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Biomedical subjects

S Mintz

Publications and source records attributed to S Mintz.

At least 55 records · Page 3Linked to original sources
PubMed1983

A systematic controlled study of pulmonary abnormalities in rheumatoid arthritis.

We have conducted a prospective comparison of 155 rheumatoid patients and 95 control subjects. Both groups were selected without regard to respiratory status, but were comparable in age, sex and smoking experience. The prevalence of respiratory symptoms, of past respiratory illnesses and of pulmonary function findings of airway obstruction was similar in both groups. However, the rheumatoids showed an increased frequency of chest crackles and abnormal chest radiographs, and had pulmonary function changes suggestive of a restrictive ventilatory defect. These pulmonary abnormalities were associated with smoking, the presence of nonpulmonary extraarticular features, the level of rheumatoid disease activity and treatment with oral corticosteroid or gold.

Adult↗
PubMed1982

Grain elevator workers show work-related pulmonary function changes and dose-effect relationships with dust exposure.

The purpose of this study was to determine whether grain handlers underwent work-related changes in their pulmonary function and, if so, to examine the dose-effect relationships with dust exposure. The pulmonary function of grain handlers was measured at the beginning and end of work shifts over a period of one week, during which their exposure to dust was measured daily. The results showed changes indicative of a within-day obstructive change, in addition to a small restrictive defect occurring over the course of a week. Civic outside labourers who were examined as a control group showed a similar within-week obstructive change without any associated restriction of lung volume. The data on the grain handlers were also used to examine the dose-effect relationships of dust exposure, both on baseline pulmonary function and on within-day changes in these measurements. The baseline flow rates of workers who did not wear a mask were found to vary inversely with their average exposure to respirable dust. In addition, the flow rates underwent a within-day decrease that varied directly with their corresponding exposure to respirable dust and was unrelated to mask wearing. The median of the slopes for this relationship indicated that 50% of the subjects had a decrease of at least 923 ml/s in the value of their Vmax50%VC for each 1 mg/m3 increase in the concentration of respirable dust. Non-respirable dust did not have a measurable effect either on the baseline or the within-day changes in pulmonary function. The acute changes were unaffected by age, duration of employment, or extent of smoking.

Adult↗
PubMed1981

Oronasal distribution of respiratory airflow.

The oronasal distribution of respiratory airflow was determined during incrementally graded submaximal exercise in 30 (14 M, 16 F) healthy adult volunteers. Nasal airflow was measured by a pneumotachograph attached to a nasal mask. Oral airflow was determined as the difference between nasal airflow and total pulmonary airflow, the latter being measured by a head-out exercise body plethysmograph. The two airflow signals were sampled every 20 msec by a microprocessor, which calculated the oral and nasal minute volumes (separating inspiration and expiration) and produced an on-line print-out of the results. Twenty subjects ("normal augmenters") switched from nasal to oronasal breathing at a VE of 35.3 +/- 10.8 1 . min-1, four subjects ("mouth breathers") habitually breathed oronasally, five subjects ("nose breathers") persistently breathed through the nose only, and one subject showed no consistent nose/mouth breathing pattern. After the switch to oronasal breathing, the nasal portion of VE decreased suddenly to 57% of total VE. With a further increase of VE, oral minute volume increased rapidly, equalling nasal minute volume at a VE of 45 1 . min-1, and accounting for 61% of the total ventilation at high respiratory minute volumes (90 1 . min-1). During oronasal breathing, normal augmenters inspired some 2 1 . min-1 more nasally than they expired. Similarly, the nasal inspiration of mouth breathers exceeded expiration by 2 1 . min-1 at rest, but the difference increased to 13.51 . min-1 at a VE of 81.51 . min-1.

Adolescent↗
PubMed1981

Use of isovolume flow curves in the detection of exercise-induced bronchospasm.

A simple 9-min progressive cycle ergometer test revealed exercise-induced bronchospasm in 23 of 29 asthmatic subjects (80%) in terms of a 15% decrement in the isovolume forced expiratory flow rate at 50% of the baseline vital capacity (Vmax iso 50%VC). A similar percentage was detected by the Vmax iso 60% TLC (78%), but that found with the FVC (35%) and FEV1.0 (48%) was somewhat lower The maximum change of Vmax iso 50%VC following exercise in normal subjects was -5.2 +/- 2.1%. The Vmax iso 50%VC thus combines sensitivity with specificity, and seems a very suitable procedure for routine clinical use. Asthmatics showing a positive reaction to this test were distinguished by poor pre-exercise lung function.

