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Biomedical subjects

K Yada

Publications and source records attributed to K Yada.

At least 91 records · Page 5Linked to original sources
PubMed1989

[Postoperative intracranial pressure in severe cases with hypertensive intracerebral hematoma].

The relationship between the postoperative ICP and the size of hematoma on CT scan and the time of operation was studied to evaluate their influence on the therapeutic results in the severe cases with hypertensive intracerebral hematoma. Twenty one patients of putaminal hemorrhage with severe neurological deficit (semicoma) were studied. ICP was monitored continuously by the Subdural balloon method after craniotomy to remove the hematoma. The relationship between the postoperative ICP level (High ICP: above 40 mmHg, Moderate ICP: 40-20 mmHg, Low ICP: below 20 mmHg), the size of hematoma estimated from CTscan (Large: more than 80 ml, Medium: less than 80 ml), the time from onset to removing hematoma and the therapeutic results were evaluated. The outcome six months after onset was determined according to the Glasgow Outcome Scale. Of 6 cases with Medium hematoma operated on within 8 hours, Low ICP was found in 5 cases (83%) and Moderate ICP was in one case (17%). Of 6 cases with Medium hematoma operated on after 8 hours, High and Moderate ICP were found in 3 cases (50%), respectively. In the cases with Large hematoma, Low ICP was not observed, but High ICP was found in 4 of 7 cases operated on within 8 hours (57.1%) and the other three indicated Moderate ICP (42.9%). High ICP was found in two cases with Large hematoma operated on after 8 hours (100%). The outcome of High ICP cases was severe disability in 4 cases, vegetative state in one and dead in 4, and that of Moderate ICP cases was moderate disability in 3 cases and severe disability in 4.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Serial changes in acute extradural hematoma size and associated changes in level of consciousness and intracranial pressure.

The authors report the cases of 37 patients encountered during the past 4 years who exhibited acute extradural hematoma but were initially treated conservatively because no or only small hematomas were observed on admission. The frequency of hematoma enlargement, hematoma size, and changes in the level of consciousness and intracranial pressure (ICP) were examined in these patients. The hematomas enlarged in 24 (64.9%) of the 37 patients, and attained a maximum thickness of 25 mm or greater in 19 patients (51.3%). The level of consciousness could be closely observed during enlargement of the hematomas in 13 patients: the level remained unchanged in eight, deteriorated in two, and improved in three, indicating relative stability in the state of consciousness despite the marked changes in hematoma size. The patients whose hematoma enlarged after the initial examination included three who underwent initial CT examination 5 hours after the injury. In five patients enlargement of extradural hematomas was observed unexpectedly during conservative treatment under ICP monitoring. The ICP also remained stable in three patients until the follow-up examination, but showed a rapid increase in two after a period of stability. However, there was no difference in the final size of the hematomas between the patients showing an increase in ICP and those who did not. These findings suggest that extradural hematomas enlarge progressively at rates varying with the condition of the source of hemorrhage. Moreover, a period of stability in the level of consciousness, such as the lucid interval seen in patients with extradural hematoma, is considered to be a period during which compensatory mechanisms can maintain the stability of the intracranial condition during progressive enlargement of the hematoma.

Adolescent↗
PubMed1988

Calcium pyrophosphate dihydrate crystal deposition disease in the cervical ligamentum flavum.

The authors describe three cases of cervical radiculomyelopathy caused by calcium pyrophosphate dihydrate crystal deposition disease (CPPDcdd). Radiological investigations revealed nodular calcifications, 5 to 7 mm in diameter, in the cervical ligamentum flavum compressing the spinal cord. Light microscopic, scanning electron microscopic, and x-ray diffraction studies were performed on all three surgical specimens obtained by laminectomy. In two of the cases x-ray microanalysis and transmission electron microscope studies were also performed. This study defined the presence of two patterns of crystal deposition in the ligamentum flavum. One is a nodular deposit, in which hydroxyapatite crystals are seen in the central part of the nodules, with calcium pyrophosphate dihydrate (CPPD) being distributed thinly around them. The other pattern is a linear deposit seen in multiple ligaments and composed of pure CPPD, which causes minimal thickening of the ligaments. A transitional pattern between the two types was also observed. This study revealed details of the nodular deposition of crystals in the ligamentum flavum and demonstrates that CPPDcdd and so-called "calcification of the ligamentum flavum" are the same disease: namely, CPPDcdd. Hydroxyapatite is assumed to have been transformed from CPPD.

