Histopathology of the muscle in rheumatic diseases.

The presence of muscular symptoms is common in rheumatological clinical practice, but often the differential diagnosis between muscular involvement in connective tissue diseases, vasculitis and drug-induced myopathy may be difficult. In addition to clinical assessment, laboratory analysis and instrumental examinations, muscle biopsy may help to clarify the diagnosis in patients with muscular involvement. The purpose of this review is to provide a critical analysis of the current medical literature on muscular histopathology, to help clinicians to identify when to perform muscular biopsy and to provide a practical guide to a better understanding of the pathology report. Moreover, we provide an overview of the muscular involvement and the most common histopathological findings in rheumatic diseases

Histopathology of the muscle in rheumatic diseases

The presence of muscular symptoms is common in rheumatological clinical practice, but often the differential diagnosis between muscular involvement in connective tissue diseases, vasculitis and drug-induced myopathy may be difficult. In addition to clinical assessment, laboratory analysis and instrumental examinations, muscle biopsy may help to clarify the diagnosis in patients with muscular involvement. The purpose of this review is to provide a critical analysis of the current medical literature on muscular histopathology, to help clinicians to identify when to perform muscular biopsy and to provide a practical guide to a better understanding of the pathology report. Moreover, we provide an overview of the muscular involvement and the most common histopathological findings in rheumatic diseases

Cheilognatopalatoschisi: Analisi morfologica ed istoenzimatica del muscolo orbicolare della bocca

Palate and lip muscle alterations with cleft are poorly known. Few data about patients orbicularis oris muscle with cleft are reported and often in contrast each other. We decided to analyze histologic and histoenzimatic features of the orbicularis oris muscles obtained from 26 biopsyes taken from the both sides of the schisis in 13 patients affected by unilateral or bilateral cleft lip and palate divided in two groups: 7 patients gone to primary cheiloplasty and 6 to secondary cheiloplasty. Muscles section were stained with hematoxylin-eosin, modified Gomori trichrome and NADH-TR. The analyzed parameters were: organization and type of muscle fibers, presence of ragged red fibers, characteristics of nuclei, degree of fibrosis, presence of adipose tissue and inflammatory infiltrate. Our results showed the presence in the first group and the persistence in the second one, although surgical repair of the schisis, of dystrophic-like alterations of the orbicularis oris muscle such as variability of fiber size, fibers disorganization and increase of connective tissue. We found no neurogenic atrophy, ragged red fiber or inflammatory infiltrate. The marked alterations of lip muscle in children with cleft, that perstist in adults even after surgery, suggest that muscle damage could represent a significant pathogenetic factor in this type of malformation. Muscular biopsy of orbicularis oris muscle during cheiloplasty could offer useful damage evaluation and functional prognostic information in patients with cleft lip and palate

Laser microdissection and primary cell cultures improve pharmacogenetic analysis in pancreatic adenocarcinoma

A key focus of research on pancreatic ductal adenocarcinoma (PDAC) is identifying new techniques to tailor gemcitabine and 5-fluorouracil treatments. Availability of tumor tissue is critical for the accurate assessment of gene expression, and laser microdissection (LMD) and primary cell cultures may be useful tools to separate tumor cells from the stromal reaction. The aim of this study was (1) to address the genetic profile relevant to drug activity and (2) to evaluate differences between microdissected and non-microdissected tumors, normal tissues, and primary cell cultures. Quantitative PCR of seven key genes was performed on mRNA from 113 microdissected and 28 non-microdissected tumors, a pool of normal tissues and four established primary cell lines. Protein expression was evaluated by western blot and immunocytochemistry and cytotoxicity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. LMD allowed the analysis of 110 samples and revealed significant differences in mRNA levels between microdissected tumors and normal tissues, as well as between non-microdissected and microdissected tumors from the same patients. In contrast, primary cell lines showed similar expression profiles with respect to their respective microdissected tumors. In particular, expression levels of human equilibrative nucleoside transporter-1 and thymydilate synthase were significantly related to gemcitabine and 5-fluorouracil cytotoxicity. We conclude that LMD is a reliable technique for mRNA extraction, and allows detection of significant differences in the expression of specific target genes when compared to non-microdissected specimens and normal tissues. Moreover, expression levels in microdissected tumors are similar to those observed in primary tumor cell cultures, both at mRNA and protein level, and are related to drug chemosensitivity. The use of these ex vivo techniques for molecular analysis of tumors therefore appears to be of some value in implementing the clinical management of PDAC