Influence of the microenvironment dynamics on extracellular matrix evolution under hypoxic ischemic conditions in the myocardium.

The extracellular matrix (ECM) consists of fibrillary and non-fibrillary components in the extracellular zone, and fulfills structural and signaling roles. Cardiac insult can lead to cardiomyocyte death, which subsequently determines dynamic changes of ECM composition and regulates cellular responses, ultimately contributing to cardiac repair. The present retrospective study on a small batch selected from the database of the Pathology Department of 'Sf. Pantelimon' Hospital aimed to determine which molecules may have a role in the dynamics of ECM using histopathology and immunohistochemistry methods. The study batch was composed of cases with cardiac ischemic conditions who died at various ages of myocardial infarcts. Tissue samples were taken from the myocardium of the left ventricle (anterior and lateral walls), and multiple series of histological sections were produced and analyzed using immunohistochemistry for collagen type I (Col-1), tenascin C (Tn-C), matrix metalloproteinase 9, CD34, and CD68. Col-1 and Tn-C showed variable patterns of fibrillar plexiform network, associated with a high micro-vascular density of newly formed capillaries revealed by CD34, and an interstitial infiltrate with histiocytes demonstrated by CD68 presence. The ECM represents therefore a polymorphic microenvironment with its own dynamics that is in continuous change, involving a large spectrum of heterogenous molecules, which play different roles in myocardium remodeling under hypoxic ischemic conditions.

A multidisciplinary approach in the diagnostic challenge of GIST.

Gastrointestinal stromal tumors (GISTs) are the most common malignant mesenchymal lesions of the gastrointestinal tract. They originate from the interstitial cells of Cajal and are characterized by overexpression of the tyrosine kinase receptor, protein product of c-KIT gene (KIT). In this retrospective study, conducted over a period of 10 years, we retrieved from our database, a total number of 57 patients, admitted and operated in the surgical department of 'Sf. Pantelimon' Emergency Clinical Hospital, Bucharest, for digestive tumors, histopathologically confirmed as GISTs. More than half of the cases presented as surgical emergencies and the tumors found during the surgical procedures, which proved to be GISTs, were sometimes difficult to differentiate from other mesenchymal tumors, both for the clinician and the pathologist. The diagnosis of GIST relies mostly on pathology and immunohistochemistry, but also on clinical and imagistic data. The most common emergencies were digestive hemorrhage (associated with gastric location), followed by intestinal obstruction (especially for the ileal localization). The largest dimensions corresponded to gastric location. For selected indications (upper digestive sites), upper digestive endoscopy approaches 100% sensitivity. This study focuses on diagnosis of GISTs sustained by both clinical and imagistic methods, along with histopathology and immunohistochemistry techniques, according to the World Health Organization 2019 criteria. Even though the differential diagnosis of these tumors is challenging, an interdisciplinary cooperation with a multiple approach increases the odds of a correct positive diagnosis.

Incidence of thyroid carcinomas in an extended retrospective study of 526 autopsies.

Thyroid cancer accounts for 1% of all malignancies, and is becoming increasingly common worldwide. The literature reports a prevalence of ~50% of thyroid nodules detected during autopsies in subjects with unknown thyroid pathology. An extended retrospective study of 526 autopsy cases was performed to identify the prevalence of thyroid carcinoma, among various types of thyroid nodules identified incidentally. Tissue samples were taken from thyroid nodules, for investigation of the presence of thyroid carcinoma, along with their macroscopic and microscopic features by means of histopathology and immunohistochemistry (IHC) methods. Histopathological diagnosis of malignancy was found in 51 cases of analyzed thyroid samples. Systematic detailed studies demonstrated that a thyroid gland, apparently normal on macroscopic examination, may be the site of pathological manifestations, sometimes presenting carcinomatous findings. Among thyroid carcinomas, the highest frequency was that of papillary microcarcinomas, which have a long evolution, and are incidentally detected during autopsies. Papillary microcarcinoma is an extremely common incidental finding and the vast majority of these tumors pursue a benign course. Furthermore, it is therefore necessary to create national screening programs for the early detection of thyroid carcinoma.

Fibroblast involvement in cardiac remodeling and repair under ischemic conditions.

