Lipid mediators modulate NMDA receptor currents in a Xenopus oocyte expression system.

We determined the modulatory effects of various lipid mediators on mouse N-methyl-D-aspartate (NMDA) receptor currents in the Xenopus oocyte expression system. Arachidonic acid, but not oleic acid potentiated NMDA receptor activity. The epsilon1/zeta1 heterodimer of the NMDA receptor was more sensitive to arachidonic acid than was the epsilon2/zeta1 heterodimer. Platelet-activating factor (PAF) and lysophosphatidic acid (LPA) both activated the NMDA currents, and the effects were more evident in the epsilon2/zeta1 heterodimer than in epsilon1/zeta1. These activations were abolished by treatment with protein kinase inhibitors, suggesting a possible phosphorylation of the receptor. Thus, lipid mediators do have modulatory effects on NMDA receptor currents, the potentiating effects of which differ depending on subtype of the NMDA receptor.

Subtemporal amygdalohippocampectomy for treating medically intractable temporal lobe epilepsy.

A SUBTEMPORAL AMYGDALOHIPPOCAMPECTOMY technique has been developed for mesial temporal lobe epilepsy. The conventional subtemporal approach has been modified to diminish temporal lobe retraction and the risk of damage to the temporal lobe. In the new technique, the surgeons' position has moved from above to below and the approach has been changed from anterolateral to posterolateral, thereby avoiding the voluminous and steeply inclined anterior temporal lobe. By this modified approach, it was unnecessary to remove the roof of the external auditory meatus and it was estimated that both the retraction pressure and the extent of temporal lobe retraction were reduced. To date, surgeons using this approach have operated on four patients with temporal lobe epilepsy whose epileptic foci were in the mesial temporal structure; the inferior temporal gyrus, the temporal tip, the vein of Labbé, and the ventral bridging veins were preserved. After surgery, two patients became completely free of seizures and the other two showed over 90% reduction in seizure frequency without neurological sequelae. Postoperative visual field examination revealed full visual fields without quadrantanopsia. This approach can preserve the temporal stem and lateral temporal lobe, it can be used to remove as much of the posterior hippocampus as necessary, and it can be extended to conventional lobectomy if it is indicated.

Mice deficient in cytosolic phospholipase A2 are less susceptible to cerebral ischemia/reperfusion injury.

To determine the role of cytosolic phospholipase A2 (cPLA2) in infarct development, wild-type and cPLA2 knock-out mice were subjected to focal cerebral ischemia for 75 min by occluding the middle cerebral artery using nylon filament and subsequent reperfusion by withdrawing the filament. The neurological deficit severity was evaluated by a modified 4-point scale. After the reperfusion period (72 h), mice were killed, and the brains were cut into four 2 mm coronal sections using a rodent brain matrix. Sections were stained with 2% 2,3,5-triphenyltetrazolium chloride (TTC). The infarct volume was 87.19 +/- 27.54 mm3 (mean +/- SD, n = 11) in the wild-type mice and 48.20 +/- 31.32 mm3 (n = 10; P < 0.01 vs. wild-type) in the knock-out mice. Less severe functional neurological deficits were observed in knock-out mice at 72 h after ischemia when compared with wild-type. Thus, disruption of cPLA2 resulted in significant reduction of infarct area and neurological deficit severity in the MCA occlusion model. These data indicate a critical role for cPLA2 in the pathogenesis of cerebral ischemia/ reperfusion injury.

[Multiple myeloma presenting with a solitary cranial tumor with subdural extension: a case report].

We report a case of multiple myeloma presenting with a solitary cranial tumor in the frontal region, extending from subcutaneous tissue to subdural space. To our knowledge, invasion of a tumor beyond the dura mater has never been described in case of multiple myeloma presenting with a solitary calvarial tumor. In the present case, the subdural extension was clearly visualized by several diagnostic means. A 53-year-old female patient visited the clinic of our University Hospital, complaining of a left frontal mass in May 1991. The mass grew rapidly, and she was hospitalized in June. On admission, neurological examination showed nothing abnormal. Laboratory studies showed normocytic normochromic anemia. Protein electrophoresis disclosed hypergammaglobulinemia with S-spike, and serum paraprotein was specific to IgA with lambda light chains by immunoelectrophoresis. Urinary Bence-Jones protein was not detected. An osteolytic lesion visualized in the frontal bone on plain skull radiographs showed destruction of the frontal bone, and an enhanced mass extending from the epidural to subcutaneous space was shown by computed tomography. The mass had compressed the frontal lobe. T1-weighted magnetic resonance images of the area showed isointensity signals, homogeneously enhanced with gadolinium-diethylenetriamide pentaacetic acid. Subdural extension in the deep area of the tumor was suggested. At operation, we confirmed infiltration of the tumor from the dura mater into the subdural space. Postoperative biopsy of bone marrow of the iliac bone demonstrated myeloma cells. The tumor was histologically diagnosed as plasmacytoma. The patient was highly resistant to postoperative combined therapy, and started on a fatal course leading to respiratory insufficiency caused by interstitial pneumonia in April 1992.(ABSTRACT TRUNCATED AT 250 WORDS)

[A case of intracranial multiple nonspecific granulomas related to rheumatic disease: with special reference to magnetic resonance imaging].

