bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new myasthenic syndrome with end‐plate acetylcholinesterase deficiency, small nerve terminals, and reduced acetylcholine release
Authors: Engel Andrew G. , Lambert Edward H. , Gomez Manuel R. 
Published: January 2005

AbstractA new myasthenic syndrome is described in a patient whose symptoms began soon after birth and included generalized weakness increased by exertion, easy fatigability, hyporeflexia, and refractoriness to anticholinesterase drugs. Electromyography showed a decremental response at all frequencies of stimulation and a repetitive response to single nerve stimulation. Miniature end‐plate potentials (mepps) were of normal amplitude but of decreased frequency. The mepp duration and half‐decay time were prolonged, and prostigmine was without any additional effect. The quantum content of the end‐plate potential was decreased due to a reduced store of quanta immediately available for release, but the probability of release was normal. Quantitative electron microscopy demonstrated a 3‐fold to 4‐fold decrease of nerve terminal size and reduced postsynaptic membrane density. The postsynaptic folds showed focal degeneration, and many were distended by labyrinthine membranous networks that communicated with the synaptic space. Degenerating nuclei were found in the junctional sarcoplasm. The ultrastructural localization of the acetylcholine receptor protein was normal. Acetylcholinesterase (AChE) was absent from the motor end‐plates by histochemical and electron cytochemical criteria. Biochemical studies indicated total absence of the end‐plate‐specific 16 S species of AChE and marked decrease in total muscle AChE. A congenital defect in the molecular assembly of AChE or in its attachment to the postsynaptic membrane might represent the basic abnormality and condition the morphological and physiological alterations.
Chronic ketosis and cerebral metabolism
Authors: Devivo Darryl C. , Leckie Mary P. , Ferrendelli James S. , McDougal David B. 
Published: January 2005

AbstractThe effects of chronic ketosis on cerebral metabolism were determined in adult rats maintained on a high ‐fat diet for approximately three weeks and compared to a control group of animals. The fat‐fed rats had statistically significantly lower blood glucose concentrations and higher blood β‐hydroxybutyrate and acetoacetate concentrations; higher brain concentrations of bound glucose, glucose 6‐phosphate, pyruvate, lactate, β‐hydroxybutyrate, citrate, α‐ketoglutarate, alanine, and adenosine triphosphate (ATP); lower brain concentration of fructose 1,6‐diphosphate, aspartate, adenosine diphosphate (ADP), creatine, cyclic nucleotides, succinyl coenzyme A (CoA), acid‐insoluble CoA, and total CoA; and similar brain concentrations of glucose, malate, calculated oxaloacetate, glutamate, glutamine, adenosine monophosphate, phosphocreatine, reduced CoA, acetyl CoA, sodium, potassium, chloride, and water content. The metabolite data in the chronically ketotic rats demonstrate an increase in the cerebral energy reserve and energy charge. These data also suggest negative modification of the enzymes phosphofructokinase, pyruvic dehydrogenase, and β‐ketoglutaric dehydrogenase; positive modification of glycogen synthase; and possible augmentation of the hexose transport system. There was no demonstrable difference in brain pH, water content, or electrolytes in the two groups of animals. We speculate that the increased brain ATP/ADP ratio is central to most, if not all, the observed metabolic perturbations and may account for the increased neuronal stability that accompanies chronic ketosis.
Intracranial arteriovenous malformations in childhood
Authors: Kelly John J. , Mellinger James F. , Sundt Thoralf M. 
Published: January 2005

AbstractDuring the 13‐year period 1964 through 1976, 37 patients less than 20 years old with an intracranial, parenchymal arteriovenous fistula were seen at the Mayo Clinic. The most frequent mode of presentation was hemorrhage or seizure. Other than angiography, computed tomography with contrast enhancement was the most helpful diagnostic test. Surgery was restricted to patients with intraparenchymal hematomas, intractable seizures, or subarachnoid hemorrhage with accessible lesions and to 1 infant with a massive, symptomatic malformation. Surgery generally was tolerated well, with reversal of most acute focal neurological deficits related to hematomas. In the nonsurgical group, follow‐up revealed a fairly stable neurological status during the period of the study.
Effects of hypothermia on the human brainstem auditory response
Authors: Stockard James J. , Sharbrough Frank W. , Tinker John A. 
Published: January 2005

