Short histological kaleidoscope - recent findings in histology. Part III.

The paper provides an overview of the current understanding of different cells' biology (e.g., keratinocytes, Paneth cells, myoepithelial cells, myofibroblasts, chondroclasts, monocytes, atrial cardiomyocytes), including their origin, structure, function, and role in disease pathogenesis, and of the latest findings in the medical literature concerning the brown adipose tissue and the juxtaoral organ of Chievitz.

Activated Hepatic Stellate Cells (Ito Cells) - Marker of Advanced Fibrosis in Chronic Viral Hepatitis C: A Pilot Study.

BACKGROUND AND AIMS: The aim of this study is to determine whether activated hepatic stellate cells (HSCs) may represent a prognostic marker of progressive liver fibrosis in chronic viral hepatitis C (VHC) before antiviral therapy. The possible correlation between HSCs immunohistochemical features, histopathological aspects and clinical data before therapy were also studied. METHODS: This retrospective pilot study was conducted on 27 liver biopsies from VHC patients before antiviral therapy. HSCs's immunohistochemical analysis used the antibodies alpha-smooth muscle actin (α-SMA), glial fibrillary acidic protein (GFAP) and vinculin. We correlated immunopositive HSCs with HCV load, liver stiffness (LS), fibrosis stage and necro-inflammatory degree before treatment. Also, we assessed the association between liver fibrosis after therapy, the sustained virological response at 12 weeks after therapy (SVR 12) and the type of therapy. RESULTS: HSCs were increased in VHC patients compared to controls, mainly in the intermediate and periportal lobular regions. α-SMA and vinculin HSCs correlated positively with fibrosis stage (p=0.044), (p=0.028). Furthermore, α-SMA and vinculin HSCs were associated with LS (p=0.027), (p=0.002) and viral load (p=0.021), (p=0.006), but not with necro-inflammation degree. GFAP HSCs inversely correlated with fibrosis stage (r= -0.475), LS (r= -0.422) and HCV load (r= -0.517), but positively with necro-inflammation degree (p=0.038). Liver fibrosis post therapy correlated positively with SVR12 (p<0.001) and the type of therapy (p=0.006) and SVR12 correlated positively with treatment's type (p=0.002). CONCLUSIONS: Activated HSCs may represent a marker of increased liver fibrosis in VHC. Different immunohistochemical markers can detect various HSCs subpopulations involved in the evolution of VHC and liver fibrosis.

Short histological kaleidoscope - recent findings in histology. Part II.

This article focuses on the latest histological knowledge in the field regarding the peripheral lymphoid system [mucosa-associated lymphoid tissue (MALT), bronchus-associated lymphoid tissue (BALT), gut-associated lymphoid tissue (GALT)], the thymus stroma, some of the various corpuscles of the human body (Hassall's corpuscles in thymus, arenaceous corpuscles in pineal gland, corpora amylacea in prostate and other locations) and Fañanas glial cells in the cerebellum.

Short histological kaleidoscope - recent findings in histology. Part I.

This article is a review of new advances in histology, concerning either classification or structure of different tissular elements (basement membrane, hemidesmosomes, urothelium, glandular epithelia, adipose tissue, astrocytes), and various organs' constituents (blood-brain barrier, human dental cementum, tubarial salivary glands, hepatic stellate cells, pineal gland, fibroblasts of renal interstitium, Leydig testicular cells, ovarian hilar cells), as well as novel biotechnological techniques (tissue engineering in angiogenesis), recently introduced.

Hepatic stellate cells - from past till present: morphology, human markers, human cell lines, behavior in normal and liver pathology.

Hepatic stellate cell (HSC), initially analyzed by von Kupffer, in 1876, revealed to be an extraordinary mesenchymal cell, essential for both hepatocellular function and lesions, being the hallmark of hepatic fibrogenesis and carcinogenesis. Apart from their implications in hepatic injury, HSCs play a vital role in liver development and regeneration, xenobiotic response, intermediate metabolism, and regulation of immune response. In this review, we discuss the current state of knowledge regarding HSCs morphology, human HSCs markers and human HSC cell lines. We also summarize the latest findings concerning their roles in normal and liver pathology, focusing on their impact in fibrogenesis, chronic viral hepatitis and liver tumors.