The senile lung. Comparison with normal and emphysematous lungs. 1. Structural aspects.

As part of a study of the structural-functional correlations of excised human lungs obtained at autopsy, the parenchyma and peripheral airways were examined by means of morphometric techniques. Among the 30 lungs characterized by the absence of fibrosis, ten differed from the normal and emphysematous lungs by a homogeneous dilatation of the airspaces, in excess of the dimensions predicted on the basis of age. Study of the standard deviations of the mean linear intercepts showed that the airspace dilatation was more regular than in emphysematous lungs; in addition, there was no clear-cut destruction, as estimated from the number of alveolar attachments. These lungs were characterized in addition by an increased thickening of alveolar septa, without inflammation or fibrosis, normal size of the diameter, and reduced density of the membranous bronchioles. Since these lungs were from people older than 60 years, it is assumed that they represent cases of exaggerated airspace enlargement of the aging lung, differing from emphysema by the absence of destruction of alveolar walls. The term "senile lung" is proposed or this condition.     

The senile lung. Comparison with normal and emphysematous lungs. 2. Functional aspects.

Senile lungs are characterized by a homogeneous enlargement of the alveolar airspaces, without fibrosis or destruction of their walls. Study of the functional characteristics of excisea senile lungs showed an increase in minimal air and a shift to the left of the elastic recoil pressure-volume curves, less pronounced than in emphysematous lungs. Maximal expiratory volumes and flows were normal. Total lung capacity was not significantly increased, but this may be a consequence of preagonal edema. Comparison of normal, senile, and emphysematous lungs showed a close relationship between recoil pressures and mean linear intercept, Lm, and between forced expiratory volume in 1 s and diameter and density of the membranous bronchioles. It is concluded that airspace enlargement may precede emphysema and may be responsible for changes in lung elasticity. In this respect, senile lungs are an example of the functional changes caused by an isolated airspace enlargement.     

Glycosaminoglycans in emphysematous and fibrotic hamster lungs

Amounts and distributions of glycosaminoglycans were measured in lungs obtained from hamsters treated intratracheally 21 to 30 days previously with either saline, purified pancreatic elastase, or bleomycin. Normal hamster lungs contained 150 to 200 micrograms glycosaminoglycans per lung. Lungs made fibrotic by bleomycin contained significantly more glycosaminoglycans per lung than saline-treated control lungs; this increase was equally distributed among all glycosaminoglycan subtypes. Emphysematous lungs also contained more glycosaminoglycans than saline control lungs; this increase was less than that of fibrotic lungs and was limited to the dermatan sulfate subtype. The latter was increased in emphysematous lungs when expressed as a percentage of total glycosaminoglycans. In these hamster models of lung diseases that affect the connective tissue framework of the lungs, changes in lung glycosaminoglycans accompany changes in the other connective tissue components.     

The destructive index and early lung destruction in smokers

The destructive index (DI), a measure of alveolar septal damage and emphysema, has been proposed as a sensitive index of lung destruction that closely reflects functional abnormalities, especially loss of elastic recoil. To better understand the progression of lung destruction in smokers, we studied the contribution of its principal components: breaks in the alveolar septa (DIb) and the presence of emphysematous spaces (DIe), and compared them to the mean linear intercept (Lm) and DI as originally described. To do this we employed lungs obtained at autopsy from non-smokers and smokers. Lungs were selected by emphysema score (ES) so that all cases were emphysema free (nonsmokers and seven smokers) or had minimal emphysema (nine smokers; ES = 5). Of these indices, only DIb was significantly increased in the lungs of smokers: 17.8 +/- 1.2 versus 12.4 +/- 1.6, p less than 0.05. We also investigated the regional distribution of destruction by comparing results in upper and lower lobes. DIe, but not DIb, was significantly increased in upper lobes of smokers. These data support the notion that increases in DI in the lungs of smokers that occur before increases in Lm or ES reflect the presence of alveolar septal breaks and highlight the importance of alveolar septal destruction as a precursor to the development of airspace enlargement in the lungs of cigarette smokers.     

Morphologic and clinical observations in human infection with Babesia microti

On admission to the hospital, a splenectomized man was found to have 85% of his erythrocytes parasitized by Babesia microti. His extensive parasitemia allowed for direct study of the morphology and ultrastructure of this organism as it appears in human infection; the need for animal inoculation and rescue techniques was thus eliminated. Positive characteristics (other than the tetrad form) that are diagnostic for babesiosis were identified. By transmission and scanning electron microscopy, parasite-induced changes in the erythrocyte membrane were observed; these alterations may explain the hemolysis seen in babesiosis. Factors that may have allowed the patient to sustain such high-level parasitemia are considered. The experience with this patient confirms that exchange transfusion is a reliable, rapid method for reduction of the parasite load in serious infection with B microti.     

The "shrinking lungs syndrome" in systemic lupus erythematosus--improvement with corticosteroid therapy.

