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Less than 5% of prenatal thymoctes express HLA-DR before week 12 of gestation. However, the number of HLA-DR- positive cells increases during the late second and third trimesters of development. To determine the role of alpha-smooth muscle actin in fetal thymic HLA-DR signaling in different stages of development we examined and compared the immunohistochemical expression of alpha-smooth muscle actin in the myoid cells of the thymic medulla stroma in the 2 nd, and 3rd trimesters of gestation respectively, over the equivalent expression of the protein in the 1 st trimester, in relation with the appearance of HLA-DR-positive thymocytes. Our results demonstrated a quantitative difference in the second and third trimesters of development concerning the expression of alpha-smooth muscle actin in the stromal myoid cells of the thymic medulla over the equivalent expression of the protein in the first (P

The fact that the CD30 molecule can mediate signals for cell proliferation or apoptosis prompted us to perform a systematic investigation of CD30 antigen expression in embryonal tissues during proliferation and differentiation stages. We first targeted the foetal human intestinal cryptae cells with positive results. The epidermis is a dynamic epithelium that is constantly renewed throughout life. The basal layer, attached to the basement membrane, contains the dividing cells of the skin and as cells move up from this layer they undergo differentiation, ending in the formation of a terminally differentiated anucleate cell called squame. It is intriguing to find out if cells in the basal layer can express the CD30 antigen. We investigated the immunohistochemical expression of CD30 antigen in 15 paraffin-embedded tissue samples representing epidermis and epidermal buds from foetuses after spontaneous abortion in the 8th, 10th and 12th weeks of gestation, respectively, using the monoclonal antibody NCL-CD30. A Northern blotting analysis was additionally performed. The results showed that: (1) the epithelial cells of the epidermis in the developing skin express the CD30 antigen; (2) CD30 expression in these epithelial cells is higher in cases of hormonal administration than in normal gestation; (3) a similar positive reaction involved the epidermal buds associated with the development of the skin appendages. Northern blots of tissue sections using a CD30 cDNA probe detected mRNAs of the same molecular mass and variety similarly to those in the positive control cell line HUT 102. [ABSTRACT FROM AUTHOR]

Aim: Sentinel lymph node (SLN) biopsy has revolutionized lymph node staging in patients with malignant melanoma. Intraoperative evaluation is a new addition to the SLN procedure that allows for a one-step regional lymph node dissection to be performed when the SLN biopsy findings are positive. The discriminatory immunostaining pattern with the S-100 and HMB45 monoclonal antibodies allows intraoperative immunocytochemical evaluation of imprint smears of SLNs for melanoma metastases., Methods: One hundred twenty eight SLNs from a cohort of 52 patient-cases that had been identified using sulfur colloid as a radioactive tracer and isosulfan blue were bisected for rapid Diff-Quick stained touch preparations. Intraopera-tive evaluation of sentinel node status by imprint cytology was correlated with the histopathological results of permanent sections. Tumor-negative nodes in routine paraffin sections were further investigated with the employment of the S-100 and HMB45 antibodies., Results: Thirty-six of all SLNs harbored metastases in paraffin sections, from which 32 were identified by imprint cytology (sensitivity 88.8%). Three SLNs were positive by imprint cytology and negative by histopathology of paraffin sections. Comparison of the results of the touch preparations with the final histopathology (hematoxylin-eosin and S-100/ HMB45 stains) demonstrated a sensitivity of 83.3% and a negative predictive value of 92.5%. The specificity and positive predictive value were 100% respectively., Conclusion: Touch imprint cytology is potentially useful for intraoperative evaluation of SLNs in malignant melanoma patients. Results can be improved if the surface sampled is appropriately enlarged and a rapid immunohistochemical S-100/HMB45 stain on the imprints is utilized.

We infected HeLa cells with low (10(-9) units), medium (10(-6) units), and high (10(-2) units) influenza B titers and compared the resulting human papilloma virus (HPV), retinoic acid receptor alpha subunit (RARalpha) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA content of surviving infected hosts with that of their uninfected precursors by semi-quantitative reverse transcriptase/polymerase chain reaction amplification (RT/PCR). This comparison revealed a moderate and drastic dependence of HPV and RARalpha mRNA content, respectively, but a complete independence of GAPDH mRNA expression on viral titer. A mechanism of adoptive replacement of tolerable cellular with viral gene expression was proposed to explain these findings. We conclude that the reported ability of influenza B viruses to specifically target and eliminate the cervical adenocarcinoma HeLa cell line studied may find practical applications in biological cancer management.

Low-grade non-Hodgkin's lymphomas (NHL) of mucosa associated lymphoid tissue (MALT) are indolent neoplasms that, although tending to remain localized for many years, may spread to other mucosal sites. Despite increasing identification of concurrent gastric and intestinal lymphoma of MALT type, the clonal relationship between the tumors and their sequential development are poorly understood. It is also unknown whether the development of these concurrent tumors is closely associated with direct antigen stimulation, which is thought to play an important role in the clonal expansion of low grade MALT lymphomas. The most important function of B-cells is production of specific antibodies. This is largely achieved during B-cell development by recombination of the Ig heavy chain variable (V), diversity (D), and joining (J) segments and hypermutation of the rearranged gene. The rearranged Ig genes of a mature B-cell record much of its evolution history. We report a case of synchronous development of intestinal and gastric low grade MALT lymphomas in a 70 years old female and discuss their possible clonal relationship and sequential appearance.

