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Background: The effect of the b-fibroblast growth factor (b-FGF) on cyclosporine A (CsA)-induced nephrotoxicity in the rat kidney was investigated., Materials and Methods: The rats were divided into six groups: A (control), B (b-FGF-treated), C, D: (CsA-treated and sacrificed on days 14 or 21), E, F (Cs A- and b-FGF- treated and sacrificed on days 14 or 21). The antibody mouse anti-rat CD31 was used to evaluate the kidney vessels present in histological preparations., Results: The kidney vessels in group B were increased in comparison with the control group (p<0.05). Reduction of kidney vessels in groups C and D (p<0.05) in comparison with the controls was observed, while in groups E and F they were increased when compared to group C (p<0.05) and D (p<0.05), respectively., Conclusion: The angiogenic role of b-FGF was confirmed in normal rats and a possible "protective" role of b-FGF was shown in rat kidney with CsA-induced nephrotoxicity.

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: CD30 antigen has long been considered to be restricted to tumour cells of Hodgkin's disease, of anaplastic large cell lymphoma and T and B activated lymphocytes. Expression of CD30 antigen has been reported in the decidual stroma, cultivated macrophages, lipoblasts, myoepithelial cells, reactive and neoplastic vascular lesions, mesotheliomas, embryonal carcinoma and seminoma cells. 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 the proliferation and differentiation stages. We first targeted foetal human intestinal cryptae cells with positive results. The epidermis is a dynamic epithelium that is constantly renewed throughout life. Its turnover is estimated at about 7 days in mice and about 60 days in humans. This rapid replacement demands, as with other epithelial tissues, that an adult has stem cells capable of supplying differentiated cells throughout life. The most basic and widely accepted criteria for these stem cells are that they have a high capacity for self-renewal and the ability to generate daughter cells that undergo terminal differentiation. Not all of the proliferative cells in the basal layer are stem cells and we were intrigued to find out if stem or other cells in the basal layer can express the CD30 antigen., Materials and Methods: 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 8th, 10th, and 12th week of gestation, respectively, using the monoclonal antibody Ki-1., Results: The results showed that the epithelial cells of the epidermis in the developing skin express the CD30 antigen and CD30 expression in these epithelial cells is higher in cases of hormonal administration than in normal gestation. A similar positive reaction was observed in the epidermal buds associated with the development of the skin appendages.

Background: Endometrial carcinoma is the most common malignancy of the female genital tract in the Western world. COX-2 is highly expressed in endometrial carcinoma, but there is controversy regarding its clinical role and its possible prognostic role. COX-2 expression was determined by immuno-histochemistry and was correlated to standard clinico-pathologic variables in a series of primary untreated endometrial carcinoma patients. COX-2 as an accurate predictor of the disease was also analyzed., Methods: One-hundred and ten cases of primary untreated endometrial carcinoma hosts who were admitted to the Department of Obstetrics and Gynecology, University General Hospital of Alexandroupolis, were investigated. Immunohistochemistry was performed using rabbit polyclonal antiserum against human COX-2., Results: Twenty-eight patients (25.5%) were scored as COX-2 positive. A statistically significant association was found between COX-2 overexpression and FIGO stage (p=0.010). A positive correlation was also found with histological grade (p=0.019) and myometrial invasion (p=0.026). No significant association was found with histologic type of the tumor (p=0.164). COX-2 positive patients had a significant association with sort survival (p=0.028)., Conclusions: COX-2 expression is an independent clinicopathologic factor and an independent prognostic factor in endometrial carcinoma. It could be used to plan treatment modalities for hosts.

Solid mural nodule within a mucinous cystic ovarian tumor occurs more often than generally presumed. One especially interesting case involving coincidental cervical carcinoma is presented. A 38-year-old woman underwent exploratory laparotomy for a right ovarian tumor. After ovarian malignancy had been diagnosed from frozen section, the bilateral salpingo-oophorectomy and hysterectomy was performed. The tumor had a unilocular cystic cavity and a mural nodule. The nodule showed undifferentiated carcinomatous features. The immunohistochemical examination revealed atypical cells in the nodule which were positive for cytokeratin, CEA, and vimentine, establishing its anaplastic nature. A synchronous cervical invasive squamous carcinoma was documented. The patient was treated with chemotherapy and radiotherapy. Currently, at 15 postoperative months, she is well and free of disease. The occurrence of ovarian mucinous cystadenocarcinoma with mural nodule of anaplastic carcinoma and cervical squamous cell carcinoma is evidently very uncommon, because we have not found a similar case in the literature.