Cardiac fibroblasts play a main role in the physiological turnover of the extracellular matrix, as well as its pathological remodeling. A study was performed on a batch of 23 cases who died of various cardiac complications secondary to scarring myocardial infarctions. The aim of the study was to assess the fibroblast involvement in cardiac repair under ischemic conditions after myocardial infarction. Tissue myocardial samples from the left ventricle were taken from these cases for microscopy examination, in order to investigate the type and degree of fibrosis as well as the presence of cardiac interstitial fibroblasts. Multiple series of histological sections were also performed and examined, along with immunohistochemical analysis. The fibroblasts were diffusely distributed in the interstitium among the residual cardiomyocytes, showing variable expression of vimentin and smooth muscle actin. During cardiac remodeling, there was a successive interstitial deposition, first of reticulin fibers and then of collagen fibers, leading to interstitial fibrosis and myocardial replacement. There was a correlation between vimentin and smooth muscle actin expression and collagen deposition. Fibrosis with cardiac remodeling is based on maintaining proliferation capacity of the fibroblast and its capacity of protein synthesis in the extracellular matrix. Under hypoxic ischemic conditions, followed by myocardial infarction, the fibroblast switches phenotype and transdifferentiate into myofibroblast, contributing to the healing by secreting extracellular matrix proteins and collagen deposition, with subsequent cardiac remodeling and regulation of the micro-environment metabolism.

Heterogeneity of antigenic constellation in human hepatocellular carcinoma.

Hepatocellular carcinoma is one of the primary liver malignancies responsible for over a million deaths per year worldwide (approximately 10% of all deaths in the adult age range). The diagnosis of HCC can be difficult and often requires the use of more than one microscopic technique. A retrospective study was performed on a study batch of 42 cases that died of HCC due to metastasis or other secondary complications. Tissue samples were taken in order to investigate the tumour antigenic constellation by means of IHC method using a large variety of antibodies. In situ hybridization was also performed for albumin mRNA to assess the albumin expression in some selected cases. Telomerase activity was investigated using IHC method for the hTERT catalytic subunit. A cocktail of hepatic cytokeratins (CK8, 18) combined with Hep Par-1 and associated to albumin proved to be more powerful than albumin alone in differentiating HCC and increased the value of tumour diagnosis. hTERT expression was proportionally reverse to the tumour degree of differentiation, but was independent from the expression of tumour-proliferating indexes. The heterogeneity of the antigenic constellation in hepatocellular carcinoma suggests an antigenic mosaicism, which can be expressed a synchronous or metachronous manner, depending on the tumour degree of differentiation.

Dormant cardiac stem cells: A promising tool in cardiac regeneration.

Stem cells represent an old niche with various new potential therapeutics. Besides drug treatment, reperfusion procedures and surgical revascularization, stem cell therapy could be a good option in ischemic cardiac diseases. A study was performed on a small group of cases who died of cardiac arrhythmia secondary to scarring myocardial infarctions. Tissue cardiac samples were taken from these cases (from the anterior and lateral wall of the left ventricle), for microscopy examination, in order to investigate the presence of cardiac stem cells (CSC). Multiple series of histological sections were also performed and examined, along with immunohistochemical analysis (IHC). The cells were identified in close contact with the residual ischemic cardiomyocytes, in the proximity of the myocardial collagenous scar, in old myocardial infarctions. They were activated by hypoxic ischemia and were influenced by the capillary microvascular density and the interstitial micro-environment conditions. In chronic intermittent ischemia they seem to turn themselves from dormant quiescent cells into activated progenitor committed cells.

A histopathological and immunohistochemical approach of surgical emergencies of GIST. An interdisciplinary study.

The tailored approach to gastrointestinal stromal tumors (GISTs) has led to better prognosis for these types of tumors. Also, finding out GIST's pathology has led to a better understanding of oncogenesis and cancer therapy in general. The rapid expansion of molecular and pathological knowledge of GISTs has given this disease a promising future. We analyze 30 cases of GISTs operated on in our clinic with confirmed diagnosis by immunohistochemistry. Most of the cases were acute cases that required urgent surgical therapy. An extended analysis of these cases is performed in order to underline their special features. We recorded 17 GISTs of the stomach, 12 GISTs of the small bowel and one esophageal GIST. Of the 30 cases, 15 cases required urgent surgery presenting with GI bleeding or shock following intraperitoneal rupture and bleeding or intestinal obstruction. Of the 15 cases that required urgent surgery 12 cases presented with serosal involvement. Twenty-four cases presented spindle cell histology, four cases were epithelioid and two cases presented mixed cellularity. Although acute presentation of GISTs is not the rule, 15 of 30 of our cases required immediate surgery and a high proportion of them (12/15) presented with serosal involvement. Serosal involvement may warrant the need for a macroscopic classification of GISTs and correlation to therapy. While overall mortality was not high in our series, morbidity is affected by acute presentation, though not specifically pertaining to the diagnosis of GIST. Acute presentations were more frequent, in our series, for small bowel GISTs, compared to gastric GISTs. Serosal involvement was more frequent in the group with acute presentation compared with non-acute GISTs and was present at the most cases of small bowel GISTs with acute onset. The Ki-67 index showed no difference between acute and non-acute onset of GISTs.

