Higher Concentration of Taenia Antigens in the CSF is Related to Slight Ventricle Enlargement and Periventricular Neuronal Decrease in Young Rats

Purpose Experimental models might help understand the pathophysiology of neurocysticercosis-associated hydrocephalus. The present study aimed to compare the extent of hydrocephalus and tissue damage in rats with subarachnoid inoculation of different concentrations of Taenia crassiceps cyst proteins. Methods Sixty young rats were divided into two groups: low- and high-concentration groups. The animals in the low concentration group received 0.02ml of 2.4mg/ml T. crassiceps cyst proteins while those in the high concentration group received 0.02 ml of 11.6mg/ml T. crassiceps cyst proteins. The animals underwent magnetic resonance imaging at 1, 3, and 6 months postinoculation to assess the ventricle volume. Morphological assessment was performed at the end of the observation period. Results Repeated measures of ventricle volumes at 1, 3, and 6 months showed progressive enlargement of the ventricles. At 1 and 3 months, we observed no differences in ventricle volumes between the 2 groups. However, at 6 months, the ventricles were larger in the high concentration group (median » 3.86mm3, range: 2.37­12.68) compared with the low concentration group (median » 2.00mm3, range: 0.37­11.57), p » 0.003. The morphological assessment revealed a few inflammatory features in both groups. However, the density of oligodendrocytes and neurons within the periventricular region was lower in the high concentration group (5.18 versus 9.72 for oligodendrocytes and 15.69 versus 21.00 for neurons; p < 0.001 for both). Conclusion Our results suggest that, in rats, a higher concentration of T. crassiceps cyst proteins in the subarachnoid space could induce ventricle enlargement and reduce the number of neurons within the periventricular area.

Alterations in extracellular matrix composition in the aging larynx.

OBJECTIVE: To study by immunohistochemistry the alterations of collagens I, III, IV, and V and elastin in the aging process of the human larynx. STUDY DESIGN: Cadaver study. SETTING: Universidade Estadual Paulista, Botucatu Medical School, São Paulo State University (UNESP), Brazil. SUBJECTS AND METHODS: Thirty vocal folds were obtained at autopsy from 10 adult men (aged 30 to 50 years) and 20 geriatric men (10 aged 60 to 75 years and 10 aged >75 years). Mid membranous vocal fold slides were subjected to immunohistochemical reactions. Digital imaging software (ImageJ) was used to quantify the increase in brownish staining of the lamina propria structures of vocal folds, from superficial to deep layers. RESULTS: There was an increase of collagen I and III immunoexpression in the elderly larynges, in both layers. Collagens IV and V were immunoexpressed in the vessels endothelium of the lamina propria and in the basement membrane. The immunoexpression of elastin decreased in the elderly larynges, in both lamina propria layers of the vocal folds. CONCLUSION: A clear increase of collagens I and III and a decrease of elastic fibers were observed in the lamina propria of vocal folds. The concentration of collagens IV and V was the same across age groups. These findings suggest that as men age, the density of the extracellular matrix increases, brought about by an increase in collagen, while the loss of elastin results in decreased viscoelasticity.