ESR of a nitroxide radical and its radical pair in irradiated 1-hydroxyxanthine single crystals.

Single crystals of 1- hydroxyxanthine have been X-irradiated at 77 K and studied by ESR at 300 K. A nitroxide radical formed by abstraction of a hydrogen atom at N1 is the primary species formed by the radiation. A nitrogen hyperfine tensor with principal values of 0.8, 2.6, and 13.6 G and a g tensor with principal values of 1.9985, 2.0031, and 2.0099 have been determined. These results indicate a spin density of 0.24 on N1. Pairwise trapping of the nitroxide radical was also detected and principal values of the dipolar coupling tensor were found to be 140.7, -69.4, and -67.8 G. These data indicate effective radical separations of 7.3 A and are consistent with molecular layer spacings of 3.5 A in this crystal structure.

The selective endothelin ETA receptor antagonist FR139317 inhibits neointimal thickening in the rat.

Endothelin is known as a potent mitogenic mediator. We tested the in vivo ability of FR139,317((R)2-[(R)-2-[(S)-2-[[1-(hexahydro- 1H-azepinyl)]carbonyl]amino-4-methylpentanoyl] amino-3-[3-(1-methyl-1 H-indoyl)]propionyl]amino-3-(2-pyridyl)propionic acid), a selective antagonist of the endothelin ETA receptor subtype, to inhibit neointimal thickening following photochemically induced injury of the endothelium of rat femoral artery. FR139,317 (32 mg/kg s.c., twice a day) was administered for 3 weeks after the injury. FR139,317 significantly decreased the neointimal area (76.3%) without changing the medial area. Therefore, it is suggested that endothelin may play an important role, via mainly endothelin ETA receptors, in neointima formation in injured artery.

Nilvadipine as a neuroprotective calcium entry blocker in a rat model of global cerebral ischemia. A comparative study with nicardipine hydrochloride.

The effects of two dihydropyridine type calcium entry blockers, nilvadipine and nicardipine hydrochloride (nicardipine), on the liberation of free fatty acids (FFAs) were investigated using an experimental model of global cerebral ischemia in rats, and were compared with their pharmacokinetic properties. Nilvadipine, but not nicardipine, at a dose of 100 micrograms/kg i.v., significantly attenuated the liberation of FFAs, particularly docosahexaenoic and arachidonic acid. Furthermore, the brain concentration of nilvadipine was higher than that of nicardipine after equivalent dosing. The results of the present study demonstrate that pharmacokinetic differences between these two calcium entry blockers might explain the difference in their pharmacological efficacy.

An endothelin ETA receptor antagonist, FR139317, ameliorates cerebral vasospasm in dogs.

The role of endothelin in the pathogenesis of cerebral vasospasm after subarachinoid hemorrhage was investigated by evaluating the effect of FR139317, a novel potent ETA receptor antagonist, on the vasospasm in a canine two-hemorrhage model. Intracisternal administration of FR139317 (0.1 mg) significantly reduced the vasoconstriction of the basilar artery at day 7 (control group, n = 6, 61.6 +/- 4.0%, FR139317 treated group, n = 6, 75.9 +/- 1.5% of basal diameter, p < 0.01). In normal anesthetized dogs, the intracisternal administration of FR139317 did not affect the basal diameter of the basilar artery, blood pressure or heart rate. These results suggest that endothelin plays an important role in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage, and that FR139317 could be a valuable tool for preventing vasospasm after subarachnoid hemorrhage.

Retrogasserian glycerol injection or percutaneous stimulation in the treatment of typical and atypical trigeminal pain.

Of 164 patients with trigeminal neuralgia treated by percutaneous retrogasserian glycerol injections, we have studied the long-term outcome (one to four years) of 72 patients. 51 patients suffered from idiopathic trigeminal neuralgia, and of these 92% were freed from pain by the operation. 21 patients suffered from symptomatic trigeminal neuralgia due to multiple sclerosis or of traumatic or infectious origin. Of these, only 38% became free of pain. A further 8 patients with facial deafferentation pain who underwent treatment by retrogasserian neurostimulation with a permanently implanted electrode were included in this study. 4 of these patients were rendered free of pain by this procedure.

Decorticate spasticity: a re-examination using quantitative assessment in the primate.

