Is routine bronchoscopic culture indicated in areas with low tuberculosis prevalence?

SETTING: Tertiary care university-affiliated medical centre. OBJECTIVE: To determine the value of routine culture of bronchoscopy samples for mycobacteria even when tuberculosis (TB) is not strongly suspected in low TB prevalence areas. DESIGN: A prospective study of 362 consecutive patients who underwent a bronchoscopy procedure. All demographic, clinical and computed tomography findings, and bacterial and mycobacterial culture results were collected. RESULTS: A total of 217 men and 145 women, with a mean age of 63 ± 15 years, were included in the study. All underwent bronchoscopy with routine culture for TB. Ten cultures (2.8%) grew mycobacteria: 2 (0.55%) Mycobacterium tuberculosis and 8 (2.2%) non-tuberculous mycobacteria (NTM). The NTM included M. avium complex (MAC) in six patients and M. simiae in two patients. Two patients had two different mycobacteria species: 1 patient with M. simiae and MAC and the other with TB and MAC. All eight patients were negative for microscopy. CONCLUSION: Based on our results, we suggest that routine culture of bronchial specimens for TB is not indicated in patients with a low clinical suspicion of active TB in countries with a low TB burden.

[Asthma management in adult emergency departments in Israel in comparison to asthma guidelines].

BACKGROUND: Asthma management is in focus all over the world. It is constantly updated, including aspects of Emergency Department (ED) care, on the basis of global and national evidence-based clinical guidelines. Despite the existence of these guidelines, the management of asthma, including management in the ED, is lagging behind. AIM: This study strives to evaluate various aspects of asthma management in the EDs in Israel. METHOD: A questionnaire was sent to each Head or Deputy Head of all the adult EDs in Israel. The questionnaires were collected within 16 days in December 2000. Ninety-six percent of all adult EDs in Israel responded. The mean response of each ED to all the questions was 99.5%. RESULTS: Oximetry on admission is performed for every patient in a third of the EDs although an oximeter is available in every ED. Measurements of airway obstruction severity by PEFRm or FEV1 in more than 50% of patients before hospital admission or discharge is only conducted in 9% of the EDs and in 52% of them it is not measured at all. Inhalation of a short beta-agonist combined with anticholinergic is performed in 84% of EDs. Corticosteroids are given to more than 80% of the arriving patients in only 54% of EDs and on discharge it is continued in all or almost all patients in 63% of EDs. A written time interval for the next medical visit after discharge from ED is not specified in 50% of EDs. In contrast to these findings, there is almost complete accordance among EDs (88%) that asthma management in the ED should follow formal guidelines and that common guidelines for asthma management should be adopted by all EDs in Israel (71%). CONCLUSIONS: The discrepancies between the existing clinical guidelines for asthma management in the ED and its actual use on the one hand, and the agreement among EDs on the importance of the guidelines on the other hand, are raising the necessity for common guidelines for asthma management in the EDs in Israel. Perhaps, more importantly, it highlights the urgent need for new effective and creative ways to implement asthma guidelines into routine ED practice.

[Attitude of hospital visitors towards cigarette smoking inside hospital buildings; one more step towards a "smoke free hospital" in Israel].

In order to determine a policy within the hospital restricting smoking we previously surveyed the attitude of the hospital staff towards smoking inside the hospital buildings. In the present survey we examined the attitude of the hospital visitors on the same issue. One hundred and fifty-seven hospital visitors participated in the survey and answered a questionnaire; 93 visitors were smokers, 64 were non-smokers. Eighty-eighth percent of the visitors smoked during their visit, 4 cigarettes on the average, during an average length of stay of 2.8 hours, until completing the questionnaire. Eighty-three percent of the smokers were aware of the law that prohibits smoking in public buildings, and 71% were aware of the signs and advertisements that prohibit smoking in the hospital. Two thirds of the smokers declared that they would have refrained from smoking in the hospital if others around them also refrained from smoking and justified the law that prohibits smoking in public buildings, including hospitals. Sixty-nine percent of the smokers declared that they were willing to cooperate with hospital management in restricting smoking to the hospital grounds outside the hospital buildings, and would accept directives regarding smoking restriction from any hospital personnel. In fact, only 11% of the smokers were requested to stop smoking during their visit. These findings reinforce the results of our pervious survey conducted among the hospital staff and indicates the existence of a paradoxical vicious cycle of behavior among smokers and non-smokers, visitors and staff, in the hospital. On the one hand the smokers do not have the self-obedience necessary to stop smoking while visiting in the hospital, although they are aware of their misdeed. On the other hand the non-smokers lack the confidence that they will obtain the cooperation of the smokers, although the smokers are willing to cooperate. Both groups except someone else to either actively restrict them from smoking or to encourage them to restrict the smokers. Our findings suggest that this "someone else" is the hospital management (and the staff endorsed to implement this directive).

