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1.
We analyzed how psoriasis patients sought professional help and correlated it to their illness attitudes and feeling of stigmatization. Semi-structured interviews of 400 patients were reanalyzed to identify homogeneous groups concerning initial reactions at first manifestations of the disease. Four groups ("isolated", "stigmatized", "socially supported" and "non-stigmatized" patients) were found and cross-tabulated with five resulting groups of a second cluster-analysis concerning the "style" of the seeking behaviour of professional and paraprofessional help and medical measures against the psoriasis ("multi-users", "arranged mini-users", "waiting-room patients", "optimists" and "self-therapists"). We were able to describe typical courses of illness behaviour depending on the initial reaction. The results are discussed with regard to the desirable identification of problematic patients within professional care units.  相似文献   

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3.
Simultaneous recordings of up to 48 single neurons per animal were used to characterize the long-term functional effects of sensory plastic modifications in the ventral posterior medial nucleus (VPM) of the thalamus following unilateral removal of facial whiskers in newborn rats. One year after this neonatal whisker deprivation, neurons in the contralateral VPM responded to cutaneous stimulation of the face at much longer minimal latencies (15.2 +/- 8.2 ms, mean +/- SD) than did normal cells (8.8 +/- 5.3 ms) in the same subregion of the VPM. In 69% of these neurons, the initial sensory responses to stimulus offset were followed for up to 700 ms by reverberant trains of bursting discharge, alternating in 100-ms cycles with inhibition. Receptive fields in the deafferented VPM were also atypical in that they extended over the entire face, shoulder, forepaw, hindpaw, and even ipsilateral whiskers. Discriminant analysis (DA) was then used to statistically evaluate how this abnormal receptive field organization might affect the ability of thalamocortical neuronal populations to "discriminate" somatosensory stimulus location. To standardize this analysis, three stimulus targets ("groups") were chosen in all animals such that they triangulated the central region of the "receptive field" of the recorded multineuronal ensemble. In the normal animals these stimulus targets were whiskers or perioral hairs; in the deprived animals the targets typically included hairy skin of the body as well as face. The measured variables consisted of each neuron's spiking response to each stimulus differentiated into three poststimulus response epochs (0-15, 15-30, and 30-45 ms). DA quantified the statistical contribution of each of these variables to its overall discrimination between the three stimulus sites. In the normal animals, the stimulus locations were correctly classified in 88.2 +/- 3.7% of trials on the basis of the spatiotemporal patterns of ensemble activity derived from up to 18 single neurons. In the deprived animals, the stimulus locations were much less consistently discriminated (reduced to 73.5 +/- 12.6%; difference from controls significant at P < 0.01) despite the fact that much more widely spaced stimulus targets were used and even when up to 20 neurons were included in the ensemble. Overall, these results suggest that neonatal damage to peripheral sense organs may produce marked changes in the physiology of individual neurons in the somatosensory thalamus. Moreover, the present demonstration that these changes can profoundly alter sensory discrimination at the level of neural populations in the thalamus provides important evidence that the well-known perceptual effects of chronic peripheral deprivation may be partially attributable to plastic reorganization at subcortical levels.  相似文献   

4.
In order to examine the effect of cemented tungsten carbide dust on the animal lung, saline suspensions were intratracheally administered into the lungs of rats in a single dosage. About one-fifth of the animals died during the first three days. The acute response of the lungs was hemorrhagic edema with intense alveolar congestion. The animals killed at six months all presented pulmonary lesions of patchy fibrosis in the vicinity of the deposited dusts, occasionally associated with focal traction emphysema and bronchobronchiolar ectasia. At twelve months, two-third of the animals had neither fibrosis nor dust deposition, although the remaining animals showed pulmonary lesions similar to those seen in the six-months responders. Fibrosis of the lungs seemed to consist of collapsed alveoli with condensation of the preexistent reticulin fibers, but without noticeable collagenization. It is supposed that both the early toxic and the late fibrogenic effects of the carbide dust are attributable to the cytotoxic action of cobalt present in the dust particles. It is possible that recovery of the pulmonary lesions results from removal of the dusts from the lesions.  相似文献   

