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Biomedical subjects

T J Witek

Publications and source records attributed to T J Witek.

At least 55 records · Page 3Linked to original sources
PubMed1988

Immunological and respiratory findings in spice-factory workers.

Immunological and respiratory findings were studied in a group of 45 female spice-factory workers (mean age: 39 years; mean exposure: 17 years). In addition a group of 45 female control workers matched by sex, age, and smoking habit were also studied. Intradermal skin testing with mixed spice dust allergen demonstrated positive skin reactions in 73.3% of exposed and in 33.3% of control workers (P less than 0.001). Increased IgE serum levels were found in 36.8% of exposed and in 9.7% of the control workers (P less than 0.01). The prevalence of chronic respiratory symptoms was significantly higher in the exposed workers than in the control workers (P less than 0.01). There was, however, no consistent correlation between skin reactivity and chronic respiratory symptoms. There was a high prevalence of acute symptoms during the work shift. These complaints were more frequent in workers with positive skin tests for the symptoms of cough, chest tightness, and irritated and dry throat. Ventilatory capacity was measured by recording maximum expiratory flow-volume (MEFV) curves. There were statistically significant mean reductions during the work shift for all measured lung function parameters in workers with positive skin reactions. In those workers with negative skin reactions only FEF50 and FEF25 reached statistical significance. Aqueous extracts of different spices (chilli pepper, paprika, caraway, coriander leaves, coriander seeds, cinnamon, ginger, onion, curry, and parsley) caused a dose-related contractile response of isolated guinea pig tracheal smooth muscle. These data suggest that immunologic reactions to spices are frequent in spice workers and may be related to acute symptoms and lung function changes, but not to chronic changes. The data further suggest that, in addition to any immunologic response these spices may produce in vivo, they probably also provoke direct irritant reactions in the airways as suggested by in vitro data.

Adult↗
PubMed1988

Consistency of repeated flow-volume parameters in airway challenge studies.

A maximal lung inflation is known to alter airway tone in man. Recent investigations, examining how this phenomenon relates to bronchial provocation testing, suggest that a deep inspiration will decrease airway resistance and underestimate the subsequent decrement in lung function following airway challenge. Because the recovery of baseline tone is rapid following a deep inspiration, we evaluated the consistency of three consecutive partial and maximal expiratory flow-volume maneuvers performed at approximately 45- to 60-second intervals. Functional parameters including the forced expiratory volume in 1 s and the maximal expiratory flow at 60% of the vital capacity below total lung capacity on the partial curve (MEF40%P) were constant at each measurement point following induced bronchoconstriction or bronchodilation in both healthy and asthmatic subjects. We suggest that with 45 s between maneuvers, repeatable parameters can be attained from three consecutive flow-volume curves.

Airway Resistance↗
PubMed1988

Bronchial responsiveness after inhalation of cotton bract extract.

This study examined nonspecific airway responsiveness to methacholine (MC) after inhalation of cotton bract extract (CBE). In a randomized double-blind, crossover trial, 13 healthy volunteers underwent an MC inhalation challenge test prior to inhalation of CBE and normal saline solution (NSS) aerosol sham as well as 2, 8, 24, and 168 h (7 days) later. The response parameter was the concentration of MC required to induce a 25% decrement in the maximal expiratory flow at 40% of the vital capacity below total lung capacity on the partial expiratory flow-volume curve (PC25MEF40%(P]. Five of 13 subjects demonstrated a ventilatory response to CBE with a 20% or larger decrement in the MEF40%(P); no subject demonstrated such change with NSS. For the group, the maximal decrement in MEF40%(P) was to 76.5 +/- 20.3% of baseline (mean +/- SD), occurring approximately 60 to 90 min after provocation, whereas the largest decrement after normal saline was to 88 +/- 10.6% of baseline, occurring immediately after inhalation. Changes in airway responsiveness to MC were transient. For example, the PC25MEF40%(P) for the group (mean +/- SD) was 51.3 +/- 41.1 mg/ml at baseline and 25.8 +/- 30.3 and 52.2 +/- 57.3 mg/ml at 2 and 8 h. After a pre-sham baseline of 50.4 +/- 43.2 mg/ml, PC25MEF40%(P) was 57.6 +/- 83.8 and 153.8 +/- 148 mg/ml at 2 and 8 h. Repeated measures ANOVA on these acute, same-day changes (i.e., 2 and 8 h after provocation) demonstrated a statistically significant effect of CBE on airway responsiveness (p = 0.048). These data demonstrate that inhalation of CBE, in addition to bronchospasm, causes a transient increase in airway responsiveness.