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.

Cutaneous infection by Herpes virus (simplex or zoster) is a common non-specific skin manifestation in patients affected by B-cell chronic lymphocytic leukemia (B-CLL) or other malignant lymphomas and is attributed to the patients' immunodeficiency. Persistent or shortly recurrent lesions, however, may represent specific cutaneous infiltrates of systemic B-CLL of several months' duration. The occurrence of these lesions as first manifestation of B-CLL is rare and previously reported only on herpes zoster scars. A case of a 63-year-old male patient with cutaneous B-CLL infiltrate of the right oral commissure at the site of herpes simplex scar as first sign of the disease is herein reported.

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.

Primary effusion lymphoma (PEL) is a recently individualized form of non-Hodgkin's lymphoma (WHO classification) that mainly develops in HIV infected males, more frequently in homosexuals and advanced stages of the disease (total CD4+ lymphocyte count below 100-200/microL). Occasionally, it appears in other immunodepressive states (such as solid organs transplant period) and even, although very rarely, in immunocompetent patients. From a pathogenetic point of view, PEL has been related to Kaposi's sarcoma associated herpes virus (also named human herpesvirus 8, HHV-8), an etiological factor of Kaposi's sarcoma. The relative infrequency of this disease, the absence of wide casuistics allowing a better characterization, and its unfavorable outcome support the need of a deeper knowledge. We present here the clinical-biological findings of a patient, HIV seronegative, who was diagnosed with peritoneal PEL of T-cell origin, and not HHV-8-associated, five years after renal transplantation.

The corticotropin-releasing hormone (CRH) system, consisting of CRH and the homologue neuropeptide urocortin together with their receptors CRH(1) and CRH(2) and a specific binding protein (CRH-BP), holds the main role in mediating the response to stressful stimuli. Besides their expression in the brain, CRH peptides and receptors have been found in multiple peripheral sites. Here we investigate the expression of CRH, urocortin, CRH receptors, and CRH-BP in the wall of human normal and inflamed gallbladders, using RT-PCR and immunohistochemistry. Urocortin, but not CRH gene transcripts, was detected in RNA isolated from human gallbladder biopsy specimens. Urocortin immunoreactivity was localized in epithelial cells of the gallbladder mucosa. Gene expression of CRH(2) receptor was also detected, and the receptor protein had a localization similar to that of urocortin. Finally, CRH-BP gene expression and low levels of protein immunoreactivity were also shown. There were no differences in the expression profiles of all the above molecules between normal and inflamed tissues. In conclusion, the CRH system is present in the human gallbladder, urocortin being the major ligand expressed, possibly exerting an autocrine/paracrine biological role via activation of the CRH(2(alpha)) receptors found locally. Further study is required to enfold the biological role of these effectors in gallbladder physiology and pathogenesis.

Salivary gland involvement in Brooke-Spiegler syndrome (BSS), an autosomal dominantly inherited disease, is known though not frequent. A case of familial cylindromatosis with parotid gland adenoma is herein reported. A 67-year-old lady presented with multiple scalp nodules and papular coalescent lesions over the nasolabial folds and the forehead. The clinical examination also revealed a left preauricular lump. Multiple biopsies of the scalp lesions and the nasolabial papules revealed cylindromas and trichoepitheliomas respectively. CT scan and FNA of the preauricular lump were suggestive of parotid gland adenoma. The patient underwent excision of the scalp cylindromas and total left parotidectomy. There is no evidence of recurrence after 4 years. The association of BSS with salivary gland tumours, emphasizes the necessity of thorough salivary gland examination in all patients with skin lesions. Knowledge of the genetic background of BSS allows for genetic counseling of patients.

