Phasic modulation of short latency cutaneous excitation in flexor digitorum longus motoneurons during fictive locomotion.

We examined modulation of transmission of short-latency excitation produced by distal hindlimb cutaneous input, as well as fluctuations in motoneuron membrane potential and input resistance, in flexor digitorum longus (FDL) motoneurons during fictive locomotion. Fictive stepping was induced in unaesthetized, decerebrate cats either by repetitive stimulation of the mesencephalic locomotor region (MLR) or by administration of Nialamide and 1-DOPA after low spinal section. In the MLR preparations, brief depolarizing waves occurred in FDL cells during the early flexion phase of fictive stepping, immediately after cessation of activity in extensor muscles.

Case-control study of associated conditions at the time of death in patients with epilepsy.

Analysis of mortality data based on underlying cause of death in epileptic patients is of limited value in view of the low case-fatality ratio of epilepsy. Recently the National Center for Health Statistics has made available all conditions mentioned on each death certificate for the entire US population. Using a case-control study design, we have analyzed all the associated conditions at the time of death in patients with epilepsy for the year 1978.

Relationship between urinary excretion of homovanillic acid and norepinephrine metabolites in normal subjects and patients with orthostatic hypotension.

Patients with neurogenic orthostatic hypotension due to multiple system atrophy (MSA) or pure autonomic failure (PAF) excrete lower amounts of homovanillic acid (HVA) than do normal subjects. There is a highly significant correlation between the rates of excretion of HVA and norepinephrine metabolites. The regression line relating excretion of the dopamine and norepinephrine metabolites suggests that about one third of dopamine formed in noradrenergic neurons is converted to norepinephrine and the remainder metabolized, mainly to HVA.

Dorsal root entry zone coagulation for intractable sciatica.

Chronic back and leg pain which is unresponsive to medical and/or surgical treatment is a common and difficult neurosurgical problem. Twelve patients with this condition underwent dorsal root entry zone coagulation of that region of the conus medullaris which correlated with the pain. Only 2 patients had a favorable result.

Successful treatment of phantom pain with dorsal root entry zone coagulation.

We studied 22 patients with amputation due to trauma, gangrene, or cancer. All developed postamputation pain, underwent a dorsal root entry zone (DREZ) procedure, and were followed from 6 months to 4 years after surgery. Overall, only 8 (36%) of these 22 patients had pain relief.

An immunochemical analysis of oxytocin and vasopressin prohormone processing in vivo.

Antisera against partially processed, unamidated forms of AVP and OT were raised and characterized by radioimmunoassay and immunocytochemistry. These antibodies, and antibodies that recognize fully processed, amidated forms of AVP and OT, were used together with various fractionation methods to study the content of prohormones, partially processed and fully processed forms of AVP and OT in the hypothalamo-neurohypophysial system of adult and fetal (E21) rats. The levels of cleaved AVP and OT in the fetus were lower than those of the adult (1 to 3 orders of magnitude for brain and pituitary, respectively), and the detection of cleaved OT in brain and pituitary was delayed compared to that of AVP.

Flow cytometric analysis of membrane potential in embryonic rat spinal cord cells.

Flow cytometric analysis of membrane potential in suspensions of embryonic rat spinal cord cells was carried out in a fluorescence-activated cell sorter (FACS) using anionic voltage-sensitive, fluorescent dyes (oxonols). The FACS or flow cytometer is an analytical instrument that measures optical properties of large cell populations at a single cell level of resolution. The incorporation of oxonol allows relative measurements of membrane potential, since the partition of oxonol within the plasmalemma is directly related to the degree of cell depolarization.

Microvascular disturbances and edema formation after repetitive ischemia of gerbil brain.