Aged↗
PubMed1988

[A clinical study of severe cases of hemorrhagic cerebral arteriovenous malformations].

The clinical study was undertaken on 24 poor risk patients out of 69 cases with hemorrhagic cerebral arteriovenous malformations, AVMs, and the surgical problems of poor risk patients with the lesions were discussed. The 24 cases, 35%, out of 69 hemorrhagic AVMs cases showed disturbances of consciousness of 3 digits (100-300) according to the Japan Coma Scale at the time of admission. All cases of these poor risk patients were observed less than 24 hours after the onset of the symptoms. Fifteen of these 24 cases showed brainstem signs including anisocoria and/or decerebrate rigidity and/or respiratory arrest. Eighty-three per cent of 24 poor risk patients had serious neurological defects as a result of the first hemorrhage. Therefore, it was impossible to prevent serious state from occurring in poor risk patients. Of the 69 cases with hemorrhagic AVMs, 56 cases were operated upon. Although 90% out of 38 good risk patients whose level of consciousness was 0 to 30 according to the Japan Coma Scale showed good recovery, only 44% of 18 poor risk patients recovered well. It could not be said that the surgical treatment gave satisfactory results for the poor risk patients when compared with the surgical results of the good risk patients. In respect to the location of AVMs, all three poor risk patients with AVMs in the corpus callosum and the ventricles showed good recovery, whereas of the poor risk patients with AVMs in the cerebrum or the cerebellum, only 4 out of 9 cases (44%) and 1 out of 6 cases (17%) showed good recovery respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

[Origin of the capsule of a chronic subdural hematoma--an electron microscopy study].

To understand the early stage of subdural neomembrane (SN) formation, we examined 23 outer SNs and two inner SNs of chronic subdural hematomas in surgical specimens. Ultrastructurally, the cellular component of the outer SN was fibroblasts, myofibroblasts, smooth-muscle cells (in four cases), blood vessels and blood-born cells. Dural border cells were observed only in limited areas. Namely, the outer SN is a simple granulation tissue which originates from multiple sources of mesenchymal cells in dura mater, and dural border cells are only one of constituent sources for SN formation. The inner SN was simply composed of slender spindle cells which were mostly fibroblasts and some were recognized as dural border cells. Our results showed that the subdural hematoma is actually an "intra" dural hematoma which is formed within the split dural border cell layer. The dura mater with rich vascular supply forms thick granulation tissue, that is outer SN and a few dural border cells on the underlying arachnoid membrane form thin fibrous inner SN.

Adolescent↗
PubMed1987

[Myelopathy caused by hypertrophy of the posterior longitudinal ligament (HPLL): case report].

A case of myelopathy caused by hypertrophy of the posterior longitudinal ligament at the cervical spine is reported. A 71-year-old man was hospitalized with myelopathy with progressed during the last two months. Plain X-ray of the cervical spine revealed only mild spondylotic change. Myelography demonstrated completely blocked contrast medium at C4 to C5 vertebral height due to epidural mass. This epidural mass was localized ventral to the spinal cord from C3 to C5. CT scan revealed slightly high density area behind the vertebral body. On surgery, no evidence of disc fragment but only hypertrophied posterior longitudinal ligament which was removed was found to be a cause of cord compression. Excellent recovery of neurological symptoms after operation was obtained. On histological study, remarkable hypertrophy, edema, hyalinoid degeneration and a little calcification of the ligament was found, which did not show any evidence of new bone formation. HPLL was characterized by thickened and broad epidural mass in the ventral side of cervical cord with Hounsfield number of 90-156 on CT scan, which is not very easy to differentiate from metastatic epidural tumor. The cause of HPLL is not well elucidated, though, this may be a new category of compression myelopathy.

