Table 3.

Incidence and integrity of the histopathological findings of the lung and mediastinal lymph nodes 4 weeks after 90-day inhalation exposure to CWAAP-A

	Male					Female
Exposure concentration (mg/m3)	0	0.3	1	3	10	0	0.3	1	3	10
No. of animals examined	8	8	8	8	8	8	8	8	8	8
4w recovery
Histopathological findings
Mediastinal lymph node
Lymphoid hyperplasia	0	0	1	1	2	0	0	0	0	1
			<1>	<1>	<1>					<1>
Lung
Deposition of test compound (AB-positive material)	0	8***	8***	8***	8***	0	8***	8***	8***	8***
		<1>	<1>	<1>	<2>		<1>	<1>	<1>	<2>
Granulomatous change, alveolar	0	0	8***	8***	8***	0	0	8***	8***	8***
			<1>	<1>	<1.9>			<1>	<1>	<2>
Multifocal lesions, alveolar
Hypertrophy/proliferation of alveolar epithelium	0	0	1	8***	8***	0	0	2	8***	8***
			<1>	<1>	<2>			<1>	<1>	<2>
Inflammation, air space	0	0	1	8***	8***	0	0	2	8***	8***
			<1>	<1>	<2>			<1>	<1>	<2>
Cholesterol creft, air space	0	0	0	0	8***	0	0	0	2	8***
					<1>				<1>	<1>
Alveolitis	0	0	0	0	3	0	0	0	0	3
					<1>					<1>
Fibrous thickening, interstitial	0	0	0	0	3	0	0	0	0	3
					<1>					<1.3>
Accumulation of lipoproteinous material, air space	0	0	0	0	6**	0	0	0	1	8***
					<1>				<1>	<1.1>

Values indicate number of animals bearing lesions

The value in angle bracket indicate the average of severity grade index of the lesion. The average of severity grade is calculated with a following equation

Σ(grade X number of animals with grade)/number of affected animals

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 each cont