Skip to main content

Table 3 Histopathological findings of the mediastinal lymph node and lung after repeated intratracheal instillation of CWAAPs

From: Mechanisms of pulmonary disease in F344 rats after workplace-relevant inhalation exposure to cross-linked water-soluble acrylic acid polymers

Experimental weeks

2w recovery

18w recovery

Treatment

PBS

CWAAP-A

CWAAP-B

PBS

CWAAP-A

CWAAP-B

No. of animals examined

6

8

8

6

8

8

Histopathological findings

      

    Mediastinal lymph node

      

        Lymphoid hyperplasia

0

8***

8***

0

4*

6**

  

 < 2 > 

 < 2 > 

 

 < 1.3 > 

 < 1 > 

    Lung

      

        Deposition of test compound (AB-positive material)

0

8***

8***

0

0

0

  

 < 1 > 

 < 1 > 

   

        Inflammation, perivascular

0

8***

8***

0

0

0

  

 < 1 > 

 < 1.4 > 

   

        Granulomatous change, alveolar

0

8***

8***

0

8***

8***

  

 < 2 > 

 < 1.6 > 

 

 < 1 > 

 < 1 > 

       Hypertrophy/proliferation of alveolar epithelium

0

8***

8***

0

8***

8***

  

 < 2 > 

 < 2 > 

 

 < 1.4 > 

 < 1.3 > 

        Inflammation, air space

0

8***

8***

0

8***

8***

  

 < 2 > 

 < 2 > 

 

 < 1 > 

 < 1 > 

        Cholesterol cleft, air space

0

0

0

0

8***

8***

     

 < 1 > 

 < 1 > 

        Alveolitis

0

0

0

0

8***

8***

     

 < 2 > 

 < 1.9 > 

        Fibrous thickening, interstitial

0

0

0

0

8***

8***

     

 < 1 > 

 < 1 > 

        Accumulation of lipoproteinous material, air space

0

8***

8***

0

0

0

  

 < 2.6 > 

 < 3 > 

   

        Hyperplasia, bronchiolo-alveolar

0

0

0

0

1

0

     

 < 1 > 

 
  1. Values indicate number of animals bearing lesions
  2. The value in angle bracket indicate the average severity grade index of the lesion. The average severity grade is calculated using the following equation: Σ(grade × number of animals with grade)/number of affected animals
  3. Grade: 1, slight; 2, moderate; 3, marked; 4, severe. Significant difference: *p < 0.05; **p < 0.01; ***p < 0.001 by Chi square test compared with the respective controls