Pulmonary alveolar proteinosis in rats after administration of quartz: its possible role in morphogenesis of lung cancer

Pulmonary alveolar proteinosis complicated by lung cancer with favorable prognosis: a case report and literature review

With the increasing incidence of lung cancer, the coexistence of pulmonary alveolar proteinosis (PAP) and lung cancer is becoming more common. However, the standard treatment protocols for patients with both conditions are still being explored. The conflict between the rapidly evolving therapeutic approaches for tumors and the limited treatment options for PAP presents a significant challenge for clinicians. Determining the optimal timing of treatment for both conditions to maximize patient benefit is a clinical conundrum. Here, we report a rare case of PAP complicated by lung adenocarcinoma, where interstitial lung changes worsened after neoadjuvant therapy but improved significantly following surgical resection of the lung adenocarcinoma. This case highlights the importance of prioritizing tumor treatment in patients with lung cancer complicated by PAP and examines the interplay between the two conditions, as well as potential therapeutic strategies.

Identification of a Gene Signature Predicting (Nano)Particle-Induced Adverse Lung Outcome in Rats

Nanoparticles are extensively used in industrial products or as food additives. However, despite their contribution to improving our quality of life, concerns have been raised regarding their potential impact on occupational and public health. To speed up research assessing nanoparticle-related hazards, this study was undertaken to identify early markers of harmful effects on the lungs. Female Sprague Dawley rats were either exposed to crystalline silica DQ-12 with instillation, or to titanium dioxide P25, carbon black Printex-90, or multi-walled carbon nanotube Mitsui-7 with nose-only inhalation. Tissues were collected at three post-exposure time points to assess short- and long-term effects. All particles induced lung inflammation. Histopathological and biochemical analyses revealed phospholipid accumulation, lipoproteinosis, and interstitial thickening with collagen deposition after exposure to DQ-12. Exposure to the highest dose of Printex-90 and Mitsui-7, but not P25, induced some phospholipid accumulation. Comparable histopathological changes were observed following exposure to P25, Printex-90, and Mitsui-7. Comparison of overall gene expression profiles identified 15 potential early markers of adverse lung outcomes induced by spherical particles. With Mitsui-7, a distinct gene expression signature was observed, suggesting that carbon nanotubes trigger different toxicity mechanisms to spherical particles.

The First Case of Pulmonary Alveolar Proteinosis With Small Cell Lung Carcinoma

Pulmonary alveolar proteinosis (PAP) is a rare pulmonary disease characterized by alveolar accumulation of surfactant lipids and proteins. It is usually autoimmune and secondary to hematologic malignancy or infection. To date, only 5 case reports of PAP associated with lung cancers, including 2 cases of squamous cell carcinoma and 3 cases of adenocarcinoma, have been published. To the best of our knowledge, no case of PAP with small cell lung carcinoma has been reported thus far. We herein report the first case of PAP associated with small cell lung carcinoma.

An intratracheal instillation bioassay system for detection of lung toxicity due to fine particles in f344 rats

It is an urgent priority to establish in vivo bioassays for detection of hazards related to fine particles, which can be inhaled into deep lung tissue by humans. In order to establish an appropriate bioassay for detection of lung damage after particle inhalation, several experiments were performed in rats using quartz as a typical lung toxic particle. The results of pilot experiments suggest that Days 1 and 28 after intratracheal instillation of 2 mg of fine test particles in vehicle are most appropriate for detection of acute and subacute inflammatory changes, respectively. Furthermore, the BrdU incorporation on Day 1 and the iNOS level on Day 28 proved to be suitable end-point markers for this purpose. An examination of the toxicity of a series of particles was performed with the developed bioassay. Although some materials, including nanoparticles, demonstrated toxicity that was too strong for sensitive assessment, a ranking order could be clarified. The bioassay thus appears suitable for rapid hazard identification with a possible ranking of the toxicity of various particles at single concentrations.

