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Biomedical subjects

D W Warren

Publications and source records attributed to D W Warren.

At least 19 recordsLinked to original sources
PubMed1992

Assessing the effects of odorants on nasal airway size and breathing.

A technique was developed to obtain continuous measurements of both respiratory behavior and nasal patency in response to well-controlled odorant stimulation. An automated apparatus similar to that described by Walker et al. (27) was used to present precise concentrations of an odorant. The pressure-flow technique (28) was used to continuously measure nasal airway cross-sectional area, nasal airflow rate, air volume and time characteristics associated with breathing before and during odorant stimulation. Immediately following each odorant presentation, subjects entered their psychophysical responses into a microcomputer via an electronic mouse. Respiratory and psychophysical responses of ten normal subjects to four concentrations of acetic acid during eight odorant trials were recorded; eight clean-air trials were also conducted. At the highest concentration, changes in respiratory behavior were observed as early as 200 ms after stimulus onset in some subjects. Inspiratory volumes during odorant presentation were lower than those seen just before stimulation. The magnitude of this decrease was directly related to the concentration of acetic acid and to the perceived intensity of the odor and degree of nasal irritation.

Airway Resistance↗
PubMed1992

Clinical application of the ACCO appliance. Part 1.

Difficult Class II, Division 1 malocclusions can be successfully treated with a combination of fixed and removable appliances. The clinical application of the Margolis ACCO appliance is demonstrated in a variety of malocclusions through the use of before-treatment progress, and posttreatment records.

Adolescent↗
PubMed1992

Controlling changes in vocal tract resistance.

There is some evidence that speech aerodynamics follows the rules of a regulating system. The purpose of the present study was to assess how the speech system manages perturbations that produce "errors" within the system. Three experimental approaches were used to evaluate the physiological responses to an imposed change in airway resistance. The first involved subjects with varying degrees of velopharyngeal inadequacy. The second and third approaches involved noncleft subjects whose airway was perturbed by bleed valves and bite blocks during consonant productions. The pressure-flow technique was used to measure aerodynamic variables associated with the production of test consonants. The results of this study provide additional evidence that the speech system actively responds to perturbations in ways that tend to minimize a change in consonant speech pressures. The degree of success in stabilizing pressures appears to reflect the capability of the system to use whatever articulatory and respiratory responses are available.

Adult↗
PubMed1992

Comparison of the vasoconstrictive and anesthetic effects of intranasally applied cocaine vs. xylometazoline/lidocaine solution.

Cocaine solution has traditionally been the agent of choice for vasoconstriction and anesthesia when applied topically to the nasal mucosa during nasal operative procedures. Because of the relative scarcity and resulting expense of cocaine, there has arisen an impetus for an alternative intranasal solution for mucosal anesthesia and vasoconstriction. As a logical alternative, we have used a mixed solution of xylometazoline and lidocaine with reasonable results. No clinical studies comparing the efficacy of the two solutions exist, however, and there is presently no such solution commercially available. A double-blind, randomized, placebo-controlled study was undertaken to assess the relative efficacy of the preparations. Both solutions resulted in a marked and roughly equivalent degree of mucosal vasoconstriction (as evidenced by comparable increases in nasal airway cross-sectional area). Subjective pain ratings of mucosal pin-prick decreased a surprisingly small degree after application of both solutions. It appears that xylometazoline/lidocaine solution is comparable to cocaine solution for purposes of vasoconstriction and anesthesia during intranasal operative procedures.

Administration, Intranasal↗
PubMed1992

The effects of an anabolic steroid (oxandrolone) on reproductive development in the male rat.