Implantation of cancer cells from needle biopsy has been reported in a wide range of malignancies. Fine needle aspiration biopsy has become an accepted method for assessment of thyroid nodules. Local reappearance of thyroid cancer from needle track dissemination is a rare complication of thyroid aspiration. A 45-year-old female developed local recurrence of papillary thyroid carcinoma four years after aspiration biopsy and thyroidectomy. Metastatic deposits appeared in the skin and the sternocleidomastoid muscle. The linear array and the site of metastases implied that seeding most probably resulted from the needle biopsy.

Originally, expression of the CD30 antigen was shown to be typical of the tumor cells of Hodgkin disease and of anaplastic large cell lymphomas. In reactive lymphoid tissue, CD30 is expressed only in a small population of activated lymphoid blasts. Since then, several reports have been published describing CD30 expression in non lymphoid tissues and neoplasms, such as embryonal carcinomas, seminomas, cultivated macrophages, histiocytic neoplastic cells, deciduals cells, and mesothelioma cells. In order to gain insight into the functions of CD30, given that it can mediate signals for cell proliferation and apoptosis, we studied the distribution of the antigen in different fetal archival paraffin-embedded tissues from week 8th to 16th of gestation. We investigated the immunohistochemical expression of CD30 in 30 paraffin-embedded tissue samples representing all three germ layers, using the monoclonal antibody Ber-H2 CD30 is expressed early in human fetal development (8th-10th week) in a wide variety of tissues, with the exception of the skin and thymus in which it is expressed later on. This is consistent with the observation that these organs are not fully differentiated before 10th and 13th week, respectively. No expression was observed in the cardiovascular and respiratory systems. The finding of CD30 expression in the terminal period of organogenesis, period, which is highly hormone related, implies that the antigen has an important role in cell development, maturation, and pathway to terminal differentiation in almost all fetal tissues and structures.

Prognosis of colonic carcinoma is poor. The two most important factors having the greatest effect on survival are pathologic stage of disease and histologic grade of the tumor. Our study points towards the value of HLA-DR antigen in the prognosis of colonic carcinoma. We studied 31 cases of normal colonic mucosa, 12 cases of tubulo-villous adenoma, and 39 cases of invasive carcinoma for the detection of HLA-DR monoclonal antigen. Yet, we investigated the association of HLA-DR and DQ genes and adenoma and carcinoma by PCR. We also studied the T helper (TH) marker (CD4) in the lamina propria of the relevant cases, given that the dependence of immune responsiveness on the class II antigens reflects the central role of these molecules in presenting antigen to TH cells. HLA-DR was expressed in 20 of 31 normal colonic mucosa (64.5%), 4 of 12 adenomas (33.3%), and in 10 of 39 invasive carcinomas (25.6%). No significant correlation between HLA-DR and DQ genes and adenoma or cancer of the colon was found. CD4 was expressed in 9 of 31 normal colonic mucosa (29%), 5 of 12 adenomas (42%), and in 26 of 39 invasive carcinomas (67%). The results showed decreased expression of HLA-DR and increased expression of CD4 as the lesion progressed to malignancy. HLA-DR and DQ genes do not contribute to a susceptibility to adenoma or carcinoma. The immune attract mechanism by low HLA-DR signaling seems to be of minor importance in the malignant and metastatic potential of the colonic carcinoma.

Objective: Serous papillary carcinomas of the endometrium are aggressive tumors that tend to permeate, in a very extensive fashion, to uterine and adnexal lymphatic and vascular channels at an early stage in their evolution, and are associated with a particularly gloomy prognosis. It is generally thought that even tumors apparently limited to the endometrium or confined to an endometrial polyp have a poor outcome. Our study points towards the value of HLA-DR antigen in the outcome of serous papillary endometrial cancer. Our aim was to assess the HLA-DR expression in inactive, endometrial intraepithelial carcinoma (EIC), and invasive serous carcinoma curretage specimens from the endometrial cavity, suggesting a role in immune response to keep tumor proliferation in check., Study Design: Thirty-one cases of inactive endometrium, twelve cases of EIC, and thirty-nine cases of serous papillary invasive carcinoma curettings were evaluated for the detection of HLA-DR monoclonal antigen. T helper (TH) marker (CD4) in the tumor 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., Results: HLA-DR was expressed in 20 of 31 inactive endometrium (64.5%), 4 of 12 in EIC (33.3%), and in 10 of 39 serous papillary invasive carcinomas (25.6%). CD4 was expressed in 9 of 31 inactive endometrium (29%), 5 of 12 in EIC (42%), and in 26 of 39 serous papillary invasive carcinomas (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 inactive endometrium, of EIC and of serous papillary invasive carcinomas agrees with the hypothesis of the inactive endometrium - carcinoma in situ sequence as the usual route for the development of serous papillary invasive carcinoma. The immune attract mechanism by low HLA-DR signaling seems to be of minor importance in the malignant and metastatic potential of the serous papillary endometrial tumours.