A 35-year-old woman had a 13-year history of systemic lupus erythematosus (SLE) with recurrent flares since 1972 responding to corticosteroid therapy. In August, 1990 she presented with a 2-month history of dyspnea at rest, 4-pillow orthopnea and paroxysmal nocturnal dyspnea. Respiratory rate was 32-36/min, chest expansion 2 cm and crackles were present at the lung bases. On chest radiograph diaphragms were elevated. Pulmonary function tests (PFT) showed further reduction in lung volumes, maximum inspiratory pressures, maximum expiratory pressures and arterial blood gases. Ventilation/perfusion and gallium lung scans were normal. A diagnosis of "shrinking lungs syndrome" was made. Treatment with 40 mg of prednisone resulted in resolution of the patient's shortness of breath. PFT showed improvement in all variables. Corticosteroid therapy for acute "shrinking lungs syndrome" in active SLE can improve symptoms and pulmonary function.     

Partial resection of the lungs in patients with newly detected destructive tuberculosis

The efficacy of partial pneumonectomies in 700 patients with newly-diagnosed destructive tuberculosis preceded by an ineffective antibacterial therapy for 3-15 months was studied. Operations were performed in 411 (58.8%) patients with fibrocavernous tuberculosis, in 173 (24.7%) with cavernous tuberculosis, in 10 (1.4%) with disseminated tuberculosis and cavitation, and in 106 (15.1%) with tuberculoma. Segmental resections were carried out in 214 (30.6%) cases, lobectomies in 309 (44.1%), and combined resections in 177 (25.3%). Immediately good and satisfactory clinical efficacy was achieved in 687 (98.1%) and 7 (1.0%) subjects respectively, the remaining 6 (0.9%) patients died. 3-15 years after the operation, the reactivation of tuberculosis was observed in 14 (2.3%) cases out of the 603 examined. An intensive antibacterial therapy as well as repeated operations made it possible to cure 6 patients, with 5 still under treatment and 3 dead. Later on a stable clinical cure was registered in 595 (98.7%) patients out of the 603 examined.     

慢性阻塞性肺病体重指数与肺功能的相关性研究

目的通过比较低体重指数和正常体重指数慢性阻塞性肺病（COPD）患者的肺功能、血气、呼吸困难评分、运动能力和呼吸肌肉功能,探讨COPD患者体重指数和肺功能的相关性。方法选稳定期中重度COPD患者为研究对象,均为男性,以体重指数（BMI）≤18．5kg／m^2者为低体重指数组和30〉BMI〉18．5kg／m^2为正常体重指数组;比较两组肺功能、血气、6分钟步行距离和最大吸气压和最大呼吸压,分析BMI和上述各项指标的相关性。结果低体重组21例,正常体重组19例,两组肺功能、血气、呼吸困难评分、6分钟步行距离无统计学差异;最大呼气气压两组无统计学差异,但最大吸气压正常体重指数组高于低体重指数组,有统计学差异（P〈0．05）;相关性分析表明除最大吸气压与BMI有较强的相关性外（相关系数0．301,P〈0．05）,其余各指标与BMI相关性均无统计学差异。结论COPD患者的体重指数和最大吸气压可能有一定的相关性。     

The eccentric coronary atherosclerotic plaque: Morphologic observations and clinical relevance

Five hundred consecutive coronary artery segments histologically narrowed 76 to 95% in cross-sectional area by atherosclerotic plaque were classified into concentric and eccentric luminal types. Of the 500 segments, 365 (73%) were eccentric and 185 (27%) were concentric. Of the eccentric lesions, an are of disease-free wall accounted for 2.3 to 32% (mean 16.6%) of the circumference of the internal elastic membrane. The average thickness of the coronary artery media was thinner in diseased segments (mean 88.4 μm) compared to disease-free wall segments in the same vessel (mean 202.9 μm). The presence of disease-free wall segments has clinical importance in at least three areas: (1) the accuracy with which angiography reflects the morphologic features of the diseased vessel, (2) coronary artery spasm, and (3) the mechanism of coronary balloon angioplasty and subsequent “restenosis” of previously dilated vessels.     

Mitochondrial function in diaphragm of emphysematous hamsters after treatment with nandrolone

Respiratory failure in patients with COPD may be caused by insufficient force production or insufficient endurance capacity of the respiratory muscles. Anabolic steroids may improve respiratory muscle function in COPD. The effect of anabolic steroids on mitochondrial function in the diaphragm in emphysema is unknown. In an emphysematous male hamster model, we investigated whether administration of the anabolic steroid nandrolone decanoate (ND) altered the activity of mitochondrial respiratory chain complexes in the diaphragm. The bodyweight of hamsters treated with ND was decreased after treatment compared with initial values, and serum testosterone levels were significantly lower in hamsters treated with ND than in control hamsters. No difference in the activity of mitochondrial respiratory chain complexes in the diaphragm between normal and emphysematous hamsters was observed. Treatment with ND did not change the activity of mitochondrial respiratory chain complexes in the diaphragm of both normal and emphysematous hamsters. In emphysematous hamsters, administration of ND decreased the activity of succinate:cytochrome c oxidoreductase compared with ND treatment in normal hamsters. We conclude that anabolic steroids have negative effects on the activity of succinate:cytochrome c oxidoreductase and anabolic status in this emphysematous hamster model.