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N Agnantis

Publications and source records attributed to N Agnantis.

33 records · Page 2Linked to original sources
PubMed1988

Therapeutic effect of bovine albumin in the experimental fat embolism syndrome.

The toxic effects of the free fatty acids (FFA) are responsible for the initiation and the clinical manifestations of the fat embolism syndrome (FES). Serum albumin binds to the FFA and by producing atoxic compounds it has a therapeutic effect on the syndrome. In this study we applied bovine albumin to 48 Sprague-Dawley rats which were previously submitted to intravenous infusions of FFA solutions (oleic, palmitic, stearic). The histopathologic lesions observed in their lungs were compared to those of 50 control animals suffering from the FES. The administration of 0.5% bovine albumin solution intravenously and 0.2% intraperitoneally, especially when it was synchronous to the FFA infusion and not metachronous, resulted in substantial and statistically significant therapeutic effects.

Animals↗
PubMedDate not supplied

Comparative study of serotonin and bombesin in adenocarcinomas and neuroendocrine tumors of the colon.

The aim of this study was to investigate serotonin and bombesin expression in colorectal adenocarcinomas and neuroendocrine colorectal tumors to clarify their role in the progression of colon cancer. The investigation was carried out by electron microscope immunocytochemistry. The ultrastructural study revealed that some cases of colorectal adenocarcinomas were characterized by the presence of amphicrine cells containing endocrine granules and mucus granules. Poorly differentiated adenocarcinomas and liver metastases were poorly granulated compared with highly differentiated tumors. Neuroendocrine tumors nevertheless were characterized by the presence of numerous malignant neuroendocrine cells filled with secretory granules and mucus granules. Bombesin appeared to be located in enterochromaffin-like endocrine cells, which are primarily responsible for the production of serotonin. In colorectal adenocarcinomas there was an inverse correlation between serotonin levels and the degree of differentiation. High serotonin levels characterized colorectal adenocarcinomas with composite phenotype and colorectal neuroendocrine tumors. Increased bombesin expression was correlated with colorectal adenocarcinomas exhibiting poor histological grade and their liver metastases. In conclusion, the findings suggest that high serotonin levels may be an indicator of neuroendocrine differentiation, and bombesin may be a useful marker for colorectal adenocarcinomas with aggressive behavior,

Adenocarcinoma↗
PubMedDate not supplied

Expression of gelatinase-A (MMP-2) in human colon cancer and normal colon mucosa.

Proteolytic enzymes, such as type IV collagenases (MMP-2 gelatinase A, 72-kD type IV collagenase and MMP-9 gelatinase B, 92-kD type IV collagenase) play an important role in tumor invasion and metastasis. In the present study the levels of MMP-2 antigenic concentration and immunohistochemical staining were compared in paired colorectal tumor (n = 64) and background colon tissue of the same patients with clinical and pathological staging. The antigenic concentrations were found to be statistically significantly higher in cancer tissue (mean 11.29 ng/mg protein) than in corresponding normal mucosa (10.23 ng/mg protein) (p = 0.008). There was also a positive correlation between MMP-2 antigenic concentration and clinicopathologic parameters such as grade (p < 0.001) and Dukes' stage (p = 0.001), but not with lymph node involvement. Immunohistological localization of MMP-2 was observed in tumor as well as in stromal cells. Staining intensity increased from adenoma to adenocarcinoma. The degree of staining was associated with grade (p < 0.001), Dukes' stage (p < 0.001) and lymph node involvement (p < 0.001).

Adenocarcinoma↗
PubMedDate not supplied

Immunohistochemical expression of cathepsin D in laryngeal epithelial lesions: correlation with CD44 expression, p53 and Rb status and proliferation associated indices.

