Pneumoconiosis was diagnosed by open lung biopsy in two dental technicians who had interstitial lung disease. Mineralogical analysis was performed to investigate the origin of the dust that had been inhaled. A marked accumulation of silicon and phosphorus was found in both cases. The hard metals chromium and cobalt were also found. Dental technician's pneumoconiosis is a complex pneumoconiosis in which such dust and hard metals may play a role.
Adult ; *Dental Technicians ; Human ; Lung/pathology ; Lung Diseases, Interstitial/*diagnosis/metabolism ; Male ; Minerals/metabolism ; Occupational Diseases/*diagnosis/metabolism ; Pneumoconiosis/*diagnosis/metabolism ; Radiography, Thoracic ; Tomography, X-Ray Computed

Extracellular vesicles (EVs) are anuclear particles composed of lipid bilayers that contain nucleic acids, proteins, lipids, and organelles. EVs act as an important mediator of cell-to-cell communication by transmitting biological signals or components, including lipids, proteins, messenger RNAs, DNA, microRNAs, organelles, etc, to nearby or distant target cells to activate and regulate the function and phenotype of target cells. Under physiological conditions, EVs play an essential role in maintaining the homeostasis of the pulmonary milieu but they can also be involved in promoting the pathogenesis and progression of various respiratory diseases including chronic obstructive pulmonary disease, asthma, acute lung injury/acute respiratory distress syndrome, idiopathic pulmonary fibrosis (IPF), and pulmonary artery hypertension. In addition, in multiple preclinical studies, EVs derived from mesenchymal stem cells (EVs) have shown promising therapeutic effects on reducing and repairing lung injuries. Furthermore, in recent years, researchers have explored different methods for modifying EVs or enhancing EVs-mediated drug delivery to produce more targeted and beneficial effects. This article will review the characteristics and biogenesis of EVs and their role in lung homeostasis and various acute and chronic lung diseases and the potential therapeutic application of EVs in the field of clinical medicine.
DNA/metabolism* ; Extracellular Vesicles/metabolism* ; Humans ; Lipid Bilayers/metabolism* ; Lung Diseases/therapy* ; Lung Injury/metabolism* ; MicroRNAs/metabolism* ; Proteins/metabolism* ; Respiratory Distress Syndrome

Mucociliary clearance system is the primary innate defense mechanism of the lung. It plays a vital role in protecting airways from microbes and irritants infection. Mucociliary clearance system, which is mediated by the actions of airway and submucosal gland epithelial cells, plays a critical role in a multilayered defense system via secreting fluids, electrolytes, antimicrobial and anti-inflammatory proteins, and mucus onto airway surfaces. Changes in environment, drugs or diseases can lead to mucus overproduction and cilia dysfunction, which in turn decrease the rate of mucociliary clearance and enhance mucus gathering. The dysfunction of mucociliary clearance system often occurs in several respiratory diseases, such as primary ciliary dysfunction, cystic fibrosis, asthma and chronic obstructive pulmonary disease, which are characterized by goblet cell metaplasia, submucosal gland cell hypertrophy, mucus hypersecretion, cilia adhesion, lodging and loss, and airway obstruction.
Humans ; Mucociliary Clearance ; Respiratory Tract Diseases ; Pulmonary Disease, Chronic Obstructive/metabolism* ; Mucus/metabolism* ; Lung ; Respiratory System

Histiocytosis, Sinus ; diagnosis ; metabolism ; Humans ; Immunohistochemistry ; Lung Diseases ; diagnosis ; metabolism ; Male ; Middle Aged

OBJECTIVEResolution of alveolar damage after lung injury requires finely orchestrated processes that include coordinated and effective tissue reconstruction to reestablish a functional barrier. Reconstitution of denuded type I alveolar epithelial cell that undergo apoptotic and necrotic death after lung injury is required in many pulmonary diseases. Disruption of distal airway development and type II-type I alveolar epithelial cell differentiation after lung injury and disordered repair of the alveolus after injury is one of the predominant pathological characteristics of chronic lung disease (CLD) of premature infants. HoxB5 belongs to the Hox gene family encoding transcription factors known for their role in skeletal patterning and the elaboration of organs. HoxB5 is required for embryonic respiratory tract morphogenesis. The present study aimed to test the hypothesis that HoxB5 may participate in the etiology of CLD and to understand possible mechanism.

