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N Papadopoulos

Publications and source records attributed to N Papadopoulos.

At least 55 records · Page 3Linked to original sources
PubMed2003

Prognostic significance of HLA-DR antigen in dysplasia, carcinoma in situ and invasive carcinoma of the gallbladder.

OBJECTIVE: Prognosis of gallbladder carcinoma is poor. The two most important factors having the greatest effect on survival are pathologic stage of disease and histologic grade of the tumour. Our study points towards the value of HLA-DR antigen in the prognosis of gallbladder carcinoma. DESIGN: Thirty one cases of dysplasia of the gallbladder, 12 cases of carcinoma in situ, and 39 cases of invasive carcinoma for the detection of HLA-DR monoclonal antigen were studied. T helper (TH) marker (CD4) in the tumour stroma of the relevant cases was also studied, given that it is now known that the dependence of immune responsiveness on the class II antigens reflects the central role of these molecules in presenting antigen to TH cells. SETTING: Pathology Departments of Drama General Hospital and Ippokration Hospital of Salonica in twelve years period (1990-2002). RESULTS: HLA-DR was expressed in 20 of 31 dysplasias (64.5%), four of 12 in situ (33.3%), and in 10 of 39 invasive carcinomas (25.6%). CD4 was expressed in nine of 31, dysplasias (29%), five of 12 in situ (42%), and in 26 of 39 invasive carcincomas (67%). CONCLUSIONS: The results showed decreased expression of HLA-DR and increased expression of CD4 as the lesion progressed to malignancy. The aberrant expression of HLA-DR by epithelial cells of dysplasias, of carcinomas in situ and of invasive carcinomas agrees with the hypothesis of the dysplasia-carcinoma in situ sequence as the usual route for the development of invasive carcinoma. The immune attract mechanism by low HLA-DR signalling seems to be of minor importance in the malignant and metastatic potential of the gallbladder, epithelial tumours.

CD4 Antigens↗
PubMed2003

Testicular tumors manifested as inferior vena cava thromboses. Case reports.

Four cases of asymptomatic testicular tumors with inferior vena cava (IVC) involvement are reported. All patients were referred to our hospital with non-specific abdominal pain and abdominal US revealed an inferior vena cava thrombosis. CT showed an IVC thrombus extending from the first to second lumbar vertebrae and also retroperitoneal lymphadenopathy in 3 patients. Scrotal US demonstrated intratesticular tumors. IVC thrombosis may result from asymptomatic intratesticular tumors (single or multiple). Because of that, scrotal US is of paramount importance as a routine screening test in patients who radiographically demonstrate caval thrombosis.

Adult↗
PubMed2003

Nucleolar organizer regions (NORs). Their significance in the determination of the origin of the lymphoid vessels.

AIM: The aim of this study is the evaluation of the cellular activity of the embryonal mesenchyme in order to investigate if the primitive lymph vessels are derived from clefts of the mesenchyme or from capillary offshoots from the endothelium of the veins. For this reason we applied the quantitative estimation of nucleolar organizer regions (NORs) in the endothelial cells of the lymph and blood vessels, as well as in the mesenchymal cells that surround these vessels. METHODS: Our material consisted of the histological sections from the proper mesenterium of 30 embryos in different stages of development (10th, 12th, 15th, 20th, 23th and 30th week). RESULTS: A statistically significant difference in the average AgNORs value in the endothelial (ANOVA, p<0.0001) and the mesenchymal cells (ANOVA, p<0.0001) between lymph vessels, blood vessels at close and blood vessels at distant regions (10th, 12th, 15th week) was found. There was no statistically significant difference of the average AgNORs value in the endothelial (ANOVA, p=0.55) and the mesenchymal cells (ANOVA, p=0.49) between lymph vessels, blood vessels at close and blood vessels at distant regions (20th, 23th, 30th week). CONCLUSION: The above results suggest that the development of the lymph vessels follows that of the blood vessels. Furthermore, the intense protein synthesis that is expressed by means of NORs in the mesenchymal cells surrounding lymph vessels from the 10th to the 15th week of development is an additional proof of the view that the primitive lymph vessels are derived from clefts into the embryonal mesenchyma and not from capillary offshoots of the endothelium of the blood vessels.

Gestational Age↗
PubMed2003

Primary lymphoproliferative lesions of the mammary gland.