Pergolide-induced dyspnea, bilateral pleural effusion and peripheral edema.

A patient with severe Parkinson's disease presented with increasing dyspnea, bilateral pleural effusion and peripheral edema that were refractory to diuretic therapy and were first misdiagnosed as signs of right-sided heart failure. Pergolide was the only culprit for this devastating condition and on its discontinuation all signs of fluid retention resolved. In this report, drug reactions to ergots and dopamine agonists are discussed.

[Smoking by an Israeli general hospital staff, and attitude to smoking in hospitals. Are we in Israel ready to institute "smoke-free hospitals"?].

Smoking within hospitals is common in general hospitals in Israel. It has a strong negative educational impact, has a negative image and curing its ill effects help keep our hospitals busy. An anonymous questionnaire was answered by 128 members of our hospital staff (28%). Their distribution, according to occupation and sex was representative of the rest of our hospital staff. 19% of our workers are smokers, a much lower proportion than in our general adult population. The proportion was highest among maintenance (40%) and sanitary-help staff (36%). 23% of nurses and 15% of physicians were smokers. This situation is better than that among Italian or Japanese medical staff, but much worse than among North American medical staff. 75% of our workers who smoke declared that they smoke outside the room in which they work. 66% and 72% of the staff believe that hospital workers and visitors, respectively, should smoke outside hospital buildings. Only 19% of all workers do not believe that a "smoke-free hospital" is attainable. 34% believe that a "smoke-free hospital" is achievable, and 47% said that it is perhaps achievable. 86% of all the workers, and 41% of the smokers, expect the hospital director to implement an effective policy of enforcing the law limiting smoking within hospitals (and other public buildings) in Israel. 60% are willing to contribute actively to this effort. We believe these results strongly suggest that the time is ripe for implementation of the "smoke-free hospital" in Israel. This requires a strong and effective central policy, like that in the USA. We suggest measures that the Israel Ministry of Health take measures to successfully implement this policy.

Generation of complement C3 and expression of cell membrane complement inhibitory proteins by human bronchial epithelium cell line.

BACKGROUND: The interrelationship between human airway epithelium and complement proteins may affect airway defence, airway function, and airway epithelial integrity. A study was undertaken to determine (1) whether unstimulated human bronchial epithelium generates complement proteins and expresses cell membrane complement inhibitory proteins (CIP) and (2) whether stimulation by proinflammatory cytokines affects the generation of complement and expression of cell membrane CIP by these cells. METHODS: Human bronchial epithelium cell line BEAS-2B was cultured in a serum-free medium. Cells were incubated with and without proinflammatory cytokines to assess unstimulated and stimulated generation of complement C3, C1q and C5 (by ELISA), and to examine the expression of cell membrane CIP decay accelerating factor (DAF; CD55), membrane cofactor protein (MCP; CD46), and CD59 (protectin) by flow cytometry analysis. RESULTS: Unstimulated human bronchial epithelial cell line BEAS-2B in serum-free medium generates complement C3 (mean 32 ng/10(6) cells/72 h, range 18-52) but not C1q and C5, and expresses cell membrane DAF, MCP, and CD59. Interleukin (IL)-1alpha (100 U/ml/72 h) and tumour necrosis factor (TNF-alpha; 1000 U/ml/72 h) increased generation of C3 up to a mean of 78% and 138%, respectively, above C3 generation by unstimulated cells. DAF was the only cell membrane CIP affected by cytokine stimulation. Interferon (IFN)-gamma (10 U/ml/72 h) and TNF-alpha (1000 U/ml/72 h) increased DAF expression up to a mean of 116% and 45%, respectively, above that in unstimulated cells. MCP and CD59 expression was not consistently affected by IL-1alpha, TNF-alpha, or IFN-gamma. CONCLUSIONS: Local generation of complement C3 and expression of cell membrane CIP by human bronchial epithelium and its modulation by proinflammatory cytokines might be an additional regulatory mechanism of local airway defence and may affect airway function and epithelial integrity in health and disease.

