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Biomedical subjects

N L Lapp

Publications and source records attributed to N L Lapp.

At least 19 recordsLinked to original sources
PubMed1996

Suspected hypersensitivity pneumonitis after exposure to a biologic forage inoculant.

A 44-year-old farmer had respiratory symptoms and bibasilar pulmonary infiltrates after three exposures to a new biologic forage inoculant. Open lung biopsy revealed chronic interstitial pneumonitis and bronchiolitis obliterans with organizing pneumonia. The patient responded to oral corticosteroids but acutely worsened after an inadvertent reexposure to the forage inoculant. He later recovered, with return of lung function and chest radiograph toward normal. This case suggests that biologic forage inoculants may be associated with hypersensitivity pneumonitis.

Adult↗
PubMed1996

Reduction of lung dust burden in pneumoconiosis by whole-lung lavage.

Pneumoconioses are characterized as irreversible, progressive respiratory diseases. No effective therapy exists to prevent progression of these diseases. Whole-lung lavage (WLL) might limit the rate of disease progression through the removal of dust, inflammatory cells, and cytokines. We performed WLL on a 54-year-old underground miner employed as a motorman and roof bolter and a 55-year-old driller at a surface coal mine. Both demonstrated normal lung function and chest radiographs showing ILO profusion category 2 nodular interstitial changes. From Subject 1, we recovered 5.24 x 10(8) cells (90% macrophages) from the right lung and 3.45 x 10(8) cells (94% macrophages) from the left lung. WLL removed 1.82 g of mineral dust (non-coal) on the right and 1.64 g on the left. From Subject 2, we recovered 7.49 x 10(8) cells (46% macrophages) from the right and 9.78 x 10(8) cells (69% macrophages) from the left lung. WLL removed 0.40 g of mineral dust on the right and 0.53 g on the left. Proinflammatory cytokines, growth factors, and cellular enzymes were also recovered. In cases of pneumoconiosis, WLL is capable of removing relatively large quantities of dust, cells, and soluble materials from the lungs. Only long-term follow-ups of individuals with progressive dust-induced disease who receive WLL therapy in the context of a clinical trial will provide information regarding the importance of removing mineral dust and inflammatory cells from the lung.

Bronchoalveolar Lavage↗
PubMed1996

Longitudinal and cross-sectional analyses of lung function in steelworkers.

We evaluated associations between dust exposure, demographic factors, and lung function by longitudinal and cross-sectional analyses in 475 steelworkers who participated in at least three spirometry tests over 5 yr between 1982 and 1991. Baseline and follow-up spirometry and changes between baseline and final follow-up assessment attributable to age, height, weight, weight gain, smoking status, pack-years, and years worked in dusty areas were examined using stepwise multiple linear regression techniques. Smoking, aging, being overweight, excessive weight gain, and dust exposure were related to a lower level and a steeper slope of decline of pulmonary function. Cigarette smoking was also an important risk factor. Dust exposure was related to the level of lung function, with a stronger effect at baseline than at follow-up. Estimated loss at baseline of FEV1, FVC, and FEV1/FVC% was 9.3, 6.4 ml, and 0.1 % per year of employment in a dusty area, respectively, whereas the association between dust exposure and longitudinal decline of lung function was weak. However, a strong relationship between weight gain and longitudinal decline of FEV1 and FVC was found. Estimated decreases in FEV1 and FVC attributable to weight gain were 4.7 and 6.3 ml per lb/yr, respectively. This work suggests that weight gain is an important determinant for longitudinal lung function decline. This large impact of weight gain in the decline of lung function in a middle-age and relatively overweight working population has not been previously reported. Additional work needs to be undertaken to show the strength of this relationship in other populations.

Adult↗
PubMed1994

Airways obstruction, coal mining, and disability.

It has recently been suggested that the inhalation of coal in the absence of complicated coal workers' pneumoconiosis (CWP) or smoking can lead to disabling airways obstruction. The cause of such obstruction has been variously attributed to emphysema or bronchitis. The frequency of significant airways obstruction in a group of United States coal miners seeking compensation for occupationally induced pulmonary impairment was therefore determined. In a sample of 611 "Black Lung" claimants there was only one subject who was a non-smoker and who in the absence of other non-occupationally related diseases,--for example, asthma and bronchiectasis--had sufficient airways obstruction to render it difficult for him to carry out hard labour. An alternative explanation for his reduced ventilatory capacity other than coal dust or smoking may be available. If the inhalation of coal dust in the absence of smoking and complicated CWP ever induces sufficient ventilatory impairment to preclude a miner from working, it is indeed rare.

Coal↗
PubMed1992

Acute silicosis responding to corticosteroid therapy.

The course of acute silicosis usually is relentlessly progressive. Death results from cor pulmonale and respiratory failure, with mycobacterial infection a frequent serious complication. Attempts to treat the illness generally have been unavailing. We report an unusual case of acute silicosis in which improvement in clinical status, chest x-ray film findings and pulmonary function occurred following therapy with corticosteroids. To our knowledge, this is the first such case reported in the medical literature.

Acute Disease↗
PubMed1992

Is asthma an inflammatory disease?