Oxandrolone is a 5 alpha-reduced anabolic steroid that is administered for the treatment of short stature disease in children. It is a commonly used substance beginning as early as prepuberty by some individuals who are seeking to enhance athletic performance or personal appearance. Because of the lack of data on the effects of anabolic steroids on the reproductive system, we have examined the effects of oxandrolone treatment on reproductive development in male rats with treatment beginning two days after weaning. Male, Sprague-Dawley rats (N = 12) received a daily subcutaneous injection of oxandrolone (32.7 mumol.kg-1.day-1) and the control group (N = 12) received vehicle only (dimethyl sulfoxide). Treatment began at age 23 days and continued to 60 days of age. The weights of the testes, prostate glands, and seminal vesicles in the treatment group were 69%, 50% and 29% below control levels, respectively and were all significantly decreased (p less than 0.01). Testicular testosterone production in a 3-h incubation was inhibited in the treated animals to 1.3% of control values (p less than 0.001). Serum FSH (11.7% of control) and LH (undetectable) in the treated animals were both significantly less than controls. Histological findings indicated an arrest of advanced spermatids and a severe depletion of Leydig cells in the interstitial compartment. It was concluded that treatment of immature male rats with oxandrolone results in effects on the adult male reproductive system which are profound and occur at several levels. The most likely affected sites are the hypothalamus, pituitary gland, and the Leydig cells.

Animals↗
PubMed1992

A preliminary study of nasal airway patency and its potential effect on speech performance.

The relationship between nasal airway size and articulatory performance was studied in a group of cleft palate patients. Articulation analysis revealed that children with bilateral cleft lip and palate were nearly twice as likely to manifest compensatory articulations as children with unilateral cleft lip and palate or with cleft palate only. When subjects were grouped according to speech performance, aerodynamic assessment indicated that children with compensatory articulations had significantly larger nasal cross-sectional areas than children without compensatory articulations. The findings suggest that children with comparatively large nasal airways may be at increased risk for developing abnormal speech patterns. If these findings are confirmed by further research, such children may be candidates for relatively early palate repair.

Articulation Disorders↗
PubMed1992

Is nasal airway size a marker for susceptibility toward clefting?

Johnston and Hunter (1989) reported that in monozygotic twins discordant for cleft lip +/- palate, the noncleft twins demonstrated what appeared to be a bimodal distribution of nasal cavity width. Two thirds showed reduced airway size and one third showed normal or slightly greater airway size. They suggested that the two-thirds group may represent reduced size of the medial nasal prominences and the other may represent underdevelopment of the maxillary prominence. We were particularly interested in the findings because the difference in distribution may represent differences in pathogenesis and therefore have etiologic significance. With this in mind we assessed nasal cross-sectional areas in 37 subjects with cleft lip or cleft lip +/- palate using the pressure-flow technique during breathing. A group of 72 noncleft individuals served as controls. As expected, the data revealed that subjects with clefts had a significantly reduced nasal airway (p = .0001). More important, the distribution of nasal airway size in the cleft group was similar to that reported by Johnston and Hunter (1989). This comparability suggests that it may be possible to assign most cleft lip +/- palate patients to a particular group. Since heredity may differ among the two groups (Chung et al., 1986), we may have a simple technique to assess the risk of occurrence for cleft lip +/- palate.

Adolescent↗
PubMed1992

Nasal airway in breathing and speech.

Clefts of the lip and palate frequently produce nasal deformities that tend to reduce the size of the nasal airway. Approximately 70% of the cleft population have nasal airway impairment and about 80% "mouth-breathe" to some extent. Surgical correction of nasal, palatal, and pharyngeal structures may further compromise breathing. Type of cleft appears to affect airway size, with unilateral clefts demonstrating the smallest airway. Although a pharyngeal flap may further decrease airway size, some individuals do not notice a postoperative change because of airway compromise prior to flap placement. Speech is a modified breathing behavior that uses the respiratory system to provide an energy source and involves structures within the respiratory tract to modulate this energy into meaningful sounds. The oral, nasal, and pharyngeal structures that are affected by cleft lip and palate during breathing are often compromised for speech as well. The nasal airway plays an important role in controlling speech pressures when velopharyngeal function is impaired. A "good" nose for breathing is often a "bad" nose for speech under such circumstances.

Adult↗
PubMed1992

Prolactin localization, binding, and effects on peroxidase release in rat exorbital lacrimal gland.