AbstractLatency measurements between three potentials (waves I, III, and IV/V) of the human brainstem auditory response can allow early detection of certain posterior fossa lesions. The diagnostic use of these interwave latencies requires knowledge of what factors may prolong them in the absence of disease. Hypothermia appears to be one such factor–in 5 neurologically and audiometrically normal patients, mean esophageal temperatures as high as 34.5°C resulted in prolongations of central auditory conduction time. Interwave latency prolongations that were abnormal relative to an age‐matched normal population were seen at 32.1° ± 0.3°C in patients with both spontaneous and induced hypothermia, and these abnormalities disappeared after rewarming to normothermia. Hypothermia often accompanies intoxication and coma and should therefore be considered when brainstem auditory response abnormalities are being interpreted in these two clinical conditions.
Clinical evaluation of metrizamide for neuroradiology in children
Authors: Swick Herbert M. , Sty John R. , Haughton Victor M. 
Published: January 2005

AbstractMetrizamide is a nonionic water‐soluble contrast medium for neuroradiological studies that is less irritating to the nervous system than other water‐soluble agents. Studies in adults have shown that metrizamide has advantages over currently available media, but experience with children has been limited.Sixty‐two children have had myelography or ventriculography using metrizamide. The children ranged in age from 11 days to 22 years. Technically satisfactory studies were obtained in every patient. No major complications were encountered. Minor side‐effects included headache in 11 children (18%), mild nausea or vomiting in 16 children (26%), and fever in 4 children (6%). Seizures did not occur. One infant in the study subsequently died of unrelated problems; there was no evidence of arachnoiditis at postmortem examination. Metrizamide is a safe, effective contrast medium for neuroradiological use in children.
Possible biochemical basis of memory disorder in Alzheimer disease
Authors: Smith Christine M. , Swash Michael 
Published: January 2005

AbstractDamage to the hippocampal formation, whether focal or diffuse, leads to severe impairment of short‐term memory. The most common presenting symptom of Alzheimer disease is loss of short‐term memory, and histologically the hippocampus is characteristically affected. Choline acetyltransferase, which is involved in the synthesis of acetylcholine, is depleted in the hippocampus in the disorder. Anticholinergic drugs administered to normal subjects can simulate some aspects of the memory defect seen in Alzheimer disease. It is postulated that damage to a cholinergic neuronal pathway running to or from the hippocampus underlies the memory disorder. This suggestion implies that it may be possible to improve memory in patients with Alzheimer disease by pharmacological means.
Radiation myelopathy in children
Authors: Sundaresan N. , Gutierrez F. A. , Larsen M. B. 
Published: January 2005

AbstractThree children, 1 with medulloblastoma, 1 with anaplastic cerebellar tumor, and 1 with acute lymphocytic leukemia, received craniospinal irradiation with an estimated cord dose between 1,100 and 1,200 rets. All 3 patients after a latent period of seven to eight months developed subacute transverse myelopathy. The myelopathy was cervical in 2 patients and thoracic in 1. Spinal fluid examination showed high protein levels in 2 patients. Myelography demonstrated a swollen cord in 2 patients and normal appearance in 1. Autopsy in 1 patient disclosed a necrotizing myelopathy. The findings suggest that children tolerate less well than adults what previously have been considered safe doses of radiation to the spinal cord.
Predictive control of eye movements in parkinson disease
Authors: Flowers K. A. , Downing A. C. 
Published: January 2005

AbstractFour parkinsonian patients who had shown evidence of an impairment of predictive manual control and 4 age‐matched normal subjects were tested for the predictive control of eye movements. Subjects tracked a target with their eyes as it moved in either irregular “noise” or regular (predictable) linear ramp or sine waveforms. Eye movements were monitored by electrooculograpy, and the overall tracking time lag for each condition was determined by cross‐correlation. Both normal and parkinsonian subjects showed prediction in eye tracking on the regular waveforms (zero time lag or anticipation of the target track), indicating that (1) the parkinsonian loss of predictive control in manual tasks is not due to defective control of eye movements, and (2) there may be separate predictor mechanisms in the brain for eyes and hands.
Unusual presentation of traumatic extracranial internal carotid artery aneurysm
Authors: Bradbury Peter Gavin , Lambert Colin Douglas 
Published: January 2005