Occasionally, the breast is the site of a localized, primary lymphoma with no evidence of concurrent widespread or preceding extramammary disease at the time of presentation (Stage I) or within 1-6 months thereafter. Cases with concurrent or subsequent ipsilateral axillary node involvement (Stage II) have also been accepted as primary lymphomas by some investigators, and such involvement has been observed in 48.5% of the cases. More commonly, the breast is involved secondarily by widespread lymphoma. Patients with PML range in age from 9 to 90 years, with a median ranging from 55 to 68 years in various reports. Clinical symptomatology varies considerably. Most patients present with a breast mass or complain of pain. About 10% of the patients may have night sweats, fever, and weight loss. Occasionally multiple nodules may be present within the breast. These nodules can cause overlying skin changes similar to those associated with carcinoma and may even involve the nipple. Mammographically, lymphomas form relatively circumscribed masses, focal or diffuse thickening and densities, and discrete nodules with irregular margins; typically, they lack calcification and retraction.

Adolescent↗
PubMed2003

Detection of chromosome 1p deletion using FISH on meningioma touch imprints suggest a region outside chromosome 22 as important in tumor recurrence.

BACKGROUND: Atypical and anaplastic meningiomas tend to recur and to invade adjacent brain, bone, and skin. They can also metastasize to extracranial organs such as the lung, liver, or bone causing death. The classic genetic abnormality is loss in chromosome 22. Recent reports have indicated that allelic deletion of chromosome 1p is associated with malignant progression of meningiomas. METHODS: Cytogenetic analysis of 4 meningiomas was performed using double target fluorescent in situ hybridization and focusing on chromosomes 1 and 22. The meningioma series included 4 patients whose tumors were histologically benign. RESULTS: One patient's tumor had recurred. FISH was performed on 500 nuclei/tumors. All our cases showed a loss of chromosome 22q while only 1 meningioma showed an additional loss of chromosome 1p, and this was the recurred one. CONCLUSIONS: The results of this study support the existence of tumor suppressor gene(s) on 1p associated with recurrence in meningiomas and suggest that status of chromosome 1p by FISH may assist physicians in predicting prognosis of patients affected by this tumor. However more in-vestigation is needed in this direction, as our re-sults refer to a small number of subjects studied.

Adult↗
PubMed2003

Imprint cytology for rapid evaluation of lung and mediastinal lesions.

BACKGROUND: Frozen-section biopsy (FSB) of pulmonary and mediastinal tumors is commonly used in the evaluation of diagnostic tissue in thoracic surgery. However, FSB can be labor intensive for the pathology department and time-consuming while the patient is anaesthetised. Imprint cytology is more rapid than the FSB procedure (average, 1 min versus 10 min per tissue sample) and allows more extensive sampling of the specimen. METHODS: In this preliminary study we compared the diagnostic accuracy of imprint cytology and permanent sections on lung and mediastinal lesions from 38 patients. RESULTS: There were no false-positive results and 2 false-negative results. The sensitivity was 99.13%, the specificity was 100% and the positive predictive value was 100%, as no false-positive results were observed. These results match favorably with those in other studies comparing the diagnostic accuracy of imprinting cytology with that of FSB and with reported accuracy rates of the FSB method. CONCLUSION: Our findings confirm the usefulness of this procedure as an adjunt or alternative for FSB in the pathologic evaluation of lung and mediastinal space-occupying lesions.

Adenocarcinoma↗
PubMed2003

Fetal thymic medulla functional alterations in Down's syndrome.

AIM: Although the thymus is usually considered a specifically T cell organ, occasional mature B lymphocytes, B cell germinal centres and rarely plasma cells can be found in this organ, particularly in children. Ultrastructural studies have shown that these lie outside the epithelial enclosure and within the perivascular spaces of the medulla, the corticomedullary junction and septa, and this has led to a concept of 2 functional compartments of the thymus, namely an intraepithelial compartment and an extraepithelial (perivascular) compartment. These cells do not originate from the thymus but enter the organ via the bloodstream, at the 16th week of gestation. Our study points towards possible alterations in the functional histology of this lymphoid organ associated with immunization. METHODS: A quantitative comparison of B lymphocytes in the thymic medulla in embryos after involuntary abortion during the 1(st) and 2(nd) trimester of gestation and embryos with Down's syndrome, respectively, was performed. RESULTS: Our results showed: 1) A statistically significant difference in the number of B cells together with infrequent primary follicles in the cases of embryos with Down's syndrome over those after voluntary abortion, during the 20(th) week of gestation (p=0.013). 2) No statistically significant difference in the number of B cells in both categories during the 1(st) trimester of gestation (p=0.34) and the 24(th) week of gestation (p=0.14). CONCLUSION: The occurrence of increased number of B cells along with primary follicles in the cases with Down's syndrome, in the 2(nd) trimester of gestation imply that the thymic medulla - at least part of it - works and behaves as a peripheral lymphoid organ receiving mature lymphocytes, and turning them from inactive to immunoefficient cells, in the affected fetuses.