5.
We have estimated lung volume, bronchial volume, vessel volume, alveolar surface area and capillary length in patients who died of lung failure due to emphysema and chronic obstructive pulmonary disease (COPD) and in patients with no clinical signs of respiratory disease. Unbiased morphometric methods were applied to the right lung. The patients with emphysema had equal lung volumes and bronchial and vessel volumes compared to the control group. The alveolar surface area and surface density were significantly decreased to about 67%, of control values. The capillary length and length density were significantly decreased to about 68% of control values. The proportional decreases in alveolar surface area and capillary length suggest that compensatory capillary proliferation has not occurred. These unbiased morphometric studies of emphysema have yielded results in end-stage emphysema that are comparable to those previously reported using biased methods. However, the unbiased methods may provide new insights when applied to earlier stages of the disease.  相似文献   

6.
A two-part population-based study investigating the occurrence of infantile colic was undertaken, in which 92% of mothers with newborn healthy infants were reached. In the prospective part 152 mothers ("diary group") registered crying and fussing in their infants during 12 weeks. In the retrospective part 224 mothers ("interview group") were contacted by telephone at an infant age of 5-7 months. The colic occurrence was determined according to four different definitions; the rate varied from 3.3 to 17.1%. The classical "Wessel-type" colic was present in 9.3%. Colic defined as "crying seen as a problem by parent" was present in 12.1% of the "interview group", but in only 3.3% of the "diary group". Some earlier studies may have overestimated colic occurrence. Another possibility is an actual decline. The contributive part of preventive measures is discussed.  相似文献   

7.
BACKGROUND: "Penetrating aortic ulcer", an atherosclerotic lesion with ulceration that penetrates the internal elastic lamina and allows haematoma formation within the aortic wall, is rarely considered in the differential diagnosis of patients with sudden onset of severe chest or back pain. It has been suggested that it is a pathologic process that involves elderly hypertensive patients with severe atherosclerosis and rarely has been observed in the ascending aorta. METHODS: To determine the characteristics of this process, 11 clinical, 2 hemodynamic, 3 angiographic and 4 surgical variables were compared between 10 consecutive patients with penetrating aortic ulcers and 20 matched patients with classic acute aortic dissection. RESULTS: Clinical and hemodynamic variables were similar in both compared groups. In the group of patients with penetrating ulcer mean age was 58 +/- 6 years, previous hypertension was observed in 6 patients and the penetrating ulcer was located in the ascending aorta in 6 cases. In comparison to patients with aortic dissection, more angiographic projections were necessary to obtain the diagnosis in the group of patients with penetrating ulcer (2.4 +/- 0.8 vs 1.7 +/- 0.6; p < 0.05). In addition, the presence of angiographic aortic valve regurgitation was only observed in the group of patients with acute dissection (60% vs 0%; p < 0.001). Severe atherosclerosis was not present angiographically in any patient with penetrating ulcer. CONCLUSIONS: Penetrating aortic ulcer can also affect middle age patients without severe atherosclerosis and is frequently observed in the ascending aorta. Its form of presentation and clinical characteristics are similar to classic aortic dissection. The lack of angiographic confirmatory evidence of dissection with suggestive clinical history, should raise the possibility of penetrating aortic ulcer.  相似文献   

8.
BACKGROUND: Early tracheal extubation is an important component of the "fast track" cardiac surgery pathway. Factors associated with time to extubation in the Department of Veterans Affairs (DVA) population are unknown. The authors determined associations of preoperative risk and intraoperative clinical process variables with time to extubation in this population. METHODS: Three hundred four consecutive patients undergoing coronary artery bypass graft, valve surgery, or both on a fast track clinical pathway between October 1, 1993 and September 30, 1995 at a university-affiliated DVA medical center were studied retrospectively. After univariate screening of a battery of preoperative risk and intraoperative clinical process variables, stepwise logistic regression was used to determine associations with tracheal extubation < or = 10 h (early) or > 10 h (late) after surgery. Postoperative lengths of stay, complications, and 30-day and 6-month mortality rates were compared between the two groups. RESULTS: One hundred forty-six patients (48.3%) were extubated early; one patient required emergent reintubation (0.7%). Of the preoperative risk variables considered, only age (odds ratio, 1.80 per 10-yr increment) and preoperative intraaortic balloon pump (odds ratio, 7.88) were multivariately associated with time to extubation (model R) ("late" association is indicated by an odds ratio >1.00; "early" association is indicated by an odds ratio <1.00). Entry of these risk variables into a second regression model, followed by univariately significant intraoperative clinical process variables, yielded the following associations (model R-P): age (odds ratio, 1.86 per 10-yr increment), sufentanil dose (odds ratio, 1.54 per 1-microg/kg increment), major inotrope use (odds ratio, 5.73), platelet transfusion (odds ratio, 10.03), use of an arterial graft (odds ratio, 0.32), and fentanyl dose (odds ratio, 1.45 per 10-microg/kg increment). Time of arrival in the intensive care unit after surgery was also significant (odds ratio, 1.42 per 1-h increment). Intraoperative clinical process variables added significantly to model performance (P < 0.001 by the likelihood ratio test). CONCLUSIONS: In this population, early tracheal extubation was accomplished in 48% of patients. Intraoperative clinical process variables are important factors to be considered in the timing of postoperative extubation after fast track cardiac surgery.  相似文献   

