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Biomedical subjects

S F Quan

Publications and source records attributed to S F Quan.

At least 19 recordsLinked to original sources
PubMed1995

The natural history of insomnia and its relationship to respiratory symptoms.

BACKGROUND: Although insomnia is a frequent complaint among patients, epidemiologic study has been limited. Researchers have reported a wide range in the prevalence of this complaint in a variety of selected populations. Other parameters, such as incidence and remission rates, have not been reported. METHODS: Subjects of the Tucson (Ariz) Epidemiologic Study of Obstructive Lung Disease were asked questions about trouble sleeping in the 1984-1985 (survey I) and 1990-1992 (survey II) surveys. Answers were analyzed along with responses to questions about age, sex, respiratory symptoms, and drug and alcohol use for sleep. RESULTS: The prevalence of insomnia was similar in both surveys, 34.4% in survey I and 34.1% in survey II. Women had a higher prevalence of insomnia than men in both surveys, and insomnia was more common among older subjects (50.6% of the women aged 65 years or older had insomnia in survey II). In addition, the incidence of new insomnia in survey II was higher in the same groups. Grouping subjects by respiratory symptoms, we found that the prevalence of insomnia was significantly related to cough, dyspnea, or wheeze. Furthermore, subjects with persistent or new respiratory symptoms at survey II were less likely to have remission of insomnia by that survey (31.6% vs 51.5%; P < .05; odds ratio, 0.43) and more likely to develop new insomnia (28.6% vs 14.5%; P < 05; odds ratio, 2.36) than subjects with either no symptoms or disappearance of their symptoms by survey II. CONCLUSIONS: In our population, insomnia is a common dynamic complaint whose frequency waxes and wanes in association with respiratory symptoms.

Adult↗
PubMed1995

Continuous oscillation: outcome in critically ill patients.

PURPOSE: To compare turning by an oscillating bed to standard 2-hour turning. Outcomes were survival, length of stay (LOS), duration of mechanical ventilation, and incidence of pneumonia. METHODS: One hundred and three intensive care patients were randomly assigned to standard turning or turning by an oscillating bed. Data, collected at baseline, daily for 7 days, and then three times weekly until study discharge, included demographics, initial Acute Physiology and Chronic Health Evaluation (APACHE II) score, ventilatory/gas exchange parameters, indicators of pneumonia, nursing measures, and chest roentgenograph. RESULTS: There were no significant differences for LOS, duration of ventilation, nor incidence of pneumonia. Higher survival for subjects on the oscillating bed reached borderline significance (P = .056) for subjects with APACHE II greater than or equal to 20. Longitudinal data were analyzed using the random effects model. No differences in ventilatory or gas exchange parameters were identified. Among subjects who developed pneumonia there was a significantly higher respiratory score (nursing acuity scale) for subjects on the oscillating bed. CONCLUSIONS: In selected critically ill patients oscillating therapy may improve survival and improve airway clearance. The frequency and degree of turning needed to prevent complications and improve outcome remains unclear. These newer beds should be used with discrimination so as to not increase hospital costs unnecessarily.

APACHE↗
PubMed1995

Effect of interleukin-5 and granulocyte-macrophage colony stimulating factor on in vitro eosinophil function: comparison with airway eosinophils.

Eosinophils are hypothesized to be crucial in the development of allergic airway inflammation; however, the actual mechanisms that determine their inflammatory activity are still largely undefined. To investigate the factors that regulate eosinophil function in allergic airway disease, we have previously used segmental bronchoprovocation with allergen to study ex vivo eosinophil function. To determine whether the functional changes associated with airway eosinophils obtained by bronchoalveolar lavage 48 hours after antigen challenge are caused by exposure to airway-generated cytokines, normodense blood eosinophils were cultured in vitro with recombinant human interleukin-5 (IL-5) or granulocyte-macrophage colony stimulating factor (GM-CSF). The effect of cytokine exposure was then evaluated on selected cell functions. In vitro incubation with these cytokines for 24 hours significantly increased eosinophil membrane expression of CD18 and CD11b compared with culture in medium alone or eosinophils obtained by bronchoalveolar lavage. N-formyl-methionyl-leucyl-phenylalanine-stimulated superoxide anion generation was slightly but significantly enhanced by incubation with IL-5 but not with GM-CSF. In addition, spontaneous adhesion to human umbilical vein endothelial cell monolayers was increased after exposure to both IL-5 and GM-CSF. However, activated adhesion was enhanced only by culture with IL-5 and stimulation with N-formyl-methionyl-leucyl-phenylalanine. The magnitude of functional changes after in vitro preincubation of eosinophils with these cytokines did not achieve levels of superoxide anion and adhesion noted with airway eosinophils obtained after segmental bronchoprovocation with allergen. These observations raise the possibility that the contribution of IL-5 and GM-CSF to phenotypic changes of airway eosinophils is principally to enhance survival and expression of adhesion proteins. These data also suggest that, in addition to the generation of proinflammatory cytokines, other factors contribute to phenotypic changes in eosinophils as they migrate from the blood to the airway.