Aim: Polymorphous low grade adenocarcinoma of the salivary glands (PLGA) is a low grade neoplasm that predominantly occurs in the minor salivary glands. In this site is amenable to biopsy and histologic diagnosis. However, experience with cytological findings in these tumors is limited. We describe the cytology of this entity., Experimental Design: Touch imprint cytology of a primary parotid PLGA is specified and correlated with histology., Results: Smears were hypercellular showing branching papillae, sheets and clusters of uniform cells with bland nuclei, dispersed chromatin and no nucleoli. The cells had a scant to moderate amount of eosinophilic cytoplasm. They formed tubular structures containing hyaline globules., Conclusions: The cytologic differential diagnosis of PLGA includes adenoid cystic carcinoma, pleomorphic adenoma, and monomorphic adenoma. PLGA should be considered in the differential diagnosis of head and neck tumors, where the cytology suggests on of the above mentioned tumors, even when the clinical findings (involvement of a major salivary gland, lymph node metastasis) is not typical of PLGA.

Aim: To determine the expression of CMV-associated antigen in the human decidual endometrial stromal cells in spontaneous abortions with no evidence of maternal relapse during the first trimester of gestation., Experimental Design: We examined 15 placentas resulting from intrauterine fetal death after spontaneous abortion during the 8th, 10th, and 12th week of gestation respectively, and in which CMV reactivation was ruled out from serological evaluation of the pregnant women at admission, versus equal controls after voluntary abortion following well-documented maternal viral recurrence. In addition, a panel of monoclonal antibodies for the identification of leukocytes (CD45/LCA), B-lymphocytes (CD20/L-26), and T-lymphocytes (CD45RO/UCHL1), was performed. All women received hormonal medication to support gestation, in the cases of spontaneous abortions., Results: Immunohistochemical examination using a specific antibody against cytomegalovirus showed large multinucleated infected cells with intranuclear inclusions, located primarily in the decidual stroma within a lymphoplasmacytic infiltrate in the cases of spontaneous abortions. No evidence of infection was observed in the chorionic villi. In the cases of voluntary abortions same findings were observed in the relevant areas, and a strong evidence of infection was observed in the chorionic villi., Conclusion: This study demonstrates 1) that the decidual endometrial stromal cells can express the CMV-associated antigen prior to serological manifestation of the viral replication, 2) the expression of the antigen is higher in cases of hormonal administration to support gestation. In these cases a mild mononuclear infiltrate of UCHL1 (T marker) positive cells, accompanies the CMV-associated antigen positive cells.

Aim: To determine the immunoreactivity of cholecystokinin (CCK) during the development of the human fetal pancreas and pancreatic adenocarcinoma, given that, CCK positive cells were demonstrated either in its embryonic anlage or in pancreatic cancer. In order to obtain possible parallels in the expression pattern of neoplastic cells in adults (well--moderately--poorly differentiated), we investigated the pattern of CCK expression in the pancreatic tissue during the various stages of development and compared these with the proliferation of tissue assessed by proliferating cell nuclear antigen (PCNA) immunohistochemistry., Experimental Design: Tissue sections from 15 pancreatic fetal specimens, and equal number of ductal adenocarcinoma specimens, were assessed using immunohistochemical methods for CCK., Results: The density of positive cells in the primitive exocrine ductal walls and outgrowing buds was significantly higher than the relevant density in the neoplastic pancreatic tissue of mixed (ductal-endocrine) and pure ductal type (p1=0.004, p2 < 0.0005, p3 < 0.0005 and p4=0.023 respectively). The above values were estimated from 20th to 22nd weeks of gestation. There was no significant difference in the density of positive cells in the islet cell epithelium from 25-30 weeks, and the neoplastic tissue of mixed (p5=0.10) and pure ductal type (p6=0.15)., Conclusions: The immunostaining for CCK identifies a sub-group of pancreatic ductal adenocarcinomas with a neuroendocrine component (initially considered as pure ductal tumors), and mixed ductal-endocrine tumors. This pattern of expression in neoplasms recapitulates the normal pattern during the embryonal development of the organ, and may be important for the development of new therapeutic approaches with eventual clinical utility.