9.
OBJECTIVE: To establish the difference between the evolutive clinical categories (CDC/93) of the HIV infection, on the basis of diverse laboratory parameters. MATERIAL AND METHOD: 332 samples of blood, from 118 patients with HIV infection revised every three months from 1986, were studied. Determinations: haematologic, biochemical and immunologic study. Classification in each review by CDC/93 system. Statistical analysis (R-SIGMA) comparing by ANOVA and NEWMANN-KEULS the averages of the laboratory variables in the clinics categories ("A", "B" and "C"). RESULTS: There are very significant laboratory differences (p < 0.01) between the asymptomatic patients ("A") and the AIDS cases ("C"), with important decrease of hemoglobin, platelets, leukocytes, albumin, CD4+ and CD8+ T cells in the "C" category. On the contrary there is a marked increase of erythrocyte sedimentation, triglycerides, immunoglobulin A and beta 2-microglobulin in those patients with AIDS. CONCLUSION: AIDS patients present very significant differences in ten laboratory parameters, compared to the asymptomatic HIV infected patients. The follow up of these parameters may have prognostic value of AIDS evolution and be useful for the therapeutic decision making.  相似文献   

10.
A preliminary attempt at experimental induction of pulmonary fibrosis in which male ICR mice received 15 weekly sc injections of 200 or 100 mg/kg monocrotaline (MC) revealed that most animals treated with the larger dose died of severe interstitial pneumonia, whereas those given 100 mg/kg exhibited only relatively slight lung injury. Based on these results, male mice were administered sc injections of 200 and 100 mg/kg MC once a week for 9 and 18 times, respectively, and then maintained without any further treatment until week 28 after the start. Mice treated with 200 mg/kg MC showed severe pulmonary damage and died by week 25. Mortalities also occurred in the 100-mg group from week 16, with 11 of 40 animals surviving at the termination of the experiment. Histologically, both dose groups demonstrated severe interstitial pneumonia and/or pulmonary fibrosis. Ultrastructurally, inflammatory edema possibly attributable to injuries of alveolar capillary endothelial cells was observed in the high-dose group at week 8, and there was a remarkable increase in collagen fibers in alveolar septa in this group thereafter. The present study results suggest that lung injuries induced by MC treatment progress to irreversible lung fibrosis and that this animal model may have advantage for studying the pathogenesis of lung cancers in patients with pulmonary fibrosis.  相似文献   

11.
BACKGROUND: Congenital lobar emphysema is an unusual condition and its pathogenesis remains unknown. The variety of findings in pathology studies of the resected specimens led to increasing academic interest. About 50 per cent of the cases have no definitive diagnosis in pathology. The most recent theory proposes an increased number of alveoli within each acinus (polyalveolar lobe). PURPOSE: The aim of this paper is to report the morphometric measures of surgical specimens of 12 patients with congenital lobar emphysema, using the Emery and Mithal technique (radial alveolar count). METHODS: We made a case-control study, classifying the cases by age. Mann-Whitney's U test and linear regression techniques were used in data analysis: Mann-Whitney's U in comparing the cases and respective controls and linear regression to evaluate the influence of age in the measures found. RESULTS: The results revealed a significantly higher radial alveolar count than expected for the age group under 3 years; no difference was observed in the age group between 3 and 7 years and in children older than 7, the radial alveolar count was lower than expected. The normal development of the lung consists in an increasing number of alveoli increase from birth until adulthood, but this number remains constant, independent of age in congenital lobar emphysema. CONCLUSIONS: Such findings allow us to conclude that polyalveolar lobe can and must be diagnosed by a simple and practical method, such as the radial alveolar count, which decreases the incidence of the unknown etiology. The findings of an increased number of alveoli on patients younger than 3 is related to congenital lobar emphysema, since the number of alveoli does not increase in congenital lobar emphysema, just the opposite to what one would expect in the normal development of the lung.  相似文献   