Background: Ki-1 (CD30) antigen expression is not found on peripheral blood cells but its expression can be induced in vitro on T and B lymphocytes by viruses and lectins. Expression of CD30 in normal tissues is very limited, being restricted mainly to a subpopulation of large lymphoid cells; in particular, cells of the recently described anaplastic large cell lymphoma (ALCL), the Reed-Sternberg (RS) cells of Hodgkin's lymphoma and scattered large parafollicular cells in normal lymphoid tissues. More recent reports have described CD30 expression in non-hematopoietic and malignant cells such as cultured human macrophages, human decidual cells, histiocytic neoplastic cells, mesothelioma cells, embryonal carcinoma and seminoma cells., Results: We investigated the immunohistochemical expression of CD30 antigen in 15 paraffin-embedded tissue samples representing small intestines from fetuses after spontaneous abortion in the 8th, 10th and 12th weeks using the monoclonal antibody Ki-1. Hormones had been administered to all our pregnant women to support gestation. In addition, a panel of monoclonal antibodies was used to identify leukocytes (CD45/LCA), B-lymphocytes (CD20/L-26) and T-lymphocytes (CD3). Our findings were correlated with those obtained simultaneously from intestinal tissue samples obtained from 15 fetuses after therapeutic or voluntary abortions., Conclusions: The results showed that: (1) epithelial cells in the developing intestinal crypts express the CD30 (Ki-1) antigen; (2) CD30 expression in these epithelial cells is higher in cases of hormonal administration than in normal gestation. In the former cases (hormonal support of gestation) a mild mononuclear intraepithelial infiltrate composed of CD3 (T-marker)-positive cells accompanies the CD30-positive cells.

Background: The thymus provides an optimal cellular and humoral microenvironment for cell line committed differentiation of haematopoietic stem cells. The immigration process requires the secretion of at least one peptide called thymotaxine by cells of the reticulo-epithelial (RE) network of the thymic stromal cellular microenvironment. The thymic RE cells are functionally specialised based on their intrathymic location and this differentiation is modulated by various interaction signals of differentiating thymocytes and other non lymphatic haematopoietic stem cells., Objectives: To study the role of another cell line in fetal thymic haematopoietic proliferation and differentiation in different stages of development: the stromal myoid cells., Design: Fifteen cases of fetal thymic specimens (4th to 8th weeks: five cases 16th to 20th weeks: five cases and 28th to 32nd weeks: five cases respectively) were studied. Tissue paraffin samples were stained immunohistochemically using (i) a monoclonal antibody recognising alpha-smooth muscle actin, a contractile microfilament expressed exclusively by smooth muscle cells, myofibroblasts and related cells, (ii) a monoclonal antibody glycophorin C recognising the erythropoietic cells., Setting: Histology-Embryology Department of Democritus University of Thrace (Alexandroupolis) over ten year period (1991-2001)., Results: The number of alpha-smooth muscle actin-positive cells significantly increased during the late second and third trimester of gestation. In the above period a relevant increase in the number of glycophorin C positive cells were observed., Conclusion: Our data suggest that a myoid cell line is involved in the formation of an appropriate microenvironment for homing and proliferation of erythropoietic cells.

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.

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.

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.

Background/aims: GERD (gastroesophageal reflux disease) occurs in 25-51% of IBS (irritable bowel syndrome) patients. Trimebutine has been effective in some IBS patients by modulating colonic motility. Furthermore, it increases gastric emptying rates, and controls esophageal motility. The aim of this study was to investigate the efficacy of trimebutine therapy in GERD patients with IBS., Methodology: Sixty-nine patients with GERD and IBS underwent upper gastrointestinal endoscopic, histologic and clinical evaluation prior to and 3 months post-treatment. H. pylori presence was determined by histology and CLOtest. Forty patients (Group A) were treated with omeprazole plus trimebutine for 3 months: in 32 H. pylori-positive patients (subgroup A1), a standard triple eradication regimen was introduced. Twenty-nine patients (Group B) were treated with omeprazole for 3 months: in 24 H. pylori-positive patients (subgroup B1), the same eradication therapy was employed., Results: Specialized intestinal metaplasia of the gastroesophageal junction was observed in 20% and in 17.2% of the patients in Groups A and B, respectively. Eradication rates were similar in subgroups A1 (84%) and B1 (83%). In Group A there was a significant improvement in GERD (P = 0.003) and IBS symptoms (P < 0.0001) as well as esophagitis (P = 0.029), when compared with Group B., Conclusions: Trimebutine appears to be effective in patients with GERD and IBS.