Effects of oral physostigmine and lecithin on memory and attention in closed head-injured patients.

In view of the evidence for the role of the central cholinergic pathways in memory and preliminary studies suggesting alteration of neurotransmitters after severe head injury, we completed a double-blind, placebo-controlled study of combined oral physostigmine and lecithin. Sixteen survivors of moderate to severe closed head injury who had unequivocal memory deficit were studied during the course of inpatient rehabilitation. Although the results generally indicated no difference in the effects of the physostigmine-lecithin combination as compared to lecithin alone, sustained attention on the continuous performance test was more efficient under physostigmine than placebo when the drug condition occurred first in the crossover design.

ACTH stimulation of adrenal epinephrine and norepinephrine release.

Epinephrine (E) and norepinephrine (NE) levels were measured simultaneously in the adrenal veins of 6 patients before and after stimulation with 0.25 mg beta 1-24 ACTH. In 1 patient with Cushing's syndrome, E and NE were also measured before and 30 min after dexamethasone.

Nucleosome core particle structure and structural changes in solution.

The radius of gyration, Rg, of chicken erythrocyte nucleosome core particles, was found to be 4.56 (+/- 0.07) nm by small-angle X-ray scattering, independent of particle concentration and of NaCl concentration between 0.

Ultrasonography of the eye and orbit.

The eye and orbit are excellent subjects for ultrasonic evaluation. Examination and interpretation are relatively simple procedures. The normal ultrasonic anatomy of the eye and orbit is presented.

Methylprednisolone and neurological function 1 year after spinal cord injury. Results of the National Acute Spinal Cord Injury Study.

A multi-center double-blind randomized clinical trial was conducted by the National Acute Spinal Cord Injury Study Group to examine the efficacy of high-dose methylprednisolone (1000-mg bolus and 1000 mg daily thereafter for 10 days) compared with that of a standard dose (100-mg bolus and 100 mg daily for 10 days). No significant difference was observed in neurological recovery of motor function, pinprick response, or touch sensation 1 year after injury between the two treatment groups, after adjustment for other potentially confounding factors. Analyses that specifically took into account the patients' total steroid dose and relative weight confirmed the lack of a steroid treatment effect.

Probe-evoked potential correlates of hemispheric asymmetries during a speech shadowing task.

Evoked potentials (EPs) to a monaurally presented probe stimulus were recorded from the vertex in subjects engaged in shadowing a word list presented simultaneously to the contralateral ear. Greater attenuation of the N1-P2 and baseline-P2 amplitude of the probe EPs was observed when the probe stimulus was presented to the right ear and the verbal material presented to the left ear than when the opposite stimulation arrangement was used. The baseline-N1 amplitude, however, was equally attenuated during the two stimulation arrangements.

Magnetic resonance imaging after 'diffuse' nonmissile head injury. A neurobehavioral study.

The diagnosis of diffuse brain injury is considered when computed tomography provides no evidence of an intracranial mass lesion in acute nonmissile head injury. Magnetic resonance imaging (MRI) of a young woman who had sustained severe diffuse brain injury five years earlier disclosed multifocal lesions involving the frontal, temporal, parietal, and occipital lobes. We report the results of serial neurobehavioral assessment for clinical correlation with the brain lesions visualized by MRI.

Advances in pediatric neurosurgery.

Pediatric neurosurgery is benefiting greatly from technologic advances in medicine that are enabling earlier and more definitive diagnosis and treatment of a variety of conditions amenable to surgical correction. This article familiarizes the pediatrician with some of the many applications of the new technology as well as some newer concepts of disease management in pediatric neurosurgery.

Impairment of olfactory recognition after closed head injury.

To investigate the effects of closed head injury (CHI) on olfactory identification, we administered a test of olfactory naming and forced choice recognition to 52 CHI patients who had no evidence of anosmia. The Olfactory Identification Test consisted of 'scratch and sniff' labels of familiar nonirritant odorants. In comparison with a normal control group (n = 19) of similar age, olfactory naming and recognition were impaired in the CHI series, particularly in patients with moderate or severe head injury.

Stimulus offset P3 and temporal resolution of uncertainty.

Stimulus offset evoked potentials were recorded to short (1 250 ms) and long (2 500 ms) tones in the context of the odd-ball paradigm. In one condition, the short tone was presented frequently with a probability of 0.85 and the long tone with a probability of 0.

Evoked potential attenuation in the two-tone paradigm.

The recovery cycle and two variants of the habituation hypothesis invoked to explain the N1-P2 amplitude attenuation of evoked potentials (EPs) to the second tone in two-tone series, were investigated. Paired stimuli were presented with a constant 360 ms inter-stimulus interval (ISI), but with different, fixed inter-pair intervals (IPIs) of 800, 1 000 and 1 200 ms in addition to a variable IPI averaging 1 000 ms. Amplitude reduction of the second tone EP was present for only the 1 000 and the 1 200 ms IPI series.