Aim: To detect whether preeclampsia influences neonatal intrahepatic hematopoiesis, given that an activation of fetal neutrophils and monocytes during the course of this disorder occurs., Experimental Design: We examined liver samples from 10 neonates of hypertensive/preeclamptic women at 27 to 28 weeks of gestation delivered by a cessarian section. All neonates were placed in incubators but they all died within 24 hours due to immaturity. The control group comprised 10 fetuses of the same gestational age, after voluntary abortion due to a neural defect. Specific antibodies against CD34, glycophorin C, hemoglobins A and F, myeloperoxidase, CD61, CD68, terminal desoxynucleotidyl transferase and the pax-5/B-cell specific activator protein, were used in each sample., Results: Neonates from hypertensive/preeclamptic women, in comparison with controls, showed: a statistically significant reduction of erythropoiesis by 25% (p=0.015); a statistically significant increase of granulopoiesis (p=0.019); a statistically significant increase in the expression of CD68 positive cells of the monocytic lineage (p=0.017); a statistically significant increase in the expression of CD34 progenitor/stem positive cells (p=0.021). No statistically significant differences were observed in both examined groups, concerning megakaryopoiesis and B lymphopoiesis., Conclusions: Preeclampsia of pregnancy has an impact on neonatal intrahepatic hematopoiesis by increasing granulopoiesis, reducing erythropoiesis and triggering endothelial and stem cell activation. We suggest that these findings reflect a state of persistent inflammation and a loss of red blood cell production possibly contributing to the neonatal morbidity related to this disorder.

Aim: Breast cancer is a frequent cause of death among women with gynaecologic malignancies despite the introduction of combination chemotherapy. There is therefore a need for new therapeutic strategies for patients with breast cancer, such as cellular immunotherapy. In this immunohistochemical study we analyzed the epithelial expression of major histocompatibility complex (MHC) class II (HLA-DR) on atypical and malignant primary mammary epithelial cells, as well as the magnitude of the stromal T lymphocytes (T4 subset) at the tumor site., Experimental Design: The study was carried out retrospectively in tumor tissue from 82 patients with mammary lesions (31 cases of atypical ductal hyperplasia -ADH-, 12 cases of ductal carcinoma in situ -DCIS- and 39 cases of infiltrating ductal carcinoma not otherwise specified -IDC-NOS). Medullary carcinomas were not included in our investigation. Material used had been formalin fixed and paraffin embedded., Results: HLA class II (DR) was expressed in 20 of 31 ADHs (64.5%), in 4 of 12 DCISs (33.3%), and in 10 of 39 IDC-NOSs (25.6%). CD4 was expressed in 9 of 31 ADHs (29%), in 5 of 12 DCISs (42%), and in 26 of 39 IDC-NOSs (67%)., Conclusions: The results showed decreased epithelial expression of HLA class II (DR) and increased stromal expression of CD4, as the lesion progressed to malignancy. Gradual loss of epithelial HLA class II expression might be a manifestation of cellular differentiation from the atypical form versus the malignant one, signaling simultaneously a selective effect on the response capacity of the immune system.

Recently we demonstrated that lipopolysaccharide (LPS) promotes activation of the Ras/ERK cascade in medfly hemocytes and that phagocytosis of Escherichia coli by insect hemocytes is mediated by an integrin-dependent process via the activation of FAK/Src complex (J Biol Chem 273 (1998) 14813; FEBS Letters 496 (2001) 55). In the current study we wanted to further elucidate the effects of LPS on medfly hemocytes, in order to better understand the regulation of the evolutionary conserved signaling mechanisms between insects and mammals. We initially observed that different stimuli, including LPS, E. coli, RGD, fibronectin and heat shock activate hemocyte ERK. The response of hemocytes to these stimuli denoted that hemocyte ERK is evidently stimulated by at least an LPS receptor and via an integrin-mediated process. The medfly hemocytes respond to LPS by changing their morphology, inducing the activation of several signaling pathways, including Ras/MEK/ERK, PI-3K/ERK and Rho pathways and contributing to LPS uptake. Experiments based on inhibitors of specific signaling pathways, such as manumycin A, toxin A, U0126, PD98059 and wortmannin revealed that Ras, MEK and PI-3K are involved in the activation of ERK. Whether PI-3K is an intermediate of Ras/MEK/ERK pathway or activates ERK via other signaling pathway it remains to be elucidated. ERK is not activated via Rho pathway, denoting that Rho may not be an upstream effector molecule of ERK pathway. Regarding the role(s) that these kinases play in hemocytes, it can be suggested that PI-3K and Rho GTPases can modulate hemocyte shape changes, whereas ERK, Ras and MEK cannot. In addition, PI-3K as well as Ras and MEK through ERK activation participate in LPS endocytosis. Therefore, PI-3K shares a dual role; it is involved both in cell shape changes and in LPS endocytosis. Since ERK activation appears to be independent of the integrity of actin filaments, as cytochalasin D and latrunculin A did not block ERK activation, it can be concluded that LPS endocytosis is independent of actin cytoskeleton remodeling as is the case in mammalian systems.

