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Biomedical subjects

R A Brumback

Publications and source records attributed to R A Brumback.

At least 73 records · Page 4Linked to original sources
PubMed1990

Metabolic myopathy produced by acute inhibition of glyceraldehyde-3-phosphate dehydrogenase with ortho-iodosobenzoic acid.

A previously developed model of exercise-induced muscle contracture using iodoacetate to inhibit glyceraldehyde-3-phosphate dehydrogenase in rat hindlimb muscles produced selective type II myofiber damage. Utilizing a modification of the same model system, rats were given intra-aortic ortho-iodosobenzoic acid (700 nmol/kg body weight), which cleaves tryptophanyl peptides from glyceraldehyde-3-phosphate dehydrogenase. Within 2-4 h, spontaneous electrically-silent contracture developed in the injected musculature resulting in a plantar-flexed position of the hindlimb. After 24 h, the extensor digitorum longus and tibialis anterior muscles appeared grossly swollen (edematous) and discolored. Microscopically, the extensor digitorum longus (composed predominantly of type II myofibers) contained many randomly scattered, damaged myofibers, reduced glycogen content, absent glyceraldehyde-3-phosphate dehydrogenase activity, interstitial edema and focal collections of mononuclear phagocytes. Damaged fibers showed degenerative changes and contained stainable intracellular calcium. On modified trichrome-stained sections, an outer red staining rim of material was identifiable in many fibers. The fibers of the soleus muscle (composed predominantly of type I myofibers) were not damaged, indicating a preferential ortho-iodosobenzoic acid effect on type II myofibers.

Animals↗
PubMed1990

Primary disorder of vigilance: a novel explanation of inattentiveness, daydreaming, boredom, restlessness, and sleepiness.

We present a novel condition, designated as a primary disorder of vigilance, that has symptoms which overlap those of attention deficit-hyperactivity disorder. Vigilance is the state of being watchful, awake, and alert. When vigilance is lost, the individual has difficulty sustaining attention. The most obvious evidence of lowered vigilance is motor restlessness (fidgeting and moving about, yawning and stretching, talkativeness, or a combination of these) to improve alertness when sitting or standing still or when involved in tasks requiring continuous mental performance. When prevented from being active to stay awake, persons with lowered vigilance will stare off, daydream, show minor hyperactivity, and finally may fall asleep. They will also have decreasing attention to current activities and usually avoid or lose interest in structured or repetitive activities (complaining of boredom and monotony). The primary disorder of vigilance (for which criteria have been established) is a dominantly inherited condition with onset in early childhood and worsening symptoms with age. Persons with the primary disorder of vigilance have a remarkably kind and caring temperament. When untreated this disorder can cause chronic failure at school and work, but when properly recognized it responds well to treatment with stimulant medication and schedules that avoid sameness and repetition.

Arousal↗
PubMed1990

Cystic optic glioma.

A pilocytic astrocytoma of the optic nerve, chiasm, hypothalamus, or third ventricle is a relatively common tumor of childhood. This case report illustrates such a tumor, originating from this location, which is unusual because of the association with two very large cystic extensions into the middle cranial fossa and into the third ventricle. The massive size and extent of this tumor and cysts was demonstrated on a magnetic resonance imaging (MRI) scan, with gadolinium enhancement. This case illustrates a novel macroscopic appearance for a pilocytic glioma of the anterior third ventricle. The purpose of this report is to alert clinicians to the varied morphology this tumor may present as we apply increasingly our improved radiological, operative, and histopathological techniques.

Astrocytoma↗
PubMed1990

Spongiform encephalopathies: the physician's responsibility.

The spongiform encephalopathies encompass several diseases affecting humans and animals. In the United States, the most common of these disorders in humans is Creutzfeldt-Jakob disease. The most frequent manifestations include dementia, pyramidal tract signs, and extrapyramidal movement disorder. Several clinically distinct syndromes can be identified. Often the diagnosis is confused with other forms of dementia, and the only definitive method for establishing the diagnosis is autopsy evaluation of brain tissue. Unfortunately, since the recognition of the infectious etiology of Creutzfeldt-Jakob disease, fear has often unreasonably interfered with clinical care and autopsy evaluation of affected patients. In actuality, because of the low and restricted infectivity of the responsible agent, affected individuals present minimal risks to clinical caretakers, and handling of patient specimens is not dangerous if appropriate precautions are taken. These precautions are well established, and physicians and other health care workers should not refuse care of appropriate evaluation (including autopsy) to individuals with suspected Creutzfeldt-Jakob disease.

Aged↗
PubMed1990

Neuroimaging findings in Alexander's disease.

We present the findings from magnetic resonance imaging, computed tomographic scan, and single photon emission computed tomography of the brain in a 2-year-old girl with Alexander's disease. Computed tomographic scans showed prominent low-density white matter throughout the cerebral hemispheres. Magnetic resonance imaging showed increased T2 signal from the cerebral white matter but not the cerebellum or brain stem. Single photon emission computed tomography revealed diminished cerebral metabolism, particularly in the frontal regions, as compared with the cerebellum.