B-Lymphocytes↗
PubMed2003

Odontogenic tumor with prominent clear cell component misdiagnosed as pleomorphic adenoma by fine-needle aspiration. A case report.

Clear cell tumors in the maxillofacial region, are usually originated in salivary or odontogenic tissues, or may be metastatic. They include calcifying epithelial odontogenic tumors, ameloblastoma and odontogenic carcinoma. Clear cell odontogenic tumor has been classified in the last WHO classification as a benign tumor, but current opinion is that it should be designated as a carcinoma. We report a case of clear cell odontogenic tumor documented by histology, in a 82 year-old female, misinterpreted as pleomorphic adenoma by fine-needle aspiration cytology.

Adenocarcinoma, Clear Cell↗
PubMed2002

Germline mutations in the ribonuclease L gene in families showing linkage with HPC1.

Although prostate cancer is the most common non-cutaneous malignancy diagnosed in men in the United States, little is known about inherited factors that influence its genetic predisposition. Here we report that germline mutations in the gene encoding 2'-5'-oligoadenylate(2-5A)-dependent RNase L (RNASEL) segregate in prostate cancer families that show linkage to the HPC1 (hereditary prostate cancer 1) region at 1q24-25 (ref. 9). We identified RNASEL by a positional cloning/candidate gene method, and show that a nonsense mutation and a mutation in an initiation codon of RNASEL segregate independently in two HPC1-linked families. Inactive RNASEL alleles are present at a low frequency in the general population. RNASEL regulates cell proliferation and apoptosis through the interferon-regulated 2-5A pathway and has been suggested to be a candidate tumor suppressor gene. We found that microdissected tumors with a germline mutation showed loss of heterozygosity and loss of RNase L protein, and that RNASEL activity was reduced in lymphoblasts from heterozyogous individuals compared with family members who were homozygous with respect to the wildtype allele. Thus, germline mutations in RNASEL may be of diagnostic value, and the 2-5A pathway might provide opportunities for developing therapies for those with prostate cancer.

Adenine Nucleotides↗
PubMed2002

Primary muscular hydatidosis. US, CT and MR findings.

We present a rare case of primary muscular hydatidosis in the left thigh of a 40-year-old female patient. US, CT and MR imaging showed a typical multilocular hydatid cyst deep in the vastus intermedius and vastus medialis muscles. Histopathological examination, which followed surgical excision, established the diagnosis of echinococcus cyst.

Adult↗
PubMed2002

Expression of alpha-smooth muscle actin in the stromal cells of bone marrow in fetuses in different stages of development, in multiple myeloma and monoclonal gammopathy of unknown significance.

Several disorders are associated with a monoclonal immunoglobulin detected by serum or urine electrophoresis, the most common being a monoclonal gammopathy of unknown significance, multiple myeloma, Waldenstrom's macroglobulinemia, and amyloidosis. Plasma cells, the immunoglobulin secretory cells of the immune system, are normal constituents of bone marrow (BM). Plasma cells are seen in small numbers in the stroma, surrounding blood vessels in the marrow. Their perivascular disposition is consistent with their secreting capacity. The hematopoietic microenvironment has a crucial role homing and regulating precursor cell growth both in physiologic and pathologic conditions. Cellular components such as branched adventitial reticular cells, macrophages, endothelial cells and fat cells constitute the supporting framework (stroma) for hematopoiesis, which takes place in the extravascular compartment. The presence of myiod cells (MCs) in human bone marrow has been observed during hematopoiesis in embryonic life, whereas during adult life, it is strictly related to various pathologic conditions. The aim of this study was to examine in the stroma of BM the presence, distribution and quantitation of cells expressing a-smooth muscle actin (MCs) from patients with monoclonal gammopathy of unknown significance, those with plasma cell myeloma and embryos (gestational age 15 to 25 weeks). For this reason, a series of 20 trephine bone marrow biopsies from adult patients and ten fetal specimens of the spine and femur were examined for the presence of stromal myoid cells using a monoclonal recognising alpha-smooth muscle actin, a contractile microfilament expressed solely by smooth muscle cells, myofibroblasts and related cells. Our results suggest that the appearance of MCs and subsequent fibrosis is not a feature of malignant BM disorders such as MM but it is also seen to a lesser degree in the BM stroma of individuals with monoclonal gammopathy of unknown significance (MGUS). Stromal cells with phenotypic smooth muscle features appear in bone marrow during pathological situations in a manner reminiscent of what occurs during normal development.