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.

A doublet of medfly hemocyte proteins with a molecular mass of about 55 and 50 kDa were precipitated with LPS. Antibodies raised against human CD14 recognize the same doublet of proteins. These results support that mammalian CD14 and the doublet of protein bands in medfly hemocytes share common epitopes. This doublet of protein bands is released from hemocytes upon LPS triggering. A portion of the released protein is clustered on the surface of a distinct hemocyte type and the other remains soluble. The membrane-bound LPS-binding protein is involved in LPS internalization and Escherichia coli phagocytosis but not in LPS signaling., (Copyright 2003 Wiley-Liss, Inc.)

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.

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.

Background: Small-cell lung carcinoma (SCLC) is a highly malignant tumour of a somewhat distinctive cell type. The aim of this study was to determine the immunocytochemical profile of tumor cells and lymphoid cell in SCLC pleural fluids., Methods: Nine cases of malignant pleural fluids of SCLC were studied using cell block preparation. In pleural effusions cytologically proven to be malignant in 9 patients with SCLC, the immunocytological features of tumor cells, together with the determination of lymphocytic subsets were documented., Results: In all 9 cases, tumor cells reacted with neuron-specific enolase (NSE) (100%), whereas in 6 of 9 cases (66,66%) tumor cell expressed synaptophysin, thyroid transciption factor-1 (TTF-1) and chromogranin A antigens. Phenotyping of the lymphocytes revealed in the majority of cases an expression of CD3 and CD4 antigens (8 and 7 cases, respectively) in contrast to CD8 and CD20 expression (1 and 1 case, respectively)., Conclusions: The reactivity pattern of the tumor cells with the markers used in our study is a specific for SCLC. No significant difference in the distribution of lymphocytic subpopulations is observed in correlation with other malignant and no malignant processes involving the pleural cavity.

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.

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.

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.

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 +).

CD44 is an adhesion molecule, which binds hyaluronic acid and participates in a number of cell-cell interactions, including lymphocyte homing. The CD44 antigen is expressed on approximately 90% of lymphocytes, monocytes, granulocytes, and, in lower amounts on thymocytes, fibroblasts, and erythrocytes. Platelets lack CD44. In non-haematopoietic tissues, CD44 is widely distributed. The secretory component is isolated from human colostrum and is of help in more precise grading of endometrial carcinoma. In this study we examined CD44 and secretory component expression in adenomatous hyperplasia, atypical adenomatous hyperplasia and well-differentiated adenocarcinoma (cribriform pattern). The results showed decreased expression of CD44 and increased expression of secretory component as the lesion progressed to malignancy.

Serous papillary ovarian cancer (SPC) is a highly aggressive tumor. About two-thirds of women have advanced disease at the time of diagnosis. Although many women with disseminated disease respond at first to combinations of surgery and chemotherapy, nearly 90% of tumors recur and women die of disease. Update progress in our knowledge of tumor-associated antigens and insight into mechanisms involved in immune-mediated recognition of these antigens, have provided a strong starting point for using the immune system as a model for novel therapy. In this study we determined the immunological profile of tumor-infiltrating lymphocytes (TILs), tumor-associated lymphocytes (TALs) in ascitic fluids, and lymphocytes from tumor draining regional lymph nodes (LNs) in SPC patients by CD20 (L26), CD8, and CD56 immunostaining. We examined 14 cases of TILs, 15 cases of TALs and 19 cases of LNs. TILs were infiltrating tumor stroma. No significant difference was detected in TILs, TALs and LNs in the expression of the B-cell marker CD20. In contrast, CD8 (T-cytotoxic) and CD56 (natural killer cell, NK) markers were dominant in LNs and TALs, but not in TILs. We conclude that SPC tumor lymphocytic infiltrate demonstrates a deplete T cytotoxic (CD8+) and NK cell (CD56+) immunophenotypic profile. This might in part explain the poor clinical outcome of the disease.