Administration, Inhalation↗
PubMed1988

The shape of the maximum expiratory flow volume curve.

Differences in the shape of the maximum expiratory flow volume (MEFV) curve have been associated with pathologic states and physiologic differences between normal individuals. We describe variations in a new parameter, angle beta, which characterizes the general configuration of the MEFV curve among healthy subjects and subjects with disease in 5,140 white individuals. Women had consistently larger beta angles than men. There was a progressive decline in beta with advancing age. Cigarette smokers had lower beta angles than did lifetime never-smokers. Subjects with abnormal lung function patterns had lower beta angles than individuals with a normal pattern. Finally, individuals with asthma, chronic bronchitis, dyspnea and wheezing had significantly lower beta angles than healthy individuals. Further clinical and epidemiologic studies are needed to evaluate this measurement's possible value in pulmonary function evaluation.

Adolescent↗
PubMed1988

Respiratory symptoms and lung function in furriers.

Forty women who had been occupationally exposed in the fur coat manufacturing industry were studied. The mean age was 30 years; mean duration of exposure was 14 years. A group of 31 females who did not work in the furrier industry also was included in the study as the control group. A higher prevalence of all chronic respiratory symptoms was found among furriers when compared with controls; these differences were statistically significant for nasal catarrh (p less than 0.05) and sinusitis (p less than 0.01). Among the furriers, the highest prevalence of respiratory symptoms was recorded for chronic cough in 20 workers (50.0%), followed by sinusitis in 12 (30.0%), dyspnea in 10 (25.0%), and nasal catarrh in 8 workers (20.0%). Among the furriers, two (5.0%) had symptoms characteristic of occupational asthma. Most of the symptomatic furriers complained of acute symptoms during their work shifts. Statistically significant mean reductions in lung function over the work shift were recorded in furriers for forced vital capacity (FVC), -4.1%; one-second forced expiratory volume (FEV1), -5.2%; and flow rate at 50% vital capacity (FEF50%), -6.3%. Furriers demonstrated significantly lower mean Monday preshift measurements for FVC and flow rate at 25% (FEF25%) (p less than 0.05) when compared with those predicted. Preshift administration (by spinhaler) of 40 mg disodium cromoglycate in three workers reduced the intensity of acute respiratory symptoms and diminished the reductions in ventilatory capacity over the work shift. Data from six additional male workers demonstrated similar findings for symptoms and lung function. Our data suggest that furriers are at risk of developing both acute and chronic respiratory symptoms as well as ventilatory capacity impairment as a result of occupational exposure.

Adult↗
PubMed1987

A study of respiratory effects from exposure to 2.0 ppm formaldehyde in occupationally exposed workers.

It has been suggested that exposure to formaldehyde (FA) induces asthmatic symptomatology. We have previously studied healthy and asthmatic individuals and found that lung function was unaltered by controlled exposures to 2.0 ppm FA with and without mild exercise. Our present study extends these observations to a group of hospital laboratory workers routinely exposed to FA. Fifteen laboratory workers were exposed in double-blind, random sequence to 0 and 2 ppm FA for 40 min in an environmental chamber with temperature and relative humidity held constant at 23 degrees C and 50%, respectively. These exposures were repeated on two more occasions with a 10-min exercise regimen (450 kpm/min) after being in the chamber 5 min. In addition, a symptom diary and measurements of peak expiratory flow rate (PEFR) were recorded for 24 hr after exposure. Lung function remained unaltered for all 4 exposure days; e.g., mean FEV1.0 for the group did not change by more than 3% at any testing time on any exposure day. Also, there were no delayed obstructive changes as measured by PEFR recordings. Symptoms were mild and transient with unusual odor and eye irritation the most frequent complaint. No lower airway symptoms were reported. We conclude that this group of healthy laboratory workers did not experience any acute or delayed lung function changes from exposure to 2.0 ppm FA at rest and with exercise and that irritative symptoms were few.