We encountered a rare case of a 48-year-old man with intracranial multiple granulomas secondarily caused by rheumatic disease. This was proven surgically after an 11-year course of remissions and deteriorations. In 1980, at the age of 32 years, the patient was first seen at the clinic of Neurology of the University Hospital, complaining of swelling and arthralgia of the joints of the knee, ankle, and wrist and with remittent fever and visual disturbance. The patient was diagnosed as having possible rheumatoid arthritis, and treated with administration of 30mg/day of prednisolone, which greatly improved the symptoms. The administration of 5 to 10mg/day of prednisolone had been continued after discharge from hospital. In 1985, visual acuity of the left eye decreased, and left facial hypesthesia developed. The patient was rehospitalized at the same clinic, and treated with 100mg/day of prednisolone, which again diminished the symptoms. Computed tomography(CT) on admission showed a high density mass with contrast enhancement in the left cavernous region. In addition to the left cavernous mass, a high density mass was detected by CT in the left parietal lobe, in 1987. Visual acuity of the left eye deteriorated in 1989. Because his response to prednisolone had decreased, the visual symptom was treated with gold sodium, which acted effectiveness. Symptoms deteriorated again in 1990. Early in 1991, CT and magnetic resonance imaging showed a new mass at the right frontal lobe, while the mass in the left cavernous region had increased in size. The patient was transferred to the clinic of Neurosurgery for surgical treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship between dihedral angles of N1 and C9 substituents in 1,4-benzodiazepines and dual cholecystokinin-A and -B antagonistic activities.

Introduction of a methyl moiety to the C9 position of a 1,4-benzodiazepine ring system afforded dual CCK-A and -B antagonistic activity. Novel derivatives having ethyl, isopropyl and chloro substituents at C9 were prepared in order to obtain more potent antagonistic activities. AM1(MOPAC93) calculations of the dihedral angles between the N1 and C9 substituents indicated that dihedral angles for dual antagonistic activities were between 50 degrees and 60 degrees. A methyl moiety was selected as the most suitable C9 substituent in this series for potent dual CCK-A and -B receptor antagonistic properties.

Expression of lysophosphatidic acid receptor in rat astrocytes: mitogenic effect and expression of neurotrophic genes.

Lysophosphatidic acid (LPA) is a phospholipid mediator with a variety of biological activities. It remains unknown, however, which cells in the brain express the LPA receptor. The present study was undertaken to identify cells in the rat brain expressing functional LPA receptors, and to explore biological roles of LPA in these cells. We found that the LPA receptor was most dominantly expressed in rat astrocytes, determined by LPA-induced Ca2+ imaging, and by Northern blot analyses. LPA induced a mitogenic response and expression of immediate early genes in astrocytes, through pertussis-toxin sensitive G-protein(s). LPA also stimulated the expression of various cytokine genes, including nerve growth factor, interleukin (IL)-1beta, IL-3 and IL-6. Thus, astrocytes are the major target of LPA in the brain. We propose that LPA may play important roles in neuronal development, gliosis and wound-healing process in the brain.

Regulation of genes for inducible nitric oxide synthase and urea cycle enzymes in rat liver in endotoxin shock.

Arginine is an intermediate of the urea cycle in the liver. It is synthesized by the first four enzymes of the cycle, carbamylphosphate synthetase I, ornithine transcarbamylase, argininosuccinate synthetase, and argininosuccinate lyase, and is hydrolyzed to urea and ornithine by arginase I, forming the cycle. In endotoxemia shock, inducible nitric oxide (NO) synthase (iNOS) is induced in hepatocytes and arginine is utilized for NO production. Regulation of the genes for iNOS and the urea cycle enzymes was studied using lipopolysaccharide (LPS)-treated rat livers. When rats were injected intraperitoneally with LPS, iNOS mRNA was markedly induced. Cationic amino acid transporter-2 and C/EBPbeta mRNAs were also highly increased. In contrast, mRNAs for all the urea cycle enzymes except ornithine transcarbamylase were gradually decreased and reached 16-28% of controls at 12 h. However, all these enzymes remained unchanged at protein level up to 24 h. In light of these results, we suggest that synthesis of urea cycle enzymes is downregulated and that the protein synthetic capacity is directed to synthesis of proteins required for defense against endotoxemia.

Platelet-activating factor and somatostatin activate mitogen-activated protein kinase (MAP kinase) and arachidonate release.

Platelet-activating factor (PAF) receptor and somatostatin receptor (SSTR4) were cloned, and their primary structures were identified. They are both highly expressed in the rat hippocampus. When expressed in Chinese hamster ovary cells, these receptors activated mitogen-activated protein (MAP) kinase cascade and phospholipase A2. Arachidonic acid or its derivatives, thus produced by the activation of these receptors may play some roles in synaptic transmission and synaptic plasticity.

