Microscopical evaluation of extracellular matrix and its relation to the palatopharyngeal muscle in obstructive sleep apnea.

Obstructive sleep apnea hypopnea syndrome (SAHS) is a complex disease of the upper respiratory airways. SAHS physiopathology is multifactorial in which airway compliance is a very important component. To evaluate the tissue changes in the palatopharyngeal muscle by morphometric, histochemical, immunohistochemical, and stereological quantification, with special attention to extracellular matrix associated with this muscle at the structural and ultrastructural levels. Thirty patients with SAHS were divided into groups of 10 according to disease severity: mild, moderate, and severe SAHS. In addition, the control group consisted of 10 patients. Fragments of palatopharyngeal muscle removed from patients with SAHS and tonsillectomies from patients in the control group were histopathologically submitted to light microscopy and transmission electron microscopy. Histopathological evaluations by light and transmission electron microscopes showed differences in analyzed groups, such as reduction of the muscle fiber diameter in patients with SAHS, taking disease severity into consideration. In contrast, stereological analysis showed a gradual increase of the collagen and elastic system fibers relative frequencies, proportionally to SAHS seriousness. MMP-2 and MMP-9 immunostaining also showed an increased reaction in the muscle fiber cytoplasm and endomisium during SAHS progression. The ultrastructural analysis showed that palatopharyngeal muscle fibers presented cytoplasmic residual corpuscles, a sign of early cell aging. In conclusion, the increase of tissue compliance in individuals with SAHS can be, in addition to other factors, consequence of diminished contractile activity of the muscle fibers, which exhibited clear signs of early senescence. Moreover, extracellular matrix components changes may contribute to muscle myopathy during SAHS progression.

Apoptosis in tongue squamous cell carcinoma and its correlation with clinically occult cervical metastasis.

Squamous cell carcinoma of the tongue is one of the most common head and neck cancer. Treatment in the early stages is still controversial. This study aims to correlate the apoptosis rate of primary tongue cancer with cervical node metastasis, found in the histopathological studies of specimens obtained from neck dissections or during clinical follow-up. Twenty patients, 65% males, mean age 64.5 years, without clinical evidence of cervical metastasis was included. Eighty-five percent were smokers and 40% were alcohol abusers. Mann-Whitney test was used for statistical analysis (p