[Proper use and the ability to teach the use of pressurized hand-held inhalers in patients with chronic airway obstruction].

Inhaling drugs via hand-held inhalers in recommended for those with chronic obstructive airway disease (COPD). Approximately 8%-9% of Israel's population use hand-held inhalers, many of them pressurized. Skill in using them and ability of chronic users to learn their proper use have not been assessed. During 1993 and 1994 we studied 200 patients with bronchial asthma or COPD who regularly used a pressurized hand-held inhaler (PI), but were not trained to use it in our out-patient pulmonary clinic. Only a third were found to be skilled in its use. About half were completely unable to use it properly, and 17% used it in a suboptimal way. Remarkably, only 40% had been taught anything with regard to its use. About 75% of the suboptimal users significantly improved their skill in its use immediately after receiving a single individual teaching and corrective demonstration session. While 15% failed to learn the proper use of the PI, many of those who improved immediately after a single teaching session retained the learned skills for months. We conclude that the physician who recommends the use of a PI is responsible for the patient's being taught its proper use in a demonstration session. Skill in its use should be reassessed periodically during the entire treatment period.

Cytokines modulate expression of cell-membrane complement inhibitory proteins in human lung cancer cell lines.

Human lung cancers overexpress several cell-membrane complement inhibitory proteins (CIP). These complement inhibitory proteins are membrane cofactor protein (CD46), decay-accelerating factor (DAF; CD55), and CD59 (protectin). These cell-membrane proteins have a wide normal tissue distribution, are known to protect normal host cells from homologous complement-mediated lysis, and are thought to facilitate tumor escape from immunosurveillance. To study whether proinflammatory cytokines that are involved in cancer growth can modulate cell-membrane CIP expression in lung cancer cells, we studied the effect of interleukin (IL)-1alpha, tumor necrosis factor (TNF)-alpha, and interferon (IFN)-gamma on two human lung cancer cell lines. ChaGo K-1 and NCI-H596 cell lines, undifferentiated carcinoma and lung adenosquamous carcinoma, respectively, were stimulated with different cytokines, and the effects of incubation time and cytokine concentration on cell-membrane CIP expression were studied. Cell-membrane CIP expression was evaluated using flow cytometry and cytokine effect was calculated as percent change in mean fluorescence intensity of each CIP molecule from its untreated control. We found that DAF was the lung cancer cell-membrane CIP molecule that was the most responsive to cytokine stimulation. Maximal stimulatory effect was usually noted 72 h after a cytokine was introduced. In ChaGo K-1 and NCI-H596 lung cancer cell lines, IL-1alpha and TNF-alpha increased DAF expression. IL-1alpha (100 U/ml/72 h) increased DAF expression up to a maximal mean of 45 and 48%, respectively, in comparison with untreated cells. TNF-alpha (1, 000 U/ml/72 h) increased DAF expression up to a mean of 131 and 46%, respectively. IFN-gamma (1 U/ml/72 h) increased DAF expression in NCI-H596 cells up to a mean of 100%, but had a slight inhibitory effect on DAF expression in ChaGo K-1 cells, decreasing expression by a mean of 17% in comparison with untreated cells. We conclude that cell-membrane DAF expression in the studied human lung cancer cell lines is modulated by IL-1alpha, TNF-alpha, and IFN-gamma, and speculate that cytokine-mediated modulation of cell-membrane DAF in human lung cancer cells might affect lung cancer cell biology.

Human lung cancer cell lines express cell membrane complement inhibitory proteins and are extremely resistant to complement-mediated lysis; a comparison with normal human respiratory epithelium in vitro, and an insight into mechanism(s) of resistance.

