HSC Section 6 Nov2016 Green Book

Otolaryngology–Head and Neck Surgery 152(2)

Figure 2. (A) Control group: collagen fibers in the lamina propria, some fibroblasts and vessels. (B, C) Elderly groups: dense collagen in the lamina propria and thickened basement membrane. Hematoxylin and eosin, 10 3 .

Table 1. Immunoexpression of Antibodies for Collagens I, III, and Elastin, Measured as Area Percentage (%). a

Antibodies

Collagen I

Collagen III

Elastin

Age Group, y

SL

DL

P Layers

SL

DL

P Layers

SL

DL

P Layers

30-50 60-75

34.2 (8.5)

3.8 (10.4) .105 25.6 (21.6-29.4) 23.6 (20.5-29.9) .046 28.2 (25.7-29.3) 27.5 (23.6- 33.3) .508

39.6 (5.1) 44.4 (7.5) 40.4 (5.7) 46.9 (9.3)

.114 31.2 (23.7-35.6) 24.6 (20.1-29.7) .0051 20.8 (19.2-23.7) 23.0 (18.7-28.2) .114 32.4 (24.8-44.4) 29.9 (22.1-40.1) .333 15.9 (10.8-24.3) 18.2 (14.3-25.9)

.114 .285

. 75

.002 *

.0061 *

.00001 *

P ages

a Mean (standard deviation) or median (minimum and maximum) according to age group and depth of vocal folds lamina propria. DL, deep layer; SL, superficial layer. * P with statistical significance.

with the respective multiple comparisons tests and the non- parametric model when necessary (median, minima, and maxima values). Means and standard deviations of each group were presented when the parametric model was used. For the nonparametric model, medians and their minimum and maximum values were presented, considering the 5% significance level ( P \ .05) within each age range. Results The starting point in our study was to analyze H&E slides to check the syntopy of the lamina propria structures in vocal folds and then perform the immunohistochemical study. In these images ( Figure 2 ), it was possible to observe in the control group adults that collagen fibers are arranged as a loose fabric between some fibroblasts and ves- sels in the entire vocal fold lamina propria. In the 60- to 75- year-old group subjects, it was possible to identify a dense collagen thickness deposited on the subepithelial layer ( Figure 2B ). Finally, in the elderly group (greater than 75 years of age), dense collagen uniformly occupied the whole lamina propria ( Figure 2C ). The immunoexpression of antibodies for collagens I, III, and elastin as well as collagens IV and V is presented in Tables 1 and 2 , respectively, and shown in Figures 3 to 7 . We observed that, for collagen I and III, there was an increase of labeling density in the elderly larynges, without

Table 2. Immunoexpression of Antibodies for Collagens IV and V, Measured as Area Percentage (%). a

Collagen IV

Collagen V

Age Group, y

SL

DL

SL

DL

30-50 60-75

20.9 (2.9) 17.6 (3.7) 38.5 (14.4) 36.6 (8.5)

20.7 (4.4) 19.3 (4.2) 36.2 (8.9) 21.3 (3.9) 20.4 (3.5) 31.8 (5.6)

35.0 (5.6) 31.3 (6.0)

. 75

P ages

.573

.2597

P Layers

.0034

.397

a Mean (standard deviation) according to age group and depth of vocal folds lamina propria. DL, deep layer; SL, superficial layer. * P with statistical significance.

any statistical difference between elderly subgroups. Regarding collagens IV and V, a greater labeling density was observed in the endothelium of vessels of the lamina propria and basement membrane. Finally, regarding elastin, we observed a decrease of this antibody as the age increased in both elderly groups. Discussion Presbyphonia is a physiological effect of the senescence process that takes place in the whole body. Trying to

81