Astrocytes↗
PubMed1990

Dementia: the importance of clinical evaluation, autopsy confirmation, and research.

Because of the increasingly elderly population, dementia is a major public health problem, currently affecting over 50,000 Oklahomans at an approximate cost of one billion dollars annually. The marked overlap in symptomatology between Alzheimer's disease and other primary central nervous system degenerations makes antemortem diagnosis based on a clinical assessment tentative at best, with error rates of 25% commonly reported. Accurate diagnosis is of vital importance in improving our understanding of these illnesses, evaluating potential therapies, and providing appropriate genetic counseling to family members. Direct neuropathologic examination at autopsy is currently the only reliable method for assuring accurate diagnosis and should be undertaken in all demented patients.

Aged↗
PubMed1990

Pediatric behavioral neurology: an update on the neurologic aspects of depression, hyperactivity, and learning disabilities.

The high incidence of poor social adjustment in long-term follow-up studies of depressed children seems to relate to the inadequacy of the pharmacotherapy necessary to sustain long-lasting remission or possibly to repetitive inappropriate stresses. Insufficient antidepressant therapy with resultant intermittent depression-induced dysfunction of the socialization functions performed by the right cerebral hemisphere would not permit the child to develop appropriate interpersonal skills (causing failure in most social situations), and associated cognitive difficulties would complicate academic performance. Repeated school failure and chronic social ineptitude preclude development of the skills necessary for successful independent living in society. Thus, if symptoms of depression are found, it is imperative that the learning-disabled or behaviorally disturbed child or adolescent receive adequate antidepressant therapy to ensure complete long-term remission of the depression. In addition, learning-disabled individuals, even without apparent diagnosable depressive illness, must be offered appropriate methods for learning and communication which reduce stress. When such appropriate educational strategies are offered and poor performance still ensues (or continues), a trial of antidepressant therapy should be considered. Recognition of the depressive nature of symptoms may not be possible until treatment-induced improvement has occurred and depression-associated learning disability has resolved. Improvement in academic performance associated with improved cognitive function after treatment-induced remission of a depressive episode can be dramatic, with resolution of apparent learning disability. Poor educational achievement associated with chronic learning difficulties ultimately affects adult social functioning, and untreated or improperly treated chronic depression may result in the development of later personality disturbances. Therefore, before attributing school problems in children to untreatable conditions, depressive disorder must be excluded, and appropriate antidepressant therapy (along with removal of all apparent inappropriate stress, including inappropriate demands on brain function) should be provided to children and adolescents with evidence of depression.

Antidepressive Agents↗
PubMed1990

Dementia and Alzheimer's disease: resources in Oklahoma.

Senile dementia and Alzheimer's disease (often considered a single process) rank as the fourth most common cause of death in the United States and outrank in cost to the nation the three leading causes of death combined. Autopsy studies of patients with the clinical diagnosis of dementia have clearly shown that a wide variety of pathological conditions can produce clinically similar symptomatology. In order to address the many possible causes and treatments of these various forms of dementia, the Alzheimer's Association (formerly known as the Alzheimer's Disease and Related Disorders Association), the Oklahoma Autopsy Assistance Network at the Oklahoma Medical Research Foundation, and The Alzheimer's Foundation (also known as the Familial Alzheimer's Disease Research Foundation) have begun a concerted effort to develop a regional network which can aid patients and their relatives in the diagnosis and management of dementia. Awareness of these organizations by all physicians will help in the development and dissemination of the newer and more specific treatments to patients (and their relatives) with Alzheimer's disease and other forms of dementia in Oklahoma.

Alzheimer Disease↗
PubMed1989

DNA synthesis in Alzheimer type II astrocytosis. The question of astrocytic proliferation and mitosis in experimentally induced hepatic encephalopathy.

Hepatic encephalopathy is associated with development of Alzheimer type II astrocytosis consisting of large, pale, frequently paired astrocytic nuclei. Previous studies have suggested that the paired forms are a manifestation of astrocytic proliferation and that the two nuclei of paired forms are in separate cells and have an equal (diploid) DNA complement. A model of hepatic encephalopathy can be produced using methionine sulfoximine to inhibit irreversibly the enzyme glutamine synthetase, resulting in elevated brain ammonia levels and development of Alzheimer type II astrocytosis. Using this model Sprague-Dawley rats were simultaneously injected with methionine sulfoximine 300 mg/kg and tritiated thymidine 15 mCi/kg. Autoradiography of cerebral sections from animals killed 18 to 36 hours after the injection revealed many heavily labeled cortical Alzheimer type II astrocytic nuclei. These findings are consistent with DNA synthesis and mitotic division of Alzheimer type II astrocytes.