Human lung cancer expresses cell membrane complement inhibitory proteins (CIP). We investigated whether human lung cancer cell lines also express cell-membrane CIP molecules and whether the biology of CIP molecules in these cell lines differs from that of CIP in normal human respiratory epithelium in culture. The cell lines ChaGo K-1 and NCI-H596 were compared with normal human nasal epithelium in primary cultures in respect to the level of cell membrane CIP expression of membrane cofactor protein (MCP; CD46), decay-accelerating factor (DAF; CD55) and CD59, in respect to the level of cell resistance to complement-mediated lysis, and in respect to the contribution of cell membrane CIP to cell resistance against complement-mediated lysis. We found, using flow cytometry, that both human lung cancer cell lines expressed MCP, DAF and CD59, as did normal nasal epithelial cells. However, normal cells showed a large subpopulation of low DAF-expressing cells (60% of all cells) and a smaller subpopulation of high DAF-expressing cells (40%), while the lung cancer cell lines showed only one cell population, of high DAF expression. In addition, both lung cancer cell lines expressed higher MCP levels, and NCI-H596 cells showed higher levels of CD59. Cell resistance to complement-mediated lysis of both lung cancer cell lines was much higher than that of normal cells. Fifty percent normal human serum, under the same concentrations of complement activators, induced lysis of less than a mean of 10% of lung cancer cells, while lysing up to a mean of 50% of nasal epithelial cells. Lung cancer cell resistance to complement was due to its ability to prevent significant activation of complement upon its cell membrane, as manifested by a failure of complement activators to increase cell membrane deposition of C3-related fragments. The exact mechanism for this resistance remains obscure. Unexpectedly, neutralizing antibodies, anti-MCP and anti-DAF were entirely ineffective and anti-CD59 was only slightly effective (18% mean cell lysis) in increasing the susceptibility of the lung cancer cell lines to complement, while the same antibodies were very effective in facilitating complement-mediated lysis of the normal nasal epithelial cells (50% mean cell lysis with CD59 MoAb). On the other hand, detachment of DAF and CD59 by phosphatidylinositol-specific phospholipase C (PIPLC) from the lung cancer cell lines abrogated their resistance to lysis. We suggest that the biology of cell membrane CIP molecules in human lung cancer cell lines is different from that of CIP in normal respiratory epithelial cells. Human lung cancer cell lines are able to prevent significant complement activation upon its cell membrane and are therefore especially resistant to complement-mediated lysis. Complement resistance may serve this common and highly lethal human cancer as an escape mechanism from the body's immunosurveillance and prevent effective immunotherapy with tumour-specific MoAbs.

Protection of human nasal respiratory epithelium from complement-mediated lysis by cell-membrane regulators of complement activation.

Complement in the respiratory tract protects the host from invading micoorganisms and other inhaled insults, but may damage normal tissue. Recently we reported that human respiratory epithelium from the nose to the alveoli expresses three cell-membrane regulators of complement activation: membrane cofactor protein (MCP, CD46), decay accelerating factor (DAF; CD55), and CD59. In this study we investigated whether two of these complement-regulatory proteins, DAF and CD59, protect human nasal epithelial cells from complement-mediated lysis. Treatment of nasal epithelial cells in suspension with 50% or 100% normal human serum (NHS) lysed small percentages of cells (8% and 16%, respectively). Addition of complement activators, rabbit serum antinasal epithelial cells (anti-NEC), or lipopolysaccharide (LPS) increased cell lysis in the presence of 50% NHS in a dose-dependent manner up to 50% and 35% lysis, respectively. Human serum deficient in C3 or C7 did not lyse nasal epithelial cells even in the presence of anti-NEC. To assay the contribution of DAF and CD59 to cell protection against lysis, nasal epithelial cells in suspension were treated with appropriate blocking antibodies. Both anti-DAF and anti-CD59 markedly increased the susceptibility of human nasal epithelial cells to lysis by complement. At 50% NHS, anti-DAF and anti-CD59 antibodies increased epithelial cell lysis from 8% to 24% and 67%, respectively. A similar pattern of response to complement was demonstrated by monolayers of substrate-anchored cultured cells. These results indicate that DAF and CD59 protect human nasal epithelial cells from complement-mediated lysis; however, intense activation of complement may overcome this protection, leading to cell death and tissue injury. We speculate that imbalance between complement regulation and complement activation in the human respiratory tract in disease may result in tissue injury and impaired tissue function.

Human nasal epithelium adsorbs complement C3-related fragments and expresses cell membrane complement regulatory proteins.

