Effect of the Growth Conditions on Organic Crystals with Rare Earth Ions and 1,10-Phenanthroline.

Using a simple solution growth technique, we grow crystals with phenanthroline as a ligand and various rare earth ions: thulium (Tm), ytterbium (Yb), gadolinium (Gd), lanthanum (La), neodymium (Nd), europium (Eu), and erbium (Er). We then selected the composition that forms thin plates with well-defined shapes, Er(NO)Phen, and explored the effects of various conditions on crystal formation and growth, including temperature regime, light illumination, and substrates where the crystals are formed and grown. The composition and local environment strongly affect the size and shape of microcrystals and substrate coverage.

Heterogeneity of cerebral cavernous hemangiomas diagnosed by MR imaging.

The cavernous hemangioma (cavernoma) is increasingly recognized as a vascular malformation of the brain that may present with seizures, hemorrhage, or progressive neurological deficit. Since 1985 we have identified 13 cases of presumed cavernoma of the brain based on the findings on CT, selective angiography, and magnetic resonance (MR) imaging. In each case CT showed a high density lesion that was "occult" or "cryptic" on angiography.

Intraoperative monitoring of evoked potentials with a spiral scalp electrode. Technical note.

Monitoring evoked potentials from the brain for prolonged periods during neurosurgical procedures ideally requires attached scalp electrodes that may be placed in a sterile field. The limitations of conventional surface and percutaneous electrodes in the operating room environment have led to the development of a disposable curved-needle electrode which is inherently self-retaining. Clinical results have demonstrated the advantages of this new electrode over other electrodes currently used for intraoperative neurophysiological monitoring.

Ozone-initiated changes in erythrocyte membrane and loss of deformability.

In vivo O3 exposure followed by in vitro incubation was observed to cause inhibition of mouse RBC deformability. The requirement for in vitro incubation to allow expression of these effects and the potential role for oxidizable membrane components were investigated. Membrane sulfhydryls (SHs) and membrane ATPase are both susceptible to oxidation by O3 and are essential for maintaining RBC membrane deformability.

Magnetic resonance imaging of the lumbar spine. A comparison with computed tomography and myelography.

Two hundred and fifty patients were referred for magnetic resonance imaging (MRI) of the lumbar spine. Computed tomography (CT) and MRI were performed in 50 patients and MRI, CT and myelography in 20 patients. Twenty patients had surgical confirmation of the imaging studies.

Benign familial chorea: an association with intellectual impairment.

Twenty-four members of a family with benign familial chorea underwent testing for evidence of intellectual impairment. Lower verbal intelligence was found in affected individuals compared to unaffected family members, as were deficits in verbal abstract concept formation. These results challenge the notion that benign familial chorea uniformly spares the intellect in all kindreds.

Simultaneous measurement of local glucose utilization and blood flow in the rat brain: an autoradiographic method using two tracers labeled with carbon-14.

A simplified technique that uses two radionuclide tracers has been devised to measure local cerebral glucose utilization (ICGU) and local cerebral blood flow (ICBF) in the same rat. The method employs [14C]-2-deoxyglucose and [14C]iodoantipyrine to produce an autoradiogram before and another after extraction into chloroform of the [14C]iodoantipyrine from the brain sections. The chloroform-extracted autoradiogram yields ICGU, and the difference in tissue carbon-14 concentration between the two autoradiograms permits calculation of ICBF.

Cerebral ischemia produced by four-vessel occlusion in the rat: a quantitative evaluation of cerebral blood flow.

Cerebral ischemia was produced in the rat by simultaneous occlusion of the vertebral and carotid arteries according to the method of Pulsinelli and Brierley (Stroke 10: 267, 1979). Local cerebral blood flow (CBF) was determined by polarographic and autoradiographic techniques. Hydrogen-clearance measurements showed that mean CBF fell in four monitored regions of the hemispheres to between 0.

Experimental air embolism of the brain: an analysis of the technique in the rat.

Air embolization of the brain produces cerebral ischemia that can be focal and reversible. The method has previously been hampered by (1) lack of selective arterial injection of the embolus, (2) disruption of local hemodynamic relationships by ligation of major arterial channels, (3) excessive volume of the air embolus, and (4) uncontrolled bubble size. To minimize these factors, a technique was devised in the rat whereby a fine catheter was advanced through a branch of the external carotid artery into the internal carotid artery.

A comparison of short-latency auditory-evoked potentials in two strains of mice: possible neurophysiological correlates of susceptibility to audiogenic seizures?

The short-latency auditory-evoked response was recorded from adult (over 8 wk) and young (16-22 day) mice of the audiogenic seizure-prone DBA/2J (D2) and seizure-resistant C57BL/6J (C6) strains. An auditory complex made up of eleven peaks and troughs was found within the first 20 ms after click stimuli. The latencies of the potentials tended to be shorter in the C6 mice and in the adults of both strains.

Influence of factor VIII/von Willebrand factor protein (F VIII/vWF) and F VIII/vWF-poor cryoprecipitate on post-ischemic microvascular reperfusion in the central nervous system.

To test the hypothesis that plasma contains native constituents capable of impairing microcirculatory flow in zones of acute ischemic tissue damage, we performed 14C-antipyrine autoradiographic blood flow studies in splenectomized dogs subjected to 35 min of cerebrospinal fluid compression ischemia followed by 30 min of recirculation to the neuraxis. The animals were anticoagulated with heparin and were divided into 4 groups by exposure to various measures before induction of ischemia. Groups 1 and 2 served for comparison with the other groups and underwent, respectively, no glass-wool filtration and glass-wool filtration via an arteriovenous shunt.