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Biomedical subjects

A Nishimoto

Publications and source records attributed to A Nishimoto.

At least 73 records · Page 4Linked to original sources
PubMed1988

[Unruptured cerebral aneurysms in two siblings screened by cerebral computed angiotomography].

The authors report two siblings, both of whom had unruptured cerebral aneurysms found by screening examination of noninvasive cerebral computed angiotomography. Other authors have reported unruptured cerebral aneurysms detected by conventional cerebral angiography in asymptomatic relatives of families in which two or more individuals had cerebral aneurysmal rupture. It is of interest that, in our cases, the unruptured cerebral aneurysms were detected by noninvasive cerebral computed angiography in two asymptomatic siblings in a family with no history of ruptured aneurysm. To the best of our knowledge, this is the first report of detection of unruptured familial aneurysm by cerebral computed angiotomography. Case 1 is a 67-year-old female who had been complaining of dullness in the head. Cerebral computed angiotomography showed a small high density nodule, suggesting an unruptured aneurysm of the right middle cerebral artery. An aneurysm with a diameter of 4 mm was found in the right middle cerebral artery. A 72-year-old male, who was a brother of case 1, had been afraid of having cerebrovascular disease, and wanted to have a neurological examination check-up. Computed angiotomography revealed a high-density nodule in the anterior communicating artery. Conventional cerebral angiogram showed a 6 X 7 mm aneurysm. However, both of the patients refused surgical treatment. Lozano et al reviewed the previously reported familial aneurysm cases. According to them, familial aneurysm tends to rupture at a younger age and at a smaller size than non-familial aneurysm. It is well known that asymptomatic members of familial aneurysm have a risk of developing aneurysm.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

[Chronic encapsulated intracerebral hematoma due to metastatic brain tumor: a case report].

Intracerebral hemorrhage from a brain tumor can mask the cause of bleeding, confuse the diagnosis, and affect the treatment and prognosis. This type of hemorrhage is generally regarded as a rapidly progressive, fulminating disease, sudden in onset, with the outcome being death or profound neurological deficits. Such hemorrhages are demonstrated by CT scan as intracerebral high density areas. Intracerebral hematomas producing chronic neurological disability and chronic intracerebral hematomas are rarely reported. We experienced a case of chronic intracerebral hematoma due to metastatic brain tumor. The patient was a 60-year-old female, and the initial symptoms were mild headache followed by right homonymous hemianopsia. The intracranial lesion was demonstrated by CT scan as an oval-shaped low density area (3 X 4.5 cm) with a ring enhancement in the left occipital lobe. MRI showed marked high intensity by short SE and long SE in the left occipital lobe. A left occipital craniotomy was performed. No tumor could be seen macroscopically except for an old encapsulated hematoma. Aspiration of the liquid hematoma and biopsy of the wall of the hematoma were done. A histological examination revealed an adenocarcinoma. Spontaneous bleeding from brain tumors was reviewed, and diagnostic problems were discussed.

Adenocarcinoma↗
PubMed1987

Prediction and evaluation of brainstem function by auditory brainstem responses in patients with uncal herniation.

Serial measurements of auditory brainstem-evoked responses (BERs) were conducted in 15 patients with supratentorial mass lesions. Significant prolongation of the latency of wave V BERs, which originates in the inferior colliculus, occurred when the intracranial pressure (ICP) approached 30 mmHg. In four of five patients whose BERs were measured before pupillary changes, a significant lengthening of wave V latency was observed prior to clinical manifestation of uncal herniation. These results suggest that immediate medical or surgical decompression of ICP should be performed when ICP approaches 30 mmHg with significant prolongation of wave V latency.

Adult↗
PubMed1987

Artificial embolization with isobutyl-2-cyanoacrylate for the treatment of carotid-ophthalmic aneurysm.