Three transient episodes of 5 min ischemia spaced at 1-h intervals were produced in Mongolian gerbils by bilateral carotid artery occlusion with an implanted vascular occlusion device. The interval of 1 h was chosen to allow for the development of post-ischemic hypoperfusion between the ischemic episodes. Three minutes and 1 h after each ischemic episode, and 6 and 24 h after the third occlusion, Evan's blue (EB) was injected intravenously to trace circulating blood, and the number of perfused capillaries was determined in various brain regions by fluorescence microscopy.

Effects of amphetamine on protein synthesis and energy metabolism in mouse brain: role of drug-induced hyperthermia.

Changes in brain protein synthesis activity, and in brain levels of glucose, glycogen, and several high-energy phosphate metabolites, were evaluated under conditions of amphetamine-induced hyperthermia in mice. Protein synthesis showed a striking dependence on rectal temperature (TR), falling abruptly at TR above 40 degrees C. A similar result was obtained following direct heating of the animals.

Antibody to human and simian retrovirus, HTLV-I, HTLV-II, HIV, STLV-III, and SRV-I not increased in patients with multiple sclerosis.

We have tested sera from patients with multiple sclerosis, matched controls, and those with other neurological diseases, as well as sera from patients with the acquired immunodeficiency syndrome and controls and patients with tropical spastic paraparesis (TSP) and controls for antibody to human T-lymphotropic virus type I (HTLV-I), HTLV-II, human immunodeficiency virus (HIV), simian T-lymphotropic virus type III, or simian retrovirus type I by immunofluorescent activity test, and for HTLV-I and HIV by the ELISA method. Sera from patients with multiple sclerosis and matched controls, and from patients with optic neuritis and Parkinson's or other neuromuscular diseases did not have antibody to any of the retroviruses tested. Specimens from TSP patients and some controls contained HTLV-I antibody.

Effect of MPTP-induced parkinsonism in monkeys on the urinary excretion of HVA and MHPG during debrisoquin administration.

During debrisoquin administration to three monkeys there were significant reductions in excretion rates of HVA, the major dopamine metabolite, and MHPG, the major norepinephrine metabolite. Excretion rates of HVA were highly correlated to those of MHPG. The regression line relating HVA and MHPG excretion suggests that a portion of HVA (about 25%) is derived from a source independent of norepinephrine metabolites.

Prevalence surveys of neurologic disorders: methodologic implications of the Copiah County Study.

This article addresses three questions to be answered during the planning of prevalence surveys of chronic disorders in geographically defined populations: (a) Should personal interviews be used alone (i.e. without accompanying physical examinations) to find and confirm cases in a household population? (b) As an alternative means of identifying cases, is it adequate to review patient records from hospitals and clinics serving the population to be surveyed? (c) Should population members residing in institutions of long-term care be made ineligible for the anticipated survey? Data on major neurologic disorders, obtained from the Copiah County Study, are used to suggest caution in answering any of these questions in the affirmative, since in particular circumstances the consequences for the intended research may be serious or even disastrous.

Cerebral necrosis after radiotherapy and/or intraarterial chemotherapy for brain tumors: PET and neuropathologic studies.

Cerebral necrosis after radiotherapy for brain tumors is being recognized as a problem more common than previously estimated. Distinction between this iatrogenic complication and tumor recurrence cannot be made by either CT or MR imaging. By using positron emission tomography (PET) with 18F-deoxyglucose (FDG) we were able to reach a diagnosis of radiation necrosis, later verified, in 10 of 95 patients referred for the purpose of differentiating tumor recurrence from necrosis.

Nuclear protein kinase substrates in AtT-20 cells: translocation of a 14 kDa phosphoprotein.

In this work we characterize some acidic nuclear substrates of protein kinase C (PKC) and cyclic AMP-dependent protein kinase (PKA), using intact anterior pituitary corticotrophic tumor cells (AtT-20/D16-16). It was found that, as in the cytosolic fraction, substrates for both PKC and PKA exist in the nucleus and that changes in the phosphorylation states of a few of these phosphoproteins are mediated by both kinases. One of the phosphoproteins examined, a 14 kDa phosphoprotein (pp14) described previously, exhibited a phorbol-ester induced translocation from nucleus to cytosol in pulse-chase experiments utilizing 35S-methionine labeling.

