Naoki Ishihara

Endothelin Immunoreactivity in Cerebrospinal Fluid of Patients with Subarachnoid Haemorrhage

A radioimmunoassay method for endothelin was developed. Antisera raised against endothelin 1 showed significant crossreaction with endothelin 2 and 3 (45 and 13%, respectively). Considerable endothelin immunoreactivity was shown to be present in the cerebrospinal fluid of patients with a subarachnoid hemorrhage, ranging from 0.3 pmol/l cerebrospinal fluid to 4.5 pmol/l cerebrospinal fluid, though no endothelin immunoreactivity was observed in the cerebrospinal fluid of controls and patients with cerebral infarction, subdural haematoma or brain tumours. Endothelin immunoreactivity was also observed in two out of five cerebrospinal fluid samples from patients with cerebral bleeding. Reverse phase high performance liquid chromatography showed that the main immunoreactive component in cerebrospinal fluid appeared to elute at the same position. There was, however, an immunoreactive component which eluted at the same position as endothelin 3. These results may support the idea that endothelin immunoreactivity in the cerebrospinal fluid originate mainly from endothelial and neural tissues and that endothelin may contribute to the generation of the vasospasm often observed in subarachnoid hemorrhage, a conclusion based on the exceptionally high endothelin immunoreactivity in cerebrospinal fluid observed in patients with subarachnoid haemorrhage.

Regional Cerebral Blood Flow, Diaschisis, and Steal After Stroke

Regional CBF was measured by 133Xe inhalation in unilateral cerebral infarction, carotid TIAs, and normal volunteers. Regional CBF values were bilaterally and symmetrically reduced in patients measured within 3 weeks after stroke. Later, rCBF values returned toward normal in the contralateral hemisphere of patients with infarction and in both hemispheres with carotid TIAs. In cases with carotid occlusive disease, flow reduction was seen in the contralateral posterior cerebral artery distribution, with hyperemia in ipsilateral occipital lobe caused by interhemispheric steal. Brainstem-cerebellar flow values were increased following acute cerebral infarction if patients were alert but reduced if consciousness was impaired.

Bilateral Thalamic Infarction Associated with Selective Downward Gaze Paralysis

A 34-year-old man presented with transient downward gaze paralysis and impairment of convergence together with prominent psychic disturbances. Cranial CT and MRI clearly demonstrated a symmetric infarction extending from the bilateral thalamus to the rostral medial midbrain. The existence of downward gaze paralysis following ischemic stroke is contributory to the diagnosis of not only the location of but also the responsible artery for the infarction.

CSF β-endorphin and leu-enkephalin levels in the acute and chronic stages of cerebral infarction

SummaryTo investigate the role of endogenous opioid peptides in the pathophysiology of cerebral ischaemia, the CSF levels of immunoreactive β-endorphin and leu-enkephalin in 16 patients with cerebral infarction were measured. Both the CSF β-endorphin and leu-enkephalin levels in the acute stage of cerebral infarction were significantly higher than the values in the chronic stage. The CSF concentrations of the two peoptides revealed a positive correlation in the acute but not the chronic stage. The increased endogenous opioid peptides in the CSF in the acute stage may modify the evolution of cerebral infarction.

Identification and characterization of adipokinetic hormone (locusta migratoria)-like immunoreactivity in the human cerebrospinal fluid☆

Using an antiserum raised against locust adipokinetic hormone I, considerable quantity of adipokinetic hormone-like immunoreactivity was demonstrated in the human cerebrospinal fluid. The immunoreactivity was characterized by gel permeation and high performance liquid chromatography. The main immunoreactive component in the cerebrospinal fluid coeluted with adipokinetic hormone I. These results suggest that adipokinetic hormone may contribute to the neuronal function in the human central nervous system.

Increase of plasma methionine-enkephalin level in patients at the acute stage of cerebral infarction

We investigated the participation of endogenous opioid peptide in cerebral ischaemia. In 13 patients with supratentorial infarction, the plasma immunoreactive methionine-enkephalin concentration at the acute stage (30.77 +/- 3.54 pg/ml) was significantly higher than that at the chronic stage (20.37 +/- 2.07 pg/ml) or that of the control subjects (19.64 +/- 1.71 pg/ml). However, it was unrelated to infarct size or patient severity. The increased methionine-enkephalin, which appears to originate from the sympatho-adrenal system or infarcted brain, may play a role in the evolution of cerebral ischaemia.

A New Curved Peritoneal Passer for Shunting Operations — Technical Note

Various operations have been reported for hydrocephalus. Even if these operations consist of minor surgery, general anesthesia or laparotomy is required. To avoiding this complicated type of procedure, we developed a peritoneal and a long subcutaneous passer. This paper indicates the usefulness of these passers for VP shunt operations.