Recent evidence suggests that complement is activated in human nasal airways in inflammatory states. Activated complement protects the nasal mucosa against microorganisms, but also has the potential to lyse the host's normal cells. Complement-mediated cell lysis depends on adsorption of complement to the cell membrane and on uninterrupted activation of the complement cascade upon the same cell membrane. In the present study, the authors investigated first whether key complement components, C3-related fragments, are adsorbed to nasal epithelial cell membrane. Second, we investigated whether nasal epithelium expresses cell membrane complement regulatory proteins that are known as interruptors of complement activation. Studies were done using fresh nasal mucosa obtained at turbinectomies from allergic rhinitis and vasomotor rhinitis patients. In addition, in order to establish an in vitro model, studies were also done using primary cell cultures of nasal epithelium. We have found that complement C3-related fragments are present on cell membranes of fresh nasal epithelium and that C3-related fragments are adsorbed to the epithelial cell membrane in nasal mucosa tissue segments and in cell cultures that were incubated with autologous serum. Adsorption of C3-related fragments to the cell membrane of cultured nasal epithelial cells was found by flow cytometry analysis to be concentration-dependent. In addition, we found that nasal epithelium in fresh tissue and in cell culture express three cell membrane complement regulatory proteins: membrane cofactor protein (MCP, CD46), decay-accelerating factor (DAF, CD55), and CD59. Our findings in fresh nasal epithelium suggest that complement activation may occur upon the nasal epithelial cell membrane during inflammation in vivo and that nasal epithelium might regulate this complement activation. Our in vitro cell culture model will allow further investigations of complement activation and regulation upon the human nasal epithelial cell membrane.

Expression and distribution of cell-membrane complement regulatory glycoproteins along the human respiratory tract.

Complement in the human respiratory tract protects the host from invading microorganisms and from other inhaled insults. However, complement may also lyse the host's respiratory tract cells, leading to tissue injury. In many extrapulmonic tissues, cells express cell-membrane complement regulatory glycoproteins that protect the cells from complement-induced lysis. To determine whether these glycoproteins are expressed in human respiratory tract tissue, we studied tissue biopsies of healthy and diseased human respiratory tract from nose to alveoli for the presence of four cell-membrane complement regulatory glycoproteins (membrane cofactor protein [MCP], decay-accelerating factor [DAF], CD59, and complement receptor type 1 [CR1]) using an immunoperoxidase technique. In addition, to establish a model for in vitro studies of these glycoproteins in respiratory cells, we studied whether they are expressed in cultured nasal epithelial cells, using the same technique. Altogether, 26 tissue specimens from 22 patients were studied. We found that normal human respiratory tract from nose to alveoli express MCP, DAF, and CD59, but not CR1, and that this expression increases in inflammation and in lung cancer. In addition, expression in nasal epithelial cells is retained under cell culture conditions. These findings suggest that human respiratory tract tissue may regulate complement activation on its surface in order to avoid self-injury. We propose that imbalances in the mechanism that regulates cell-membrane complement may predispose the respiratory tract to tissue injury and disease, and that iatrogenic modulation of such imbalances may help to prevent these adverse consequences.

Normal serum increases adhesion of neutrophils to tracheal epithelial cells by a CD11b/CD18-dependent mechanism.

Airway inflammation is characterized by intraluminal influx of inflammatory cells, exudation of plasma, and increased procoagulant activity. We speculated that inflammatory cells might adhere to the airway surface epithelium in order to better localize and regulate airway inflammatory responses. Therefore, in this study, we asked whether neutrophils adhere to airway epithelial cells, whether serum or plasma factors increase adhesion, and, if so, what the characteristics of the involved adhesion molecules are. To answer these questions, we incubated human 51Cr-labeled neutrophils from peripheral blood with dog tracheal epithelial cells in culture in the presence or absence of normal human serum or plasma. After 30 min, nonadhering neutrophils were centrifuged away and neutrophil adhesion was assessed by radioassay. We found that unstimulated adhesion of neutrophils to cultured epithelial cells was quite low (< 6%). However, incubation with 10% serum or plasma increased adhesion of neutrophils to epithelial cells dramatically (up to a mean of 71%). The serum-induced increase in adhesion was concentration dependent; even 1% serum was effective (19% adhesion). Serum adhesion factor acted selectively on epithelial surfaces, was heat sensitive, had a molecular weight > 12,000, and depended on the presence of divalent cations. mAb 60.3 (anti-CD18) and mAb anti-Mol (anti-CD11b, anti-CR3) inhibited serum-induced adhesion by > 50% each. We conclude that normal serum and plasma contain a potent adhesion factor that induces adhesion of neutrophils to tracheal epithelium in culture.(ABSTRACT TRUNCATED AT 250 WORDS)

Endogenous digoxin-like immunoreactive factor is elevated in advanced chronic respiratory failure.

