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Biomedical subjects

M Suga

Publications and source records attributed to M Suga.

At least 55 records · Page 3Linked to original sources

Characteristic elevation of matrix metalloproteinase activity in idiopathic interstitial pneumonias.

Destruction of subepithelial basement membrane is a key event in the pathogenesis of idiopathic pulmonary fibrosis (IPF). To evaluate the role of matrix metalloproteinases (MMPs) in parenchymal remodeling in idiopathic interstitial pneumonia (IIP), we studied MMP-2 and -9 activity, in bronchoalveolar lavage fluid (BALF) by zymography and the expression of MMP-2 and -9 and TIMP-2 in lung tissue by immunohistochemistry. BALF and lung tissues were collected from 26 patients with usual interstitial pneumonia (IPF-UIP), 11 with nonspecific interstitial pneumonia (NSIP), and 6 with bronchiolitis obliterans organizing pneumonia (BOOP). IPF-UIP cases showed predominant expression of MMP-9, whereas NSIP and BOOP cases showed predominant MMP-2 expression in BALF and in tissues. In BALF samples from rapidly progressive IPF-UIP cases, neutrophil-derived MMP-9 activity, as well as MMP-9 active form were characteristically detected. Furthermore, the MMP-9 activity correlated significantly with an increase of neutrophils in BALF, whereas the MMP-2 activity associated with NSIP and BOOP correlated with an increase of lymphocytes. These results indicate that MMP-9 in IPF-UIP and MMP-2 in NSIP and BOOP may contribute to pulmonary structural remodeling through type IV collagenolytic activity. The characteristic contributions of matrix-degrading proteins may relate to the distinct prognostic features of these diseases.

Adult↗

Dynamic changes in apoptotic and necrotic cell death correlate with severity of ischemia-reperfusion injury in lung transplantation.

Ischemia-reperfusion (IR) injury is a major cause of organ dysfunction following lung transplantation. We have recently described increased apoptosis in transplanted human lungs after graft reperfusion. However, a direct correlation between ischemic time, cell death, and posttransplant lung function has not yet been demonstrated. We hypothesized that an increased ischemic period would lead to an increase in cell death, and that the degree and type of cell death would correlate with lung function. To investigate this, we preserved rat lungs at 4 degrees C for 20 min and 6, 12, 18, and 24 h, and then transplanted the lungs and reperfused them for 2 h. Cell viability was determined with a triple staining technique combining trypan blue, terminal deoxynucleotidyl transferase-uridine nucleotide end-labeling, and propidium iodide nuclear staining. Percentages of apoptotic and necrotic cells were calculated from total cell numbers. Following 20 min and 6 and 12 h of cold preservation, less than 2% of graft cells were dead, whereas after 18 and 24 h of cold preservation, 11% and 27% of cells were dead (p < 0.05), the majority of which were necrotic. After transplantation and reperfusion, the mode of cell death changed significantly. In the 6- and 12-h groups, approximately 30% of cells were apoptotic and < 2% were necrotic, whereas in the 18- and 24-h groups, 21% and 29% of cells, respectively, were necrotic and less than 1% were apoptotic. Lung function (Pa(O(2))) decreased significantly (p < 0.05) with increasing preservation time. The percentage of necrotic cells was inversely correlated with posttransplant graft function (p < 0.0001). The study demonstrates a significant association among cold preservation time, extent and mode of cell death, and posttransplant lung function, and suggests new potential strategies to prevent and treat IR injury.

Animals↗

RANTES plays an important role in the evolution of allograft transplant-induced fibrous airway obliteration.

Although lung transplantation is a widely applied therapeutic modality for end-stage pulmonary disease, the long-term survival following this procedure is limited by the development of bronchiolitis obliterans (BO). We investigated the role of RANTES, a C-C chemokine, in the evolution of fibrous airway obliteration (FAO) using a rat heterotopic tracheal transplant model. RANTES was highly expressed in infiltrating mononuclear cells in both allogeneic and isogeneic grafts as revealed by immunohistochemistry. Using a miniosmotic pump, neutralizing anti-RANTES antibody was locally and continuously infused to allografts, whereas recombinant rat RANTES was administered to isografts. Anti-RANTES antibody treatment decreased the number of CD4(+) infiltrating cells in allotracheas and preserved luminal patency compared with those of allocontrols. However, RANTES infusion in isografts did not induce FAO, even though CD4(+) cell migration was increased by this treatment. It appears that RANTES is relevant to the recruitment of CD4(+) cells and the development of FAO in the process of allorejection. Local administration of anti-RANTES might be a therapeutic option for BO following lung transplantation.

