PubMed HealthSearch

Biomedical subjects

A S Rose

Publications and source records attributed to A S Rose.

At least 19 recordsLinked to original sources

The role of glucocorticoids in endotoxin-mediated otitis media with effusion.

OBJECTIVE: To understand the actions of glucocorticoids on the development and progression of endotoxin-mediated otitis media with effusion. METHODS AND DESIGN: The middle ears of 20 Sprague-Dawley rats were exposed to 35 microL of either 300-mOsm Krebs-Ringer solution (control; n = 5) or lipopolysaccharide, 1 mg/mL, dissolved in Krebs-Ringer solution (n = 15). Among the group that received lipopolysaccharide, 10 rats were randomly selected to receive dexamethasone (1 mg/kg intramuscularly), either 2 hours (n = 5) or 24 hours (n = 5) before the introduction of lipopolysaccharide. Middle ear fluid was sampled after 2, 4, and 6 hours of exposure. OUTCOME MEASURES: Middle ear fluid volume and albumin content were determined as measures of vascular extravasation. Histological sections of the middle ear mucosa were used to quantify the degree of leukocyte exudation. Data were analyzed by 1- or 2-way analysis of variance with the significance level set at P < .05. RESULTS: Lipopolysaccharide exposure caused a significant increase in the mean +/- SEM middle ear fluid volume from 29.9 +/- 0.99 to 45.8 +/- 1.4 microL between the 2- and 6-hour samplings. Lipopolysaccharide exposure caused a significant increase in the albumin content of middle ear fluid from 70.1 +/- 19.2 to 271.0 +/- 93.1 micrograms between the 2- and 6-hour samplings. Both increases were significant compared with controls. Lipopolysaccharide also caused a significant increase in leukocytes localized to the middle ear mucosa. Pretreatment of animals with dexamethasone for either 2 or 24 hours inhibited the lipopolysaccharide-induced changes. There were no differences between 2- and 24-hour pretreatment with dexamethasone. CONCLUSIONS: Dexamethasone inhibits the development of endotoxin-induced otitis media with effusion.

Albumins

Nitric oxide is a mediator of neurogenic vascular exudation in the nose.

Rhinorrhea is a troublesome symptom of rhinitis seen commonly by otolaryngologists. The sources of nasal fluid production are glandular secretions and exudation from submucosal blood vessels. This study was designed to investigate the role of nitric oxide in neurogenically mediated vascular exudation in the nose. A rat model of the nasonasal reflex was developed in which one nasal cavity was challenged with histamine while albumin exudation was measured on the contralateral side. Histamine challenge was associated with a significant rise in albumin leakage, indicating an increase in vascular permeability. Perfusion with a nitric oxide synthase inhibitor (N-nitro-L-arginine methyl ester (L-NAME)) in the nasal cavity contralateral to nasal challenge was found to block albumin exudation on that side. This inhibition was overcome by the addition of L-arginine, the natural substrate of nitric oxide synthase, to the perfusate. Treatment of the ipsilateral nasal cavity with L-NAME did not significantly decrease the contralateral response. These findings indicate that NO is an important mediator of the effector arm of the nasonasal reflex that increases vascular permeability but is not involved in the sensory nerve afferent pathway. Further elucidation of the role of NO in nasal physiology may lead to novel pharmacotherapeutic approaches to the treatment of allergic and nonallergic rhinorrhea.

Albumins

Nitric oxide mediates mucin secretion in endotoxin-induced otitis media with effusion.

The mechanisms that regulate mucin release in chronic otitis media with effusion, a leading cause of hearing loss in children, remain largely unknown. We developed an animal model using Sprague-Dawley rats to determine the factors responsible for mucin production in chronic otitis media with effusion. N-nitro-L-arginine methyl ester (L-NAME), a competitive inhibitor of nitric oxide synthase, was used to investigate the role of nitric oxide in mucin secretion by the middle ear epithelium. All rats underwent eustachian tube obstruction. In the first set of rats, the middle ear was then injected transtympanically with 35 microl of either 300 mOsm Krebs-Ringer bicarbonate buffer (control group) or 1 mg/ml lipopolysaccharide in Krebs-Ringer (experimental group 1). In a second set of rats, the middle ear space was injected with lipopolysaccharide and then infused at a continuous rate for 7 days with either Krebs-Ringer (experimental group 2) or 1 mmol/L L-NAME in Krebs-Ringer (experimental group 3) through an osmotic infusion pump. After 7 days the volume of effusion and the quantity of mucin collected were significantly greater in lipopolysaccharide-exposed ears than in controls. In addition, antimucin immunostaining demonstrated mucous cell hyperplasia in response to lipopolysaccharide. The lipopolysaccharide-induced production of mucin and mucous cell hyperplasia was inhibited in ears treated with lipopolysaccharide and L-NAME. These results suggest that nitric oxide is a mediator in the pathway of mucin secretion in chronic otitis media with effusion.

Animals

Long-term care of patients with multiple sclerosis: a neurologist's perspective.

Multiple sclerosis is a chronic disease with varying degrees of disability and progression. Because there is no known specific therapy, for best care, patients are individualized, with attempts to deal with each patient and each complication separately, thoughtfully, and with psychological support when required. Efforts are directed toward helping the patient adjust to the realities of the disease and to specific disabilities. Ways and means of gaining patient confidence are discussed--and emphasis is placed on the known pathologic processes involved and how information, personalized professional attention, and support might function to aid the body's defense mechanisms for containment of the disease process. Several clinical cases were summarized (at the symposium) to illustrate the favorable and unfavorable effects of personality and emotional characteristics over a long term of care.

Humans

Methodology for analyzing clinical neurological data: ACTH in multiple sclerosis.

From 1965 to 1968 a multicenter (USA) clinical trial was conducted to compare ACTH with placebo for the treatment of multiple sclerosis patients in a stage of acute exacerbation. Of seven evaluation systems which were used, one was a quantitative neurological examination. In this report, the quantitative neurological data have been re-evaluated using a transformation of the data which express patient scores in terms of a percentage of age- and sex-matched normal function followed by a reduction of the data into composite neurological functions vs time. The results support the positive findings of previous reports. In addition, the methodology helps to simplify the therapists' task of interpreting results by enabling him to determine how near normal function the patient came following the treatment trial.

Adrenocorticotropic Hormone

Some thoughts on the nature of mind. A holistic concept of nervous system function.

Some practical neurological ideas concerning the nature of mind are presented to assist clinicians in appreciating the fact that brain physiology first creates and then serves the mind--the highest of the hierarchical functions of the nervous system. The qualities of the mind are shaped and modulated by life experience and many disturbed responses can be tempered by a knowledgeable approach. To gain a holistic concept of the functioning nervous system one must recognize and accept that all manifestations of behavior, including those termed psychological, are the product of physiological processes.

Animals