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Biomedical subjects

D F Proctor

Publications and source records attributed to D F Proctor.

At least 19 recordsLinked to original sources
PubMed1996

Historic development and medical use of nasopharyngeal radium irradiation treatments.

Nasopharyngeal radium irradiation was a medical treatment that replaced eustachian tube inflation and was itself replaced by tympanotomy tubes. Research and development began in 1924 when Samuel J. Crowe was awarded funds to develop an otologic research laboratory. He observed that recurring adenoids and serous otitis were associated with childhood deafness. In collaboration with Curtis Burnam, he developed a nasopharyngeal radon applicator in the 1930s. This was modified in the 1940s to a nasopharyngeal radium applicator, which had a much longer half-life and did not need treatment lengths recalculated twice each day. Numerous reports on the clinical use of nasopharyngeal radium irradiation in the United States were published. Papers have cautioned against possible dangers of nasopharyngeal radium irradiation, but there have been no substantiated reports. This report ends with three concluding suggestions for research.

History, 20th Century↗
PubMed1983

Nasal mucous transport and our ambient air.

The nose usually serves to conduct air in and out of the lungs; but it also defends the body against airborne noxious materials and modifies the physical condition of inspired air prior to its arrival in the lungs. A major factor in these physiological functions is mucociliary clearance which depends on the secretion of airway secretions and ciliary activity. This function is impaired by certain air pollutants, but not by relative humidity or temperature of the ambient air.

Air↗
PubMed1983

Human response to controlled levels of toluene in six-hour exposures.

The nasal mucus flow, lung function, subjective response, and psychometric performance of 16 young healthy subjects was studied during 6-h exposures to clean air and to 10, 40 or 100 ppm of toluene under controlled conditions. The toluene exposures did not affect nasal mucus flow or lung function. At 100 ppm irritation was experienced in the eyes and in the nose. There was a significant deterioration in the perceived air quality and a significant increased odor level during all exposures to toluene. The test battery investigated visual perception, vigilance, psychomotor functions, and higher cortical functions and comprised five-choice, rotary pursuit, screw-plate, Landolt's rings, Bourdon Wiersma, multiplication, sentence comprehension, and word memory tests. In these eight tests measuring 20 parameters, no statistically significant effects of the toluene exposure occurred. For three tests (multiplication errors, Landolt's rings, and the screw plate test) there was a borderline significance (0.05% less than p less than 0.10%). The subjects felt that the tests were more difficult and strenuous during the 100-ppm exposure, for which headache, dizziness, and feeling of intoxication were significantly more often reported. The exposures to 10 and 40 ppm did not result in any adverse effects.

Adult↗
PubMed1983

The naso-oro-pharyngo-laryngeal airway.

Many of the muscles affecting the caliber of the upper airways have been shown to undergo a change in tone rhythmically timed to fit the breathing cycle. Failure in this function can adversely affect airway patency as in sleep-apnea. In normal persons the action of these muscles stabilizes the upper airways in a manner analagous to the action of the intercostals on the intrathoracic portion of the breathing apparatus. An important subject for future investigation is the exact nature of the nervous pathways involved.

Humans↗
PubMed1982

A new apparatus for generating hygroscopic radioactive aerosols for inhalation studies.

Radioaerosols are being used increasingly to assess pulmonary ventilation in patients, and to study patterns distribution and rates of clearance in experimental studies. No completely satisfactory means have been developed to permit the safe and effective administration of suitable aerosols. In this report, a new system is described for producing and delivering monodisperse radioactive aerosol particles. The major advantages of the system are: (1) the monodispersion (sigma g=1.23) of the particles from modifier A; (2) 95% of the particles are less than 2 micrometer in diameter from modifier B, and (3) the method is simple and compact.

Aerosols↗
PubMed1981

Human response to controlled levels of combinations of sulfur dioxide and inert dust.

Under controlled conditions in an environmental chamber 16 healthy young volunteers were exposed to combinations of sulfur dioxide (SO2) (2.6 or 13 mg/m3) and inert plastic dust (2 or 10 mg/m3) or of SO2 (13 mg/m3) and dust (10 mg/m3) coated with vanadium. During periods of clean air and during exposures of 5-h duration nasal mucus flow rate, nasal airflow resistance, forced vital capacity, and subjective discomfort were measured. Reductions in nasal mucus flow rate, forced expiratory flow (FEF25-75%), and discomfort were related principally to the SO2 concentration. The combined effects of SO2 and dust were, at the most, additive, and there was no indication of potentiation effects. No effect could be attributed to the coating of the dust with vanadium.

Adult↗
PubMed1979

Effects of temperature, relative humidity, and mode of breathing on canine airway secretions.

Airway secretions were collected from the upper trachea of eight healthy nosebreathing mongrel dogs under general anesthesia, and the electrolytes and osmolality of these secretions were determined. Compared to plasma, secretions contained 15% higher Na+ and 33% higher Cl-, were 18% higher in osmolality, but had a lower Na+/Cl- throughout the 6-h experiments. When six nose-breathing dogs were exposed to air at 28.5 degrees C and 95% relative humidity, secretion osmolality became lower, but Na+/Cl- remained unchanged. In four other dogs, secretions approached the osmolality of plasma when inspired air was at 36.4 degrees C and 100% relative humidity. These secretions contained 22% higher Cl- and a lower Na+/Cl- than plasma. The differences between airway secretions and interstitial fluid suggest that secretions are formed by active Cl- transport. In another four dogs, secretion osmolality was higher with mouth breathing than breathing through the nose. Inasmuch as humidified and warmed air lowered and mouth breathing raised the osmolality of airway secretions, we postulate that the hyperosmolality of secretions results from water loss from the airway surface during conditioning of inspired air.