Aged↗
PubMed1986

Pyloric stenosis: an unusual complication of Behçet's disease.

A 20-yr-old Japanese man with longstanding Behçet's disease had pyloric stenosis and multiple duodenal ulcers. The pyloric stenosis was due to edematous hypertrophy of the pyloric ring and was unrelated to duodenal ulceration. The evidence suggests that the pyloric stenosis and multiple duodenal ulceration were a manifestation of Behçet's syndrome and not merely incidental peptic ulcer disease.

Adult↗
PubMed1985

[The usefulness of prolonged high dose delayed contrast computed tomography for the diagnosis of intracranial angiographically occult vascular malformations].

It is difficult to diagnose angiographically occult vascular malformations. When conventional CT (plain & contrast enhancement) can not demonstrate the lesions, it was impossible to diagnose in the past. We developed a new technique which enabled us to diagnose them. Materials and methods; Seven cases of spontaneous intracerebral hemorrhage, in which no abnormality was detected by repeated magnified serial angiography with subtraction technique and prolonged injection technique, were examined. In each case, conventional CT (plain & enhancement using 100 ml of 60% meglumine iothalamate) was performed first, which was immediately followed by the administration of 220 ml of 30% meglumine iothalamate for one hour. CT is taken at the end of the infusion. It, we call, is prolonged high dose delayed contrast CT: PHDD-CT. Total dose of iodine used in this technique was 59.22 gI (1.0 gI/kg body weight: BW). Results; Contrast enhancement effect of PHDD-CT was much better than that of conventional CT in all the cases. In three cases, the lesions were more clearly delineated in PHDD-CT. In four cases, only PHDD-CT could demonstrate the lesions. No side effect was observed. Comments; Several techniques for better enhancement have been reported, however they used large volume of contrast medium such as 1.5 or 2.0 gI/kg BW. Our technique can be performed with more security. Based on our good results, we recommend to use this PHDD-CT technique for the diagnosis of angiographically occult vascular malformations.

Adolescent↗
PubMed1984

[The mechanism of intracranial pressure-reducing effect of mannitol].

The effect of mannitol to decrease the raised ICP is well documented and mannitol is now widely used in clinical practice. However, its mechanism of lowering ICP still remains controversial, especially under the condition of vasogenic edema. The objective of this study is to reexamine and delineate the mechanism of ICP reducing effect of mannitol, using quantitative vasogenic edema model, specific gravimetric technique to measure the brain water content, and the method to estimate the CSF dynamics without disturbing the physiological condition of intracranial compartments in cats. Quantitative increase of water content of the white matter was produced by the infusion of 0.5 ml of normal saline though stereotaxically inserted 25-G needle into the left frontal white matter. In control group, cats were sacrificed and water content of the gray and white matter of each coronary sliced brain was measured by specific gravimetric technique. In the mannitol group, 20% of mannitol (2 g/kg) was administrated via femoral vein within 3 minutes. The maximum reduction of ICP was achieved at the average of 30 minutes. At this time, the cats were sacrificed and the water content of brain was measured in the same way as in the control group. PVI, Ro, If (Marmarou) were calculated before and after mannitol administration. In parameter group, BP, ICP, CVP, serum osmotic pressure and osmolarity were measured without terminating the experiment. The changes of water content of the gray and white matter before and after mannitol administration in the area of infusion edema were 80.7% to 80.8% and 76.8% to 77.1% respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

[Pisio-hamate hiatus syndrome].