Adult↗
PubMed1986

Smoking and cotton dust effects in cotton textile workers: an analysis of the shape of the maximum expiratory flow volume curve.

Cotton textile workers have an increased prevalence of both obstructive and restrictive lung function patterns when compared to control subjects. Similar abnormal lung function patterns may occur with other respiratory diseases, notably those associated with cigarette smoking. The shape of the maximum expiratory flow volume (MEFV) curve has been used to characterize patterns of lung function abnormality. We defined a new functional parameter (angle beta) related to the shape of the MEFV curve in order better to characterize the respiratory effects of cotton dust exposure. In this study, 477 cotton textile workers, both current smokers and never smokers 45 years and older, were compared to 932 similarly aged control subjects from three communities: Lebanon and Ansonia, CT, and Winnsboro, SC. Smokers, regardless of their occupational exposure of sex, have smaller values of beta than do nonsmokers. Cotton textile workers who have more abnormal lung function than do controls, cannot be distinguished from controls by beta. We suggest that such functional differences between cotton and smoking effects may reflect injury to different portions of the bronchial tree.

Aged↗
PubMed1986

Bacterial colonization of ultrasonic nebulizers: implications for frequency of circuit changing.

UNLABELLED: We conducted a prospective study of 50 consecutive postoperative patients over a 5-month period to characterize the bacterial contamination of ultrasonic nebulizers (USNs) after 24, 48, and 72 hours (h) of use. METHODS: Samples of the USN effluent mist and reservoir fluid were cultured and the results were correlated with clinical data from patient records, especially indications of pneumonia or related infections. RESULTS: Two thirds of the USNs were bacteria-free at the three times they were tested. After 24 h, cultures of the mist revealed bacterial growth in only 1 of the 50 patients. After 48 and 72 h, cultures of the mist showed bacterial growth in 6 instances (12%). Colonization of the reservoir fluid was also limited to 1 patient after 24 h. Reservoir-fluid cultures were positive in 10% of the USNs at 48 h and in 18% at 72 h. No clinically significant signs of pneumonia developed in any patient. CONCLUSIONS: These results suggest that colonization of USNs is minimal during the first 72 h of use by postoperative patients with uncomplicated clinical courses and that clinical consequences are unlikely in such patients even when the USN is found to have been colonized. Although the Centers for Disease Control has recommended daily changing of USN circuits, this practice may not be warranted in all clinical settings. Further studies are needed to determine the colonization of USNs used by patients with more complicated clinical courses.

Connecticut↗
PubMed1986

A study of isoetharine mesylate in patients with chronic bronchial asthma.

We performed a double-blind, random crossover study to investigate the respiratory effects of a single dose isoetharine mesylate (IM), administered by a metered aerosol canister in 19 subjects with mild, stable asthma. In addition, we studied the influence of the dose (number of actuations) and the mode of administration (delay between actuations) on these respiratory effects. The protocol consisted of a screening day and four test days: (1) one inhalation IM (2) two inhalations IM (3) one inhalation placebo (P), and (4) two inhalations P. In addition, the first nine asthmatics paused one minute between inhalations whereas the last ten paused five minutes between inhalations. Lung function was assessed using maximal and partial expiratory flow volume curves. Measurements were taken prior to aerosol delivery and for six hours after aerosol. Significant differences between IM and P were seen for up to two hours. The maximum effect was observed at 15 minutes, corresponding to a 23% and 25% increase in FEV1 from baseline with one and two puffs, respectively (P less than .001). The differences between one and two actuations were, in general, not significant. No significant differences were observed between individuals who waited one versus five minutes between inhalations. We conclude that IM aerosol results in significant improvement compared with placebo for two hours. Differences between one and two inhalations and the interval between two inhalations did not, in general, lead to enhanced effectiveness of this drug in the group of asthmatics studied.

Adolescent↗
PubMed1985

Respiratory symptoms associated with sulfur dioxide exposure.