Clinical studies in several tumour types have shown a strong correlation between cathepsin D expression and tumour progression. Immunohistochemical staining for cathepsin D (clone D13A) was performed in paraffin embedded-tissues from 39 invasive squamous cell carcinomas, 13 in situ carcinomas, 35 cases of dysplasia, 10 papillomas and 17 cases of keratosis. The association between cathepsin D expression and CD44, p53, Rb proteins and proliferation indices (Ki-67, PCNA) was assessed by univariate analysis. Cathepsin D was highly positive in the groups of carcinomas compared to other lesions (p < 0.0001). A statistically significant correlation of cathepsin D expression with CD44 expression was observed in invasive cancers (p = 0.037). The relationship of cathepsin D immunoreactivity with p53, Rb and proliferation indices was insignificant. The results show that cathepsin D is expressed in a higher proportion of cancerous lesions of the larynx than in non cancerous or premalignant lesions, a fact which suggests that cathepsin D may be involved in laryngeal tumour cell growth process.

Carcinoma in Situ↗
PubMedDate not supplied

u-PA expression in benign, borderline and malignant ovarian tumors.

The malignant potential of solid tumors is related to their ability to invade adjacent tissue and to metastasize. The plasminogen activation system is one of the critical factors in tumor progression since it is involved in tumor invasion and metastasis. This study was performed to examine the expression of u-PA in benign, borderline and malignant tumors of the ovary by immunohistochemical evaluation on formalin-fixed, paraffin-embedded specimens applying monoclonal antibody 3689 directed to the b-chain of u-PA. Normal epithelial cells of the ovary (n = 5) showed no staining of u-PA but some stromal cells were slightly stained. Invasive carcinomas (n = 16) and borderline tumors (n = 15) showed a moderate to strong diffuse cytoplasmic staining. Benign tumors (n = 20) showed a variety of staining. The observation of randomly positive u-PA stromal cells is noteworthy. The percentage of u-PA-positive tumors was higher in carcinomas than in other tumors. There was no correlation with other known risk factors of malignancy such as differentiation, stage or type of tumor. In conclusion there are noticeable differences in u-PA expression among ovarian tumors and u-PA increase in ovarian tumors can be attributed to an increased diffuse cytoplasmic content in the neoplastic epithelial cells.

Adult↗
PubMedDate not supplied

Immunoelectron study of somatostatin, gastrin and glucagon in human colorectal adenocarcinomas and liver metastases.

The aim of this study was to investigate the role and function of somatostatin, glucagon and gastrin in 35 colorectal adenocarcinoma and 25 liver metastases. The investigation was carried out at the electron immunocytochemistry level. Our results showed that well-differentiated tissues have the highest somatostatin levels compared to poorly-differentiated tumors while glucagon levels remain high. We also found gastrin immunoreactivity in cell membranes of poorly-differentiated primary adenocarcinoma tissues and in liver metastases. Low somatostatin expression, high glucagon expression and the presence of gastrin were found in tumors of poor grading and therefore poor prognosis.

Adenocarcinoma↗
PubMedDate not supplied

Correlation between serum and tissue deoxyribonuclease levels in breast cancer patients.

Acid and alkaline DNAse levels were determined in the serum of 224 breast cancer patients and in the extracts of 121 breast tissue and 48 lymph node biopsies of the above patients. The DNase levels were compared to the histological diagnoses of the tumors. Serum and tissue DNase levels were found to be significantly increased in malignancies as compared to benign conditions. A close correlation was found between serum and tissue DNase levels. Measurement of DNase levels within tumors could become clinically important i.e. screening of patients for metastatic disease, or in vitro testing of tumor cells sensitivity to therapeutic regimes.

Adult↗
PubMedDate not supplied

Expression of proliferating cell nuclear antigen (PCNA) and nucleolar organizer regions (NORs) in multiple myeloma.

We have studied 72 cases of multiple myeloma (MM) bone marrow trephine biopsies using the monoclonal antibody PC-10 and the colloid silver nitrate method for identification of proliferating cell nuclear antigen (PCNA) and nucleolar organizer regions (NORs), respectively. PC-10 and AgNOR scores were statistically significantly different between low versus intermediate and low versus high grade of malignancy (P < 0.001), whereas their difference was not significant between intermediate and high grade. A strong correlation was identified between these two proliferation-associated indices in each histological grade. There is evidence that the proliferative state of myelomas belonging to the intermediate grade is approximately the same as that observed in high grade (blastic) ones.