Impairment of remote memory after closed head injury.

Evidence of partial retrograde amnesia for episodic memories of no personal salience was found in head injured patients (n = 10) tested during posttraumatic amnesia or shortly after its resolution (n = 10), but there was no selective preservation of the earliest memories. In contrast, head injured patients tested during posttraumatic amnesia exhibited relatively preserved retention of early autobiographical memories which they recalled as accurately as oriented head injured patients. It is suggested that reminiscence of salient, early events increases their resistance to partial retrograde amnesia and contributes to the observed temporal gradient.

Temporal pattern effects on auditory evoked potentials.

The question whether stimuli forming temporal patterns are processed differently from identical stimuli belonging to irregular temporal aggregates was investigated. Tones forming either regular or irregular triads were presented to eight normal subjects. The N1-P2 amplitude of evoked potentials to tones forming temporal patterns were consistently lower than those to tones in the irregular aggregates.

High-affinity transport of glutamate in rat brain microvessels.

The maintenance of low extracellular concentrations of glutamate in the brain is a complex process in which the role of capillary transport is poorly understood. We examined the kinetics and substrate specificity of glutamate uptake by isolated rat brain microvessels. We showed that these microvessels take up glutamate by an energy- and temperature-dependent, concentrative, high-affinity active transport system with Km of about 2 microM.

Computed tomogram-guided stereotactic brain biopsy in the pediatric patient.

Experience with computed tomogram-guided stereotactic biopsy is described with special reference to technical considerations important to the application of the Brown-Roberts-Wells system in pediatric patients. Eleven procedures were performed in 9 patients aged 9 months to 16 years of age. In all cases, the lesion was either deep seated or related to deficit prone areas making open biopsy hazardous.

Sequential electrocoagulation and resection for carcinoma of the rectum.

Sequential electrocoagulation followed by resection of carcinoma of the rectum provides better survival results than have been previously obtained. More than 200 patients have been treated by this combined approach during the past ten years. The over-all five year survival rate is 67 per cent.

Auditory evoked potentials in senescent forgetfulness.

Two evoked potential (EP) techniques and the selective reminding test were employed to investigate an apparently benign forgetfulness in seven elderly subjects and seven age-matched elderly subjects with normal memory. EPs were also recorded in a group of seven young adults. Latency of the P3 component, which has been demonstrated to increase in primary degenerative dementia, displayed the normal age-related variation in both elderly groups, but did not differ between the forgetful subjects and the elderly controls.

Interaction of chromatin with NaCl and MgCl2. Solubility and binding studies, transition to and characterization of the higher-order structure.

Chicken erythrocyte chromatin containing histones H1 and H5 was carefully separated into a number of well-characterized fractions. A distinction could be made between chromatin insoluble in NaCl above about 80 mM, and chromatin soluble at all NaCl concentrations. Both chromatin forms were indistinguishable electrophoretically and both underwent the transition from the low salt "10 nm" coil to the "30 nm" higher-order structure solenoid by either raising the MgCl2 concentration to about 0.

Nucleosome core particle stability and conformational change. Effect of temperature, particle and NaCl concentrations, and crosslinking of histone H3 sulfhydryl groups.

We have studied the reversible dissociation of core size DNA from chicken erythrocyte nucleosome core particles in solutions containing 0 X 1 M to 0 X 6 M-NaCl. Dissociation increases with increasing NaCl concentration, increasing temperature and decreasing particle concentration. At high particle concentrations, no free DNA is observed below 0 X 3 M-NaCl, whereas above 0 X 3 M-NaCl a lower limit of dissociation is reached.

Evoked potential correlates of posttraumatic amnesia after closed head injury.

The P-300 component of evoked potentials to a rare tone was measured in normal volunteers and in patients with closed head injuries who either were confused (in posttraumatic amnesia) or had recovered from posttraumatic amnesia and were oriented at the time of recording. The latency of this component, which reflects cortical processing of stimuli, varied reliably, with the degree of orientation being longest for confused patients and shortest for normal subjects. On the basis of these data, we suggest that the P-300 latency can be used as a physiological index of cognitive function in patients with closed head injury.

Interaction and conformational changes of chromatin with divalent ions.

We have investigated the interaction of divalent ions with chromatin towards a closer understanding of the role of metal ions in the cell nucleus. The first row transition metal ion chlorides MnCl2, CoCl2, NiCl2 and CuCl2 lead to precipitation of chicken erythrocyte chromatin at a significantly lower concentration than the alkali earth metal chlorides MgCl2, CaCl2 and BaCl2. A similar distinction can be made for the compaction of chromatin to the "30 nm" solenoid higher order structure which occurs at lower MeCl2 concentration in the first group but at the same MeCl2 concentration within each group.