Animals↗

[Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (1998)].

The bacteria isolated from the patients with lower respiratory tract infections were collected by institutions located throughout Japan, since 1981. Ikemoto et al. have been investigating susceptibilities of these isolates to various antibacterial agents and antibiotics, and analyzed some characteristics of the patients and isolates from them each year. Results obtained from these investigations are discussed. In these 18 institutions around the entire Japan, 532 strains of presumably etiological bacteria were isolated mainly from the sputa of 438 patients with lower respiratory tract infections during the period from October in 1998 to September in 1999. MICs of various antibacterial agents and antibiotics were determined against 85 strains of Staphylococcus aureus, 100 strains of Streptococcus pneumoniae, 96 strains of Haemophilus influenzae, 75 strains of Pseudomonas aeruginosa (non-mucoid strains), 6 strains of Pseudomonas aeruginosa (mucoid strains), 38 strains of Moraxella subgenus Branhamella catarrhalis, 26 strains of Klebsiella pneumoniae etc., and the susceptibilities of 517 strains were assessed except for those strains that died during transportation. S. aureus strains for which MICs of oxacillin (MPIPC) were higher than 4 micrograms/ml (methicillin-resistant S. aureus: MRSA) accounted for 60.0%. Vancomycin (VCM) and arbekacin (ABK) showed the most potent activities against MRSA. But one of MRSA showed resistance to ABK with the MIC of 64 micrograms/ml. The sensitive strains of MRSA to VCM have decreased. The frequency of penicillin (PC)-intermediate S. pneumoniae (PISP) + PC-resistant S. pneumoniae (PRSP) have increased in 46.0% for 1998 comparatively from 30.9% of 1997's. But PRSP decreased, and PISP increased into 39.0% of 1998 years from 19.8% of 1997's. Panipenem (PAPM), imipenem (IPM) and faropenem (FRPM) showed the most potent activities against S. pneumoniae with MIC80s of 0.125 microgram/ml or below. Against H. influenzae and M. (B.) catarrhalis, almost all the drugs showed good activities. The sensitive strains of them against ceftazidime (CAZ) decreased in 1997, but those have increased in 1998. Inversely, the susceptibility of them against cefotiam (CTM) had been higher in 1997, but those have been lower in 1998. Tobramycin (TOB) showed the most potent activity against P. aeruginosa (both mucoid and nonmucoid strains). All drugs except ampicillin (ABPC) were active against K. pneumoniae. A quite few of K. pneumoniae showed low susceptibilities. Also, we investigated year to year changes in the characteristics of patients, their respiratory infectious diseases, and the etiology. The examination of age distribution indicated that the proportion of patients with ages over 70 years was 48.6% of all the patients showing a slight increase in every year. About the proportion of diagnosed diseases as follows: Bacterial pneumonia was the most frequent with 40.2%. The ratio of it has increased slightly, and the increased rate was 10% in patients with ages over 70 years compared with the results in 1997. Chronic bronchitis have decreased slightly with 27.6% in 1998. Number of strains isolated from patients before administration of antibiotics were more than those after administration of them in chronic bronchitis, but these were almost same number in bacterial pneumonia. Administration of antibiotics has changed the results of the frequency of isolation of bacterial species. Bacterial isolations before administration of antibiotics were as follows: S. pneumoniae 26.7%, H. influenzae 23.8%, S. aureus 13.3% and M. (B.) catarrhalis 10.8%. The frequencies of S. aureus decreased after antibiotics administration over 15 days, but the frequencies of P. aeruginosa (both mucoid and non-mucoid) was not affected. The frequencies of P. aeruginosa was 45.5% after administration over 15 days. The frequencies of S. pneumoniae decreased upon administration of antibiotics, these were only 4.5% over 15 days. The frequencies of H. (

Anti-Bacterial Agents↗

Sensible human projects: haptic modeling and surgical simulation based on measurements of practical patients with MR elastography--measurement of elastic modulus.