Digoxin-like immunoreactive factor (DLIF) is an endogenous substance with natriuretic and diuretic activity. Elevated plasma levels of DLIF are found in various clinical states characterized by water and sodium retention. Chronic respiratory failure, particularly of an advanced stage, also is frequently associated with water and sodium retention. In order to determine whether elevated plasma levels of DLIF are present in chronic respiratory failure, we measured plasma DLIF levels in seven patients (four with COPD [two of whom had associated sleep apnea disturbance] and three with kyphoscoliosis) suffering from advanced chronic respiratory failure with severe hypoxemia and hypercapnia. We found that in these patients plasma levels of DLIF were significantly higher than in healthy control subjects. We conclude that patients with advanced chronic respiratory failure respond with increased levels of DLIF. This may represent an attempt at homeostasis of water and sodium metabolism which is frequently deranged in this clinical condition.

Turnover of cell-surface macromolecules in cultured dog tracheal epithelial cells.

We studied the metabolism of sulfated cell-surface macromolecules in dog tracheal epithelial cells in primary culture. To examine the time-course and rate of appearance of sulfated macromolecules at the cell surface, the cells were pulsed with 35SO4 for short periods (5-15 min), and the incubation medium was sampled for spontaneously released macromolecules (basal secretions) and for release induced by trypsin (trypsin-accessible secretions). Trypsin-accessible 35S-labeled macromolecules appeared on the cell surface within 5-10 min, increased linearly, and plateaued by 40 min; the median transit time for 35S-labeled macromolecules to reach the cell surface was 21 min. 35S-labeled macromolecules in basal secretions increased with a similar time-course, reaching a plateau by 40 min. Incorporation of [3H]serine into the protein moiety of trypsin-accessible macromolecules occurred more slowly; trypsin-accessible 3H-labeled macromolecules were barely detectable at 1 h and increased to a maximum after 2 h, suggesting the presence of a preformed pool of nonsulfated core protein. Pretreatment with cycloheximide, an inhibitor of protein synthesis, decreased trypsin-accessible 35S-labeled macromolecules log-linearly depending on the duration of pretreatment providing an estimate of the rate of depletion of the core protein pool (t1/2 = 32 min). During continuous exposure to 35SO4, 35S-labeled macromolecules accumulated on the cell surface (trypsin-accessible compartment) for 16 h, at which point the cell-surface pool was saturated (t1/2 = 7.5 h). After pulse-labeling the cells with 35SO4 for 15 min, the 35S-labeled macromolecules disappeared continuously from the cell surface (t1/2 = 4.6 h), and 79% of the radioactivity was recovered in the medium as nondialyzable macromolecules. Release of the 35S-labeled macromolecules from the cell surface was abolished at 4 degrees C, indicative of an energy-dependent process, but multiple proteinase inhibitors did not affect the release. We conclude that sulfate is metabolized rapidly into epithelial cell-surface macromolecules, which accumulate continuously into a relatively large cell-surface pool, before they are released by an undefined energy-dependent mechanism.

Selective adhesion of mast cells to tracheal epithelial cells in vitro.

In allergic and nonallergic lung diseases, if intraluminal mast cells adhere to airway epithelium, inflammatory mediators released from activated mast cells may reach high local concentrations and thus greatly affect airway function. To determine whether mast cells adhere to airway epithelial cells, radiolabeled or unlabeled dog mastocytoma cells were incubated with cultured dog tracheal epithelial cells, with extracellular matrix substrates, and with cryostat-cut sections of dog trachea. Mast cells adhered well to cultured epithelial cells (35 +/- 13% adhesion, mean +/- 1 SD, n = 23) but adhered poorly to types I and IV collagen or to fibronectin (less than 7.5% mean adhesion in all cases). Similarly, in tracheal tissue sections, mast cells adhered preferentially to epithelial cells in surface epithelium or in submucosal glands but not to basal membrane or connective tissue. Adhesion to cultured epithelial cells was a characteristics of a subpopulation of mast cells, could persist for more than 48 h, did not require energy or the presence of divalent cations, and was not mediated by a known family of leukocyte-associated adhesion glycoproteins. Adhesion was completely abolished by pretreatment of mast cells with pronase E or proteinase K but not with trypsin (up to 10 micrograms/ml at 37 degrees C for 20 min each). In contrast, pretreatment of cultured epithelial cells with any of these proteinases had no effect on adhesion. It is concluded that dog mastocytoma mast cells adhere to dog tracheal epithelial cells and do so selectively. It is suggested that mast cell adhesion to airway epithelium may play a role in the effectiveness of mast cell-epithelial cell interactions, and thus, in certain lung diseases, airway function may be affected by intraluminal mast cells more than is currently appreciated.

