the ligature, than the Yaşargil clip after electric coagulation, and finally the Yaşargil clip used normally; in all of them the correlation with the passage of time was noted. 5. In the group of duration three months or more, concentric intimal proliferation was noted peripheral to the clip, and intimal proliferation was also noted exclusively localized to the side of a branch on the central or truncal side of a clip. This correlated in degree with the passage of time. 6. Clipping and ligation are liable to cause necrosis and fragmentation, but on the other hand it was considered that rupture of the vessel wall did not result because of the reinforcing and reparative effect of the reactive granulation tissue and the intimal proliferation which developed in such a manner as to strengthen the area involved.

Animals↗
PubMed1982

Histological change in permanently clipped or ligated cerebral arterial wall. Part II: Autopsy cases of aneurysmal neck clipping.

An investigation was carried out on clinical autopsy cases into histological changes in the vessel wall and into the surrounding tissue reaction after permanent clipping. 1. There were 17 autopsy cases of cerebral aneurysm, which included seven cases treated with the Yaşargil clip, five with the Heifetz clip, and five control cases. 2. Clipping period ranged from 6 days to 11 months. Both the Yaşargil and the Heifetz clips, even with long duration of clipping, caused no changes, and inflammatory reaction was slight. 3. As for the necrosis of the vessel wall beneath the blade, the Yaşargil clip produced marked necrosis at the blade edge in 4 of 7 cases (57%), while the Heifetz clip caused necrosis under the midconvexity of the blades in all 5 cases (100%). 4. The granulation tissue reaction round the clip began to occur after one month, and was enough to embed the blade of the clip after three months. We considered it very unlikely for a slip-out accident to occur after this stage. 5. Formation of mural red thrombus and deposition of fibrin with irregular intimal thickening were noted in the aneurysmal lumen in cases clipped for less than 13 days. After one month the intimal thickening was diffuse, and organized thrombus was noted. After three months or more, the aneurysmal lumen was found to have been filled almost completely by intimal thickening. Based on the above finding, the optimum condition for temporary and permanent clips was also considered.

Adult↗
PubMed1982

Oculomotor nerve anastomosis.

We report a patient who underwent anastomosis of the left oculomotor nerve, which had been inadvertently and bluntly severed during the resection of a left parasellar chromophobe pituitary adenoma. Neural regeneration was confirmed by the reappearance of voluntary adduction of the eyeball, clinical signs of aberrant regeneration, and the appearance of an action potential on electromyography of the levator palpebrae superioris muscle 1 year after end-to-end anastomosis of the nerve.

Adenoma, Chromophobe↗
PubMed1982

Recurrence of cerebral aneurysm after initial neck clipping.

Neck clipping has generally been believed to be among the most reliable of the operative modalities for cerebral aneurysm. However, recurrences with catastrophic outcome have been known to occur. We recently treated two patients who each had a new aneurysm at the site of the initial clipping. In both cases, the recurrence was found several years after the aneurysm neck had been closed successfully with a silver clip, which had been confirmed by intraoperative inspection and by postoperative angiographic studies demonstrating disappearance of the aneurysm. Histological examination of the recurrent aneurysm showed that the arterial wall had apparently been damaged by the clip edge, which resulted in thinning and disruption of both the muscle layer and the internal elastic lamina. Therefore, local fragility of the arterial wall adjacent to the aneurysm seems to have been the cause of the formation of a new aneurysm. The need to reinforce the thin-walled parent artery and the usefulness of high resolution computed tomography for the early detection of recurrent aneurysms are emphasized.

Cerebral Angiography↗