METHODSPremature rat pups were taken out surgically at gestational age 21 d. CLD was induced by hyperoxia exposure in neonatal premature rats. Eighty premature rats were randomly exposed to hyperoxia (FiO2 = 0.90, CLD group) and to room air (FiO2 = 0.21, control group) (n = 40 each). Lung specimens were obtained respectively on days 1, 3, 7, 14 and 21 after exposure. Histopathologic changes was assayed after hematoxylin and eosin (HE) staining and pulmonary development was evaluated by lung coefficient and radical alveolar counts (RAC), dynamic changes of RAC were observed; and the expression of HoxB5, AQP-5, and SP-B mRNA were assayed by reverse transcription polymerase chain reaction (RT-PCR).

RESULTSThere were no significant differences in the RAC and the expression level of HoxB5, AQP-5, and SP-B mRNA between the CLD and the control groups within 3 days after birth (P > 0.05). However, compared to the control group, the RAC of the CLD group was reduced (6.35 +/- 0.83 vs. 7.67 +/- 0.52), and the expression of HoxB5 (0.98 +/- 0.14 vs. 1.20 +/- 0.16), AQP-5 (0.78 +/- 0.11 vs. 1.04 +/- 0.19) mRNA were significantly lower (P < 0.05), while the expression of SP-B mRNA was increased on the 7th day (P < 0.05). On the 14th day, the RAC and the expression of HoxB5, AQP-5 mRNA of CLD group were significantly lower than those of the control group (P < 0.05), and the expression of SP-B mRNA continued to increase (P < 0.05). On the 21st day, the expression of HoxB5, AQP-5 mRNA decreased to the nadir (0.64 +/- 0.11 vs. 1.18 +/- 0.13 and 0.67 +/- 0.12 vs. 0.97 +/- 0.01, respectively) (P < 0.01), on the same day the expression of SP-B mRNA reached to the pinnacle (1.43 +/- 0.07 vs. 1.12 +/- 0.09) (P < 0.01). The expression of HoxB5 mRNA was positively correlated with RAC in the CLD group (r = 0.685, P < 0.01).

CONCLUSIONSWith hyperoxia exposure, the mRNA expression of specific marker of type I alveolar epithelial cell, AQP-5, was decreased while specific marker of type II alveolar epithelial cell, SP-B, was increased; and the expression of HoxB5 mRNA in lung tissues kept on decreasing. Decreased expression of HoxB5 may associate with the disruption of type II-I alveolar epithelial cell differentiation and thus may play an important role in inhibition of lung development with CLD. The altered Hox gene expression may predispose lung pathology.

Animals ; Animals, Newborn ; Female ; Homeodomain Proteins ; genetics ; metabolism ; Hyperoxia ; complications ; Lung ; growth & development ; metabolism ; pathology ; Lung Diseases ; etiology ; metabolism ; pathology ; Pregnancy ; RNA, Messenger ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the effect of melatonin, a potent antioxidant both in vitro and in vivo, on hyperoxia-induced oxidant/antioxidant imbalance in the lung of neonatal rats with chronic lung disease (CLD).

METHODSNinety neonatal rats were randomly divided into three groups (n=30 each): air-exposed, hyperoxia-exposed, melatonin-treated (4 mg/kg melatonin was administered 30 minutes before hyperoxia exposure and once daily after exposure). CLD was induced by hyperoxia exposure (FiO2=0.85). Lung specimens were obtained 3, 7, and 14 days after exposure (n=10 each) for histopathologic examination. The levels of total antioxydase capacity (T-AOC), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), myeloperoxidase (MPO), catalase (CAT), nitrite/nitrate, and malondialdehyde (MDA) in the lung were assayed by the spectrophotometer.