AbstractA young man presented with apparent transient ischemic attacks following a motorcycle accident in which he sustained minor injuries only. Computerized axial tomography demonstrated a small right frontal infarct, and angiography revealed an aneurysm of the right internal carotid artery in its extracranial course. This was thought to be traumatic in origin.
Experimental scrapie in mice: Ultrastructural observations
Authors: Baringer J. Richard , Prusiner Stanley B. 
Published: January 2005

AbstractScrapie, kuru, and Creutzfeldt‐Jakob disease are characterized by a similar spongiform pathology, prolonged incubation periods, and an agent with unique physical, chemical, and biological properties. Swiss mice were inoculated with the scrapie agent and sacrificed three to five months later for light and electron microscopy. At three months, small vacuoles were seen within the neuropil of the cerebral cortex and basal ganglia. By the fifth month these vacuoles had increased in number and size and were accompanied by moderate astrocytic proliferation. The brainstem, cerebellum, and spinal cord showed variable changes of much less intensity. Many dialted postsynaptic processes contained osmiophilic particles in random or crystalline arrays. The particles, measuring approximately 23 nm in diameter, appeared consistently in postsynaptic processes of brain from scrapie‐infected mice, were lacking in controls, and were of a size consistent with sedimentation and filtration data for the scrapie agent. Whether these particles represent the scrapie agent must await further studies.
Clinical studies of intrathecal autologous lymphocyte infusions in patients with malignant glioma: A toxicity study
Authors: Neuwelt Edward A. , Clark Kemp , Kirkpatrick Joel B. , Toben Howard 
Published: January 2005

AbstractThe feasibility and toxicity of intrathecal lymphoid cell infusions in patients with glioma were examined in this study. Blood rich in lymphoid cells was obtained using the Haemonetics Model 30 cell separator; the lymphoid cells extracted were further purified on Ficoll‐Hypaque gradients. Four patients received a total of eighteen autologous lymphoid cell infusions, with between 1 × 106 and 5 × 109 lymphoid cells being infused on each occasion. No toxicity was observed, but the CSF glucose declined in 2 patients. In 1 patient examined at autopsy the lymphoid cells appeared to have gained access to the tumor bed as well as to the rest of the subarachnoid space.
The pathophysiology of myotonia produced by aromatic carboxylic acids
Authors: Furman R. E. , Barchi R. L. 
Published: January 2005

AbstractA series of nine related aromatic monocarboxylic acids (ACAs) previously shown to inhibit muscle membrane chloride conductance (GCl) selectively in the rat were studied for their ability to produce myotonia. All nine induced characteristic repetitive electrical activity and delayed relaxation in isolated muscle, although the concentrations required for this action varied widely. In each case, myotonia was observed at concentrations that correlated closely with previously determined half‐maximal concentrations for inhibition of GCl. Intracellular recordings from muscle made myotonic with ACA revealed prolonged latencies at rheobase, multiple driven spikes, and self‐sustaining repetitive activity similar to that previously reported in hereditary goat myotonia. Phase‐plane diagrams of membrane action potentials recorded after exposure to the most effective of these compounds suggested little effect on the voltage‐dependent sodium system. The changes seen could be duplicated by simple removal of chloride ion.The expression of repetitive electrical activity in the presence of low membrane GCl depends on ambient temperature and on the concentration of calcium ion. Increasing temperature and decreasing Ca++ predispose toward myotonic activity; converse conditions inhibit myotonia. Myotonia induced by ACA is inhibited by concentrations of diphenylhydantoin that are clinically effective in controlling hereditary myotonia in humans.
Tissue carnitine in reye syndrome
Authors: Willner Joseph H. , Chutorian Abe M. , Dimauro Salvatore 
Published: January 2005