Two patients with atrophy and weakness of intrinsic had muscles innervated by the deep branch of the ulnar nerve except abductor digiti quinti muscle and without any sensory symptoms were reported. They were house-wives aged thirty and fourty-four, respectively, without any specific history of trauma or occupation. Neurological and neurophysiological examination pointed out that the lesion situated in the deep branch of the ulnar nerve. Both of them were operated on. At operation, no abnormal structure were found in the canal of Guyon, though, the deep branch of the ulnar nerve was enlarged at the pisio-hamate hiatus where the branch to the abductor digiti quinti has taken off. In one of the cases, microsurgical removal of the epineurium of the deep branch revealed that each funiculus has lost its course into irregularly enlarged mass, which thought to be neoplastic change. In this case the deep branch was replaced by cable grafts about two centimeters in length by using the sural nerve. Histological findings of this case were as follows: there was no neoplastic or inflammatory change, there was no normal axon pa surviving and that very little regenerated axon and marked interneural fibrosis were observed, which indicates that the nerve lesion was caused by chronic compression. In the other case, the attachment of the membranous tendon of the flexor digiti quinti brevis and opponence digiti quinti muscle to the hook of the hamate was removed. No marked improvement was obtained in both of the cases, because they were too late to be operated on (ten and three years has passed since they noticed muscular atrophy, respectively).

Adult↗
PubMed1984

[Posterior longitudinal myelotomy as a surgical treatment of acute cervical spinal cord injury].

Although it is of great tragedy to lose motor and sensory function of the spinal cord by spinal cord injury, there is no effective measure for complete cord lesions. In the central gray of the spinal cord at the region of injury, hemorrhagic necrosis and edema advance causing secondary damage to the spinal cord in rather early stage after injury. It has not been proved whether to remove necrotic tissue in the central gray matter can be effective to prevent secondary damage of the spinal cord or not. Operative result of six patients with acute physiologically complete cervical spinal cord lesion who have been subjected to posterior longitudinal myelotomy and removal of hematoma and necrotic tissue of the central gray of the spinal cord were evaluated. All of them admitted to Kitasato University Hospital within 24 hours after injury. They were five males and one female aged twenty to fifty-three. All the patients showed complete block of contrast medium on myelography at the level of one to two segments above the neurologically estimated level or injury of the spine, indicating marked swelling of the spinal cord. Average duration from injury to operation was sixteen hours ranging from six to thirty nine. Posterior longitudinal myelotomy was performed by using microsurgical technique. Skull traction was performed by using Crutchfield tongs for six weeks in five and twelve weeks in one of the patients. On admission forty mg of dexamethasone was used as steroid therapy followed gradual reduction.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1984

[Acute traumatic hydrocephalus].

We have experienced two rare cases of acute traumatic hydrocephalus which developed within several hours after head injury. Case 1. A 4-year-old boy was stuck by an automobile. After losing consciousness for a few minutes, he became agitated and vomited. He was brought to our hospital 3 hours after accident. On admission, he scored 8 points on the Glasgow Coma Scale. CT scan on admission disclosed slightly enlarged ventricles, but there were no findings indicating cerebral contusion nor intracranial hemorrhage. His state of consciousness gradually deteriorated, thereafter right sided convulsive seizures occurred. 7 hours after accident, CT scan was repeated and demonstrated a marked enlargement of the ventricles. Continuous ventricular drainage was performed. The ventricular fluid was slightly bloody. After the ventricular drainage, the state of consciousness improved rapidly. 6 days after the accident, ventricular drainage was discontinued. Afterward, size and shape of the ventricles became nearly normal and the patient was discharged 36 days after the head injury without any neurological deficits. Case 2. A 3-year-old girl was buried under a burden. 30 minutes after the accident, her consciousness began to deteriorate with vomiting. She was brought to our hospital 3 hours after the accident. On her arrival, she scored 13 points on Glasgow Coma Scale. CT scan, which performed 4.5 hours after the accident, showed slightly enlarged ventricles and intraventricular hemorrhage in the third and fourth ventricles. Her state of consciousness gradually worsened with generalized seizures. Repeated CT scan 8 hours after the accident, demonstrated a marked enlargement of the ventricles. Following ventricular drainage, the patient's state of consciousness improved rapidly.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1983

Oligodendroglioma-like cells (clear cells) in ependymoma.