Prolactin immunoreactivity has been detected in human tears and in lacrimal glands, and it has been suggested that this hormone might be a modulator of lacrimal secretion as well as a component of lacrimal gland fluid. The present study was designed to confirm the immunocytochemical localization of prolactin in the rat lacrimal gland, to determine the source of the prolactin, and to evaluate the acute effects of prolactin on lacrimal secretory function. We have confirmed that prolactin-like immunoreactivity is present in secretory vesicles of acinar cells of male and female Sprague-Dawley rats. Prolactin message was present at detectable levels in RNA extracts of lacrimal glands from males, indicating that at least a component of the prolactin-like immunoreactivity was the product of synthesis within the lacrimal glands. Crude membrane fractions from acini isolated from males bound 43.1 +/- 3.2 femtomoles prolactin/mg protein (mean +/- standard error of the mean; n = 6), which was significantly (P less than 0.01) more than comparable fractions from females (15.4 +/- 2.4 fmoles/mg protein, n = 6). Preincubating membranes at 65 degrees for 20 min to release endogenous ligands increased prolactin binding to 84.8 +/- 20.8 fmoles/mg protein for males and 63.8 +/- 17.4 fmoles/mg protein for females (P greater than 0.1), suggesting that, on average, similar numbers of receptors are expressed in acinar cells of male and female rats but a larger fraction of the receptors is occupied by endogenous prolactin-like peptides in females. Because prolactin binding triggers prolactin receptor internalization in various cell types, we propose that the prolactin-like immunoreactivity in lacrimal acinar cells of females has been accumulated from the circulation, while the immunoreactivity seen in males results, at least in part, from de novo synthesis. Ovine prolactin at concentrations of 10-20 ng/ml inhibited carbachol-induced peroxidase release by 19.6% +/- 6.9% (n = 8, P less than 0.02) but failed to alter peroxidase release in the absence of carbachol. These observations suggest that prolactin might function as an endocrine, paracrine, or autocrine modulator in the lacrimal gland.

Animals↗
PubMed1991

The effect of cleft palate speech aid prostheses on the nasopharyngeal airway and breathing.

This study determined the effect of a speech aid prosthesis on resting breathing. Nasal cross-sectional area was measured during inspiration and expiration in eight cleft palate patients. The measurements were made for the unobturated defect during both phases of respiration and then repeated while the defect was obturated by a speech aid prosthesis. The results of the study revealed that the presence of a speech aid prosthesis significantly decreased the cross-sectional region of the nasal airway. In 50% of the subjects, the cross-sectional region was less than 0.40 cm2 with concomitant impairment in nasal respiration when the speech aid prosthesis was present in the oral cavity. The data suggest that the design of these prostheses should account for breathing requirements as well as for speech.

Analysis of Variance↗
PubMed1991

Nasal airway impairment: the oral response in cleft palate patients.

The purpose of this study was to assess the oral response to severe nasal airway impairment in patients with cleft palate. Inductive plethysmography was used to measure the percent of nasal breathing, and the pressure-flow technique was used to estimate nasal area in 15 persons with severe nasal airway impairment. Mean nasal area was 0.17 cm2, and the average percent of nasal breathing was 20%. Analysis revealed a strong correlation (0.87) between nasal size and percent of nasal breathing in this selected group. Modeling studies based on the mean values from the subjects' data indicated that the model "mouth" would have to open 0.5 cm2 to shunt 80% of the airflow orally, an amount equivalent to the mean value of the subjects' respiratory mode. More important, the extrapolated data revealed that upper-airway resistance decreased in the model from 8.7 cm H2O/L/sec to a level of 3.2 cm H2O/L/sec, which is an average value for healthy adults. These data support the concept that the mouth acts as a variable resistor to maintain an optimal respiratory tract resistance when the nasal airway is impaired.

Adult↗
PubMed1991

The identification of nasal obstruction through clinical judgments of hyponasality and nasometric assessment of speech acoustics.