To provide realistic surgical simulation, 3D visualization and haptic feedback are important. In the existing surgical simulators, the fidelity of the deformation and haptic feedback is limited because they are based on the subjective evaluation of the expert-user and not on an objective model-based evaluation. To obtain accurate elastic modulus of whole human tissues, we have started a new project called the Sensible Human Project (SHP). This paper deals with establishing the measurement of elastic modulus by the magnetic resonance elastography (MRE) technique, as a first step of the SHP Project.

Computer Simulation↗

[A case of hypertrophic cranial pachymeningitis developed skull lesion].

We report a case of hypertrophic cranial pachymeningitis (HCP) developed skull lesion. A 70-year-old male presented with the symptom of left hemiconvulsion. MRI revealed that the enhanced intraosseous mass infiltrated into the the dura and brain parenchyma under the parasagittal region of the right parietal bone. Histological examination revealed chronic inflammation with lymphoplasmacytic infiltrate and fibrosis of both intraosseous mass and dural invasive lesion. Steroid therapy resulted in improvement of clinical symptoms and enhanced lesion of MRI. Three years later, the patient presented with generalized convulsion and weakness of right upper and lower limbs. MRI revealed dural thickening with gadolinium enhancement in the bilateral parasagittal region and falx. Angiography showed occlusion of the superior sagittal sinus. The cause of relapsing symptoms in this patient may have been related to the occlusion of the superior sagittal sinus, due to HCP. We considered that the incipient intraosseous mass resulted from a response of the marrow by destructive progression of chronic inflammation passed through the fracture crack or the cavity of arachnoid granulation.

Aged↗

Regulated CD44 cleavage under the control of protein kinase C, calcium influx, and the Rho family of small G proteins.

CD44 is a cell surface receptor for several extracellular matrix components and is implicated in tumor cell invasion and metastasis. Our previous studies have shown that CD44 expressed in cancer cells is proteolytically cleaved at the extracellular domain through membrane-associated metalloproteases and that CD44 cleavage plays a critical role in CD44-mediated tumor cell migration (Okamoto, I., Kawano, Y., Tsuiki, H., Sasaki, J., Nakao, M., Matsumoto, M., Suga, M., Ando, M., Nakajima, M., and Saya, H. (1999) Oncogene 18, 1435-1446). In the present study, we first demonstrate rapid degradation of the membrane-tethered CD44 cleavage product through intracellular proteolytic pathways, and it occurs only after CD44 extracellular cleavage. To address the mechanisms regulating CD44 cleavage at the extracellular domain, we show that 12-O-tetradecanoylphorbol 13-acetate (TPA) and the calcium ionophore ionomycin rapidly enhance metalloprotease-mediated CD44 cleavage in U251MG cells via protein kinase C-dependent and -independent pathways, respectively, suggesting the existence of multiple distinct pathways for regulation of CD44 cleavage. Concomitant with TPA-induced CD44 cleavage, TPA treatment induces redistribution of CD44 and ERM proteins (ezrin, radixin, and moesin) to newly generated membrane ruffling areas. Treatment with lysophosphatidic acid, which is known to activate the Rho-dependent pathway, inhibits TPA-induced CD44 redistribution and CD44 cleavage. Furthermore, overexpression of Rac dominant active mutants results in the redistribution of CD44 to the Rac-induced ruffling areas and the enhancement of CD44 cleavage. These results suggest that the Rho family proteins play a role in regulation of CD44 distribution and cleavage.

Calcium↗

N-Nitrosodi-n-propylamine induces organ specific mutagenesis with specific expression times in lacZ transgenic mice.

The mutagenic and clastogenic effects of N-nitrosodi-n-propylamine (NDPA) in lacZ transgenic mice (MutaMouse) were investigated as a part of the second collaborative study of the transgenic mouse mutation assay by a subgroup of the Mammalian Mutagenesis Study Group, a suborganization of the Environmental Mutagen Society of Japan. Male MutaMouse mice were administered NDPA intraperitoneally at a dose of 250 mg/kg, which is half of the LD(50) of the compound. The clastogenicity of NDPA was examined by the peripheral blood micronucleus test just before and at 24, 48 and 72 h after the treatment. The mutant frequencies in the bone marrow, liver, lung, kidney and urinary bladder were examined by the positive selection method for lacZ kidney. These findings demonstrate that NDPA induces organ-specific mutagenesis with specific expression times, and that the mutagenicity of NDPA in lacZ transgenic mice is consistent with its carcinogenicity.