Decorticate spasticity in the squirrel monkey was chosen as a convenient laboratory model of spasticity capable of quantitative assessment upon which to evaluate various currently popular clinical spasmolytic measures. The effects of a wide variety of cortical lesions were studied involving primary and supplementary motor, premotor and parietal cortex unilaterally and bilaterally, measuring muscle tone with the evoked integrated E.M.G. technique. Measurable spasticity resulted only if primary motor cortex was ablated bilaterally usually but not always preferentially involving biceps brachii and quadriceps. Resulting postures were variable offering no justification for the term "decorticate posture". The integrated evoked E.M.G. was proportional to rate of stretch and chiefly phasic in type as in hemiplegic man. Stereotactic dentatectomy resulted in profound ipsilateral reduction in this spasticity, but was without effect in intercollicular or anemic decerebrate cats. The mechanism of the spasticity and of the cerebellar effects are discussed.

WS009 A and B, new endothelin receptor antagonists isolated from Streptomyces sp. no. 89009. II. Biological characterization and pharmacological characterization of WS009 A and B.

WS009 A and B, produced by Streptomyces sp. No. 89009, were found to be competitive and specific antagonists against endothelin (ET)-1 receptors in in vitro studies and also active in in vivo studies. Furthermore, WS009 A and B were specific antagonists for vascular ET-1 receptors (ETA receptors) and significantly prevented the accumulation of intracellular inositol 1,4,5-triphosphate (IP3) in endothelin treated rat aorta tissues.

[Dural arteriovenous malformation in the falx with subarachnoid hemorrhage].

A case of falx dural arteriovenous malformation was reported. A 62 year old man was admitted to Nakamura City Hospital on August 15, 1989, with severe headache as his chief complaint. On admission, his consciousness was lethargic. CT scan showed subarachnoid hemorrhage with ventricular perforation and hematoma of the corpus callosum. Angiograms demonstrated a dural arteriovenous malformation (DAVM) in the frontal falx, which was fed by bilateral middle meningeal arteries and the left anterior falx artery and drained into the superior sagittal sinus via the dural vein. Bifrontal craniotomy was performed. At first, bilateral middle meningeal arteries were coagulated, and the frontoparietal dura was excised widely. Then, the falx was cut at the crista galli. The DAVM was found in the falx, including a vascular sac embedded in the brain tissue. The DAVM was coagulated as much as possible. Carotid angiograms revealed complete disappearance of the DAVM, 4 months after the operation. Although angiograms performed after only one month still showed a small residual DAVM. On reviewing the literature we found only 5 patients with the DAVM in the falx. In 6 cases including our own, intracranial hemorrhage occurred in 4 cases (3 cases were subarachnoid hemorrhage). Vascular sacs were seen in 4 cases, and drainage to the pial vein was noted in 3 cases. It seemed to be rare that the DAVM drained into the dural vein. In our particular case, operative findings showed the DAVM drained into the dural vein without the pial vein, and intracranial hemorrhage was attributed to rupture of the vascular sac.

[The usefulness of dynamic computed tomography scanning in predicting the outcome of acute stroke patients].

The aim of this study was to investigate whether brain dynamic computed tomography (CT) is useful in predicting clinical outcome. Thirty patients suffering from cerebral ischemia in the territory of the middle cerebral artery (MCA) underwent dynamic CT scanning within 6 hours of stroke onset. Regions of interest (ROIs) were placed in the bilateral MCA territories and three parameters, peak value (PV), time to peak (TP), and PV divided by TP, were calculated from time-density curves (TDCs) on ROIs. After conventional treatment using pharmacological agents, the 30-day clinical outcome was evaluated on the Glasgow outcome scale. To investigate the relationship between the disease-to-contralateral side ratio of each parameter's value and 30-day clinical outcome, TDCs were classified into the following four types; type 1, with TP ratio less than 1.1; type 2, with TP ratio ranging from 1.1 to 1.5 and PV/TP ratio more than 0.75; type 3, with TP ratio ranging from 1.1 to 1.5 and PV/TP ratio less than 0.75; and type 4, with TP ratio more than 1.5 and PV/TP ratio less than 0.3. Clinical outcome in patients with type 1 or 2 TDC was better than in patients with type 3 or 4 TDC (p < 0.01, Fisher's exact test). We can conclude that dynamic CT is a useful means for estimating the clinical prognosis of acute stroke patients after conventional treatment. Poor clinical outcome following conventional therapy is expected in patients with type 3 or 4 TDC in contrast to patients with type 1 or 2 TDC.

[Primary endodermal sinus tumor of the fourth ventricle (author's transl)].