Adult↗
PubMed1981

Association between celiac disease and lung disease.

An association has been suggested between celiac disease and diffuse interstitial lung disease of the hypersensitivity pneumonitis type in several reports from Europe. The present report consists of a study of 18 North American, biopsy-proved celiac patients, who were compared with an equal number of control subjects balanced for age, sex, and smoking. The celiac patients showed no evidence of interstitial lung disease as assessed by chest roentgenograms and pulmonary function tests. However, a history of asthma or chronic cough was present in a higher proportion of the celiac than control subjects. Also the celiac patients showed objective evidence of airway obstruction, as demonstrated by differences between the two groups in FEV1 (P less than 0.05) and Vmax 50% and Vmax 25% (P less than 0.01 and less than 0.05, respectively). These results confirm a recent report questioning whether there is truly a relationship between celiac disease and interstitial lung disease. Nevertheless, our findings suggest an association between celiac disease and airway obstruction.

Antigen-Antibody Complex↗
PubMed1980

The current role of thymectomy for myasthenia gravis.

Myasthenia gravis is an autoimmune disease characterized by muscle weakness and fatigability due to a reduction in available acetylcholine receptors at the neuromuscular junction. Treatment with anticholinesterase drugs and corticosteroids has improved the prognosis for patients with this disease. However, controversy continues concerning the indications for thymectomy. During a 9 year period, 27 patients who underwent thymectomy by median sternotomy were reviewed. Eighty-one percent of these patients benefited from the procedure. Clinical improvement did not correlate with age, sex, duration of symptoms, severity of disease or thymic histology, This suggests that the indications for thymectomy should be liberalized to include most patients with generalized myasthenia who fail to respond readily to conventional medical therapy. The importance of immunosuppression nd plasmapheresis in the therapy of myasthenia gravis awaits further delineation of the immune defect associated with the disease.

Adolescent↗
PubMed1980

The switching point from nasal to oronasal breathing.

The switching point from nasal to oronasal breathing during incrementally graded submaximal exercise was determined in 30 (14 M, 16 F) healthy adult volunteers. Nasal airflow was measured by a pneumotachograph attached to a nasal mask. Oral airflow was determined as the difference between nasal airflow and total pulmonary airflow, the latter being measured by a head-out exercise body plethysmograph. The airflow and pressure signals were sampled every 20 msec by a micropressor, which calculated respiratory volumes and nasal work of breathing, and produced an on-line print-out. Twenty of the 30 subjects (normal augmenters) switched from nasal to oronasal breathing at submaximal exercise of 105.0 W (SD = 30.1), four subjects (mouth breathers) breathed habitually oronasally, five subjects (nose breathers) persistently breathed through the nose only, and one subject showed no consistent nose/mouth breathing pattern. In normal augmenters, the onset of oronasal breathing (VE 35.3 +/- 10.81 . min-1) was quite consistent individually, but varied considerably between inividuals without showing a significant sex difference. The factors most closely related to the switching point were rating of perceived exertion of breathing and nasal work of breathing.

Adolescent↗
PubMed1980

Effect of layoff and rehire on respiratory variables of grain elevator workers.

A group of 77 grain elevator workers was examined at monthly intervals over a 7-month period. Approximately half of the workers were temporarily laid off for several months of this period, during which those who were steadily employed were involved in processing a reduced throughput of grain. The men who were laid showed a transient decrease in some respiratory symptoms during the months of layoff, followed by an increase after rehire. Those who were steadily employed showed a corresponding increase in these symptoms during the period of reduced grain movement, which did not change when the elevator returned to full activity. All of them demonstrated the greatest maximal expiratory flow rates during the midportion of the period of reduced work status, and the lowest values after either rehire or the restoration of full elevator activity. These longitudinal changes in respiratory variables are largely consistent with the effects of grain dust exposure, which may be at least partially reversible.

Absenteeism↗
PubMed1979

A head-out exercise body plethysmograph.