RESULTSThe histopathologic examination showed that lung damage was obviously alleviated in the melatonin-treated group. The levels of T-AOC, GSH-Px, SOD and CAT in the lung were significantly higher in the melatonin-treated group than those in the other two groups at all time points (p<0.05). The levels of MPO, nitrite/nitrate and MDA in the lung increased significantly in the untreated hypoxia-exposed group compared with those in the air-exposed group at all time points (p<0.05 or 0.01), while the levels of MPO, nitrite/nitrate and MDA in the melatonin-treated group were significantly reduced as compared with the untreated hypoxia-exposed group (p<0.05).

CONCLUSIONSMelatonin may reverse oxidant/antioxidant imbalance in hyperoxia-induced lung disease, thus providing a protective effect against CLD in neonatal rats.

Animals ; Animals, Newborn ; Antioxidants ; pharmacology ; Chronic Disease ; Female ; Hyperoxia ; metabolism ; Lung ; metabolism ; Lung Diseases ; metabolism ; Male ; Malondialdehyde ; analysis ; Melatonin ; pharmacology ; Nitric Oxide ; analysis ; Peroxidase ; metabolism ; Rats ; Rats, Wistar

OBJECTIVE: To determine the dynamic expression of E2F1 in lung of premature rats with hyperoxia-induced chronic lung disease and the relation between E2F1 and pulmonary fibrosis. METHODS: Premature Wistar rats at 21 days gestation were randomly and equally divided into a hyperoxia group and a room air group. The hyperoxia group was continuously exposed to hyperoxia (90%) while the air group in room air. Lung tissues in the 2 groups were obtained at 3, 7 and 14 days after exposing to either room air or hyperoxia. The changes of pulmonary histopathology at different time points were observed by hematoxylin and eosin staining; the severity of pulmonary fibrosis was evaluated; and the expression of E2F1 in lung tissue was detected by immunohistochemistry and Western blot. RESULTS: After 3 days of hyperoxia, no significant interstitial fibrosis was observed; while after 7 days in the hyperoxia group, interstitial fibrosis was observed. These changes became more obvious after 14 days of prolonged hyperoxia exposure. No significant difference in the expressions of E2F1 protein was found between the hyperoxia group and the room air group 3 days postnatally (P>0.05). The expression of E2F1 in the hyperoxia group significantly increased 7 days and 14 days postnatally (P<0.05, P<0.01). CONCLUSION Abnormality of E2F1 expression is involved in the pathological process of the proliferation of lung fibroblasts in hyperoxia-induced chronic lung disease neonatal rats, and it plays an important role in lung fibrosis.
Animals ; Animals, Newborn ; E2F1 Transcription Factor ; metabolism ; Hyperoxia ; metabolism ; pathology ; Immunohistochemistry ; Lung ; pathology ; Lung Diseases ; metabolism ; pathology ; Pulmonary Fibrosis ; Rats ; Rats, Sprague-Dawley ; Rats, Wistar

To explore the mechanism of Notch in hyperoxia-induced preterm rat lung injury, 2-days-old preterm SD rats were randomized into control and hyperoxia group (FiO2 > or = 0.85). On day 1, 7, 14 and 21, 8 rat pups of each time point were used to assess histopathological changes of lung with HE staining and to evaluate the expression of Notch1 and Notch3 with immunohistochemistry. Notch1, Notch3, Aquaprin5 (AQP5) and surfactant protein C (SP-C) mRNA were measured by reverse transcription polymerase chain reaction (RT-PCR). The results showed that the lung injury in the hyperoxia group was characterized by retarded lung alveolization and differentiation of alveolar epithelial type II cells (AEC II). Positive staining of Notch1 in hyperoxia group was weaker than controls at every time point (except for day 7), while positive staining of Notch3 was much stronger (P < 0.05, P < 0.01). Notch1, Notch3 mRNA level showed similar change as protein level. AQP5, SP-C mRNA decreased significantly as compared with that of the controls (P < 0.01). We are led to conclude that hyperoxia results in abnormal expression of Notch, which is likely to contribute to the pathogenesis of lung injury through regulating proliferation and transdifferentiation of alveolar epithelial cells.
Aerobiosis ; Animals, Newborn ; Lung/*pathology ; Lung Diseases/etiology ; Lung Diseases/*metabolism ; Lung Diseases/pathology ; RNA, Messenger/biosynthesis ; RNA, Messenger/genetics ; Random Allocation ; Rats, Sprague-Dawley ; Receptors, Notch/*biosynthesis ; Receptors, Notch/genetics