Alzheimer Disease↗
PubMed1989

A pilot controlled study of the use of imipramine to reduce myotonia.

It has been hypothesized that myotonic dystrophy is caused by a generalized disorder of membrane aminergic and petidergic receptors. A single uncontrolled study has suggested that the affective symptomatology and muscular disability of this disorder might be improved by tricyclic antidepressant treatment. In the present study, 12 adult patients with myotonic dystrophy (age range 18-55 yr) were treated with imipramine and placebo in a double-blind crossover paradigm. Both grip and percussion myotonia were significantly improved by imipramine treatment independent of change in depressive symptomatology. Serum drug levels revealed nonlinear elimination kinetics for imipramine in this patient population.

Adult↗
PubMed1989

Comparison of paragraph comprehension test scores with reading versus listening-reading and multiple-choice versus nominal recall administration techniques: justification for the bypass approach.

Eight groups of learning disabled children (N = 100), categorized by the clinical Lexical Paradigm as good readers or poor readers, were individually administered the Gilmore Oral Reading Test, Form D, by one of four input/retrieval methods: (1) the standardized method of administration in which the child reads each paragraph aloud and then answers five questions relating to the paragraph [read/recall method]; (2) the child reads each paragraph aloud and then for each question selects the correct answer from among three choices read by the examiner [read/choice method]; (3) the examiner reads each paragraph aloud and reads each of the five questions to the child to answer [listen/recall method]; and (4) the examiner reads each paragraph aloud and then for each question reads three multiple-choice answers from which the child selects the correct answer [listen/choice method]. The major difference in scores was between the groups tested by the recall versus the orally read multiple-choice methods. This study indicated that poor readers who listened to the material and were tested by orally read multiple-choice format could perform as well as good readers. The performance of good readers was not affected by listening or by the method of testing. The multiple-choice testing improved the performance of poor readers independent of the input method. This supports the arguments made previously that a "bypass approach" to education of poor readers in which testing is accomplished using an orally read multiple-choice format can enhance the child's school performance on reading-related tasks. Using a listening while reading input method may further enhance performance.

Achievement↗
PubMed1989

Depression, learning disability, and school behavior problems.

It is possible that recurrent depression (primary affective illness) is the most significant variable related to school problems of a behavioral nature in children manifesting developmental specific learning disabilities. The association of school problems and depression was investigated at a private school for children with developmental specific learning disabilities. These children were of normal intelligence and were free of primary conduct or thought disturbances. Prior to entering school, 95% of the students fulfilled criteria for developmental specific learning disabilities and 64% for depression with or without hyperactivity. Students manifesting no diagnosable behavioral condition prior to entrance continued to be relatively free of behavioral problems during their stay at school. Students with both depression and hyperactivity showed the most problematic behavior followed by students with depression without hyperactivity.

Adolescent↗
PubMed1989

Comparison of nominal recall (standard) and multiple-choice methods for administration of WISC-R information subtest: a preliminary study indicating a learning effect of multiple-choice testing.

The Wechsler Intelligence Scale for Children--Revised (WISC--R) Information subtest was administered to learning disabled children using two methods of administration, the standard (recall) method and a multiple-choice format. Those children who were tested first with the multiple-choice format and subsequently with the standard format did better on the standard format than expected. This preliminary study suggests a learning effect of such multiple-choice testing and the desirability of further research being undertaken.

Child↗
PubMed1989

Acidophil stem-cell pituitary adenoma in a prepubescent female. Case report.

Acidophil stem-cell pituitary adenomas account for less than 5% of pituitary tumors. Only 15 cases have previously been reported, with a mean age of occurrence of 38.7 years. A case of this unusual tumor is reported in a prepubertal girl. Clinical symptoms included prominent behavioral disturbance with associated headache and visual disturbance. There was marked elevation of serum growth hormone concentration without clinical features of growth hormone excess, suggesting that this tumor has the capacity to excrete biologically inactive hormones. The clinical and pathological features of this unusual invasive pituitary tumor are reviewed; the age spectrum for this neoplasm must be expanded to include prepubertal children.

Adenoma, Acidophil↗
PubMed1989

Modification of the silver impregnation technique of Bielschowsky for use in glycol methacrylate-embedded brain tissue.

The modified Bielschowsky stain has become the standard silver impregnation technique for use in paraffin-embedded tissue sections for identifying abnormalities of neuritic processes in a variety of neurodegenerative disorders such as Alzheimer's disease. Recently, glycol methacrylate embedding has been used increasingly as a substitute for paraffin embedding of tissue, because it results in less tissue distortion during processing and provides greater clarity and resolution of cellular architecture and structural details. We have been able to modify the Bielschowsky stain for use in glycol methacrylate-embedded brain sections. The use of this technique will permit more accurate quantitation of the histopathologic changes in neuritic processes in neurodegenerative diseases.

Acrylates↗