Animals↗

Induction of cell shape changes through activation of the interleukin-3 common beta chain receptor by the RON receptor-type tyrosine kinase.

The RON receptor-type tyrosine kinase, a member of the hepatocyte growth factor receptor family, is a receptor for macrophage-stimulating protein (MSP). Recently, we observed that MSP induces morphological changes in interleukin (IL)-3-dependent Ba/F3 cells ectopically expressing RON. We show here that stimulation of those cells with either MSP or IL-3 increases tyrosine phosphorylation of proteins of 130, 110, 90, 62, and 58 kDa and induces similar morphological changes, accompanied by unique nuclear shape and redistribution of F-actin. A tyrosine kinase inhibitor, genistein, blocked both the increase in tyrosine phosphorylation and morphological changes. Upon stimulation with either MSP or IL-3, prominent tyrosine-phosphorylated pp90 was similarly co-immunoprecipitated with the common beta chain of IL-3 receptor (betac). Unlike IL-3, stimulation with MSP increased tyrosine phosphorylation of betac without activation of JAK2, resulting in morphological changes with modest cell growth. Confocal immunofluorescence analyses showed colocalization of RON, betac, and tyrosine-phosphorylated proteins. In vitro kinase assays revealed that autophosphorylated RON phosphorylated betac. These results suggest that the signaling pathway for morphological changes through betac and its associated protein pp90 is distinct from the pathway for cell growth in the IL-3 signal transduction system.

Actins↗

Structural organization of the human Elk1 gene and its processed pseudogene Elk2.

In the ets gene family of transcription factors, ELK1 belongs to the subfamily of Ternary Complex Factors (TCFs) which bind to the Serum Response Element (SRE) in conjunction with a dimer of Serum Response Factors (SRFs). The primary structure of the human Elk1 gene was determined by genomic cloning. The gene structure of Elk1 spans 15.2 kb and consists of seven exons and six introns. The coding sequence resides on exons 3, 4, 5, 6 and 7. Sequencing of cDNA clones isolated from human hippocampus library revealed that the second exon was often skipped by an alternative splicing event. All introns commenced with nucleotides GT at the 5' boundary and ended with nucleotides AG at the 3' boundary, in agreement with the proposed consensus sequence for intron spliced donor and acceptance sites. Sequence inspection of the 5'-flanking region revealed the absence of a 'TATA' box and the presence of putative cis-acting regulatory elements such as Sp1, GATA-1, CCAAT, and c-Myb. Moreover, the sequence analysis of Elk2 locus on 14q32.3 confirmed that Elk2 gene corresponds to a processed pseudogene of Elk1 which has been reported between alpha 1 gene (IGHA1) and pseudo gamma gene (IGHGP) of immunoglobulin heavy chain. Furthermore, the results of Southern analysis using DNAs from human-mouse hybrid cell lines carrying a part of 14q32 region revealed that there is another locus hybridizing to Elk1 cDNA on 14q32.2 --> qter region in addition to Elk2 locus between IGHA1 and IGHGP loci.

Alternative Splicing↗

CD44 cleavage induced by a membrane-associated metalloprotease plays a critical role in tumor cell migration.

CD44 is a cell surface receptor for hyaluronate, a component of the extracellular matrix (ECM). Although CD44 has been implicated in tumor invasion and metastasis, the molecular mechanisms remain to be elucidated. Here we find that CD44 expressed in cancer cells is cleaved at the membrane-proximal region of the ectodomain and the membrane-bound cleavage product can be detected using an antibody against the cytoplasmic domain of CD44. Furthermore, we report that CD44 cleavage is mediated by a membrane-associated metalloprotease expressed in cancer cells. A tissue inhibitor of metalloproteases-1 (TIMP-1), as well as metalloprotease inhibitors, inhibit CD44 cleavage in the cell-free assay. Contrary, serine protease inhibitors enhance CD44 cleavage, and the enhancement can be prevented by pretreatment with a metalloprotease inhibitor. Thus, CD44 cleavage is regulated by an intricate balance between some proteases and their inhibitors. Interestingly, treatment with the metalloprotease blocker 1,10-phenanthroline, which strongly prevent the CD44 cleavage, suppressed RERF-LC-OK lung cancer cell migration on a hyaluronate substrate, but not on several other substrates. These results suggest that CD44 cleavage plays a critical role in an efficient cell-detachment from a hyaluronate substrate during the cell migration and consequently promotes CD44-mediated cancer cell migration. Our present data indicate that CD44, not only ECM per se, is one of the targets of pericellular proteolysis involved in tumor invasion and metastasis.