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.

Ewing's sarcoma arising in the right fibula was diagnosed in a 12 years old female, considering clinical presentation, radiological findings and histological features. Our work points towards a possible neuroectodermal origin of Ewing's sarcoma, since MIC2/12E7 marker was found to be positive. Translocation t (11;22) (q24;q12) was found as the main cytogenetic change in this tumor, by means of FISH analysis.

Recently we demonstrated that lipopolysaccharide promotes activation of the Ras/mitogen-activated protein cascade in hemocytes and that phagocytosis of Escherichia coli by insect hemocytes is mediated by an integrin-dependent process [Foukas et al. (1998) J. Biol. Chem. 273, 14813--14818]. Here we report data concerning the focal adhesion kinase (FAK) tyrosine phosphorylation status in hemocytes in response to E. coli. We demonstrate that E. coli-triggering stimulates a significant increase in tyrosine phosphorylation of FAK in hemocytes. Furthermore, immunoblotting analysis using anti-Y397 demonstrated intense FAK activity at the Y397/SH2-binding site in hemocytes treated with E. coli. In addition, antibody-mediated inhibition of FAK and Src-kinase has been shown to abolish FAK phosphorylation and E. coli phagocytosis, indicating a specific role for the FAK/Src complex in the processes of promoting cell phagocytosis. These findings expand the known signaling functions of FAK and provide insight into signal transduction events associated with hemocyte phagocytosis in response to E. coli.

A high proportion of extranodal lymphoid infiltrates are diffuse small lymphocytic proliferations [1, 2] and therefore pose a particularly challenging diagnostic problem [1-4]. Their benign or malignant nature cannot be determined using clinical and radiologic criteria. The application of traditional morphologic criteria (i.e., cytologic maturity and polymorphism favor benignancy, while cytologic atypia and monomorphism favor malignancy) [5, 6], has probably improved diagnostic accuracy. However, these criteria generally have not been helpful in evaluating the large number of lymphoid infiltrates composed of monomorphic collections of small cytologically-mature appearing lymphoid cells [1-4] and, therefore, have not always accurately predicted clinical behavior. Extranodal lymphoid proliferations are also of considerable biologic interest since their pathogenesis and natural history have not been fully elucidated. Localized non-Hodgkin's lymphoma, extranodal-MALT-type. was diagnosed in our Department in three cases: Two arose in the orbit and the third one in the tonsil. The tumors had a typical histologic appearance. The microscopical features and immunohistochemical profile are discussed.

We describe a rare case of an extragonadal retroperitoneal endodermal sinus (yolk sac) tumor in the minor pelvis. Radiologic investigation, which included abdominal ultrasound and computed tomography (CT), showed a large soft tissue mass occupying the pelvic cavity. Radionuclide bone scans demonstrated bone metastases. The serum alpha fetoprotein was elevated. Pathologic examination of the surgical specimen revealed extragonadal yolk sac tumor. Immunohistochemically, the tumor was positive for a-feto-protein and cytokeratins. After postoperative combination therapy, follow-up CT showed decreasing tumoral disease, while serum alpha fetoprotein returned to normal.

Abdominal wall endometriosis (AWE) is a rare event. Only a few reports in the literature mention sonographic features of this clinical entity. We describe a case of a young woman with subcutaneous endometriosis under the surgical scar of a previous cesarean section. Physical examination, ultrasound findings, histopathological features and differential diagnostic problems are discussed. Ultrasound examination, in combination with clinical history, is a useful method in the diagnosis of abdominal wall endometriosis and the avoidance of diagnostic pitfalls.

A case of mucinous carcinoma of the breast is reported in a female aged 71 years. On gross examination of the left mastectomy specimen two relatively well-circumscribed masses with a gelatinous cut surface were found. Touch imprint cytology was consistent with a low-grade malignancy and histologic and histochemical examination revealed a mucinous carcinoma. Careful prospective correlation between the cytological appearances of cells in imprints and the subsequent histopathology may lead to a more precise cytodiagnosis of a tumor associated with a comparative good prognosis.