AbstractSkeletal muscle carnitine palmityltransferase and muscle or liver carnitine content were determined in biopsies from children during and after attacks of Reye syndrome. No consistent abnormaility of enzyme or cofactor was found. Reye syndrome is biochemically distinct from the clinically similar syndrome of systemic carnitine deficiency.
Introduction of automated systems to evaluate touch‐pressure, vibration, and thermal cutaneous sensation in man
Authors: Dyck Peter James , Zimmerman I. R. , O' Brien Peter C. , Ness Anders , Caskey Patrick E. , Karnes Jeannine , Bushek Wilfred 
Published: January 2005

AbstractSystems for automatic assessment of cutaneous touch‐pressure, vibratory, and thermal sensation have been developed. These systems use stimuli which are quantified and reproductible, a two‐alternative forced‐choice technique, and programmed steps to test, score, and report. If normal responses from series of healthy persons have been measured, percentile values specific for test, site, age, and sex can be determined. Abnormality, as in neurological disease, can then be defined as the response which has a value greater than that of the 95th (or other) percentile. These systems may be used to detect and validate abnormalities of sensation in neurological disease and in persons at risk from new medications or from industrial toxins, and to monitor worsening or improvement of sensation in follow‐up of a patient or in evaluation of therapeutic regimens.
The splanchnic autonomic outflow in shy‐drager syndrome and idiopathic orthostatic hypotension
Authors: Low Phillip A. , Thomas Juergen E. , Dyck Peter James 
Published: January 2005

AbstractSince splanchnic outflow is important in the maintenance of postural normotension in man, we performed a quantitative analysis of preganglionic autonomic neuron cell bodies of the seventh thoracic spinal cord segment and their corresponding axons in 2 patients with Shy‐Drager syndrome (SDS) and 1 with idiopathic orthostatic hypotension (IOH) and compared these values to control data. The intermediolateral column (ILC) neuron cell body counts were reduced to 17% of control levels in SDS and 52% of control levels in IOH. The B fiber counts in the corresponding ventral spinal root were reduced to 21% and 41% in SDS and IOH, respectively. From the present study and our previous results of ILC counts with age, we infer that orthostatic hypotension does not develop until half or more of the preganglionic autonomic neurons have degenerated. An additional finding in SDS is that there is involvement beyond autonomic neurons.
Palatal myoclonus and denervation supersensitivity in the central nervous system
Authors: Matsuo Fumisuke , Ajax Ernest T. 
Published: January 2005

AbstractWe postulate that palatal myoclonus after infarction of the brainstem or cerebellum, or both, is the manifestation of denervatio supersensitivity secondary to lesions involving the dentatorubroolivary system. Two cases of our own and 31 from the English and French literature were analyzed in order to determine the delay between the occurrence of presumed anatomical lesions and the recognition of palatal myoclonus. The intervals varied from 2 to 49 months with the median between 10 and 11 months. The natural history of palatal myoclonus following brainstem infarction seemed consistent with the hypothesis.
Creutzfeldt‐Jakob disease: Patterns of worldwide occurrence and the significance of familial and sporadic clustering
Authors: Masters Colin L. , Harris Jonathan O. , Gajdusek D. Carleton , Gibbs Clarence J. , Bernoulli Christoph , Asher David M. 
Published: January 2005

AbstractThe worldwide epidemiology of Creutzfeldt‐Jakob disease (CJD) is presented from an analysis of 1,435 patients. In the United States, the average annual mortality rate is at least 0.26 deaths per million. Temporal‐spatial clustering of cases was not found in the United States, but reports from other countries indicate that such clustering does occur. Fifteen percent of the cases were of the familial type, suggesting a genetic susceptibility to infection.Iatrogenic transmission by corneal transplantation and neurosurgical operations has occurred, and the possibility is raised that previous surgery or preexisting neurological disease may be associated with an increased risk of developing CJD. It remains to be determined whether the virus of CJD is maintained only by patient‐to‐patient transmission, has a zoonotic reservoir such as scrapie, or causes widespread latent infection of man that is occasionally activated.
Creutzfeldt‐Jakob disease in France: I. Retrospective study of the Paris area during the ten‐year period 1968–1977
Authors: Brown Paul , Cathala Françoise 
Published: January 2005