Animals↗
PubMed1979

Human response to controlled levels of inert dust.

We studied nasal mucous flow, airway resistance, and subjective response in 16 young healthy subjects during 5-hour exposures to 2, 10, and 25 mg of inert dust per m3 in an environmental chamber. The dust was a fully polymerized plastic dust containing carbon black. The number of these particles in room air, expressed as a per cent of the total number of particles was 36, 41, 14, 7, and 2, respectively, for the aerodynamic size ranges less than or equal to 1.8, 1.9 to 5.3, 5.4 to 8.9, 9.0 to 12.4, and greater than or equal to 12.5 micron. No significant changes in nasal mucociliary clearance rate or nasal resistance were observed. At all dust concentrations there was a decrease in 1-sec forced expiratory volume, but not in the forced vital capacity or the forced expiratory flow during the middle half of the forced vital capacity. The nasal penetration fraction of particles was approximately 55 per cent for the smallest particles and 20 per cent for the largest particles. Discomfort was proportional to the concentration of dust, but lagged almost 2 hours behind the changes in dust concentration. The discomfort was never excessive; the main complaints were dryness in the nose and pharynx.

Adult↗
PubMed1978

Nasal mucociliary clearance in man.

Nasal mucociliary clearance was measured in healthy young human subjects and tracheal clearance in the experimental animal under a wide variety of conditions. There is a broad range of clearance rates whether at standard ambient conditions (23 degrees C, 50% relative humidity) or in the face of a number of environmental variables. The degree to which those differences are attributable to the effectiveness of ciliary beating or the character of airway secretions is not known. Studies of tracheobronchial secretions simultaneous with clearance measurement in the anaesthetized dog have not yet provided a definite answer. Variations in upper respiratory defence mechanisms may bear some relationship to the aetiology of small airway disease in the lungs.

Adult↗
PubMed1978

Tracheobronchial secretions collected from intact dogs. I. Protein and mucous glycoprotein composition.

Tracheobronchial secretions (TBS) were collected in situ from intact, anesthetized dogs, and the protein composition and distribution were studied. TBS were separated into supernatant and pellet phases by centrifugation. The supernatant phase comprised 85%, by weight, of the secretory mixture; yet it contained only 58% of the total protein. Peptides of apparent molecular weights ranging from 16,000 to 154,000 daltons were present in the supernatant phase. Electrophoretic and immunochemical comparisons with canine serum suggested that certain of the peptides were of plasma origin including albumin, IgG, IgA, and IgM. Albumin and IgG comprised approximately 70% of the supernatant phase protein. Three percent of the total TBS protein was contributed by the peptide portion of mucous glycoproteins (mucins), and 97% of the mucin protein separated into the pellet phase. When compared to mucus collected from a canine tracheal pouch, TBS was less concentrated in mucins, and differences were observed in electrophoretic profiles between the two samples.

Animals↗
PubMed1978

Tracheobronchial secretions collected from intact dogs. II. Effects of cholinomimetic stimulation.

The effect of cholinomimetic stimulation on the quantity and composition of tracheobronchial secretions (TBS) collected from intact dogs was studied. After the administration of methacholine chloride, the collection rate of TBS increased over threefold within 10 min and returned to the control level by 50 min. Even though there was an increase in the total amount of protein collected, the protein concentration of the secretions decreased initially by 40%, returning to normal by 30 min. This was the result of an apparent dilution of the secretions by nonproteinaceous components. In addition, at 10 min, there was an increase in the protein associated with mucins. These responses were blocked by the preadministration of atropine. When TBS was separated into supernatant and pellet phases by centrifugation, we found that, following methacholine, there was a 35% increase in the ratio of albumin to IgG in the supernatant phase. These results suggest that the increased secretion due to methacholine may result, in part, by a selective filtration of fluid from the interstitial and/or vascular compartment(s) with proteins appearing in the secretory mixture based partially on their size.

Animals↗
PubMed1978

Tantalum tracheography in upper airway obstruction: 100 experiences in adults.

A total of 100 tantalum cine laryngotracheograms were performed in adults with documented or suspected upper airway obstruction. With appropriate precautions, tantalum powder proved to be a safe material for delineating tracheal and laryngeal abnormalities. A cine recording to document tracheomalacia as well as a careful evaluation of the larynx are useful extensions of examination of patients with suspected upper airway obstruction. Tracheomalacia was found in 35% of our series; 29% showed laryngeal abnormalities. With modifications to correct for magnification, the tantalum tracheogram gives the surgeon the exact length of trachea to be resected. When tantalum becomes approved by the Food and Drug Administration, we expect that tantalum cine laryngotracheography will be the preferred means for study of upper airway obstruction.

Adult↗
PubMed1977

Human nasal mucosal function at controlled temperatures.

We exposed 16 healthy human volunteers to air temperatures ranging from 7 to 39 degrees C and measured nasal mucus flow, nasal airflow resistance, forced vital capacity, rectal and body surface temperature, and air temperature within the nasal passage. A moderate fall in nasal mucus flow rate in the anterior and middle parts of the nose was observed with temperature above or below 23 degrees C. The nasal airflow resistance decreased in warm air and tended to increase in cold air. No significant changes in forced vital capacities or rectal temperature were observed. Nasopharyngeal end inspiratory air temperatures at 23 degrees C averaged 32.6 degrees C. At environmental temperatures of 15 and 31 degrees C they average 28.1 and 32.8 degrees C, respectively. Although we found alterations in upper airway function associated with altered inspired air temperature, over the range of 32 degrees C studied these changes were of minor physiological significance.

Acclimatization↗