In the 1950s, asthma was defined in terms of reversible airflow obstruction; and then during the 1980s, the emphasis on the diagnosis and treatment of asthma centered on airway hyperreactivity. Recent advances in molecular biology and immunopathology have focused diagnosis and treatment of asthma on inflammatory mechanisms. This article briefly reviews some of the inflammatory components of asthma and the rationale for using inhaled (topical) anti-inflammatory agents in treatment. It also calls attention to some potential and actual adverse effects of inhaled corticosteroids. It mentions some agents used as alternate therapy for "steroid resistant" patients. The alteration of airway immunopathology of asthmatics before and after use of inhaled corticosteroids is described. There is evidence that treatment directed solely towards airway inflammation without use of inhaled B-agonist agents does not eliminate airway hyperresponsiveness.

Adrenal Cortex Hormones↗
PubMed1992

Coal workers' pneumoconiosis.

CWP is a disease distinct and separate from silicosis. Simple CWP is clearly related to the amount of dust deposited within the lungs. Complicated CWP (PMF) results from dust deposition plus other factors. Immunologic and local cellular factors may contribute to the development of this form of the disease. Studies of lung cell response and function may further elucidate mechanisms and mediators of lung dust reaction. Complicated CWP (PMF) is clearly associated with alterations in ventilatory, mechanical, and vascular function of the lungs. These abnormalities in PMF contribute to the observed premature morbidity and mortality of this disease.

Bronchoalveolar Lavage Fluid↗
PubMed1991

Erythromycin ototoxicity: a call to heighten recognition.

Bilateral sensorineural hearing loss developed in a 64-year-old woman treated with intravenous erythromycin lactobionate for bacteremic pneumococcal pneumonia. Discontinuance of the antibiotic led to prompt correction of the hearing deficit. Reversible hearing loss is an infrequently described adverse effect attributed to high-dose erythromycin therapy. Possible risk factors, including age, gender, and hepatic and renal function, may contribute to the development of erythromycin ototoxicity.

Erythromycin↗
PubMed1991

Serum angiotensin-converting enzyme is elevated in association with underground coal mining.

Serum angiotensin-converting enzyme activity (SACE) and lysozyme activity were measured in a group of 40 underground coal miners and two control groups, 20 subjects with sarcoidosis and 15 normal non-dust-exposed volunteers. The miners were grouped first according to whether they had recent exposure (still actively mining or retired three years or less prior to measurement) or temporally more distant exposure (retired more than three years prior to measurement). Secondly, they were grouped as to whether or not they had coal workers' pneumoconiosis (CWP). The subjects with sarcoidosis were grouped according to disease activity. As expected, the subjects with active sarcoidosis had elevated SACE activity compared with normal subjects. The coal miners as a group did not have elevation of their SACE activity. However, the coal miners with recent exposure had elevated SACE activity (57.1 +/- 3.9 U/ml) compared with normal controls (43.8 +/- 1.5 U/ml, p = 0.007). The SACE activity in miners without recent exposure was not elevated (39.8 +/- 1.3 U/ml) compared with the normal controls. No increase in SACE activity was found when the miners were grouped according to the presence or absence of CWP. In contrast, the miners' serum lysozyme activity was not elevated. Since alveolar macrophages are a potential source of SACE, elevation of SACE activity in underground coal miners may reflect alveolar macrophage activation caused by increased pulmonary mixed coal mine dust burden. Furthermore, since both SACE and serum lysozyme are elevated in association with silicosis, these findings may confirm that the macrophage responses to inhaled silica and coal dust differ.

Coal Mining↗
PubMed1988

Long-term survival after endobronchial fire during treatment of severe malignant airway obstruction with the Nd:YAG laser.

We present a case of Nd:YAG laser treatment of nearly total airway obstruction by malignant tumor in which an endobronchial fire occurred. The patient survived without complications of the fire and was followed-up until death over 22 months after the fire. The events leading to the fire are presented and recommendations provided to prevent similar occurrences.

Aged↗
PubMed1985

Nd:YAG laser followed by radiation for treatment of malignant airway lesions.

Patients with malignant obstructive airway lesions often present with total or segmental atelectasis of lung. In spite of prompt initiation of palliative external radiation alone, some patients were unable to complete the planned course of radiation therapy. Since May 1983, 17 patients with malignant obstructive endobronchial lesions have been treated by endoscopic Nd:YAG laser vaporization of the tumor. One to seven days later, fractionated external radiation therapy was initiated. Endoscopic use of the laser was repeated as needed during the course of treatment. Fifteen out of 17 patients successfully completed the planned course of therapy. The improved performance status was sustained in 13 of 15 patients for 2-13 months. A control group was selected from among patients with similarly located lesions who underwent external radiation treatment only prior to the availability of the Nd:YAG laser therapy. One patient developed radiation pneumonitis six weeks after completion of a second course of external radiation, another patient developed bronchopleural fistula after laser treatment which healed following closed chest tube drainage. The others had longer palliation of symptoms and improved quality of life. The results indicate that relief of airway obstruction by use of the Nd:YAG laser improved the patients' ability to tolerate subsequent external radiation treatment.

Bronchial Neoplasms↗
PubMed1985

Endoscopic laser therapy for respiratory distress due to obstructive airway tumors.

Neodymium-YAG laser therapy for unresectable malignant airway obstructions has a promising future. Nine patients with moderate to severe respiratory distress all experienced rapid relief of dyspnea and substantial improvement in pulmonary function within hours to days after treatment with laser phototherapy. The quality of life and survival was improved in otherwise hopeless cases. A nonfatal case of pneumothorax was the only major complication.

Adult↗