Amino Acid Sequence↗

Keyhole method for high-speed human cardiac cine MR imaging.

Although electrocardiographic (ECG)-gated magnetic resonance (MR) imaging is widely used for cardiac imaging, it has several disadvantages, such as long imaging time, respiratory artifacts, and motion artifacts induced by arrhythmia. An MR image can be acquired within about 0.3 seconds by using a fast gradient-echo imaging method. When this method is continuously applied, only two to three images can be obtained during a single cardiac cycle. The goal of this study is to obtain cine MR images in a single cardiac cycle using fast gradient-echo imaging combined with the "keyhole" method. The optimal conditions for the keyhole method for cardiac cine imaging were obtained by computer simulation based on a simplified cardiac model. When the read-out direction was set parallel to the cardiac short axis, left ventricular motion was almost correctly reproduced by the keyhole method with acquisition time reduced to one-fourth. J. Magn. Reson. Imaging 1999;10:778-783.

Computer Simulation↗

Functional roles of MCP-1 in Propionibacterium acnes-induced, T cell-mediated pulmonary granulomatosis in rabbits.

The immunological manifestation of granuloma formations in humans largely depends on the delayed-type hypersensitivity response. We investigated the involvement of monocyte chemoattractant protein-1 (MCP-1) in a rabbit model of T cell-mediated pulmonary granulomatosis. Intravenous injection of Propionibacterium acnes (P. acnes) into sensitized rabbits induced massive and diffuse pulmonary granulomas. Levels of MCP-1 in sera and bronchoalveolar lavage fluids (BALF) peaked before the granuloma formation reached the peak (on days 1 and 3 after challenge, respectively). Chemotactic activities toward monocytes and T cells in BALF were inhibited by anti-MCP-1 IgG by 80 and 36%, respectively. The phenotypic analysis of the migrating T cells revealed that activated and memory T cells rather than naive cells were preferentially attracted to the BALF. Administration of anti-MCP-1 antiserum inhibited the development of granuloma formation in both size and number, the numbers of infiltrating leukocytes in BALF, the expression of adhesion molecules on peripheral monocytes/T cells, and on macrophages/T cells in BALF, and the production of TNF-alpha in the lung. Anti-MCP-1 resulted in a trend toward decreased level of IL-1beta in the lung. The inhibition of the production of these cytokines appeared to be induced indirectly through the inhibition of the recruitment of macrophages that produce these cytokines. The results suggest important roles of MCP-1 in the development of granuloma formation in this model through the attraction and activation of specific types of cells.

Animals↗

Chronic hypersensitivity pneumonitis in Japan: a nationwide epidemiologic survey.

BACKGROUND: Pulmonary fibrosis inevitably develops in patients with chronic hypersensitivity pneumonitis (HP). OBJECTIVE: We conducted a nationwide epidemiologic study in Japan to evaluate the frequency and clinical characteristics of chronic HP. METHODS: This report is on 36 cases of chronic HP, including 10 patients with summer-type HP, 5 patients with home-related HP, 7 patients with bird fancier's lung, 5 patients with isocyanate-induced HP, 4 patients with farmer's lung, and 5 patients with other types of chronic HP. Chronic HP was further subgrouped into 2 types: one type of patients were first seen with chronic disease (9 patients), and the other type became chronic with fibrosis after repeated acute episodes (27 patients). RESULTS: The upper lung field was frequently involved in chronic HP (17%). Ground-glass opacities were observed in 57% and air space consolidation in 30% of the patients. Honeycombing was apparent in 37%. Twenty-six of 28 patients had antibodies to the presumptive antigens. Five of 8 patients with chronic HP were positive for antigen-induced lymphocyte proliferation. In 2 cases patients did not have detectable antibodies to causative antigens, although antigen-induced lymphocyte proliferation was detectable. The ratio of CD4 to CD8 in BAL lymphocytes was lowest in isocyanate-induced HP (mean 0.22) and tended to be high in farmer's lung and bird fancier's lung. Granulomas were observed in 39% and Masson bodies in 42% of specimens on histologic examination. Administration of prednisolone was effective in 58% of patients. CONCLUSIONS: The insidious form of chronic HP has probably been misdiagnosed as idiopathic pulmonary fibrosis when a good history was not taken and immunologic (especially antigen-induced lymphocyte proliferation) and BAL testing were not counted.

