Median preoptic neurones projecting to the supraoptic nucleus are sensitive to haemodynamic changes as well as to rise in plasma osmolality in rats.

Extracellular single unit activity was recorded from 73 neurones in the median preoptic nucleus (MnPO), identified by antidromic activation as projecting to the supraoptic nucleus (SON) area in urethane-anaesthetized male rats. Thirteen of 73 identified MnPO neurones were silent, and 44 of 60 spontaneously active MnPO neurones were tested for their responses to electrical stimulation of the nucleus tractus solitarius (NTS). The cells were divided into 4 groups according to their responses; those which were excited orthodromically (OD+; n = 15), those which were unresponsive (UN; n = 21), those which were inhibited orthodromically (OD-; n = 4), those which showed initial inhibition followed by excitation (OD-+ n = 4). Some of these neurones were further tested for their responses to haemorrhage and/or produced by intraperitoneal injection of 1.5 M NaCl. Six out of 10 OD+ cells were excited by haemorrhage, 6 out of 11 OD+ cells were inhibited by phenylephrine, and 5 out of 9 OD+ cells were excited by hypertonic saline. On the other hand the UN cells tended to be unresponsive to each type of stimulus. Three out of 7 OD+ cells were excited by both haemorrhage and hypertonic saline, and 3 out of 8 OD+ cells were inhibited by phenylephrine and excited by hypertonic saline. The results may suggest that MnPO neurones which receive afferent input from the NTS may be sensitive not only to haemodynamic change but also to change in plasma osmotic pressure and that such population of MnPO neurones may integrate a part of the haemodynamic and osmotic information and contribute to the control of neurohypophysial hormone release.

Histological studies of intracranial vessels in primates following transluminal angioplasty for vasospasm.

Percutaneous transluminal angioplasty for treatment of cerebral vasospasm was performed in primates. Chronic cerebral vasospasm was induced by placement of an autologous blood clot over the right internal carotid artery (ICA), middle cerebral artery (MCA), and anterior cerebral artery (ACA). Cerebral angiography on Day 7 showed that the diameters of the ICA, MCA, and ACA were reduced to 55.7% +/- 1.3%, 55.3% +/- 2.6%, and 59.6% +/- 1.3%, respectively, of baseline. The angioplasty was carried out with a silicone microballoon attached to a microcatheter under somatosensory evoked potential (SEP) monitoring on Day 7. The angioplasty for ICA was performed satisfactorily; however, the balloon could not be advanced to the spastic M1 or A1 portions of the cerebral artery. Following angioplasty, the diameters of the ICA, the M1 segment, and the A1 segment were 79.6% +/- 2.9% (p < 0.001), 67.6% +/- 4.3% (p < 0.05), and 61.7% +/- 2.2% (not significant), respectively, of baseline. Histological studies demonstrated that the vessels were well dilated and patent without endothelial cell damage.

Activation of paraventricular neurosecretory cells by local osmotic stimulation of the median preoptic nucleus.

Both electrical and local osmotic stimulation of the median preoptic nucleus (MnPO) predominantly produced excitation of paraventricular (PVN) neurosecretory cells in the rat. By contrast osmotic stimulation of the medial septal region was without effect, although electrical stimulation excited most cells. The results suggest that the MnPO is one of the osmosensitive sites controlling electrical activity of PVN neurosecretory cells.

Effect of leukotriene antagonist on experimental delayed cerebral vasospasm.

Experimental delayed cerebral vasospasm was produced in 16 adult mongrel dogs by the "two-hemorrhage" method of intracisternal injections of autologous arterial blood. Group 1 was a control group. Group 2 was a treatment group that received an intravenous injection of ONO-1078, a novel potent leukotriene antagonist, once a day for 7 days just after the first cisternal injection of the blood. Angiography was performed on Days 0 and 7, and the cerebrospinal fluid levels of leukotriene C4 (LTC4) were measured on Days 0, 3, and 7. The cisternal levels of LTC4 increased after subarachnoid hemorrhage in both groups. But the cerebrospinal fluid levels of LTC4 in the treatment group were significantly lower than those in the control group (P less than 0.05). The angiographic vasospasm after subarachnoid hemorrhage was partially prevented with the treatment of intravenous injections of ONO-1078 (P less than 0.001). These results suggest that LTC4 may play a role in the pathogenesis of delayed cerebral vasospasm, directly or indirectly, and ONO-1078 may have a therapeutic effect on the prevention of the development of delayed cerebral vasospasm.

[A case of malignant glioma associated with verbal recent memory disturbance due to left hippocampal atrophy; case report].

Verbal recent memory disturbance was observed in a patient with a malignant glioma associated with left hippocampal atrophy. A 25 year-old male was admitted because of seizures. CT scan and MRI showed enhanced mass lesions in the left temporal lobe associated with ipsilateral hippocampal atrophy. Neurological examination disclosed right homonymous hemianopsia, word amnesia, alexia, agraphia and acalculia. Neuropsychological examination disclosed verbal recent memory disturbance, which consisted of impaired recall of the precisely memorized words after some interruption. Although hippocampal lesions are known to be often associated with cerebrovascular disease, hippocampal atrophy due to brain tumor is quite unusual. This case suggested that the left hippocampus is closely related to verbal recent memory. Hippocampal atrophy in this case conceivably derived from the decreased arterial flow due to perifocal edema or obstructive hydrocephalus.

Corticotroph cell hyperplasia in a patient with Addison disease: case report.

A woman with Addison disease developed hyperpigmentation, headache, and nausea despite conventional replacement therapy with cortisone. Excessively elevated plasma adrenocorticotropic hormone (ACTH) with absence of response to administration of corticotropin-releasing factor (CRF), and roentgenological evidence of enlargement of the sella turcica, as well as detection of enlarged pituitary gland on magnetic resonance images, led to a diagnosis of ACTH-producing microadenoma, which was removed by transsphenoidal microsurgery. The specimen obtained at surgery evidenced corticotroph hyperplasia, as demonstrated by immunohistochemical staining for ACTH. Fine structure exhibited densely granulated cells with a few bundles of microfilaments and an abundance of large lysosomal bodies. Surgical removal of the hyperplasia alleviated the patient's symptoms, and hyperpigmentation faded remarkably. Her plasma ACTH level returned to normal, has remained normal for more than 3 years, and responds adequately to CRF administration.

EC-IC bypass for adult patients with moyamoya disease.

We have performed 10 bypass operations on 7 adult patients with moyamoya disease over the past 6 years. Four had haemorrhagic episodes and three had ischemic episodes. Three patients underwent superficial temporal artery-middle cerebral artery (STA-MCA) bypass on both sides and the other four had the procedure on one side. Six of 7 patients showed angiographical improvement after the bypass operation while one patient did not. This patient underwent the second severe stroke and became vegetative during the course of follow-up. Another patient died of myocardial infarction during the follow-up time. Five patients are capable of carrying out their original work. Considerations regarding the cause, operative methods and disease course in the patients are discussed.