12.
The purpose of this investigation was to determine the effects of aging and endurance training on lactate dehydrogenase (LDH) activity and isozyme pattern in liver and skeletal muscle. Male Fischer 344 rats (n = 30) of three different age groups (young, 4 months; middle-aged, 12 months and old, 22 months) were trained on a treadmill at 75% running capacity for 1 h/day, five times per week for 10 weeks. Age-matched sedentary controls (n = 36) were used for comparison. Total LDH enzyme activity was measured spectrophotometrically; LDH isozymes were separated by native 5.5% polyacrylamide gel electrophoresis and quantified densitometrically. With increasing age, hepatic LDH activity decreased 28%. Old sedentary animals displayed significantly less (22%) hepatic LDH 5 than young and middle-aged animals, and significantly more (40%) hepatic LDH 4 than middle-aged animals. Training resulted in a significant decrease (38%) in total hepatic LDH activity in young rats only. Young animals displayed a significant increase in hepatic LDH 3 (28%), whereas middle-aged animals exhibited a significant decrease in hepatic LDH 3 (40%) with training. No change in total hepatic LDH activity was exhibited in middle-aged or old rats with training. Neither aging or training had a significant effect on LDH activity or isozyme pattern in extensor digitorum longus (EDL). Similarly, LDH activity was maintained in soleus with age, and isozyme pattern was only negligibly affected. We conclude that with age there is a decline in hepatic LDH activity and a decrease in the LDH 5 isozyme. Endurance training induced significant decreases in hepatic LDH activity of young animals. However, these decreases were not a result of shifts in isozymal pattern. Further, LDH activity was maintained in EDL and soleus muscle with age. Finally, endurance training did not have a significant effect on LDH activity or isozymal pattern of EDL or soleus.  相似文献   

13.
Stapled lung volume reduction surgery (LVRS) has recently been described for treatment of emphysema. Many questions arise regarding physiologic mechanisms of response from surgical treatment of emphysema. The objective of this study was to develop an animal model for the study of lung volume reduction surgery in diffuse heterogeneous emphysema. We hypothesized that elastic recoil would increase, static respiratory system compliance would decrease, and expiratory flows would increase after lung volume reduction surgery in animals with emphysema. In the study, emphysema was induced in 31 New Zealand White rabbits (3-5 kg) with endotracheally aerosalized porcine elastase (10,000-12,000 U). Lateral thoracotomies were performed 4-6 weeks postinduction under general anesthesia and mechanical ventilatory support. Stapled volume reduction was performed on the right lower lobe using a standard multirow pediatric stapler (U.S. Surgical). Pulmonary function tests were performed at baseline (preinduction), before stapling LVRS (postemphysema induction), immediately post stapling LVRS, and 1 week poststapling. Static respiratory system compliance, flow, conductance and forced expiratory flows, and peak flows at 20 and 40 cm3 of exhaled volume were analyzed. Animals were sacrificed 1 week poststapling, and bilateral lungs were harvested for histopathology. Diffuse but heterogeneous pulmonary emphysema was seen in these animals treated with high-dose aerosolized elastase. Static compliance increased, while expiratory flows and conductance decreased after induction of emphysema. Immediately post stapled volume reduction therapy, animals had decreased static compliance. By 1 week following surgery, animals showed increased forced expiratory flows and decreased expiratory resistance, although compliance was similar to preoperative levels. In conclusion, we describe initial results in an animal model of obstructive emphysema suitable for the study of lung volume reduction surgery. Changes in pulmonary function indicate that unilateral lower lobe LVRS increases airway conductance in the rabbits. Findings from LVRS studies in animal models such as this may help explain clinical improvement following LVRS in humans.  相似文献   