Aged↗

Clinical significance of MCP-1 levels in BALF and serum in patients with interstitial lung diseases.

It has previously been reported that the expression of monocyte chemoattractant protein-1 (MCP-1) in the lung tissues of patients with idiopathic pulmonary fibrosis (IPF) was different from that in the tissues of patients with other interstitial lung diseases (ILDs). The aim of this study was to determine whether this difference reflects the amount of MCP-1 in the bronchoalveolar lavage fluid (BALF) or serum of patients with ILD, and whether such a correlation, if it exists, is clinically useful. MCP-1 concentrations in the BALF and sera were evaluated in 86 patients with ILDs including IPF, acute interstitial pneumonia, interstitial pneumonia with collagen vascular disease (IP-CVD), chronic interstitial pneumonia (CIP), bronchiolitis obliterans-organizing pneumonia, sarcoidosis, hypersensitivity pneumonitis, and in 10 normal healthy volunteers who were controls (NC). BALF MCP-1 levels were significantly elevated in the IPF, IP-CVD, CIP and sarcoidosis groups compared with the NC group. The level in the IPF group was significantly higher than that in any other patient group. Serum MCP-1 levels in the IPF, IP-CVD, CIP and sarcoidosis groups were significantly higher than the NC group. No statistical difference was found in serum MCP-1 levels between the IPF, IP-CVD and CIP groups. BALF MCP-1 levels were significantly higher than serum MCP-1 levels in the IPF group and lower than in the IP-CVD and CIP groups. Serum MCP-1 levels correlated with the clinical course of ILD treated with corticosteroid therapy. These results show that measurement of monocyte chemoattractant protein-1 levels in both bronchoalveolar lavage fluid and serum may be helpful in discriminating idiopathic pulmonary fibrosis from other types of interstitial lung disease and that monitoring of serum monocyte chemoattractant protein-1 may be useful for predicting the clinical course of interstitial lung diseases.

Adrenal Cortex Hormones↗

Elevated bronchoalveolar concentrations of MCP-1 in patients with pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis (PAP) is a rare disease of unknown aetiology characterized by accumulations of lipoproteinaceous material within the alveoli. The alveolar macrophages become increasingly foamy, and are thought to have a role in the pathogenesis of PAP. However, the mechanisms of macrophage recruitment are unclear. In the bronchoalveolar lavage fluid (BALF) of four patients with PAP and 20 normal control subjects, the following were examined: the monocyte chemotactic activity due to the chemokine monocyte chemoattractant protein (MCP)-1 with the use of a chemotactic chamber assay, the levels of MCP-1 by enzyme-linked immunosorbent assay, and the MCP-1 expression on lavage cells by immunocytochemistry and in situ hybridization. The monocyte chemotactic activity in the BALF of the PAP patients was markedly elevated, and the activity was completely absorbed by treatment with anti-MCP-1. The MCP-1 levels in the BALF were surprisingly high in the PAP group (25,100+/-472 pg x mL(-1)), whereas low levels of MCP-1 were detected in the normal control subjects (mean: never smokers 4.8; smokers 10.4 pg x mL(-1)). MCP-1 protein and messenger ribonucleic acid were expressed by macrophages from the PAP patients, and the expression was reduced according to foaming of the cells; there were monocyte-like macrophages with strong expression, small foamy cells with moderate expression, large foamy cells with a faint expression of MCP-1, and ghost cells with no expression. However, the increase of macrophage number in the PAP BALF was relatively small. These data suggest that monocyte chemoattractant protein(-1) expression by alveolar macrophages represents an amplification mechanism for the recruitment of additional macrophages to the alveoli in pulmonary alveolar proteinosis. It is possible that an ingestion of an excess of alveolar materials in pulmonary alveolar proteinosis may impair the macrophage function and the survival, resulting in the lack of a prominent increase in the macrophage number in bronchoalveolar lavage fluid.

Adult↗