Cell Division↗
PubMedDate not supplied

Regional intraarterial infusion of methotrexate with leucovorin rescue in a rat tumor model.

Walker 2S6 carcinosarcoma was transplanted in the paw of 52 male Wistar rats. A week later, the animals were divided into 6 separate groups and treated in different ways, as follows. Group I (control): no treatment. Group II: femoral artery ligation (FAL). Group III: ligation-intraarterial chemotherapy (LIC) with methotrexate (MTX). Group IV: the same treatment followed by leucovorin rescue (LIC+RES). Group V: tourniquet intraarterial chemotherapy and rescue (TIC+RES). Group VI: the same treatment applied via the iliac artery (iliac TIC+RES). The best results (primary tumor eradication: 8/10 cases, propagation of the tumor to the inguinal region: 4/10 cases, necroses of the distal part of the paw: 0/10 cases, p > 0.05) were observed in group VI, where iliac LIC+RES was performed. Analysis of the treatment's mechanism of action revealed that there is an area of optimal treatment in the middle of the limb, and two peripheral zones of under-treatment. At the proximal zone (inguinal region) propagation of the tumor can occur, whereas at the distal zone necrosis of the paw can be manifested.

Animals↗
PubMedDate not supplied

Expression of C-myc p62 oncoprotein in multiple myeloma: an immunohistochemical study of 180 cases.

The immunohistochemical expression of C-myc p62 oncoprotein was investigated using the immunoperoxidase method and the monoclonal antibody (Mab) MYC 1-9E10 in bone marrow paraffin sections. 180 cases of multiple myeloma (MM) were studied. C-myc expression was found to correlate well with the grade of malignancy, type of myeloma and tumor cell burden (p < 0.001). A relationship was also observed between C-myc p62 and IgA-secreting myelomas. It was found that intermediate grade myelomas are heterogeneous as far as C-myc expression is concerned. Our findings strongly suggest that C-myc might be involved in myelomutagenesis. The evaluation of its expression in MM may be helpful in determining the grade of malignancy and possibly the biological behaviour of this tumor.

Antibodies, Monoclonal↗
PubMedDate not supplied

Overexpression of C-myc, Ras and C-erbB-2 oncoproteins in carcinoma of unknown primary origin.

The role of oncogenes in carcinoma of unknown primary site (CUP) has not yet been elucidated. In the present study the expression of the c-myc p62, ras p21 and c-erB-2 p185 oncoproteins were studied by a 3-step immunoperoxidase technique in 26 cases of CUP. Positive immunoreactivity was observed in 96% of the cases for c-myc, 92% for ras and in 65% for c-erb-2, with at least half of tumor cells labelled in 85%, 92% and 58% respectively. The degree of staining intensity was considered moderate or strong in more than half of the cases for all oncogene products. In conclusion, our results showed that patients with CUP have an extremely high overexpression of all three oncogenes studied. Nevertheless, the biological role of these overexpressed oncoproteins, their relationship with different histological or clinical parameters and their diagnostic or prognostic value need further evaluation.

Adenocarcinoma↗
PubMedDate not supplied

Topographical immunohistochemical expression of bcl-2 protein in human liver lesions.

Immunolocalization of the bcl-2 protein was investigated in 60 hepatocellular carcinomas, 10 cholangiocarcinomas. 15 metastatic adenocarcinomas as well as in 37 non-neoplastic liver lesions. The three-step immunoperoxidase method was performed in archival, routinely processed material. bcl-2 protein was not identified either in neoplastic, dysplastic or normal hepatocytes, whereas it was observed in bile ductules and small bile duct epithelia, but not in the epithelium lining large bile ducts. All cases of cholangiocarcinoma and 60% of metastatic adenocarcinomas were bcl-2 positive. bcl-2 appears to be an additional marker in distinguishing hepatocellular carcinoma from cholangiocarcinoma or metastatic adenocarcinoma. Also, bcl-2 does not seem to be involved in human liver hepatocyte survival.

Adenocarcinoma↗