Blood Cells↗
PubMed1995

Incidence and remission of habitual snoring over a 5- to 6-year period.

Habitual snoring is associated with an increased prevalence of hypertension, stroke, and ischemic heart disease. To determine factors that influence the incidence and remission of habitual snoring, we analyzed responses to successive self-administered questionnaires with questions pertaining to snoring in a group of subjects participating in the Tucson Epidemiologic Study of Obstructive Airways Disease. In this study, 1,476 subjects were surveyed 5.8 +/- 0.6 (SD) years apart. Among subjects who habitually snored on the initial survey, 58.2% snored persistently and 35.5% remitted on the ensuing survey. Among subjects who did not habitually snore in the initial survey, 10.5% developed it on the subsequent survey. In further analyses, we found that male sex, obesity, and respiratory symptoms were significant independent risk factors for development of habitual snoring. Age over 65 years, the absence of obesity, and the absence of respiratory symptoms were associated with remission of habitual snoring.

Adult↗
PubMed1992

Bronchoalveolar lavage fluid cytology reflects airway inflammation in beagle puppies with acute bronchiolitis.

Beagle puppies infected with both canine parainfluenza virus type 2 (CPI2) and Bordetella bronchiseptica (Bb) develop more severe acute bronchiolitis and airways hyperresponsiveness than do those infected with CPI2 or Bb alone. The aim of our study was to characterize the inflammatory response associated with airway hyperresponsiveness, and to determine whether the inflammatory cell response of bronchoalveolar lavage fluid (BALF) reflected changes in the bronchioles in this model. We investigated 25 beagle puppies (ages 76 +/- 5 days, mean +/- SEM) in four groups: controls (n = 6), or puppies inoculated with both CPI2 and Bb (CPI2-Bb) (n = 11), with only CPI2 (n = 4), or only Bb (n = 4). The puppies were killed 3-4 days after inoculation, the lungs excised, the intermediate lobe lavaged, and BALF and the bronchiolar wall tissue examined for neutrophils and other inflammatory cells. Control puppies had no evidence of inflammation. However, the CPI2-Bb puppies had developed cough and rhinitis, positive cultures for CPI2 and Bb, and a neutrophilic cellular response in both the bronchioles and the BALF. Puppies inoculated with only CPI2 or Bb had milder illnesses and no significant bronchiolar and BALF neutrophilic response. For all groups, the severity of bronchiolar wall inflammation correlated with the total number of BALF inflammatory cells, and bronchiolar wall neutrophil counts correlated with the percentage of neutrophils in the BALF. The illness and the airway hyperresponsiveness observed in the CPI2-Bb group were associated with airway neutrophilia. Our studies support the hypothesis that neutrophils are associated with airway dysfunction in this model, and the use of BALF to study the process.

Acute Disease↗
PubMed1992

Risk factors associated with complaints of insomnia in a general adult population. Influence of previous complaints of insomnia.

BACKGROUND: Insomnia is a common complaint both in the general population and also in physician's offices. However, risk factors for the development of insomnia complaints have not been completely identified. METHODS: To identify population characteristics associated with increased prevalence of insomnia complaints, we surveyed a large general adult population in 1984 through 1985. We evaluated the relationship among current complaints of initiating and maintaining sleep and obesity, snoring, concomitant health problems, socioeconomic status, and documented complaints of difficulty with insomnia 10 to 12 years previously. RESULTS: The strongest risk factor for complaints of initiating and maintaining sleep was previous complaints of insomnia (odds ratio, 3.5). In addition, female gender (odds ratio, 1.5), advancing age (odds ratio, 1.3), snoring (odds ratio, 1.3), and multiple types of concomitant health problems (odds ratios, 1.1 to 1.7) were all risk factors associated with an increased rate of complaints of initiating and maintaining sleep. CONCLUSION: Complaints of insomnia tend to be a persistent or recurrent problem over long periods of time. Female gender, advancing age, and concomitant health problems also are important risk factors.