Exposures to sulfur dioxide (SO2) have been associated with progressive, dose-dependent bronchoconstriction in sensitive individuals. The clinical significance of such changes remains poorly characterized. We studied subjective responses following exposure to low level concentrations of SO2 (less than 1 ppm) in a group of 10 healthy and 10 asthmatic subjects. The number and severity of complaints associated with SO2 increased with concentrations in both healthy and asthmatic subjects. Asthmatics indicated progressive lower respiratory complaints, such as wheezing, chest tightness, dyspnea and cough with increasing levels of SO2 while healthy subjects complained more frequently of upper airway complaints such as taste and odor with increasing levels of SO2. Exercise increased the frequency of lower airway symptoms in asthmatics but led to no increases in symptoms in healthy subjects.

Adult↗
PubMed1985

Skin testing with an aqueous extract of cotton bract.

Airway challenge with cotton bract extract (CBE) causes reversible bronchospasm in most volunteers never before exposed to CBE or the textile industry. Lung function abnormalities develop slowly after inhalation with a maximum effect reached within 2 hours and lung function slowly improving thereafter. When CBE was injected intradermally in three naive subjects with negligible airway response to CBE, we observed an initial wheal-and-flare reaction within minutes followed by erythema and subsequent induration that persisted for 24 to 48 hours. Microscopic examination of skin biopsy specimens obtained during the course of these reactions revealed edema in the early phase followed by perivascular infiltration of a mixed cellular nature in the subsequent stages of the reaction. Degranulation of mast cells was noted throughout the course of the reaction. These findings indirectly suggest that a nonspecific inflammatory reaction initiated by mast cell-derived mediators and sustained by the presence of infiltrating cells may be responsible for some of the airway effects observed in byssinosis.

Byssinosis↗
PubMed1985

Formaldehyde (CH2O) concentrations in the blood of humans and Fischer-344 rats exposed to CH2O under controlled conditions.

The effect of exposure to formaldehyde (CH2O) on the CH2O concentration of the blood was determined. Eight male F-344 rats were exposed to 14.4 +/- 2.4 ppm of CH2O for 2 hours and the blood was collected immediately after exposure. Formaldehyde concentrations in the blood were determined by gas chromatography/mass spectrometry. The blood of eight rats unexposed to CH2O was collected and analyzed in the same manner. Measured CH2O concentrations (micrograms/g of blood) were: controls, 2.24 +/- 0.07; exposed, 2.25 +/- 0.07 (mean +/- S.E.). Formaldehyde concentrations in human blood were determined by analyzing samples of venous blood collected before and after exposure of six human volunteers (4 M, 2 F) to 1.9 +/- 0.1 ppm of CH2O for 40 min. Average CH2O concentrations (micrograms/g of blood) were: before exposure, 2.61 +/- 0.14; after exposure, 2.77 +/- 0.28. In neither experiment was there a statistically significant effect of exposure on the average CH2O concentration of the blood. However, human subjects differed significantly with respect to their blood CH2O concentrations, and significant differences (either an increase or a decrease) were found between the CH2O concentrations of the blood taken before and after exposure from some of the subjects, suggesting that blood CH2O concentrations may vary with time.

Adult↗
PubMed1985

Airway reactivity and cotton bract-induced bronchial obstruction.

Most seemingly healthy persons challenged with an aerosol of cotton bract extract develop some degree of bronchospasm. The role of nonspecific reactivity of the airways in this reaction to cotton bract extract is undefined. We examined the relationship between airway responses to cotton bract extract and to methacholine, as well as between airway responses to cotton bract extract and to a bronchodilator. Twenty-two healthy subjects were screened for sensitivity to inhaled cotton bract extract. Pulmonary function was measured using partial expiratory flow-volume curves on which flow at 60 percent of the control vital capacity below total lung capacity was measured (MEF40%[P]) following ten minutes of inhalation of cotton bract extract. In the group screened, 12 were found to be responders to the extract, with drops in MEF40%(P) of 20 percent or more, and ten were found to be nonresponders. On separate days, we measured the responses of our subjects' airways to inhaled metaproterenol and methacholine. The mean threshold dose for methacholine in the responding group was 26.8 mg/ml, as compared to 55.6 mg/ml for the nonresponders (t = 2.52; p less than 0.05). Furthermore, the mean percent increase in MEF40%(P) following inhalation of metaproterenol was 41 percent in responders and 24 percent in nonresponders (t = 2.19; p less than 0.05). We conclude that some responders to cotton bract extract exhibit greater reactivity of the airways than nonresponders.

