Biomedical subjects

H Nawashiro

Publications and source records attributed to H Nawashiro.

62 records · Page 4Linked to original sources

PubMed1996

Immunohistochemical analysis of the nm23 gene product (NDP kinase) expression in astrocytic neoplasms.

The expression levels of nm23-H1 have been reported to correlate with the metastatic potential of some tumours. We have treated a child with a rare case of astrocytoma with diffuse osteoblastic metastases. We therefore decided to examine the expression of the nm23 gene product in 24 gliomas in order to clarify the association of its expression with the clinical features of the disease. A polyclonal antibody against a GST/nm23-H1 fusion protein was raised in rabbits. Twenty-four specimens, including 5 recurrent gliomas and one extraneural metastasis, were obtained from 19 patients treated surgically between 1990 and 1993 in our hospital. Immunohistochemical staining was performed on paraffin sections using an avidin-biotinyl peroxidase complex method. Of the 24 astrocytic neoplasms, 3 (12.5%) specimens from one patient with diffuse bony metastases stained intensely with nm23-H1. Two specimens obtained from glioblastoma multiforme patients stained weakly. The other 19 specimens were negative for nm23-H1 expression. Little or no nm23 expression was observed in adjacent nontumourous cerebral tissues. The results suggest that high levels of nm23 expression might correlate with extraneural metastatic potential in astrocytic neoplasms.

Adolescent↗

PubMed1996

Fatal subarachnoid hemorrhage from an inflammatory cavernous carotid artery aneurysm: failure of conservative treatment after early diagnosis--case report.

Inflammatory carotid artery aneurysm is a rare complication of acute paranasal sinusitis. A 50-year-old female presented with a ruptured giant carotid artery aneurysm secondary to infection of the sphenoid sinus and cavernous sinus. She had been healthy until 5 days before admission, when she developed orbital phlegmon and meningitis. She received antibiotic therapy for 10 days. Computed tomography (CT) of the brain 2 days after admission showed no abnormality. However, repeat CT on day 6 showed a round isodense mass in the suprasellar cistern suggesting a cerebral aneurysm. Twelve days after admission, she suffered a fatal subarachnoid hemorrhage. Cerebral angiography revealed a giant left cavernous carotid artery aneurysm with a very irregular shape. Autopsy found sphenoid sinusitis and osteomyelitis extending into the cavernous sinuses. Diagnosis of bacterial inflammatory aneurysms before rupture is very important. Appropriate surgical intervention should be considered if there is enlargement of the original aneurysm or appearance of a new aneurysm indicating a potentially dangerous situation.

Anti-Bacterial Agents↗

PubMed1995

Immediate cerebrovascular responses to closed head injury in the rat.

Changes in cerebrovascular dynamics were investigated immediately after closed head injury in the rat using a newly developed closed head injury model developed by Marmarou et al. Intracranial pressure (ICP) and mean arterial blood pressure (MABP) were monitored before and after trauma. Regional cerebral blood flow (rCBF), regional cerebral plasma volume (rCPV), and blood-brain barrier (BBB) permeability were measured autoradiographically with iodo[14C]antipyrine [14C]sucrose, and [alpha-14C]aminoisobutyric acid, respectively. rCBF responses to induced hypertension after trauma were measured by laser-Doppler flowmetry to investigate the status of autoregulation. Before injury, baseline ICP values ranged from 6 to 10 mm Hg in all animals. Immediately after trauma, ICP increased synchronously with MABP to > 100 mm Hg and then rapidly returned to baseline values: MABP increased rapidly by 20% after trauma and returned to baseline values within 30 sec. At 30 sec after injury, a significant increase in rCBF was observed in five subcortical regions (p < 0.05), and a significant increase in rCPV was observed in the frontal cortex, parietal cortex, thalamus, and hypothalamus (p < 0.05). At 10 min after injury, BBB permeability (the transfer constant for [alpha 14C]aminoisobutyric acid) was < 0.1 mL/kg/min for all regions except those with a relatively permeable BBB, for example, median eminence, choroidal plexus, pineal body, and pituitary gland. Induced hypertension resulted in a prolonged increase in rCBF after trauma. Thus, in this closed head injury model, which is not associated with marked hypertension or prolonged BBB disruption, widespread increases in rCBF and impaired cerebral autoregulation were apparent immediately after injury.

Animals↗

PubMed1995

[A penetrating injury of the extracranial vertebral artery: a case report].