Actins↗
PubMed2002

Nucleolar organizer regions: their significance in protein synthesis and consequent release of factors that attract immature lymphocytes in different types of thymic epitheliocytes and in different stages of thymic development.

The thymus is a lymphoepithelial organ that has the central role in T-lymphocyte development. Unlike other lymphoid structures, where the supportive framework is chiefly collagenous reticular tissue, the thymus is permeated by a network of interconnected epithelial cells (thymic epitheliocytes) between which lodge lymphoid and other cells of the organ. There is much evidence that many distinctive functional roles are subserved by the thymic epitheliocytes such as, the differentiation of T lymphocytes, the production of soluble thymic factors or hormones, supportive functions, or their role in MHC restriction of T-cell immune responses. Nucleolar organizer regions (NORs), which are important for regulating protein synthesis, were identified in 30 fetal thymuses in different stages of development ( 10th, 14th, 15th, 19th, 20th, 23rd, 31st, and 35th week), by means of a silver (Ag) staining technique (AgNOR). The aim of our study was to estimate the AgNOR counts in the six different types of fetal thymic epitheliocytes, following suggestions that there may be a possible association between AgNOR values and consequent protein synthesis in the different types of these cells and in different stages of thymic development. The results showed that: First Type I epitheliocytes (subcapsular-perivascular) of the cortex represent a higher number of AgNORs in comparison with the other cellular types, a difference that was observed every week of our study, and especially between the 10th and 15th week of development (p < 0.01). The increased number of AgNORs in Type I epitheliocytes reflect their intense protein synthesis, a fact that explains the increased secretion of factors, e.g. beta2-microglobulin, that release immature lymphocytes from the yolk sac and the liver. Second, gradual increase of the average AgNOR in all thymic epitheliocytes from the 10th till the 35th week, without any statistical variation. This increase might be due to the intense functional activity of the whole number of epitheliocytes that participate in the proliferation, differentiation and issue in the circulation of mature T lymphocytes, which takes place after the 17th week of development. The 17-week thymus appears fully differentiated, and after this time it produces the main type of thymocyte also present throughout life (designated TdT +).

Embryonic and Fetal Development↗
PubMed2002

Nucleolar organizer regions: their significance in the maturation of the gut-associated lymphoid tissue.

Nucleolar organizer regions (NORs) are important for regulating protein synthesis. Our study points towards the possibility of determining gut-associated lymphoid (GAL) cell proliferation and maturation in fetuses from ten to 35 weeks of gestation by means of the Argyrophilic (Ag) staining for NORs. This technique was performed on paraffin-embedded small intestine and mesentery tissue sections from 30 fetuses at the 10th, 14th, 15th, 19th, 20th, 23rd, 31st, and 35th week of gestation. Our results showed that there was no statistically significant difference concerning the mean AgNOR values, between GAL cells and mesentery lymphoid cells (2.81 +/- 0.63 to 2.63 +/- 0.71; p > 0.1), from ten to 15 weeks' gestation. In this specific period, the lymphoid cells first appear and Peyer's patches are formed in the small intestinal mucosa. In contrast, in fetuses from 19 to 35 fetal weeks NOR counts were statistically significantly greater in GAL cells than in fetuses from ten to 15 gestational weeks (as compared to NOR counts in GAL cells in fetuses at an earlier fetal age) (3.28 +/- 0.73 to 2.81 +/- 0.63). Mean AgNOR values in mesentery lymphoid cells remained unchanged (2.62 +/- 0.57) (p < 0.001). In conclusion, increasing protein synthesis from the 19th till the 35th week of gestation is indicative of immune system maturation, given that at the same time GAL cells become fully mature. Mesentery lymphoid cells pass (migrate) to the small intestinal mucosa from the bloodstream, and they form the whole out-associted lymphoid tissue (GALT) organ (Peyer's patches). The lymphatics associated with mucosa associated lymphoid tissue (MALT) are all efferent; it seems that during fetal life due to genetically determined factors, draining vessels operating as afferent lymphatics at that time, change to efferent (where the immunological response is greatly amplified) as embryonal life progresses.

Cell Count↗
PubMed2002

A quantitative study of collagen production by human smooth muscle cells during intestinal morphogenesis.