Herpes-simplex-related antigen in human demyelinative disease and encephalitis.

Using immunohistochemical methods optimized to detect herpes simplex virus type 2 (HSV-2) antigen, paraffin sections from human central nervous system tissues from 31 cases pathologically diagnosed as multiple sclerosis (MS), 34 cases of other neurological diseases, 4 adult cases of HSV encephalitis, and mouse brains infected with various HSV strains were examined. Two distinct patterns of immunoreactivity with HSV antisera were seen. In typical acute human and experimental encephalitis, antigen was readily detected using high dilutions of antisera to both HSV types -1 and -2, and was found nonselectively in both neurons and glia.

Perinatal infections and immunity.

An increasing number of infectious agents are now recognized to be important causes of perinatal morbidity and mortality. Most of these agents produce asymptomatic or mild infections in the mother; however, some can cause severe or fatal disease in the fetus. In each case, the infectious agent is transmitted from the mother to the child, usually by the transplacental, hematogenous route.

Sympathoadrenomedullary hyper-responsiveness to yohimbine in juvenile spontaneously hypertensive rats.

We examined responses of arterial plasma levels of the sympathetic neurotransmitter, norepinephrine (NE), of the adrenomedullary hormone, epinephrine (E), and of the intraneuronal NE metabolite, dihydroxyphenylglycol (DHPG), after intravenous administration of the alpha-2 adrenoceptor antagonist, yohimbine, in conscious, freely-moving juvenile (4-week old) or mature (12-week old) rats with spontaneous hypertension (SHRs) and their normotensive Wistar-Kyoto (WKY) controls. Mature SHRs and WKY rats had similar levels of plasma catechols at rest, whereas juvenile SHRs had significantly higher levels of NE (400 +/- 109 (SD) vs 233 +/- 62 pg/ml), E (371 +/- 168 vs 148 +/- 67 pg/ml), and DHPG (800 +/- 147 vs 589 +/- 54 pg/ml). After yohimbine, average responses of NE in the juvenile SHRs were more than 5 times, of E more than 7 times, and of DHPG more than 11 times those of the juvenile WKY rats.

Treatment of human immunodeficiency virus-related polyneuropathy with 3'-azido-2',3'-dideoxythymidine.

A 72-year-old woman with human immunodeficiency virus (HIV)-related axonal polyradiculoneuropathy of the lower extremities was treated with 3'-azido-2',3'-dideoxythymidine (AZT), 250 mg every 4 hours. Before therapy she had rapidly progressive weakness in both legs and when treatment began she could move only her toes. Six weeks after therapy, there was mild improvement in her strength, which peaked 2 months later.

Unilateral lesion of the nigrostriatal pathway decreases the firing rate and alters the firing pattern of globus pallidus neurons in the rat.

Activities of spontaneously firing neurons in the globus pallidus of intact rats and rats that survived unilateral lesions of the nigrostriatal pathway for 3 days, 1 week, or 6-11 weeks were compared. No significant differences in neuronal firing rate, firing pattern, and number of cells per pass were observed between chloral hydrate-anesthetized control and lesioned animals. However, in locally anesthetized animals, pallidal cells fired significantly faster than in chloral hydrate-anesthetized animals, and the lesion caused a decrease in the firing rates of pallidal cells 1 week and 6-9 weeks postlesion.

Experimental hantavirus infection in nonhuman primates.

Mild, transient proteinuria and azotemia were produced in three cynomolgus monkeys (Macaca fascicularis) and a chimpanzee (Pan troglodytes) following intravenous inoculation with Prospect Hill virus, a hantavirus isolated from meadow voles in the United States. This is the first demonstration of an acute nephropathy in nonhuman primates with the viruses causing hemorrhagic fever with renal syndrome.