Adult↗
PubMed1985

Mechanically assisted ventilation in a community hospital. Immediate outcome, hospital charges, and follow-up of patients.

In 100 consecutive patients undergoing mechanically assisted ventilation, we prospectively determined immediate survival, hospitalization charges, and subsequent one-year outcome. Sixty percent of the patients survived the episode of assisted ventilation. This survival decreased to 50% at the time of hospital discharge and to 33% one year after hospitalization. There were no posthospitalization deaths in patients less than age 50 years. In those patients older than 70 years, however, 51% were dead by the time of hospital discharge and 73% died by one year following discharge. Comparison of features that reflect the magnitude of intensive respiratory care, such as hours of ventilation and intensive care unit (ICU) length of stay, disclosed no statistically significant differences between survivors and nonsurvivors at discharge. Hospitalization charges averaged $10,968 per patient. The total charge for respiratory therapy services (including arterial blood gas determinations) averaged $2,200. Respiratory care service charges were only marginally different between survivors and nonsurvivors. By contrast, total charges and total length of stay were greater for the survivors. Resource use in the intensive care setting as reflected by hours of mechanical ventilation and ICU length of stay was similar in both survivors and nonsurvivors, with the larger total cost for survivors relating primarily to care outside the ICU. Also, we confirm that prognosis is excellent in patients less than 50 years of age who survive mechanically assisted ventilation for acute respiratory failure and that extubation in elderly patients is not necessarily indicative of a good prognosis.

Adolescent↗
PubMed1985

Airway responses to sulfur dioxide and methacholine in asthmatics.

Sulfur dioxide (SO2) is a common air pollutant found in the workplace. Considerable variation exists in the airway responses of asthmatics to the inhalation of SO2. To determine if such variation among asthmatics is related to nonspecific airway reactivity, we compared the threshold doses of methacholine and SO2 required to produce significant changes in flow rates at 60% of the vital capacity below total lung capacity on the partial expiratory flow volume curve in a group of eight mildly asthmatic subjects. A significant correlation between the dose of SO2 and the dose of methacholine required to produce bronchoconstriction (r = .86, p less than .05) was observed, suggesting that there is a relationship between the response to SO2 and the response to methacholine in mildly asthmatic individuals. More generally, nonspecific airway hyperreactivity may help to predict untoward airway responses to inhaled SO2 in the workplace.

Adult↗
PubMed1984

Detection of sulfur dioxide in bronchodilator aerosols.

Several bronchodilator drugs commonly used in respiratory therapy contain sodium metabisulfite as an antioxidant preservative. When aerosolized, these agents may release the irritant gas SO2 as a result of bisulfite decomposition. We found that agents that contain bisulfites generated SO2 concentrations of 2.0 ppm and greater, while bronchodilator solutions without bisulfite did not. Such levels are known to induce or to exacerbate asthmatic symptoms. Levels of SO2 were higher when solutions were nebulized with compressed air from a tank or electric compressor than when they were nebulized from a hand-bulb nebulizer. No significant lot-to-lot variations were found in the solutions tested.

Aerosols↗
PubMed1984

The acquired immune deficiency syndrome (AIDS): current status and implications for respiratory care practitioners.

The acquired immune deficiency syndrome (AIDS) has affected more than 2,600 persons since 1981, with the number of reported cases rising exponentially. The disease is characterized by a deficiency in the cell-mediated immune system, which allows entrance to a host of opportunistic infections as well as tumors. The most common infection associated with AIDS is Pneumocystis carinii pneumonia, a previously uncommon infection of immunocompromised hosts. The most common neoplasm associated with AIDS is an otherwise rare skin tumor, Kaposi's sarcoma. AIDS is most often seen in homosexuals and intravenous-drug abusers, but the spectrum of the disease is widening and now includes other high-risk groups. The pulmonary manifestations of AIDS range from a nonproductive cough to acute respiratory failure. Once hospitalized, the AIDS patient may require several diagnostic and therapeutic services from respiratory care personnel. We review the epidemiology of this new syndrome, provide the basic framework for an understanding of the immunologic dysfunction in AIDS victims, review the clinical manifestations, and discuss the implications of the communicability of AIDS for the respiratory care practitioner.

Acquired Immunodeficiency Syndrome↗