Mammary non-Hodgkin's lymphomas are uncommon and account for 2% of all extranodal lymphomas. Stringent diagnostic criteria are applied in the diagnosis of primary lymphoma considering that the breast is a recognized site for disseminated extranodal lymphoma. Our case report was established by histology alone.

Lymphocytes are a constituent of normal marrow. Both B and T lymphocytes are derived from bone marrow stem cells. Lymphocytes are found in normal marrow as single cells and in lymphoid aggregates or follicles. Lymphocytes and precursors are particularly prominent in bone marrow from children in which they may account for up to 40% of the bone marrow cells. The development of hematopoetic cells within the bone marrow (BM) occurs in intimate association with cells of the bone marrow microenvironment. This phenotypically diverse population of connective tissue-type cells includes fibroblasts, macrophages, adipocytes and endothelial cells and, collectively, represents the stromal tissue of the bone marrow. The presence of myoid cells in human bone marrow has been observed during hemopoiesis in embryonic life, whereas during adult life, it is strictly related to different pathologic conditions such as metastatic carcinoma, Hodgkin's disease, hairy cell leukemia and chronic myelo-proliferative diseases. Under normal circumstances, lymphoid cells may constitute up to 20% of the population of nucleated cells in the bone marrow. However, there may be an absolute or a relative increase, the latter due to a reduction in hematopoietic tissue, as in some skeletal areas in advancing age, or in hypoplastic conditions. The aim of this study was to examine the presence, distribution and quantitation of cells expressing alpha-smooth muscle actin in the stroma of the BM of patients with nodular type b-cell chronic lymphocytic leukemia (B-CLL), patients with autoimmune disorders and embryos (gestational age 15 to 25 weeks). For this reason, we investigated the presence of myoid cells (MCs) in a series of 20 trephine bone marrow biopsies from adult patients and ten fetal specimens of the spine and femur, using a monoclonal antibody recognizing alpha-smooth muscle actin, a contractile microfilament expressed exclusively by smooth muscle cells, myofibroblasts and related cells. The results of our study showed that: 1. BM stromal myoid cells represent a distinct subpopulation of reticular cells in the bone marrow, undergoing cytoskeletal remodeling in response to various stimuli (fetuses). 2. The appearance of BM stromal myoid cells is not only seen as a characteristic feature in B-CLL, but is also seen, to a lesser degree, in the stroma of bone marrow in patients with autoimmune disorders. 3. Stromal cells with phenotypic smooth muscle features appear in bone marrow during pathological situations in a manner reminiscent of what occurs during normal development.

Non-specific granulomatous mastitis (NSGM) is a tumor-like inflammatory condition involving breast lobules. Its recognition is of great significance because of clinical masquerade to invasive carcinoma. A 25-year-old woman developed a palpable breast lump with clinical and mammographic findings suggestive of malignancy. Touch imprint cytology of the excised lump was consistent with a granulomatous inflammation while histopathological examination documented a NSGM with central necrosis. Clinical, radiologic and laboratory testing failed to identify any specific causative agent.

Insect hemocytes in response to lipopolysaccharide (LPS) of Gram-negative bacteria facilitate binding and internalization of either cell-associated or cell-free LPS (Charalambidis, N. D., Foukas L. C., and Marmaras V. J. (1996) Eur. J. Biochem. 236, 200-206). An early event in LPS signaling in hemocytes involves protein tyrosine phosphorylation (Charalambidis N. D., Zervas C. G., Lambropoulou M., Katsoris P. G., and Marmaras V. J.(1995) Eur. J. Cell Biol. 67, 32-41). Here we report further data of LPS-mediated signal transduction responsible for Escherichia coli phagocytosis. We demonstrate that both adhesion of hemocytes to substrata and LPS stimulation can cause activation of p44(MAPK) in Ceratitis capitata hemocytes but with distinct kinetics indicating different functions. In addition, we showed that Drk, a homolog protein to the mammalian GRB2, is implicated in the transmission of LPS signaling, indicating that the Ras/mitogen-activated protein kinase pathway is involved. Either the cell-free or the cell-associated LPS appears to attach to the hemocyte surface by the same mechanism that is based on the cross-linking of LPS to membrane-associated p47 via the intermediacy of tyrosine derivatives generated by the action of phenol oxidase. By contrast, the cell-free LPS internalization into the hemocytes differs from the cell-associated LPS internalization. For E. coli internalization integrin receptors as well as cytoskeletal rearrangements are required, as judged by inhibition of E. coli internalization in the presence of the RGD peptide, beta3-integrin antibodies, and cytochalasin D.