14.
BACKGROUND: Patients undergoing cardiac surgery have a substantial incidence of neurologic complications related to cerebral embolization during cardiopulmonary bypass. The purpose of this study was to determine if adjustments in the arterial carbon dioxide (PaCO2) level can reduce cerebral and ocular embolization. METHODS: Twenty pigs underwent cardiopulmonary bypass at 38 degrees C. At either hypercarbia (PaCO2 = 50-55 mmHg, group H, n = 10) or hypocarbia (PaCO2 = 25-30 mmHg, group L, n = 10), an embolic load of 1.2 x 10(50 67-microm orange fluorescent microspheres was injected into the aortic cannula. Before and after embolization, cerebral and ocular blood flows were determined at normocapnia using 15-microm fluorescent microspheres. After cardiopulmonary bypass was completed, the eyes were enucleated and brain tissue samples were collected. Microspheres were isolated and the fluorescence was measured. RESULTS: In groups H and L, the mean PaCO2 values at embolization were 52+/-3 mmHg and 27+/-2 mmHg, respectively (P < 0.0001). Total and regional embolization were significantly less in hypocapnia than in hypercapnic animals: 142% more emboli were detected in the brain in group H than in group L (P < 0.0001). Cerebral blood flow after embolization was unchanged in both groups. Similarly, fewer ocular emboli occurred in hypocapnic animals than in hypercapnic animals (P = 0.044), but in contrast to the brain, ocular blood flow decreased significantly in both groups after embolization. CONCLUSIONS: Cerebral embolization is determined by the PaCO2 at the time of embolization. In cardiopulmonary bypass practice, reductions in PaCO2 during periods of embolic risk may reduce the risk for brain injury.  相似文献   

15.
The aim of our study was to examine the combined contribution of computer-assisted histomorphometry of lungs with blood strontium (BS) measurement to the diagnosis of drowning in cadavers recovered from fresh water. The study population comprised 116 drowned subjects. The results for this group were compared with those obtained for three non-drowned groups: 22 subjects who died from causes other than asphyxia, 13 subjects who died of asphyxia (strangulation or hanging); and 23 healthy living subjects in whom normal BS level was measured. Samples of water where the bodies had been found were analyzed in order to establish a relation with the BS concentration of the drowned subjects. Histologically, each type of pulmonary lesion (congestion, edema, alveolar macrophages, alveolar hemorrhage, and emphysema aquosum) was evaluated semiquantitatively using a score according to the severity of the pathology. Then, a quantitative histomorphometric study was performed using a computer-assisted image analyzer to measure the length and thickness of the alveolar walls, and the area and density of the alveolar cavities. The mean values of the BS levels in the 116 drowned subjects and of the water strontium concentrations were found to be much higher than in the living individuals. Although the ranges were wide, we found no overlap between values found in drowned subjects and those in non-drowned subjects. Emphysema aquosum and to a lesser extent alveolar hemorrhage were found to be the most significant histologic changes in the drowned and asphyxia groups compared with the nonasphyxia control groups.  相似文献   

16.
By using a chronological lead-labelling technique and computer image analysis the volume of this newly formed bone was evaluated. Rat maxillary first molars were moved mesially by a fixed, closed coil-spring appliance for 6 days using three different magnitudes of initial tensile force (27, 60 and 136 g). Sham-treated rats wearing an inactivated appliance were used for the control study. All animals were injected twice intraperitoneally with lead-disodium EDTA, 3 hr before the beginning and 3 hr before the end of treatment. The unit volumes of newly formed bone (mm3/mm2) were assessed with reference to lead-labelling lines in the alveolar walls of the root socket by computer image analysis. In the control group, two distinct lead-labelling lines indicated continuous bone formation on the mesial side of the root sockets, but only a jagged line was found on the distal side. After experimental mesial tooth movement, only a single lead line could be found on the mesial/pressure side of the root sockets; on the distal/tension side, a wide layer could be detected between the two lead lines. The volume of newly formed bone on the distal/tension side in the experimental groups was significantly greater than that in the control group. However, there was no significant difference in the volumes of newly formed bone among the three experimental groups. The study demonstrates that the volume of newly formed bone in the alveolar walls during the initial stage of tooth movement can be quantified and that the magnitude of the tensile force of tooth movement may not influence directly the volume of newly formed bone in the alveolar wall on the tension side.  相似文献   