A large carotid-ophthalmic aneurysm was successfully obliterated by the combined treatment of clipping the aneurysmal neck and intraaneurysmal injection of isobutyl-2-cyanoacrylate. Reflux of the glue into the artery was prevented by temporary trapping of the carotid artery. The obliteration of an aneurysm with isobutyl-2-cyanoacrylate is an effective procedure in cases where clipping of the aneurysmal neck is not completed due to technical difficulties.

Bucrylate↗
PubMed1987

An immunohistochemical study on the distribution of glial fibrillary acidic protein, S-100 protein, neuron-specific enolase, and neurofilament in medulloblastomas.

In order to clarify the differentiation of medulloblastomas, the authors studied on the morphological features and immunohistochemical expression of glial fibrillary acidic protein (GFAP), S-100 protein, neuron-specific enolase (NSE), and neurofilament (NF) in 31 medulloblastomas. GFAP was detected only in a small number of tumor cells of 5 medulloblastomas; S-100 protein in both small tumor cells and some so-called spongioblastic cells in 16 medulloblastomas; NSE in the more abundant tumor cells and the matrix in 28 medulloblastomas; NF in a few tumor cells of 12 medulloblastomas; GFAP and NF in 2 medulloblastomas, but each of them in different tumor cells. These results suggest that medulloblastomas have a capacity of differentiation along neuronal and/or glial lines. The conventional morphological markers of differentiation in medulloblastomas such as spongioblastic cells and Homer Wright rosettes were not necessarily compatible with expression of immunohistochemical markers such as GFAP or NF. NSE and S-100 protein seem less valuable markers of differentiation because they were detected in both neuronal and glial elements. But NSE, which was observed in most medulloblastomas, might have a value as a marker for medulloblastomas.

Adolescent↗
PubMed1987

[Giant, fusiform and dissecting aneurysms at the vertebro-basilar junction--report of five cases and their clinical pathophysiological aspects].

Five cases of giant, fusiform, and dissecting aneurysms of the vertebro-basilar junction, in which direct surgical treatment was not feasible, are reported. Their initial symptoms were as follows: 3 subarachnoid hemorrhages (2 fusiform aneurysms, 1 giant aneurysm), 1 mass sign (giant aneurysm), and 1 ischemic sign (dissecting aneurysm). In two patients, one with a giant and one with a dissecting aneurysm, preoperative proximal vertebral occlusion was carried out by inflated balloon for 30 to 100 minutes, under observation of clinical signs and measurement of distal arterial pressure. This catheter technique with an inflated balloon provides the means to assess the effect of vertebral artery occlusion in the alert patient, and to determine if occlusion is tolerated or not. In one case with a giant aneurysm, the proximal vertebral artery was occluded extracranially with no complications and no recurrent subarachnoid hemorrhage for 1 year. The other four patients (1 thrombosed giant aneurysm, 2 fusiform aneurysms, 1 dissecting aneurysm) whose contralateral vertebral arteries were hypoplastic, and who refused to operation, were treated conservatively for 6 months to 6 years. Their outcomes were better than expected, with no recurrent subarachnoid hemorrhage nor aggravation of clinical symptoms except for the one case with a dissecting aneurysm whose deterioration was presumed attributable to late cerebellar cortical atrophy.

Aortic Dissection↗
PubMed1987

[The effect of lidocaine on brain edema and neural function].