A head-out exercise body plethysmograph has been developed to facilitate investigations of the extrathoracic airways. An airtight seal around the neck is provided by a pliable sheet of dental dam braced by a tubular bean bag. A set of bicycle pedals is connected by a chain drive, axle, and wall-mounted sealed ball bearing to an external ergometer. The box is air-conditioned to allow exercise up to work loads of 200 W with a temperature increase of less than 1 degree C above ambient laboratory readings. Nose, mouth, and extrathoracic airways are easily accessible for airflow and pressure measurements. O2, CO2, and humidity levels of respired air are not disturbed, verbal communication with the subject is possible, and the subject is unlikely to feel claustrophobic. The plethysmograph has a flat frequency response to 4.2 Hz; it thus functions accurately in both resting and exercise measurements of respiratory minute ventilation. The plethysmograph can also be used for determinations of nasal and oral airflow and pressure, and the study of breathing patterns.

Humans↗
PubMed1979

Comparison of respiratory variables in grain elevator workers and civic outside workers of Thunder Bay, Canada.

We compared respiratory variables in 441 grain elevator workers with 180 civic outside laborers in Thunder Bay. The grain handlers had a lower frequency of both positive skin reactions to pollens and molds and a family history of asthma, which suggests that they may have been self-selected for a decreased tendency to develop allergic respiratory disease. There was a higher frequency of cough and rales and a small decrease in forced vital capacity and forced expiratory volume in one sec among the grain handlers, as compared to the civic workers matched for smoking. However, these differences between grain and nongrain workers were small in comparison to those between smokers and nonsmokers. There was no clear indication of a worsening of respiratory functions that could be attributed specifically to duration of employment as a grain elevator worker.

Adult↗
PubMed1979

Work of nasal breathing: measurement of each nostril independently using a split mask.

The work of nasal breathing was determined in human subjects as a measure of impedance to respiratory airflow. The nasal cavities were examined separately and simultaneously with a split mask; flow and pressure signals were fed to a microprocessor for on-line computation and printout of respired volumes and work of nasal breathing. An alternating resistive nasal cycle of 3--4 hours' duration was demonstrated in the majority of normal, resting subjects. Reciprocity of the resistive changes in each nasal cavity maintained a constant total nasal respiratory work load of about 0.2 Joules/litre. Moderate changes in breathing rate and tidal volume had little influence on work. Inspiratory work was 1.6 times that of expiration. Increases in resistance of the dependent nostril were seen when the lateral decubitus position was adopted. Increase in cephalic venous pressure and pathological nasal obstruction increased the work of nasal breathing.

Airway Obstruction↗
PubMed1979

Nasal aerodynamics.

The historical development of nasal aerodynamic measurement is discussed. Attention is drawn to the absence of a consensus on adequate rhinometric techniques and standards, which hampers the elevation of rhinometry to the universal clinical status of audiometric, impedance, or nystagmus measurement. A computer-aided technique is described which overcomes some problems of rhinometry, by measurement of the amount of energy the body devotes to moving respiratory air through each separate nasal cavity. Although the approach is different, our preliminary results confirm previous work and suggest that assessment of the work of breathing is a promising technique in the investigation of nasal respiratory airflow.

Airway Obstruction↗
PubMed1977

Steroid-dependent asthma treated with inhaled beclomethasone dipropionate. A long-term study.

The efficacy of inhaled beclomethasone dipropionate has been examined in 44 steroid-dependent asthmatics observed for 9 months to 2 years. A 3-month double-blind trial found that subjects treated with beclomethasone had a significant diminution in symptoms, were able to reduce their use of medication, and had improved maximum expiratory flow rates. Approximately one half were able to discontinue the use of oral prednisone within 9 months after starting beclomethasone, and a further one third reduced their dose by at least 50%. No characteristics could be defined to predict responsiveness to beclomethasone. The effectiveness of beclomethasone was sustained for as long as 2 years and was not associated with any abnormal urine, blood, or serum values or chest X-ray findings. Candidiasis of the palate appeared in approximately one third of the subjects and was usually transient. The chronic use of beclomethasone did not result in endocrine suppression.

Administration, Oral↗
PubMed1977

Peripheral ameloblastoma: report of case and review of the literature.

A case of an extraosseous ameloblastoma occurring in a 33-year-old woman has been described. Of the 11 cases documented in the literature, only nine fulfill the histologic and clinical criteria for a true peripheral ameloblastoma. In contrast to the intraosseous ameloblastoma, the diagnosis of extramedullary or peripheral ameloblastoma implies a less aggressive neoplasm that can be treated by a more conservative surgical approach.

Adult↗