Clusterin expression in non-neoplastic adenohypophyses and pituitary adenomas: Cytoplasmic clusterin localization in adenohypophysis is related to aging

Clusterin is a circulating multifunctional glycoprotein produced in several kinds of epithelial and neuronal cells. Clusterin is upregulated during different physiological and pathological states, such as senescence, type-2 diabetes mellitus, Alzheimer disease, and in various neoplasms. Herein, we investigated the immunohistochemical expression of clusterin in non-neoplastic adenohypophysis of human autopsy subjects and pituitary adenomas. We also investigated the association of clusterin increase with age in adenohypophysis of autopsy subjects. Immunohistochemically, clusterin was found positive in the cytoplasm of all adenoma cases, and in the cytoplasm of parenchymal cells, stellate cells, mixed cell follicles and in colloidal material inside of the follicles of non-neoplastic adenohypophysis as well. Clusterin expression in pituitary adenomas was found significantly higher than in non-neoplastic adenohypophyses. In addition, in non-neoplastic adenohypophysis, a significant increase in clusterin expression levels between young (= 61 years) subjects (p<0.00001, analysis of variance [ANOVA]) was found. In addition to clusterin accumulation, presence of calcification (p<0.045, ANOVA) and presence of large follicles with colloid accumulation (p< 0.004, ANOVA) were also statistically significant factors related to aging in non-neoplastic adenohypophysis. In conclusion, the present study demonstrated that clusterin expression was found in non-neoplastic adenohypophysis and in upregulated amounts in pituitary adenomas. This study also demonstrated that in non-neoplastic adenohypophyses, increase of clusterin positive cells; histopathological findings of calcification or presence colloidal material accumulation in large follicles were associated with age. To our knowledge, immunohistochemical localization of clusterin in pituitary adenomas was not reported previously.Yeditepe Üniversitesi Hastanesi Patoloji Laboratuvar

In vitro release and In vivo biocompatibility studies of biomimetic multilayered alginate-chitosan/beta-TCP scaffold for osteochondral tissue

Biomimetic three-layered monolithic scaffold (TLS) intended for the treatment of osteocondral defects was prepared by using alginate, chitosan and beta-tricalcium phosphate (beta-TCP)to study drug release behavior of the alternative drug delivery system and to investigate the therapeutic efficacy of the scaffold. Dexamethasone sodium phosphate (Dex) as a model drug was incorporated into the scaffold by solvent sorption method and in vitro release studies were conducted. In addition, the scaffold was implanted into the defects formed in the trochlea of Sprague-Dawley rats to assess the healing potential of the TLS on the osteochondral defect against reference Maioregen (R) comparatively. The release studies showed that after an initial burst at 3rdh, dexamethasone is released slowly during a 72-h period. In vivo studies indicated that the TLS has good tissue biocompatibility and biodegradation rate and showed better results during osteochondral healing process compared to the reference. All results demonstrated that the alginate-chitosan/beta-TCP scaffold could be evaluated as a good candidate for osteochondral tissue applications