Recently lidocaine (Ld) has been reported to have beneficial effects on neural suppression caused by experimental cerebral ischemia or spinal cord injury. In this paper, the effects of Ld on brain edema, local cerebral blood flow (lCBF), and neural function in the thalamocortical and cortical structures were experimentally studied. Vasogenic brain edema was induced by exposure of the cat's cerebral surface to the air in the manner of Prados et al. The dura mater over the left cerebral hemisphere was resected, and the brain was exposed to room air for 12 hours. The animals were divided into two groups. In the control group of 31 cats, Ld was not administered. In the treated group of 8 cats, Ld (4.5 mg/kg) was given intravenously immediately after the beginning of the air-exposure and thereafter administered as a drip infusion at the rate of 2 mg/kg/hour. In the untreated group, 12 hours after exposure, the cerebral water content measured by gravimetry in the cortex, white matter and thalamus increased by approximately 1.9, 4.1, 0.7%, respectively, compared to the control values. Local CBF measured by the hydrogen clearance method decreased to about 71, 57 and 56% of the control value, respectively. The latency of the N1 component of the somatosensory evoked response (SER) was prolonged significantly 6 hours after air-exposure. The amplitude of the direct cortical response (DCR) decreased significantly 6 hours after air-exposure, and became approximately 50% of the control 12 hours after exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

[Transcervical and transoral approach to clival and upper cervical chordoma: a case report].

The patient, a 48-year-old man, was first admitted in 1981 for the chief complaints of retropharyngeal tumor and anosmia. Computerized tomography scan disclosed destruction of the lower half of the clivus and retropharyngeal tumor predominantly located in the third prevertebral region. The tumor was removed partially via the transcervical approach and was histologically a typical chordoma. Two years later the tumor recurred and was operated on by the same approach. However, only partial removal of the tumor was realized due to difficulties in dissecting the fibrous adhesion. In 1986 (7 years after onset of the symptoms), the patient was readmitted due to severe dysphagia. The sagittal MRI scan demonstrated a huge oval retropharyngeal tumor with precise delineation between the tumor and clivus, clivus upper cervical spine and brain stem. The tumor was extirpated subtotally on the midline via the transoral approach. Dysphagia completely improved postoperatively and the patient regained normal smell sensation. The advantages and disadvantages of the transcervical and transoral approach to clival lesion are discussed and the advantage of the MRI imaging is stressed for preoperative information for the transoral approach.

Chordoma↗
PubMed1987

[Interaction between neurogenic and metabolic factors upon deterioration in cerebrovascular tonus--experimental study on the etiology of cerebral vasoparesis].

It is widely accepted that a tremendous increase in cerebral blood volume (CBV) due to progressive cerebral vasoparesis is an essential to the development of acute brain swelling. This study was designed to determine whether neurogenic and/or metabolic factors are predominant and how these interact with each other in producing cerebral vasoparesis. Fifty-one awake cats immobilized with pancuronium bromide were divided into 4 groups: group I, control; group II, normocapnic hypoxia (PaO2 = 50 mmHg); group III, normoxic hypercapnia (Pa-CO2 = 70 mmHg), and group IV, increased intracranial pressure (ICP = 40 mmHg) by brain compression. Systemic arterial pressure (BP), CBV (photoelectric method), and ICP (epidural pressure) were continuously recorded. The dorsomedial hypothalamic nucleus (DM) and the reticular formation of the midbrain (MB-RF) were bilaterally coagulated by a stereotaxic technique (3mA, 1 min). Therefore alterations in cerebrovascular tonus created by destruction of the cerebral vasomotor centers were examined in the animals with metabolically induced cerebral vasodilatation to various degree's. In group I, vasomotor center destruction resulted in an immediate and transient decrease in BP (DM; -14.1 +/- 6.7 mmHg, MB-RF; -10.2 +/- 4.8 mmHg) and simultaneous increase in CBV and ICP (DM; 7.6 +/- 7.0 mmHg, MB-RF; 6.0 +/- 5.6 mmHg) for 3 to 4 minutes. Increase in ICP by destruction of vasomotor centers reduced significantly in group II (DM; 2.3 +/- 2.6 mmHg, MB-RF; 1.6 +/- 1.2 mmHg) and reduced slightly in group IV (DM; 7.5 +/- 4.0 mmHg, MB-RF; 4.8 +/- 3.2 mmHg). In these 3 groups, autoregulation of cerebral blood flow and CO2 vasoreactivity were not changed by destruction of vasomotor centers.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

[Fundamental study of differential hypothermia treatment of brain tumor using an interstitial microwave antenna].

