@entity35 were exposed to @entity3759 by inhalation exposure to concentrations of 0, 10, 50, and 250 mg/m3 for 6 hr/day, 5 days/week for 2 years. There were no abnormal clinical signs, body weight changes, or excess mortality in any exposed group. Exposed groups showed slight increases in the incidence of @entity55 , @entity6062 , and @entity2490 with @entity1544 in the anterior nasal cavity. The pulmonary response at 10 mg/m3 satisfied the biological criteria for a "nuisance dust." The lung reaction was characterized by dust-laden macrophage (dust cell) infiltration in the alveolar ducts and adjoining alveoli with @entity1373 of @entity1605 . @entity35 at 50 and 250 mg/m3 exposure concentrations revealed a dose-dependent dust cell accumulation, a foamy macrophage response, @entity1373 , @entity5970 , alveolar bronchiolarization, @entity165 @entity738 , focal @entity5641 , and dust deposition in the tracheobronchial lymph nodes. Minute collagenized @entity82 occurred in the alveolar walls enclosing large dust cell aggregates. The @entity358 with massive dust accumulation appeared to be the result of an overwhelmed lung clearance mechanism at 250 mg/m3 exposure. @entity652 and @entity957 occurred at 250 mg/m3 exposure, while no compound-related @entity2 were found in @entity35 exposed to either 10 or 50 mg/m3. In addition to excessive dust loading in the lungs of @entity35 exposed chronically at 250 mg/m3, the @entity2 were different from common @entity1 @entity2 in terms of @entity5 type, anatomic location, tumorigenesis, and were devoid of @entity5 @entity3 . Therefore, the biological relevance of these @entity2 and other @entity358 for @entity1 is negligible.

Pulmonary response of XXXX exposed to titanium dioxide ( @entity3759 ) by inhalation for two years.

@entity1 :: ('9606', 'Species') :: ['human', 'man'] @entity1605 :: ('OMIM:217000', 'Disease') :: ['Type II pneumocytes'] @entity82 :: ('MESH:D005355', 'Disease') :: ['fibrosis'] @entity6062 :: ('MESH:D014136', 'Disease') :: ['tracheitis'] @entity738 :: ('MESH:D006099', 'Disease') :: ['granulomas'] @entity55 :: ('MESH:D011014', 'Disease') :: ['pneumonia'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor'] @entity1373 :: ('MESH:D006965', 'Disease') :: ['hyperplasia', 'Type II pneumocyte hyperplasia'] @entity957 :: ('MESH:D002294', 'Disease') :: ['cystic keratinizing squamous cell carcinomas'] @entity2 :: ('MESH:D008175', 'Disease') :: ['lung cancers', 'lung tumors'] @entity5641 :: ('MESH:D010998', 'Disease') :: ['pleurisy'] @entity2490 :: ('MESH:D012220', 'Disease') :: ['rhinitis'] @entity1544 :: ('MESH:D018307', 'Disease') :: ['squamous metaplasia'] @entity358 :: ('MESH:D008171', 'Disease') :: ['pulmonary lesions'] @entity5970 :: ('MESH:D011649', 'Disease') :: ['alveolar proteinosis'] @entity3 :: ('MESH:D009362', 'Disease') :: ['metastasis'] @entity35 :: ('10116', 'Species') :: ['Rats', 'rats'] @entity652 :: ('MESH:D000236', 'Disease') :: ['Bronchioloalveolar adenomas'] @entity3759 :: ('CHEBI:32234', 'Chemical') :: ['TiO2'] @entity165 :: ('MESH:D002784', 'Chemical') :: ['cholesterol']
@entity35 :: (10116,Species) :: ['rats']