17.
This study examined the role of cysteine proteinases and their inhibitor in the development of emphysema in comparison with neutrophil elastase (NE) complexed with alpha1-protease inhibitor (NE-alpha1-PI), which was previously demonstrated to be increased in bronchoalveolar lavage (BAL) fluid from subjects with subclinical emphysema. Eight nonsmokers and 31 current smokers with (n=17) and without (n=14) emphysema, as evidenced by lung computed tomographic scans, were studied. The concentrations of immunologically detected cathepsin L and cystatin C, but not cathepsin B, were significantly increased in BAL fluid from the smokers with emphysema compared with those without emphysema, although the activity of cathepsin L, measured using a synthetic substrate and cathepsin L, released from cultured alveolar macrophages at 24 h, did not show any significant difference between the two groups. When comparison was made only for the subjects aged <60 yrs, the difference between the two groups disappeared for cathepsin L, but remained for NE-alpha1-PI. There was no significant correlation between the level of cathepsin L and that of NE-alpha1-PI in BAL fluid from the subjects with emphysema. In conclusion, increased levels of cathepsin L and cystatin C were demonstrated in bronchoalveolar lavage fluid from subjects with subclinical emphysema. However, the roles of cathepsin L and neutrophil elastase in the development of emphysema may vary between subjects and between the young and the old.  相似文献   

18.
The experimental rats were randomly divided into three groups: i.e. control group; endotoxic shock group (the model of endotoxic shock was induced by intravenous administration of E. Coli endotoxin, 16 mg/kg); and electroacupuncture (EA) group ("Renzhong" or "Zusanli" acupoint was stimulated for 15 minutes at 1 hr after injection of endotoxin). The experimental rats were decapitated at 75 minutes after injecting endotoxin. Their livers were taken out for cryostat section, and histochemical observation. The results were as follows: 1) The glycogen in the hepatic cells of endotoxic shocked rats were almost completely depleted. The activities of SDH Mg(++)-ATPase and G-6-Pase and 5'-Nase were decreased; especially the activities of 5'-Nase in the biliary canaliculi and sinusoids were apparently reduced. 2) The content of hepatic glycogen in EA group was increased, but some of them was still depleted. The activities of SDH, Mg(++)-ATPase and G-6-Pase were slightly increased as compared with that of the endotoxic shock group. The activity of 5'-Nase was obviously increased after EA. The preliminary results indicated that EA at "Renzhong" or "Zusanli" acupoint of rats with endotoxic shock might play certain role on improving the hepatic metabolism and promoting the membrane transport action.  相似文献   

19.
We reported the immediate recovery period of 705 consecutive patients post general or head-neck-breast surgery, 590 were looked after in the recovery room (RR) and 115 were admitted into the intensive care unit (ICU) right after surgery. Group I were "young" (aged 15-45 years), group II were "middle aged" (46-60 years) and group III were "elderly" (> 60 years). Twenty-seven per cent of the elderly patients were sent to the ICU, whereas, 8.4 per cent of the young and 14.7 of the middle-aged group were looked after in the ICU. In RR patients, the young group were in better ASA class and had significantly fewer underlying diseases than the middle-aged and elderly groups; the most common of which were hypertension, diabetes and anemia. Elderly patients spent a significantly longer time in the RR than the young group but the risk of complication was not different. The most frequent complication was pain and elderly patients more frequently suffered from pain than the young group. Post-anesthetic recovery score (after Aldrete and Kroulik) was lower in the elderly on arrival and at 15, 30, 60 minutes in the RR but there was no clinical significance. In ICU patients, the 3 groups' intubation rates were not different and although the duration of intermittent positive pressure ventilation and duration of stay in the ICU were longest in the elderly group, there was no statistically significant difference. The mortality rate was highest in the elderly. We concluded that elderly patients had a worse immediate recovery period.  相似文献   

20.
This report questions several commonly used definitions and commonly accepted concepts. It suggest that the term, "chronic airflow obstructions," should replace the terms, "chronic obstructive pulmonary disease," "chronic obstructive lung disease," or "chronic airway obstruction," because it is flow that is obstructed. It is suggested the term, "chronic mucous hypersecretion," be used, rather than "chronic bronchitis," and that the latter be avoided. Chronic bronchitis should not be equated with narrowing of the airway and emphysema with loss of elastic recoil. Chronic bronchitis, emphysema, and lesions of the small airways probably occur together more frequently than chance will allow because of a common etiologic agent, tobacco smoke. Chronic mucous hypersecretion without other airway or parenchymal lesions seldom produces airflow obstruction and does not impair prognosis significantly. Central airways are important in chronic airflow obstruction. It is time that someone found out what is happening in subjects with abnormal results on tests of the function of small airways. The definition of "destruction" as it occurs in emphysema is deceptive, and loss of recoil and emphysema may be separate conditions. The dysfunction that occurs in emphysematous lungs is due mainly to associated airway lesions and may perhaps be due in part to the site and nature of emphysematous lesions (as opposed to loss of elastic recoil).  相似文献   

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