AbstractA systematic search for cases of Creutzfeldt‐Jakob disease occurring in the ten‐year period 1968 through 1977 was conducted in the city of Paris and surrounding departments which comprise the greater Paris area. Fifty‐six cases were found among the total population of approximately 10 million inhabitants, with a maximum incidence of 1.1 cases per year per million people in the densely populated city of Paris and a progressively lower incidence in the less heavily populated suburban and rural areas of the region. There was no temporal or geographic clustering of disease. Attention is drawn to the often rapid onset and short duration of illness (nearly two‐thirds of the patients died within five months of onset) and the frequent early occurrence of symptoms such as asthenia, diaphoresis, and disturbances of sleep and appetite.
Sporadic distal myopathy with early adult onset
Authors: Miller Robert G. , Blank Nathan K. , Layzer Robert B. 
Published: January 2005

AbstractWith the exception of the large series of adult‐onset hereditary distal myopathy from Sweden, few cases of primary muscle disease with a definite distal predilection have been published. We report 3 sporadic cases of distal myopathy with the following features: (1) early adult onset (26 to 33 years); (2) slowly progressive weakness affecting first the distal leg muscles and later the arms; (3) marked elevation of creatine phosphokinase (more than 10 times the normal value); and (4) electromyographic and histological evidence of myopathy in distal muscles. The differential diagnosis is discussed and other reported cases are reviewed. The differences between hereditary cases reported by others and the sporadic cases reported here form the basis for a tentative subclassification of this syndrome.
Central somatosensory conduction time in comatose patients
Authors: Hume Ann L. , Cant B. R. , Shaw N. A. 
Published: January 2005

AbstractSomatosensory conduction time between the dorsal column nuclei and the cerebral cortex may be measured following median nerve stimulation by recording evoked potentials from both scalp and neck. Central conduction times were significantly increased relative to normal (5.6 ± 0.5 msec) in 11 of 24 comatose patients. Results within 10 and 35 days of onset of coma were correlated with the final outcome. Conduction times were independent of serum phenobarbital (0 to 630 μmol per liter) and of central body temperature (35.0 to 38.5°C). Serial studies in coma demonstrated (1) short‐term increases during temporary metabolic disorders, and (2) sustained increases with gradual recovery over many months, particularly after head injury.
Thrombocytopenia associated with sodium valproate treatment
Authors: Neophytides Andreas N. , Nutt John G. , Lodish Jules R. 
Published: January 2005

AbstractThe administration of sodium valproate to 30 patients in daily doses of 1,200 to 3,000 mg was associated with a significant reduction of the platelet count. Thrombocytopenia without any concomitant bleeding abnormalities occurred in 10 of the patients. Platelet counts returned to baseline levels after withdrawal of the drug.
Horizontal pursuit defect nystagmus
Authors: Abel L. A. , Daroff R. B. , Dell'Osso L. F. 
Published: January 2005

AbstractA teenage girl with a chronic large posterior fossa tumor had primary position right‐beating nystagmus with a constant‐velocity slow phase. Smooth pursuit was normal to the left but absent to the right. Vestibuloocular movements were present in both directions. The findings are analogous to downbeat and upbeat nystagmus, in which unidirectional pursuit palsies have been postulated as the pathogenic mechanism. This is the first reported case of a horizontal pursuit defect causing nystagmus.
Ontogeny of spontaneous blinking and of habituation of the blink reflex
Authors: Zametkin Alan J. , Stevens Janice R. , Pittman Richard 
Published: January 2005

AbstractHabituation of the blink reflex to glabellar percussion was examined in 164 infants and children from ages 2 days to 18 years and in 18 adults aged 18 to 50 years. Spontaneous blink rates were measured in 269 children and 179 adults. The mean number of glabellar taps required for habituation of the blink reflex increased from 2.7 (SD 1.2) at 0 to 2 months of age to a peak of 13.3 (SD 5.6) at age 3 to 4, remained at more than 10 until age 6, after which a rapid decline occurred, reaching the adult level of 2 to 5 blinks to habituation at age 12 years. The mean rate of spontaneous blinking was less than 2 per minute in early infancy and increased steadily during childhood up to age 14 or 15. The inverse relationship of spontaneous blink rate and number of blink reflexes to habituation in early childhood and in disorders of dopamine transmission suggests that spontaneous blink rate and habituation of the blink reflex reflect maturation and integrity of dopaminergic circuits in the brain.