Adult↗
PubMed1991

Changes in lung mechanics and histamine responsiveness after sequential canine adenovirus 2 and canine parainfluenza 2 virus infection in beagle puppies.

We determined the effects of an immediately antecedent viral lower respiratory tract infection (LRI) on the severity of clinical illness, changes in lung function and airway histamine responsiveness produced by a subsequent LRI in 9-12 week old beagle puppies inoculated with canine adenovirus 2, followed in 2 weeks by inoculation with canine parainfluenza 2 virus (CAV2-CP12, n = 7). We compared their acute responses to puppies infected with CP12 alone (n = 5), CAV2 alone (n = 7), and no infection (control, n = 6). Puppies inoculated with either virus alone developed a LRI 3 to 6 days after inoculation which resolved by 12-14 days after inoculation. However, the illness was more severe in the CAV2 group. In the CAV2-CP12 group, CP12 infection following CAV2 infection resulted in a clinical illness nearly comparable to that observed with CAV2 alone. Whereas in control and CP12 puppies, lung resistance (RL) decreased and dynamic lung compliance (Cdyn) increased during the study due to normal growth, RL increased and Cdyn remained unchanged in the CAV2 group. In contrast, RL did not change and Cdyn increased in the CAV2-CP12 group. Airway histamine responsiveness in the CAV2-CP12 group increased during infection with CP12 and was similar to that observed with CAV2 alone. In contrast, infection with CP12 alone produced a small, but non-significant increase in histamine responsiveness. The duration of the increase in histamine responsiveness was not prolonged in the CAV2-CP12 group in comparison to CP12 or CAV2 alone. However, the length of clinical illness was extended in the CAV2-CP12 group in comparison to the other infected groups. These data suggest that an immediately antecedent viral LRI can potentiate the clinical and physiologic effects of a subsequent viral LRI.

Adenoviridae Infections↗
PubMed1991

Canine parainfluenza type 2 and Bordetella bronchiseptica infection produces increased bronchoalveolar lavage thromboxane concentrations in beagle puppies.

Acute infections in beagle puppies with canine parainfluenza virus type 2 (CP12), and CP12 in combination with Bordetella bronchiseptica (Bb) produce bronchiolitis and increased airways responsiveness to aerosolized histamine during the acute infection. In order to determine whether these observations were associated with increased levels of eicosanoids, the stable metabolites of thromboxane A2 and prostacylin, thromboxane B2 (TXB2) and 6-keto-prostaglandin F1 alpha (6-keto-PGF 1 alpha) respectively, and leukotriene B4 were measured in the bronchoalveolar lavage (BAL) fluid of 25 beagle puppies (age = 76 +/- 1 days, mean +/- SEM) 3-4 days after no infection (control, n = 6), inoculation with both CP12 and Bb (CP12-Bb, n = 11), inoculation with CP12 alone (CP12, n = 4), and inoculation with Bb alone (Bb, n = 4). In addition, plasma levels of TXB2 and 6-keto-PGF1 alpha were measured before and after infection in the CP12-Bb and control groups. The BAL concentration of thromboxane B2 was increased in the CP12-Bb group (520 +/- 120 pg/ml), but not in the CP12 (88 +/- 40 pg/ml), Bb (235 +/- 100 pg/ml), or control groups (120 +/- 60 pg/ml, p less than 0.01). There also was a borderline increase in BAL concentration of LTB4 in the CP12-Bb group. No differences were observed in the BAL concentration of 6-keto PGF1 alpha. Furthermore, neither TXB2 nor PGF1 alpha was elevated in the plasma of control or CP12-Bb puppies. These data suggest that increased thromboxane concentrations in BAL fluid are associated with histamine hyperresponsiveness during acute infection in the CP12-Bb group.

6-Ketoprostaglandin F1 alpha↗
PubMed1991

Effect of smoke inhalation on immediate changes in lung chemical mediators.