A case, a 18-year-old male, of an endodermal sinus tumor (yolk sac tumor) in the fourth ventricle, was reported. The patient had a month history of headache, vomiting and gait disturbance prior to the hospitalization, when he admitted to our service he was in lethargic condition with left cerebellar ataxia and horizontal nystagmus. Lumbar tap revealed clear CSF under normal pressure of 110 mm H2O with the CSF protein of 432.5 mg/dl and cell count of 147/3. The vertebral angiography demonstrated space occupying lesion in the posterior fossa. Plain CT demonstrated only disappearance of the fourth ventricle and slightly dilated bilateral ventricles and third ventricle. However diffuse high density area around the fourth ventricle was demonstrated and the wall of bilateral anterior horn was slightly enhanced, after injection of contrast media. There was no other abnormal findings around the pineal region. Suboccipital craniectomy was performed and the tumor was totally removed macroscopically. The tumor was situated in th floor of the fourth ventricle and infiltrated into the fourth ventricular wall and th adjacent cerebellar tissue. The tumor was with soft, greyish color and extremely vascular. Histologically the tumor was diagnosed as endodermal sinus tumor according to Teilum's classification. There were stellate cells arranged in a loose with vacuolated network which formed cystic cavities and a complicated network of honeycomb appearance with a system of communicating cavities and channels. Various size of intra- and extracellular PAS-positive hyaline globules were also seen. Glomerular-like structure (Schiller-Duval body) was not observed. Immunoperoxidase study clearly demonstrated the presence of intra- and extracytoplasmic alpha-fetoprotein granules in the tumor tissue. The amount of the serum alpha-fetoprotein, measured by radioimmunoassay, showed 400 ng/ml. After irradiation in the posterior fossa (5000 rad) the patient was discharged. Three months later, follow up CT demonstrated small high density area in the anterior horn of the left lateral ventricle, so he was rehospitalised. Irradiation in the whole brain was again administered. The tumor was very radiosensitive. CT, after 800 rad, demonstrated complete disappearance of the tumor. After irradiation totally (3000 rad), he discharged with left cerebellar ataxia.

[Two cases of coronary artery fistula with coronary artery aneurysm].

Two cases of coronary artery fistula with coronary artery aneurysm were reported. Coronary angiography showed dilated right coronary artery with the formation of aneurysm drained to the right atrium and to the right ventricle respectively. The inflow ostium from the coronary artery to the aneurysm were closed from inside adding aneurysmorraphy. Postoperative clinical courses were uneventful and residual shunts were not detected by angiography. We reported these cases with literature.

[Surgical treatment of subaortic stenosis].

We reviewed 10 cases with subaortic stenosis (SAS) who underwent surgical repairs in our hospital. They were divided into 3 groups. Group I-A included patients with discrete SAS which had been detected before the initial operation. Group I-B included patients with discrete SAS which became apparent following the initial operations. Group II patients included SAS except the discrete type. Surgical treatment of each group was discussed. In group IA, there were no early deaths nor late deaths. There was 1 reoperation due to restenosis. Group IB had 3 cases which included VSD with CoA, Taussig-Bing anomaly, and common atrioventricular canal with VSD. In the Taussig-Bing anomaly case, an arterial switch (Lecompte maneuver) was performed 3 years ago. SAS was successfully relieved with the right ventriculotomy and VSD patch incision. Group II had 3 cases. There were 2 operative deaths and 1 late death. SAS was relieved by, in two cases, Stansel anastomosis with BT shunt and, in the last one, palliative arterial switch operation. It was extremely difficult to detect SAS in group II, when SAS had rapidly progressed following PAB in neonate and early infant. Our present policy is that PAB would be performed if there is no apparent SAS before the initial operation. SAS should be relieved as soon as possible if it is apparent at the postoperative period. Either Stansel anastomosis with BT shunt or palliative arterial switch operation would be the best choice in such a difficult case.

Luminescence of Novel Neodymium Sulfonylaminate Complexes in Organic Media.

Luminescence of Nd(III) in an organic solvent having C-H bonds was achieved for the first time by complexing Nd(III) with long-chain perfluoroalkylated ligands such as bis(perfluorooctylsulfonyl)aminate (pos). The complex [Nd(pos)(3)] gave an emission quantum yield of 3.0+/-0.5 % in undeuterated acetone. The bulky pos ligands suppress the excitation of C-H vibrations, energy migration at diffusional collision, and the coordination of acetone molecules (see picture) to the Nd(III) center, which otherwise quench the luminescence.