Penetrating injury to the vertebral artery is a very rare accident and no case except ours has been reported to date in Japan. We reported a case of successful treatment of a penetrating injury by a nail to the left vertebral artery with the use of interventional radiologic procedure. A 27-year-old man was admitted to our hospital with a complaint of penetrating injury in his neck. Left vertebral angiography revealed that a nail had penetrated into the vertebral artery at the C6 level. Considering the possibility of thrombus formation around the metallic foreign body and the risk of uncontrollable bleeding, we performed embolization of the injured vertebral artery with Interlocking Detachable Coil.

Adult↗

PubMed1995

Selective vulnerability of hippocampal CA3 neurons to hypoxia after mild concussion in the rat.

Immunohistochemical staining for microtubule-associated protein 2 (MAP2) and synaptophysin was used to investigate the effect of hypoxia on hippocampal neurons after mild concussion in the rat. Male Sprague-Dawley rats were divided into four groups: Group 1 (n = 3) was subjected to a mild impact-acceleration closed head injury, group 2 (n = 3) was subjected to 30 min of moderate hypoxia, group 3 (n = 5) was subjected to head trauma followed by 30 min of moderate hypoxia, and group 4 (n = 3) comprised sham-operated controls. All rats were fixed by transcardial perfusion 24 h after insult. No damage was observed in CA1 or CA2 neurons in any of the rats. However, rats in group 3 showed selective damage of hippocampal CA3 neurons manifested by a pycnosis and a marked decrease in MAP2 immunoreactivity. Presynaptic terminals visualized by synaptophysin immunostaining showed no differences among groups. The loss of immunoreactivity for the post-synaptic somal and dendritic protein marker MAP2 from the CA3 subfield 24 h after combined insults indicates an increased vulnerability of pyramidal cells in this brain area.

Animals↗

PubMed1994

Blood-brain barrier, cerebral blood flow, and cerebral plasma volume immediately after head injury in the rat.

The purpose of the present study was to determine blood-brain barrier (BBB) permeability, regional cerebral blood flow (rCBF) and regional cerebral plasma volume (rCPV) in the period immediately after head injury, and thereby to evaluate the effects of vascular factors in the pathophysiology of traumatic brain injury. Male Sprague-Dawley rats (350-450 g) anesthetized with 1.0-1.5% halothane were subjected to an impact acceleration closed head injury at the moderate level. BBB permeability (n = 5), rCBF (n = 8) and rCPV (n = 9) were measured by quantitative autoradiographic techniques using 14C-alpha-aminoisobutyric acid (AIB), 14C-iodoantipyrine and 14C-sucrose, respectively. Intravenous administration of each radiotracer was simultaneous with the traumatic impact. At 10 min after injury, BBB permeability, the transfer constant for AIB, was less than 0.1 ml/kg/min for all regions except for those with a relatively leaky BBB. At 30 s after injury, a significant and heterogeneous increase in rCBF was observed at 9 subcortical regions (p < 0.05). RCPV increased significantly in the frontal cortex, parietal cortex, thalamus, and hypothalamus (p < 0.05). In our closed head injury model without severe hypertension, BBB disruption did not occur immediately after trauma. Vascular responses in the period immediately after trauma may result from the derangement of cerebral autoregulation.

Animals↗

PubMed1993

Successful treatment of increased intracranial pressure by barbiturate therapy in a patient with severe sinus thrombosis after failure of osmotic therapy. A case report.

A patient with sinus thrombosis and characteristic magnetic resonance imaging (MRI) findings, who was managed successfully by barbiturate therapy is reported. MRI showed massive high intensity lesions on T2-weighted image which indicated venous cerebral infarction and brain oedema. Intravenous infusion of thiopental decreased increased intracranial pressure (ICP). The effectiveness of barbiturate therapy is discussed in terms of the similarity between this case and experimental sinus thrombosis. Barbiturate therapy should be considered in cases of severe sinus thrombosis with elevated ICP.

Adult↗

PubMed1991

Myelopathy due to thickened ligamenta flava and abnormal fibrous tissue of the cervicothoracic junction--case report.

A 49-year-old female with subacute myelopathic symptoms due to thickened cervicothoracic yellow ligament and abnormal epidural fibrous tissue is reported. Myelography showed a complete block at the Th3 level. Magnetic resonance imaging demonstrated an extra-axial mass lesion in the spinal canal at the cervicothoracic junction causing the spinal cord compression. Laminectomy with resection of the lesion resulted in good neurological recovery. Histological examination revealed a thickened ligamenta flava and abnormal epidural fibrous tissue without calcification foci.

Cervical Vertebrae↗