Differentiating mesenchymal cells and the extracellular matrix that these cells produce constitute the structural basis for developing organs. The splanchnopleuric mesenchyme surrounding the developing gut and respiratory tubes provides connective tissue cells to the lamina propria/submucosa and smooth muscle cells to the muscularis musosae/muscularis externa. In human fetal intestine, the identity of the matrix-producing cell or cells has begun to be elucidated. The smooth muscle cell is one of the sources of collagen fibers in the extracellular matrix in the developing human fetal intestine and collagen production is a significant function of smooth muscle cells during intestinal organogenesis. The aim of the current study was the quantitative investigation of collagen production by human fetal intestinal smooth muscle cells in various stages of development (10 to 23 weeks of gestational age). Identification of the mesenchymal cells/extracellular matrix was confirmed by immunohistochemical techniques using the following monoclonal antibodies: actin, desmin, vimentin, collagen IV and fibronectin. Histochemical stains for the presence of extracellular matrix components were also performed. Immunohistochemical analysis and the results of the histochemistry of the fetal human intestine in various stages of development revealed that the muscle cells of the muscularis externa contribute to the production of collagen in collaboration with the mesenchymal cells. This is more evident between 10 to 14 weeks of gestational age.

Actins↗
PubMed2002

Large granular lymphocytes (LGLS) activity in women with spontaneous abortions during the 1st trimester of gestation.

BACKGROUND: Despite increasing knowledge about the cell subsets that exist in the decidua in normal early pregnancy, little is known about the decidual cell subsets in women with spontaneous pregnancy failure. Decidual large granular lymphocytes (LGLs) are the most abundant lymphoid cell type found in 1st trimester maternal decidua. The function of LGLs remains controversial although freshly isolated LGLs have been shown to exert a weak natural killer cell (NK) activity. METHODS: Decidual leukocytes were investigated in 15 cases of spontaneous abortion and 15 cases of voluntary miscarriage, at 8th, 10th and 12th gestational week using a panel of monoclonal antibodies against Granzyme B (GRAN-B), CD2, CD38, CD56, and CD57 antigens and the immunoperoxidase technique. LGLs were demonstrated with the phloxine-tartazine stain. RESULTS: There was a statistically significant increase in the number of CD56 and CD57 positive cells (33.3%) to the advantage of spontaneous abortions (p<0.0001). No statistically significant difference was found in the number of GRAN-B, CD2 and CD38 positive cells in normal early pregnancy and in spontaneous abortion (overall gestational age p=0.22, 8th gestational week p=0.18, 10th and 12th gestational week, p=0.091). CONCLUSIONS: Our findings confirm previous studies referring that LGLs may have a cytotoxic activity similar to the NK activity and suggest an adverse pregnancy outcome.

Abortion, Spontaneous↗
PubMed2002

Immunohistochemical expression of vimentin and secretory component antigens in endometrial hyperplasia and neoplasia.

Vimentin is an intermediate filament protein normally expressed in mesenchymal cells, but evidence is accumulating in the literature which suggests that the aberrant expression of vimentin in epithelial cancer cells might be related to local invasiveness and metastatic potential. Previous studies strongly support the implication of vimentin in the metastatic progression of breast and cervical lesions. The secretory component is isolated from human colostrum and is of help in more precise grading of endometrial carcinoma. In this study we examined vimentin and secretory component (SC) expression in adenomatous hyperplasia, atypical adenomatous hyperplasia and well-differentiated adenocarcinoma (cribriform pattern). The results showed decreased expression of vimentin and increased expression of the secretory component as the lesion progressed to malignancy.

Adenocarcinoma↗
PubMed2002

Immunophenotypic profile of tumor infiltrating lymphocytes in medullary carcinoma of the breast.

Medullary carcinoma (MC) of the breast is considered to carry a more favorable prognosis than other subtypes of infiltrating ductal carcinoma. This is a biological paradox because its clinical behavior contrasts with its anaplastic morphology. MC is characterized by a dense lymphocytic infiltrate. In this study, we determined the immunological profile of tumor infiltrating lymphocytes (TILs) in MC by CD20 (L26), CD8, and CD45RO (UCHL 1) immunostaining on paraffin-embedded sections. We examined 14 cases of typical MC (TMC), 15 cases of atypical MC (AMC) classified according to Ridolfi criteria (1977) and 19 cases of poorly differentiated infiltrating ductal carcinoma (PDC-NOS). TILs were quantified separately into cells infiltrating tumor nests (intraepithelial) and cells infiltrating tumor stroma (stromal). The number of CD8 positive and CD20 positive cells infiltrating tumor nests and tumor stroma were significantly increased in TMC and AMC as opposed to the PDC-NOS group. There was a loss in the number of CD45RO positive cells, both intraepithelial and stromal, in TMC and AMC as opposed to the PDC-NOS group. We conclude that MC tumor lymphocytic infiltrate demonstrates a mixed-T cytotoxic (CD8+) and B cell (CD20+)-immunophenotypic profile. This might in part explain the improved clinical outcome of the disease.

Antigens, CD20↗