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Biomedical subjects

F H Norris

Publications and source records attributed to F H Norris.

At least 91 records · Page 5Linked to original sources

Computerized graphic methods for determining dissociation constants of agonists, partial agonists, and competitive antagonists in isolated smooth muscle preparations.

Computer programs have been written that calculate dissociation constants for agonists, partial agonists, and competitive antagonists from data generated in isolated smooth muscle preparations. The data are analyzed according to standard procedures and are presented in graphical form with the aid of an inexpensive digital plotter. The digital plotter coupled with a computer markedly decreases the time required to perform these fundamental analyses and also reduces the chance for error and experimenter bias.

Animals↗

Spirometry in amyotrophic lateral sclerosis.

Clinical evaluation and pulmonary function tests were performed in 218 patients with motor neuron disease, mainly amyotrophic lateral sclerosis (ALS). Serial studies were obtained in 103 patients, in 31 until death from ALS. Most patients, regardless of the pattern of motor neuron involvement, had characteristic abnormalities in pulmonary function, including reduced forced vital capacity (FVC) and maximum voluntary ventilation (MVV). Reductions in the FVC and MVV to as low as 50% were commonly missed by clinical evaluators. Spirometry is therefore of value in detecting early involvement of respiratory neurons. Progressively greater reductions in the FVC and MVV in all the fatal cases indicate that serial spirometry has prognostic value in ALS.

Adult↗

Amyotrophic lateral sclerosis. Impairment of neuromuscular transmission.

Neuromuscular transmission was studied in the ulnar-hypothenar group in 55 patients with amyotrophic lateral sclerosis. A decremental response was found in 67.0%. The decrement was larger and present more often in muscles showing atrophy. In addition, muscles with frequent fasciculations showed a larger decrement than the ones with rare fasciculation. A temperature effect similar to that in myasthenia gravis was observed, with a reduction of the decrement following local cooling of the muscles. Administration of edrophonium chloride improved the synaptic defect. Posttetanic exhaustion was observed as well. It is thought that the defect of neuromuscular transmission is due to a decreased trophic function of the neuron followed by morphological changes at the endplate.

Adolescent↗

Trial of baclofen in amyotrophic lateral sclerosis.

A trial of the antispastic drug baclofen was made in amyotrophic lateral sclerosis. Some patients noted reduction of tonus and spasticity; but others had no benefit, nor was the course of the disease altered by long-term administration of baclofen. No major side effects occurred.

Adult↗

Myokymia.

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Humans↗

Current status of the search for virus in amyotrophic lateral sclerosis (ALS).

Clinicians have noted resemblance between ALS with predominantly lower motor involvement and a chronic type of poliomyelitis. Occasional cases of ALS show lymphocytic infiltrations in the neuropathology. Cytoplasmic inclusion bodies as well as possible transmission of ALS to the monkey, were noted by Soviet investigators. Major questions about the latter remain, but inclusion bodies have been seen in cases outside the USSR, and search for a virus has been pursued. So far, efforts at culture, including the technique of co-cultivation, have not been successful in 3 different laboratories using material from ALS autopsied within 2 hours of death. Nor has such material and specimens from other cases produced transmissible disease in animals of laboratories where kuru, Jakob's disease and SSPE have been transmitted. Study of serum antibodies has also been negative. These negative culture, transmission and antibody studies do not exclude a viral etiology: in kuru, for example, many years passed before transmission was demonstrated, which remains the only evidence of kuru's infectivity. Evidence of an immunologic disorder in ALS has been obtained from kidney biopsies, the lack of any clinical benefit from immunosuppression may indicate that the kidney finding reveals a response to infection, though whether viral or even relevant is unknown. Two recent ALS cases will be illustrated in which virus-like particles were demonstrated post mortem by electronmicroscopy. In one, myxovirus-like tubules were seen mainly in motor neurons; in the other, picorna-virus-like crystals were found in skeletal muscles. Different viruses can cause identical disease, but 2 different viruses in different sites in ALS also suggest that at least one type of particle is an adventitious finding of no general significance. An additional impetus to continue the search is the slowly progressive type C-virus myelitis in wild mice. This disease has many dissimilarities to ALS, including different morphology of the virus, but may provide a model for slow-virus amyotrophy.

Adult↗

Enkephalin-induced depression of single neurons in brain areas with opiate receptors--antagonism by naloxone.

Enkephalin, applied microiontophoretically, depressed spontaneous and glutamate-induced firing of single neurons in frontal cortex, caudate nucleus, and periaqueductal gray matter, where enkephalin and high concentrations of opiate receptors are found. Many of the depressions were blocked by the specific narcotic antagonist naloxone. The data are compatible with a neurotransmitter or neuromodulator role for this new brain pentapeptide.

Action Potentials↗

Evidence for immune-complex formation in patients with amyotrophic lateral sclerosis.

Immune complexes have been found in several chronic diseases of unknown aetiology and identification of the constituents of the complexes might lead to recognition of aetiological agents. Sera and renal tissues from patients with amyotrophic lateral sclerosis (A.L.S.) were studied for evidence of immune complexes. C1q precipitation testing demonstrated that sera from 10 of 25 patients with classic A.L.S. bound significantly more radiolabelled C1q than sera from 15 controls. In renal glomeruli studied for deposition of host 1gG, C3, fibrinogen, and albumin by means of direct immunofluorescence, 9 of 33 patients with A.L.S. (27 biopsy and 6 necropsy specimens) had moderate amounts of both IgG and C3 of granular basement membrane and mesangia. This pattern of immunofluorescence is characteristic of immune complex deposits. Of these 9, 8 had rapidly progressive neurological courses, whereas among the remaining 18 patients with no evidence of immune-complex disease, 9 of 12 available for clinical follow-up had stable or slowly progressive courses.

Amyotrophic Lateral Sclerosis↗

Viruslike particles in muscle from a patient with amyotrophic lateral sclerosis.

An electron microscopic study of muscle and central nervous tissue from a case of amyotrophic lateral sclerosis showed crystalline arrays of 20 to 24 nm viruslike particles in muscle. The particles were located between the myofibrils, adjacent to the Z bands, and near the perinuclear region, but were never seen within the nucleus. Cell cultures from the same muscle specimens showed no such particles. Central nervous system tissues and cultures also failed to show viruslike particles. The cultures were negative by the indirect fluorescent antibody technique with serums from patients with amyotrophic lateral sclerosis. The nature of these particles or their relationship to amyotrophic lateral sclerosis is unknown.

Amylases↗

Cricopharyngeal myotomy in amyotrophic lateral sclerosis.

Reported herein is the experience of the authors with 38 amyotrophic lateral sclerosis (ALS) patients for whom cricopharyngeal myotomy was performed. The major surgical objectives were facilitation of swallowing and amelioration of the tendency of these patients to aspirate ingestants and secretions. In the group of these patients in which the follow-up information has been adequate, 64% were improved and 36% experienced no significant benefits. The authors' surgical indications, methods of anesthesia, surgical technique, and postoperative care are described.

Adult↗