To investigate role of Notch1 - 3 in hyperoxia-induced lung injury in newborn rat exposed to 85% O2, SD rat litters born on the 22th day were randomly divided into two groups: room air group and hyperoxia group. The animals were sacrificed 1, 4, 7, 10, 14 and 21 days after continued exposure to oxygen (n = 40, oxygen > 0.85) or room air (n = 40). 6 rats each group were used to assess lung histological changes by HE staining and expression of Notch in lungs by immunohistochemistry. Total RNA was extracted by Trizol reagent from frozen lung tissues. Notch mRNA were measured by reverse transcription polymerase chain reaction (RT-PCR). Our results showed that 7, 14 and 21 days after O2 exposure, hyperoxia group showed lung injury characterized by pulmonary edema, hemorrhage and lung development arrest. Positive staining for Notch1, Notch 2 in hyperoxia group was much lower than those in room air group at all time points (P < 0. 01, P < 0.05), but compared with the controls, the hyperoxia group showed higher expression of Notch3 (P > 0.05). Immunostained cells were typically airways epithelia, alveolar epithelial and inflammatory cells, and fibroblasts in hyperoxia group (P < 0.01). Notch mRNA levels showed similar change as protein level (P < 0.01). It is concluded that the prolonged exposure to 85% O2 resulted in abnormal expression of Notch receptors, which might contribute to the pathogenesis of hyperoxia-induced lung injury in newborn rats. The decreased inhibition of Notch1 might be one of the protective reaction and major mechanisms for proliferation/differentiation of type II alveolar epithelial cells. The up-regulation of Notch3 activity might result in the lung development arrest of the newborn rats.
Aerobiosis ; Animals, Newborn ; Lung/*pathology ; Lung Diseases/etiology ; Lung Diseases/*metabolism ; Lung Diseases/pathology ; RNA, Messenger/biosynthesis ; RNA, Messenger/genetics ; Random Allocation ; Rats, Sprague-Dawley ; Receptors, Notch/*biosynthesis ; Receptors, Notch/genetics

BACKGROUND: Elevation of resting energy expenditure(REE) in patients with lung cancer has been described in earlier studies and may contribute to cancer cachexia, but limited information is available regarding the prevalence and determinants of the increased REE. The aim of this study was to assess the prevalence and contributing factors of a hypermetabolic state in newly detected patients with lung cancer and to assess the energy balance in order to improve our knowledge about weight loss in patients with lung cancer. METHODS: Thirty one consecutive, newly detected patients with lung cancer and 20 control patients with benign lung diseases were included in this study. Resting energy expenditure(REE) was measured by indirect calorimetry using ventilated hood system and predicted REE was calculated by the Harris-Benedict formular. RESULTS: The energy balance in newly detected lung cancer patients was disturbed in a high proportion of patients, and hypermetabolic state occurred in 61% of the patients. Tumor volume, cancer type, location, stage, the presence of atelectasis or infiltration, pulmonary fuction, or smoking behavior were not associated with increase in REE. But patients with distant metastasis had significantly higher REE comparing with patients without metastasis. Thirty nine percents of the patients with lung cancer had substantial loss of more than 10% of their pre-illness weight. Weight losing patients with lung cancer were not accompanied by an increase in REE. CONCLUSION: We concluded that the REE was elevated in a higher proportion of patients with lung cancer and distant metastasis was found to be contributing factor to the elevated REF.
Cachexia ; Calorimetry, Indirect ; Energy Metabolism* ; Humans ; Lung Diseases ; Lung Neoplasms* ; Lung* ; Neoplasm Metastasis ; Prevalence ; Pulmonary Atelectasis ; Smoke ; Smoking ; Tumor Burden ; Weight Loss