An interstitial microwave antenna system was devised for differential hypothermia treatment. It was evaluated for its ability to induce localized brain hyperthermia in hypothermic monkey. Ten brain hyperthermia trials have been performed in 6 monkeys. Under general anesthesia, the animals were put into ice water bath to keep the total body temperature at 30 degrees C. Following parieto-occipital craniectomy, a microwave antenna of 1.5 mm in diameter was inserted into the brain at depth of 2 cm, and the brain tissue was heated by 2450 MHz microwave irradiation. Thermal distribution was measured by thermistor probes and local cerebral blood flow (1-CBF) before and after heating was simultaneously measured by hydrogen clearance method. After the experiment, the animals were sacrificed and histopathological changes of the heated brain tissue were studied. Under total body hypothermia of 30 degrees C, the maximum cross-sectional diameter of the heated brain to 37 degrees C or above was about 4 cm. The temperature profile on the vertical plane presented a bell-shaped distribution. The 1-CBF of the heated brain increased with the elevation of the brain temperature and the blood flow at 37 degrees C is nearly twice as much as that of 30 degrees C. After one hour DH treatment, necrotic tissue was noted along the antenna axis where the temperature was maintained more than 50 degrees C, and this change was not recognized at a distance of 1 cm from the antenna where the temperature was maintained at 42 degrees C. This study indicates that interstitial microwave hyperthermia system can be used effectively to heat the localized brain tissue.

Animals↗
PubMed1987

Decreased dopamine level in the epileptic focus.

Catecholamine and serotonin in the focus tissues of 12 intractable epileptic patients who underwent surgery were analysed by high performance liquid chromatography with electrochemical detection, and it was found that dopamine contents in epileptic foci were clearly lower than in surrounding tissue in 7 of the 12 epileptics examined. In the other 5 patients, dopamine levels were much lower than in non-convulsive neuropathic patients.

Adolescent↗
PubMed1987

[Clinical study of late onset Chiari type I malformation].

Eight cases, 5 males and 3 females, of Chiari type 1 malformation aged from 9 to 51 years (mean 33.3 years) were analysed. The average age of the onset of symptoms was 29.6 years, between 7 and 44 years, and that from the onset of symptoms to the presentation to the hospital was 3.3 years ranged from 1 month to 16 years. Pain (87%) in the head or in the cervical region was the most common symptoms, the former was 5 cases and the latter was 2. The next common symptoms were unsteadiness and gait disturbance (50%). Weakness of one or more limbs was the complaints of 3 (38%) of the patients, and sensory impairment was 38%. Other symptoms included stiffness of the neck and shoulder, limitation of the neck movement, abnormal head posture, rectourinary incontinence and so on. In physical examination, foramen magnum compression signs (63%) and cerebellar signs (63% were most common and lower cranial nerve palsy (38%) and intracranial hypertension (25%) were included. Abnormalities of the skull and cervical spine were common on X-ray films. The were cervical fusion or occipitalization and basilar impression. On the angiograms, descended PICA was visualized in all cases. CT metrizamide myelography was performed in 2 cases and MRI was done in 1 case. They could clearly demonstrate the descended tonsils and were found to be the most reliable radiographic examination in the disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

[Primary empty sella syndrome treated by transsphenoidal extradural balloon expansion--a case report].

A 34-year-old woman was admitted for the chief complaints of headache and blurred vision. She had bilateral papilledema and slight increase in CSF pressure (175mmH2O) with normal visual acuity and field. Neurological and hormonal examination were normal except for over response of PRL and TSH to TRH test. The sella was enlarged and MRI and metrizamide CT demonstrated intrasellar CSF filling with remodeling of the pituitary gland. The patient was diagnosed as primary empty sella syndrome associated with benign intracranial hypertension. The complaints did not subside for six months. The patient was treated via the transsphenoidal approach. The dura mater of the floor of the sella was elevated by extradural balloon expansion filled with silicone, and subsequently the empty sella was obliterated. Her headache disappeared and amblyopic attack also improved. Obliteration of the empty sella with an extradural silicone balloon via the transsphenoidal approach seemed to have been effective for headache and visual complaints of primary empty sella syndrome which did not respond to medical therapy.