This study examined the records of a consecutive series of 79 patients referred for evaluation at the Oral-Facial and Communicative Disorders Program during a 3-month period in 1989. The purpose was to determine whether clinical judgments of hyponasality, based on a six-point equal-appearing interval scale or an acoustic assessment with a Kay Elemetrics nasometer could provide information concerning nasal airway patency comparable to that obtained by means of aerodynamic measurement techniques. Among the 40 adults in the series, the sensitivity of hyponasality ratings was 0.55 when nasal airway impairment was defined as a condition in which the airway was less than 0.40 and 0.71 when the definition was limited to airways of less than 0.30 cm2. Specificities for the two groups were 0.89 and 0.85, respectively. Similarly, the sensitivity of nasometer ratings was 0.30 for the first group and 0.38 for the second group, while the specificity for the two groups was 0.83 and 0.92, respectively. Comparable analyses for children were not possible because of the extent to which nasal airway size varies in children younger than 15 years of age. Possible reasons for the findings and their clinical significance are discussed.

Adolescent↗
PubMed1991

Relationship between vertical dentofacial morphology and respiration in adolescents.

The relationship between vertical dentofacial morphology and respiration has been debated and investigated from various approaches. The purpose of this study was to use contemporary respirometric techniques to compare the breathing behavior of normal and long-faced adolescents. Sixteen normal and 32 long-faced subjects 11 to 17 years of age were chosen clinically and verified by means of a discriminant function. Vertical and anteroposterior facial form was assessed from lateral cephalometric radiographs according to the following measurement criteria: six skeletal angular, eight skeletal linear, four dental linear, and three skeletal ratios. Breathing behavior was quantified according to tidal volume, minimum cross-sectional nasal area, and percent of nasal breathing as assessed by pneumotachography, measurement of differential pressures, and inductive plethysmography. The data indicated that the normal and long-faced groups were significantly different with respect to lower face form, and each group in the study was comparable to groups that had been chosen by previous investigators. Multiple regression analysis demonstrated that the normal and long-faced groups had similar tidal volumes and minimum nasal cross-sectional areas, but the long-faced subjects had significantly smaller components of nasal respiration. These results illustrate that groups without significant differences in airway impairment can have significantly different breathing modes that may be behaviorally based, rather than airway-dependent.

Adolescent↗
PubMed1991

A preliminary investigation concerning the use of nasometry in identifying patients with hyponasality and/or nasal airway impairment.

A series of 76 patients referred for evaluation at the Oral-Facial and Communicative Disorders Program was studied in an attempt to determine the extent to which acoustic assessments of speech, made utilizing a Kay Elemetrics Nasometer, corresponded with clinical judgments of hyponasality and aerodynamic measurements of nasal cross-sectional area. Among the 38 adults, the sensitivity of Nasometer ratings in correctly identifying adult subjects with moderate to severe nasal airway impairment was 0.38, whereas the specificity was 0.92. Comparable analyses for the group of 38 children were not possible because of the extent to which nasal airway size varies up to the age of 15 years. Among the entire group of patients, the sensitivity and specificity of nasometry in correctly identifying the presence or absence of hyponasality was 0.48 and 0.79, respectively. However, when patients with audible nasal emission were eliminated from analysis, the sensitivity rose to 1.0 and the specificity rose to 0.85. Possible reasons for the findings obtained and their clinical significance are discussed.

Adult↗
PubMed1991

Effects of age, gender, and body size on nasal cross-sectional area in children.

The long-term goal of this research is to define the dimensions of nasal airway adequacy in children. Nasal airway size and variables associated with growth were assessed in 138 healthy children aged 7-15 years. The pressure-flow technique (Warren, 1984) was used to calculate the smallest cross-sectional area of the nasal airway. Mean nasal area was 0.38 +/- 0.12 cm2 for 7-9-year-olds, 0.40 +/- 0.13 cm2 for 10-12-year-olds, and 0.46 +/- 0.16 cm2 for 13-15-year-old children, the effect of age being statistically significant. Nasal airway size did not vary systematically with body size nor was there any clear difference between girls and boys. We conclude that age should always be considered when assessing the status of the nasal airway in children and adolescents.

Adolescent↗