Lung cancer may develop subsequently or coincidently with pulmonary alveolar proteinosis

Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by an accumulation of periodic acid-Schiff (PAS) positive lipoproteinaceous material in the alveolar space. It is usually idiopathic, and secondary to hematologic malignancy or some atypical infection. To date, there are only five published case reports of PAP occurring in association with solid organ cancer. We herein report two cases of PAP associated with lung cancer: one, a case of idiopathic PAP with subsequent development of lung cancer, and the other, a case of coexisting lung cancer and PAP. In conclusion, PAP can occur prior to or coincidently with lung cancer.

Bioassay by intratracheal instillation for detection of lung toxicity due to fine particles in F344 male rats

We have established and documented an in vivo bioassay for detection of hazards with intratracheally instilled fine particles, which can be used for risk assessment of toxicity of materials inhaled into deep lung tissue of humans (Yokohira et al. Establishment of a bioassay system for detection of lung toxicity due to fine particle instillation: sequential histopathological changes with acute and subacute lung damage due to intratracheal instillation of quartz in F344 male rats. J Toxicol Pathol 2005;18:13-8). For validation we here examined toxicity of fine particles from quartz, hydrotalcite, potassium octatitanate, palladium oxide and carbon black with this bioassay. A total of 108, 10-week-old F344/DuCrj male rats were randomly divided into 8 groups. Groups 1 to 5 underwent intratracheal instillation of the 5 test particles (4 mg/rat) suspended in 0.2 ml vehicle (saline or 10% propylene glycol and 1% sodium carboxymethyl cellulose in saline: PG-CMC) with a specially designed aerolizer, and subgroups of 7 rats were killed on Days 1 and 28 thereafter. Groups 6 and 7 similarly were exposed to saline and PG-CMC, respectively, as vehicle controls, while group 8 was maintained untreated. Using histopathological changes and immunohistochemically assessed bromodeoxyuridine (BrdU) labeling indices, inducible nitric oxide synthase (iNOS) and matrix metalloproteinase-3 (MMP-3) levels as end points, the quartz treated group exhibited high toxicity, while the values for the other particle-treated groups pointed to only slight effects. Although additional efforts are needed to establish advantages and disadvantages with our bioassay, models featuring intratracheal instillation clearly can be useful for detection of acute or subacute lung toxicity due to inhaled fine particles by using histopathological scoring and markers like BrdU and iNOS for screening purposes in short-term studies.

Needle crystals of vitamin B2 induce polyploidy in Chinese hamster lung (CHL/IU) cells

Induction of polyploidy by vitamin B2 (VB2) was investigated in cultured Chinese hamster lung (CHL/IU) cells. We report that VB2 in the form of needle crystals induces polyploidy via the formation of CHL/IU cells with more than one nucleus. The incidence of polyploid cells depended on the amount of needle crystals. No induction of polyploidy was observed when VB2 was used in solution. Electron-microscopic examination revealed that needle crystals adhered to the cell surface, and were enclosed by viscous cellular materials. These results indicate that needle crystals of VB2 have the ability to induce polyploidy in cultured CHL/IU cells, probably by physically fixing the shape of the cells and by this preventing normal mitosis.

Up-regulation of antigens on alveolar macrophages in quartz exposed rats

We have analysed the expression of the OX-6 and OX-42 antigens on alveolar macrophages in rats after intratracheal exposure to quartz. Eight female Sprague Dawley rats were included in the study. Four were exposed to physiological saline and four to quartz dust. The rats were sacrificed after 58 +/- 2 weeks and alveolar macrophages were harvested and analysed by flow cytometry. We found a significant higher amount of both antigens on alveolar macrophages harvested from quartz exposed rats. However, we did not find any significant difference in the percentage positive labeled cells between the two groups. We conclude that quartz dust induces up-regulation of functional receptors on alveolar macrophages in rats and that quantitative analysis of these receptors may serve as inflammatory markers in the bronchoalveolar space.