Immunofluorescence expression of Ki-67, p53 and cyclin inhibitors (p16ink4a, p21 and p27) in low-grade cervical lesions versus high-grade cervical lesions. Research study on cell cultures.

OBJECTIVE: The aim of this research was to assess the immunofluorescence expression (IFE) of cell cycle regulators p16ink4a, p21, p27, in association with proliferation and prognosis factors Ki-67, p53 respectively, in cell cultures, obtained from different types of cervical intra-epithelial lesions. The final purpose was to distinguish a best marker able to identify with high accuracy the high-grade squamous intra-epithelial lesion. MATERIALS AND METHODS: The study was carried out on 68 epithelial cell cultures. Three senior specialists have analyzed 500 cells/case individually. The statistic analysis for correlation between used markers has been performed. RESULTS: The study batch revealed a very low expression of investigated parameters (<1%) in negative cases for malignancy and intraepithelial lesion (NMIL), a progressive exponential expression in low-grade squamous intraepithelial lesion (LSIL), and a very high expression in high-grade squamous intra-epithelial lesion (HSIL) and invasive squamous cervical carcinoma (ISCC). Ki-67 and p53 were overexpressed in nuclei both in LSIL and HSIL. A slightly direct correlation between p21 and Ki-67 (r=0.35, p<0.001) was observed in HSIL. Statistically significant correlations were noticed between some markers: p16ink4a and p27 (r=0.4, p=0.03), p16ink4a and Ki-67 (r=-0.4, p=0.002). CONCLUSIONS: The most reliable parameters for assessing HSIL and ISCC proved to be Ki-67 and p16ink4a. Both were with percentages and intensity of IFE around 100% and higher immunoexpression within the nucleus of cell cultures. Our study reveals that p27 cyclin inhibitor was not reliable in differentiating between LSIL and HSIL.

P53, p63 and Ki-67 assessment in HPV-induced cervical neoplasia.

Carcinoma of the uterine cervix is the most frequent malignancy in women, with an incidence of approximately 456.000 cases per year, leading to 200.000 deaths per year. Twenty-six archived formalin-fixed paraffin-embedded samples of squamous cell carcinoma, selected from 30 Papanicolaou-positive smears, have been analyzed using standard HE stain and the IHC indirect tristadial ABC peroxidase method for four antibodies: p53, p63, Ki-67, HPV. Statistical analysis has been done using the Student t-test, one-group two tails, "paired two samples for mean" variant. Two thirds of the cases were medium and poor differentiated carcinomas. The expression pattern of the proliferation and prognostic factors was biologically correlated with the histopathological type and HPV-infection. Two statistically significant correlations were found between p63 and Ki-67 and between p63 and p53 (p<0.001). The significant increase of the expression of the analyzed immunomarkers was observed in most of the cases with late stage of cervical neoplasm. P63, followed by Ki-67, showed better correlation with cancer progression than p53. This observation could be used in clinical practice with the purpose of identifying those patients requiring more aggressive treatment.

Mast cells and dendritic cells in basal cell carcinoma.

Basal cell carcinoma (BCC) is a very frequent skin malignancy, with slow evolution and rare metastases. Host tissues react to tumor invasion through complex inflammatory response, comprising varied inflammatory cells. We assessed the expression of mast cells and dendritic cells in 37 archived formalin-fixed paraffin-embedded tissue samples of BCC from the oral and maxillofacial region by means of immunohistochemical (IHC) method, using the SABC (Streptavidin-Biotin Complex) indirect tristadial technique for CD117 and S100 markers. Undetermined cases were eliminated. Mast cells were found in great number at the periphery and in between the tumor islands, the positivity to CD117 being high in three cases, moderate in 11 cases and low in 16 cases. Dendritic cells were also found within the tumor stroma, but they penetrated deep inside the tumor nests. The positivity to S100 was high in one of the 20 conclusive BCC cases, moderate in seven cases and low in nine cases. Three cases were negative to S100. The characteristic location of dendritic cells prove their role as antigen-receptor cells while mast cells might play dual roles in tumor biology.