A brain tumor of a 22-year-old man was composed mostly of round cells with perinuclear halos (clear cells), forming clusters intersected by small blood vessels. In some areas, the tumor cells showed perivascular arrangement and epithelial pattern. Phosphotungstic-acid hematoxylin stain and immunoperoxidase stain for glial fibrillary acidic protein (GFAP) technique failed to stain the clear cells. Electron microscopy of the clear cells revealed them to be classical ependymoma cells with well developed intercellular junctions, microvilli and cilia. As no reporters in the past showed the evidence to clarify the nature of the clear cells, this case is considered a good example to support the viewpoint that the clear cells (oligodendroglioma-like cells) commonly observed in ependymomas are in reality ependymoma cells. It is stressed that the diagnosis of "mixed glioma" or "oligoependymoma" should be made with sufficient caution despite the recent advances of GFAP technique.

Adult↗
PubMed1983

Three-dimensional visualization of Golgi-stained neurons by a projection X-ray microscope converted from a scanning electron microscope.

Trying to obtain the three-dimensional images of neuronal elements, Golgi-stained thick sections were examined by a projection X-ray microscope converted from a scanning electron microscope. An attachment unit for the projection X-ray microscope consists of a target holder, specimen stage and film cassette. Two kinds of target material, titanium and gold, were tested. The system was operated at 10 to 30 kV. The electron beam into the target was about 20 nA with the use of a pointed cathode. The stereopair of X-ray micrographs were taken by tilting the specimens. Quality and contrast of the X-ray micrograph taken with a titanium target was better than that with a gold target. The spatial resolution was estimated about 1 to 2 micrometers for 100 to 350 micrometers thick sections with a titanium target. Compared with the light microscope, strong penetrating ability of X-ray permitted to visualize the internal structures of optically opaque materials. Further, almost all objects were in focus in X-ray micrographs even for relatively thick sections (100 to 350 micrometers). The three-dimensional morphology of neurons and glial cells was demonstrated by a stereopair of X-ray micrographs.

Animals↗
PubMed1982

Contiguous malignant astrocytoma and Wilms'-like tumor in the brain.

A case of primary brain tumor composed of two contiguous neoplasms in presented. At operation, a nodular tumor was embedded in the infiltrating tumor within the brain parenchyma. With light and electron microscopy, the nodular tumor was similar to Wilms' tumor (nephroblastoma). The infiltrating tumor was malignant astrocytoma. Autopsy revealed, besides the recurrence of malignant astrocytoma in the brain and its subarachnoid dissemination, extracranial metastases to the abdominal cavity, liver, lung, and bone marrow. Recurrent and metastatic tumors were glioblastoma multiforme, which was more malignant than the surgical specimen. The possibility of metastatic Wilms' tumor from the kidney was completely ruled out by extensive autopsy survey. The authors present an extremely rare tumor including detailed observations on the electron microscopic appearance of the tumor; the histogenesis of these tumors is briefly discussed.

Adult↗
PubMed1982

Effect of hyperdynamic therapy on cerebral ischaemia caused by vasospasm associated with subarachnoid haemorrhage.

Ten patients who developed neurological deficits associated with angiographically proven cerebral vasospasm caused by ruptured aneurysm were treated with hyperdynamic therapy induced by administration of a large amount of human serum albumin. No vaso-active drugs were administered. Cardiopulmonary function and intracranial pressure were monitored during the treatment. Marked improvement of neurological function was observed in all cases. Nine patients recovered completely without any neurological residual following treatment. The degree of the improvement observed during treatment closely correlated with the decrease in total peripheral resistance. Infusion of albumin did not cause elevation of intracranial pressure. It was concluded that the hyperdynamic therapy induced by administration of albumin has a dramatic effect on the ischaemic cerebral insult caused by vasospasm. It is postulated that the main effect of this treatment is produced by cerebrovascular dilatation.

Brain Ischemia↗