Peri-operative immunotherapy with OK-432.

Pre- and postoperative intradermal administration of OK-432 enhanced the SU-PS skin reaction in patients with gastric cancer, but failed to prevent a fall in the NK activity induced by the operation. The change in NK activity was not associated with a change in the proportion of Leu 7-positive cells, but was related to Leu 11a-positive cells. Intradermal injection of OK-432 increased the proportion of Leu 7-positive cells in the patients in whom they accounted for less than 20% of lymphocyte population. The case was the same with Leu 11a-positive cells. Intravenous injection of OK-432 tended to increase suppressor-inducer T cells (CD4+2HA+ cells), B cells and Leu 7-positive cells. Particularly, the proportions of OK-M1-positive cells and MHC class II antigen-positive cells increased in all patients. Immunotherapy with OK-432 given intravenously at a dose of 0.1 KE appeared to be safe because no side effects were essentially observed.

Preventive effects of interleukin 1 beta for ACNU-induced myelosuppression in malignant brain tumors: the experimental and preliminary clinical studies.

The effect of recombinant human interleukin 1 beta (rHuIL-1 beta) on myelosuppression induced by 3-[(4-amino-2-methyl-5-pyrimidynyl)methyl]-1-(2-chloroethyl)-1-nit rosourea hydrochloride (ACNU) was studied. In in vivo study using BALB/c mice, pretreatment with 1 microgram/mouse of rHuIL-1 beta as a single intraperitoneal (i.p.) injection had a significant preventive effect on thrombocytopenia as well as granulocytopenia induced by ACNU at an intravenous dose of 60 mg/kg. Facilitated recovery by rHuIL-1 beta administered seven days after injection of high-dose ACNU was also observed. Experimental combination immunochemotherapy with high-dose ACNU and rHuIL-1 beta was performed in nude mice inoculated with human glioblastoma subcutaneously. The elongation of the survival time of the tumor bearing nude mice was also observed in combined use of high dose ACNU with rHuIL-1 beta. Seven patients with malignant brain tumors received intravenous 2.5-3 mg/kg ACNU. All patients were subcutaneously injected with 2 x 10(4)-U or more rHuIL-1 beta twice a week or daily. The mean nadir of leukocyte, granulocyte, and thrombocyte counts of the 7 patients received 2.5-3 mg/kg ACNU were significantly higher than in matched historical controls. In combination with rHuIL-1 beta, it may be possible to use chemotherapeutic agents at a relatively high dose.

A novel pyridazinone derivative as a nonprostanoid PGI2 agonist.

A novel optically pure pyridazinone derivative was synthesized and identified as a nonprostanoid PGI2 agonist. It inhibited ADP-induced aggregation of human platelets with an IC50 value of 0.081 microM and has high oral bioavailability (56%) with a long half-life (4.3 h) in rats.

[Radiation therapy of choroidal metastases].

A retrospective study was performed on 30 cases with choroidal metastases referred to the Cancer Institute Hospital between July 1975 and June 1986. Of these 30 cases, 32 eyes of 26 patients were treated with irradiation of 4.3 MV X-rays or 12 MeV electron beam therapy in the range of 20-60 Gy to restore vision and prevent blindness. The tumor response to radiation therapy confirmed by ophthalmoscopic examination was described as complete, partial or no response. Of the 32 eyes, 31% had complete response, and 47% showed partial response. The overall response rate was 78%. A visual response as defined by marked or partial improvement of visual acuity and/or subjective symptoms was obtained in 16 out of 26 patients (62%). All of these patients were free of recurrence of symptoms in their quality of life. This proved radiotherapy to be a useful modality of treatment for choroidal metastases. No obvious radiation injuries were encountered in this series.

Dual CCK-A and CCK-B receptor antagonists (II). Preparation and structure activity relationships of 5-alkyl-9-methyl-1,4-benzodiazepines and discovery of FR208419.

In our continuing research for dual CCK-A and -B antagonists, according to our hypothesis that dual CCK-A and -B antagonists should be more efficacious than selective CCK-A antagonists for the treatment of pancreatitis, we have prepared various 5-alkyl-9-methyl-1,4-benzodiazepines. From the compounds prepared, 1-cyclohexyl-carbonylmethyl-5-ethyl-9-methyl-3- (m-tolylureido)-2-oxo-1,4-benzodiazepine, (40) was selected as a candidate for development due to its well-balanced high affinity for both receptors. The R-enantiomer of 40, (R)-40 (FR 208419), had 27-fold higher affinity for the CCK-A receptor and 8-fold more potent CCK-B receptor binding activity than (S)-40. The biological activity after p.o. administration of (R)-40, estimated from the ID50 value (0.23 mg/kg p.o.) obtained by preliminary evaluation by gastric emptying effects, is considered to be high enough for further development. This compound is now undergoing further biological evaluations with a view to clinical development.