We studied the effects of acute smoke exposure on lung and alveolar macrophage (AM) function in New Zealand white rabbits. Six rabbits were exposed to smoke (SE, N = 6) and a control group of rabbits (SS, N = 6) were exposed to sham smoke. The smoke exposure consisted of 60 tidal volume breaths of air and smoke which were aspirated by syringe from a sampling port of a smoke chamber. The smoke was generated by the combustion of 20 ml diesel fuel and 0.2 g polycarbonate plastic shavings. The smoke was administered in 8-9 min. The rabbits were then killed and the lungs were removed for lavage. Acute smoke exposure caused a significant (p = 0.037) increase in bronchoalveolar lavage fluid levels of leukotriene B4 in the SE rabbits; 643 (+/- 30, SEM) pg/ml compared to 539 (+/- 43, SEM) pg/ml for SS rabbits at 3-4 min post-exposure. Lung surfactant, measured as mumoles/kg phosphatidylcholine, was decreased (p = 0.039) in SE rabbits' bronchoalveolar lavage fluid, 1.07 (+/- 0.12, SEM) -vs- 1.45 (+/- 0.15, SEM) for SS. Furthermore, cultured SE alveolar macrophage superoxide secretion after stimulation with phorbol myristate acetate was significantly decreased versus SS alveolar macrophage superoxide values at 40 min in culture. We conclude that acute smoke exposure causes immediate increases in bronchoalveolar lavage fluid levels of LTB4, and decreases in alveolar macrophage superoxide production and lung surfactant. These changes in chemical mediators may contribute to the lung injury caused by the smoke insult.

Animals↗
PubMed1991

Effects of intravenous and aerosolized arachidonic acid on alveolar epithelial permeability in rabbits.

To determine whether arachidonic acid (AA) alters alveolar epithelial permeability, we studied the effect of both continuous intravenous and aerosolized AA on clearance of [99m]Tc-DTPA from lung to blood in rabbits. Although intravenous AA increased prostacyclin production and aerosolized AA decreased systemic blood pressure, neither continuous intravenous nor aerosolized AA augmented alveolar epithelial permeability.

Aerosols↗
PubMed1990

Changes in lung mechanics and reactivity with age after viral bronchiolitis in beagle puppies.

We measured changes with growth in lung function and airway reactivity after acute canine parainfluenza virus type 2 (CPI2, n = 5), canine adenovirus type 2 (CAV2, n = 7), and sequential CAV2-CPI2 (n = 6) infections or no infection (controls, n = 6) in beagle puppies (age approximately 79 days). In the CPI2 and CAV2 groups, a lower respiratory illness developed by day 3 postinfection with clinical recovery by day 14. In the CAV2-CPI2 group, puppies were inoculated initially with CAV2 and 12 days later with CPI2. In this group, illness persisted until day 14 after infection with CPI2. Lung resistance (RL), dynamic (Cdyn) and static (Cst) lung compliance, functional residual capacity (FRC), and responsiveness to aerosolized histamine were measured before infection and at periodic intervals until 239 +/- 43 days of age. Lung function data were analyzed using a longitudinal random effects model. In all groups, FRC, Cst, and Cdyn increased with age. In all infected groups, the regression slopes for Cdyn were steeper than in controls. RL decreased linearly with age without group slope differences. Histamine reactivity increased with age, but there were no differences in slope among groups. Lung pathological studies showed areas of obliterative bronchiolitis and chronic small airways inflammation particularly in the CAV2 and CAV2-CPI2 groups. Thus, viral bronchiolitis produces chronic small airways inflammation in beagle puppies and alters the changes in lung function occurring with growth. Histamine reactivity increases with age and is not modified by viral infection.

Adenoviridae Infections↗
PubMed1990

Canine parainfluenza type 2 bronchiolitis increases histamine responsiveness in beagle puppies.

Histamine hyperresponsiveness with viral bronchiolitis may depend on previous exposures to viruses or to other pathogens. We studied 32 outbred beagle puppies 80 to 155 days of age who were raised in isolation and who were specific pathogen-free. Puppies were inoculated with canine parainfluenza type 2 (CPI2, n = 8), Bordetella bronchiseptica (Bb, n = 7), or both CPI2 and Bb (CPI2-Bb, n = 9). Control puppies (C, n = 8) were not inoculated. The puppies were anesthetized with sodium thiopental (5 mg/kg) and chloralose (80 mg/kg) and were ventilated mechanically. Lung resistance (RL), dynamic lung compliance (Cdyn), functional residual capacity (FRC), and responsiveness to aerosolized histamine were measured 3 days prior to inoculation (Day -3), on the day of inoculation (Day 0), and on Days 3-4, 6, 8-10, and 12-14 after inoculation. Histamine responsiveness was measured as: (1) the concentration of histamine base that increased RL to 150% (PC 150% RL) or decreased Cdyn to 75% (PC 75% Cdyn) of the response to saline (RL sal and Cdyn sal, respectively), and (2) the change in RL or Cdyn after inhalation of 11 mg/ml of histamine when compared with RL sal and Cdyn sal. On Day 0 there were no significant (p greater than 0.05) differences among groups with regard to age-corrected weights, FRC, RL, Cdyn, or histamine responsiveness. Control puppies remained healthy, and their pulmonary function and histamine responsiveness did not change. CPI2-Bb puppies increased RL and decreased FRC on Day 3-4, and were moderately ill and histamine-hyperresponsive on Day 3-4 and on Day 6.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance↗
PubMed1990

Acute canine adenovirus 2 infection increases histamine airway reactivity in beagle puppies.