Enkephalinase inhibitors potentiate substance P-induced secretion of 35SO4-macromolecules from ferret trachea.

To study the roles of substance P (SP) and endogenous peptidases in regulating mucus secretion from ferret trachea, we measured the SP-induced release of 35SO4-labeled macromolecules after incubating segments of trachea in Ussing chambers in the presence and absence of selected inhibitors of proteolytic enzymes. Our strategy was based on the idea that if endogenous peptidases degrade SP, then inhibitors of these enzymes should potentiate SP-induced secretion. We found that tracheas of ferrets contained SP-like immunoreactivity, and that SP stimulated the release of bound 35SO4 with rapid onset and offset. Eighty-five percent of the total macromolecular radioactivity released was contained in fractions of molecular weights greater than 10(6). The response to SP was concentration-dependent and reproducible. Thiorphan potentiated the secretory response to SP in a concentration-dependent fashion and phosphoramidon potentiated SP-induced secretion, whereas other inhibitors of proteinases and peptidases were without effects. These results suggest that substance P may regulate mucus secretion in ferrets, and that enkephalinase (dipeptidyl carboxypeptidase II, EC 3.4.24.11) in the airway degrades SP in a physiologically significant fashion, and thereby regulates peptide-induced secretion.

Dog tracheal epithelial cells in culture synthesize sulfated macromolecular glycoconjugates and release them from the cell surface upon exposure to extracellular proteinases.

To determine whether glycoconjugates can be released into airways by surface epithelial cells that do not contain secretory granules and, if so, whether extracellular proteinases can affect this release, we studied dog tracheal epithelial cells after 8-10 days in culture. Ultrastructurally, these cells showed an extensive cell surface coat and no secretory granules. Cells were pulse labeled with radioactive sulfate (Na2 35SO4, 50 microCi/ml/24 h) and washed free of the unbound label. Release of sulfated products was then measured at 20-min intervals under basal conditions and again after 20 min of incubation with various extracellular proteinase. We found that these cells synthesized sulfated products and released them spontaneously and continuously into the medium. In addition, trypsin, Pseudomonas aeruginosa elastase, thermolysin, Staphylococcus aureus proteinase, mast cell chymase, plasmin, and kallikrein (each at 10(-7) M except plasmin, at 5 X 10(-6) M) increased the release of sulfated products to 77-667% over baseline release (p less than 0.01, n = 5 dogs for each); preliminary results showed that human neutrophil elastase was also very potent. The sulfated products released by trypsin had an apparent molecular weight of greater than or equal to 10(6) da as determined by gel filtration on Sepharose Cl-4B. Over 50% of these 35S-labeled products were digested to low-molecular-weight products (500-2000 da) upon incubation with endo-beta-galactosidase or with keratanase, suggesting that they are glycoconjugates containing poly(N-acetyllactosamine)-type carbohydrate chains. Decrease in cell staining by lectins specific for poly(N-acetyllactosamine), which accompanied the release of glycoconjugates, indicates that these sulfated glycoconjugates were released by proteinases from the apical cell surface. We conclude that cultured tracheal epithelial cells synthesize and transport sulfated macromolecular glycoconjugates to apical cell surfaces. These glycoconjugates are released from cell surfaces when exposed to extracellular proteinases. We therefore suggest that macromolecular glycoconjugates in airway secretions can originate not only from secretory granules but also from epithelial cell surfaces during airway inflammation.

Kaposi's sarcoma and angioimmunoblastic lymphadenopathy.

Kaposi's sarcoma (KS) and angioimmunoblastic lymphadenopathy (AILD) are exceptionally rare neoplastic diseases, although the former has recently been more frequently reported among certain populations, and is lately a topic for extensive medical and investigational interest. This case is unique in that it describes an association between KS and AILD. Such an association raises the question of a common pathogenic mechanism. The authors believe that predisposition to each of both diseases may be related to acquired immune deficiency which in turn may be induced by specific viral infections.