Adult↗
PubMed1986

[Cisplatin, vinblastine and bleomycin (PVB) combination chemotherapy in the treatment of intracranial malignant germ cell tumors--a preliminary report of a phase II study--The Japanese Intracranial Germ Cell Tumor Study Group].

Cisplatin, vinblastine and bleomycin (PVB) combination chemotherapy was undertaken in 30 patients with primary intracranial malignant germ cell tumors in 11 neurosurgical clinics. The response rate of 17 evaluable patients with nonrecurrent tumors was 64.7% (eight CR and three PR), and that in eight patients with recurrent tumors was 50% (two CR and two PR). The one-year and two-year survival rates were 76.2% and 67.7%, respectively, which are better than the treatment results by radiation therapy alone, i.e., 69.8% and 46.5%. These findings suggest that PVB therapy is effective for intracranial malignant germ cell tumors.

Adult↗
PubMed1986

[Clinical studies of cefoperazone in neurosurgery].

A multicenter trial consisting of 164 institutions through out Japan, has been conducted to study the transfer of cefoperazone (CPZ) into the cerebrospinal fluid (CSF), and the clinical effectiveness of CPZ as a therapeutic or prophylactic agent in neurosurgery. The levels of CPZ in serum and CSF were determined in 96 patients. After initial dose of 2 g CPZ (intravenous drip infusion for 30 minutes), the serum level of CPZ after 1 hour was 124.5 +/- 6.6 micrograms/ml (Mean +/- S.E.), and even after 6 hours, it maintained as high as 47.8 +/- 16.6 micrograms/ml. The peak CPZ levels in CSF in patients with normal or minimal impairment in blood-CSF-barrier (BCB) (group I) and in those of localized impairment in BCB (group II) were 1.0 +/- 0.5 micrograms/ml at 2 hours and 3.0 +/- 1.8 micrograms/ml at 3 hours, respectively. The highest CSF level was seen in patients with meningitis (group III) and showed 5.0 +/- 2.4 micrograms/ml at 6 hours. After multiple dose of 2 g CPZ (intravenous drip infusion for 30 minutes), the serum kinetics of CPZ were not significantly different from those obtained after initial dose. However, the CPZ levels in CSF were higher than those observed after initial dose in all 3 groups and were higher than MIC75 against relevant pathogens for meningitis such as Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus. Moreover, in group III peak level of CPZ in CSF exceeded the MIC75 against Pseudomonas aeruginosa which is also frequently isolated from patients with meningitis in neurosurgery. As a therapeutic agent CPZ administered as sole agent was effective in 42 out of 55 cases (76.4%) in meningitis, in 78 out of 116 cases (67.2%) in pneumonia and in 36 out of 47 cases (76.6%) in urinary tract infection (UTI). Its efficacy rate against all infections treated was 72.2% (184/255). Regarding CPZ's prophylactic use, 39 out of 514 cases (7.6%) were judged as having or possibly having infections as follows; meningitis (13/514, 2.5%), pneumonia (15/514, 2.9%), UTI (2/514, 0.4%). In prophylactic use of CPZ, the incidence rates of postoperative meningitis and other central nervous system (CNS) infection following ventricular drainage and supratentorial craniotomy for aneurysm were higher than those observed in other types of operation, 12.0% (3/25) and 6.2% (8/130), respectively. Also, regarding prophylactic use of CPZ, the organisms isolated by culture from 13 cases of postoperative CNS infections included 2 strains of Staphylococcus sp., 1 strain of Serratia sp. and 3 strains of other Gram-negative bacteria (GNB).(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