Acute infection with canine adenovirus was studied in 23 specific pathogen-free outbred beagle puppies (median age = 78 days, range = 67 to 86 days) to determine its effects on pulmonary function and airway responsiveness to aerosolized histamine. The following groups were studied: uninoculated (n = 6, Control); inoculated with canine adenovirus type 2 (CAV2) (n = 11, Infected); and subclinical spontaneous infection with CAV2 (n = 6, Subclinical). While anesthetized with chloralose and mechanically ventilated, lung function and responsiveness to aerosolized histamine were measured 3 days before inoculation (Day -3), the day of inoculation (Day 0), and 3 to 4 (Day 3-4), 6 (Day 6), 8 to 10 (Day 8-10), and 12 to 14 (Day 12-14) days after inoculation. Histamine responsiveness was assessed by calculating the provocation concentration of histamine diphosphate to increase lung resistance (RL) to 150% (PC 150% RL), or decrease dynamic lung compliance (Cdyn) to 75% (PC 75% Cdyn) of the response to saline [RL(sal) and Cdyn(sal), respectively]. Arterial blood gases, functional residual capacity (FRC), specific static lung compliance (spCst), RL, Cdyn, and histamine responsiveness were not significantly different on Day 0 among the groups (p greater than 0.05). Control and Subclinical puppies remained healthy, had a mean weight gain of 0.7 kg, and did not change their histamine responsiveness during the study period. Infected puppies developed moderate to severe clinical illnesses, had poor weight gain, and were histamine hyperresponsive on Days 3-4 and 6. One infected puppy died on Day 3-4, and two died on Day 6 of their illness.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1990

Localization of inflammation and virions in canine adenovirus type 2 bronchiolitis.

Beagle puppies develop bronchiolar inflammation and histamine hyperresponsiveness with canine adenovirus type 2 (CAV2) infections. We determined the distribution of bronchiolar lesions and correlated inflammation with virions and bronchoalveolar lavage fluid (BALF) cytology. Nineteen beagle puppies were inoculated with tissue culture fluid (control puppies, n = 8), or CAV2 (CAV2, n = 11). The puppies had clinical assessments and measurements of lung resistance (RL), and dynamic compliance (Cdyn) immediately before inoculation (Day zero) and 3 days later (Day 3). The puppies were killed on Day 3, the lungs were removed, and the right intermediate lobe was lavaged. The BALF was assessed for total and differential cell counts. Bronchiolar inflammation was quantitated by bronchiolar inflammation scores (BIS). CAV2 was localized by immunofluorescent antibody staining and electron microscopy. The control puppies remained healthy. The CAV2 puppies had positive cultures for CAV2, respiratory symptoms, and generalized necrotizing bronchiolitis. Alveolar inflammation was quantitatively less prominent than bronchiolar inflammation, and RL and Cdyn were unchanged. The BALF neutrophilia correlated with the BIS. CAV2 was present within bronchiolar epithelium, alveolar epithelial type 2 cells, neutrophils, and macrophages. CAV2 was not found in airways smooth muscles or nerves, nor in any noninflamed tissues of CAV2 puppies or in control animals. Our data suggest that acute CAV2 in beagle puppies produces an inflammation of most bronchioles. Intracellular CAV2 was found in bronchiolar epithelium, macrophages, neutrophils, and alveolar epithelial type 2 cells. Bronchiolar inflammation was reflected in BALF cytology. We conclude that bronchiolar inflammation as indicated by BIS and BALF cytology is related temporarily to histamine hyperresponsiveness in our beagle puppies.

Adenoviridae↗
PubMed1990

Bilateral paramediastinal post-traumatic lung cysts.

Unilateral post-traumatic and paramediastinal lung cysts are uncommon. Conservative therapeutic measures are usually sufficient. This report describes a patient whose bilateral post-traumatic paramediastinal lung cysts, a previously undescribed entity, were presumed to be bilateral hemidiaphragmatic hernias and, consequently, led to unnecessary surgery.

Adult↗