Insect hemocytes (blood cells) synthesize the major nonself recognition protein (47 kDa) during 3rd instar larvae (V.J. Marmaras, S. Tsakas, Dev. Biol. 129, 294-303 (1988)). In this study we show the presence of the 47 kDa protein in plasmatocytes (main hemocyte type) and prohemocytes. In plasmatocytes this protein appears to be localized both in vesicles and in the cell surface. The cell surface-associated 47 kDa protein was released from membrane fraction by 1 M NaCl, indicating that it is not tightly bound. Bacterial lipopolysaccharide (LPS) can function on isolated hemocytes from Ceratitis capitata larvae, inducing their spreading and degranulation. During degranulation (exocytosis) the plasmatocytes release the 47 kDa protein, among others. This protein could not be normally traced in serum, nor is it released by basal secretion. The secretion of the 47 kDa protein was found to be LPS-dependent, whereas its presence on plasmatocyte surface is LPS independent. LPS-stimulated exocytosis of the 47 kDa protein appears to be dependent on protein tyrosine phosphorylation. We have now demonstrated that LPS increases tyrosine phosphorylation of 19 and 22 kDa polypeptides in C. capitata hemocytes. Inhibition of the LPS-induced tyrosine phosphorylation mediated by tyrosine kinase inhibitor, genistein, was accompanied by the inhibition of the secretion of the 47 kDa protein. These results support the hypothesis that tyrosine protein phosphorylation is a signal reaction in hemocytes after LPS exposure. These LPS responses of insect plasmatocytes show strong similarities to mammalian macrophages (S. Weinstein et al., J. Immunol. 151, 3829-3838 (1993)). In a model we propose that the LPS-independent cell surface-associated 47 kDa protein is responsible for the phagocytosis and for the formation of nodules and capsules, whereas the LPS-dependent secreting counterpart is responsible for the extracellular killing of bacteria.

A defense mechanism in the hemocytes and cuticle of developing Ceratitis capitata has been demonstrated (Marmaras and Charalambidis, 1992; Marmaras et al., 1993a; Marmaras et al., 1993b). To elucidate further the mechanism and the regulation of defense reactions, we studied this process in relation to melanization in the major larval tissues, in two distinct developmental stages; the feeding and wandering larval stages. The results demonstrate that defense reaction depends on reactive tyrosine derivatives of either early or late stages of the sequence of reactions involved in eumelanin biosynthesis. However, defense and melanization occur independently e.g. hemocytes exhibit a high degree of Escherichia coli immobilization and entrapment, but not any ability to biosynthesize melanin. Serum on the other hand, showed a high degree of melanin formation in wandering stage larvae, but had not any ability for E. coli immobilization. In integuments of wandering stage larvae, both processes occur simultaneously. These findings suggest independent control mechanisms for these processes. Indeed, our results suggest that defense seems to be controlled by the presence of proteins responsible for nonself recognition and melanization by developmental regulation of dopachrome conversion factor.

Studying defense and melanogenesis processes in the cuticle of the "white pupae" (wp) and "dark pupae" (dp) mutant strains of Ceratitis capitata, we showed that both processes function equally well only in the cuticle of dp mutants, as in the wild-type cuticle. The cuticle of wp mutants lacks the ability to form Escherichia coli aggregates and to melanize in vivo. However, in this mutant, tyrosinase and dopachrome conversion factor activities, as well as melanin content and nonself-recognition proteins are expressed as in the wild strain. The present results indicate that the inability of wp mutant cuticle to immobilize E. coli seems to be due to lack of suitable site(s) on nonself-recognition proteins for adduct formation with tyrosine derivatives by the action of tyrosinase, and the inability to melanize, very probably due to deficiency of tyrosine derivatives (tanning precursors).

The mechanism of recognition of foreignness and entrapment of invaders by the immune system of insects is unknown. In this report using hemocyte monolayer preparations and biochemical analysis we demonstrate the requirements for recognition of E. coli in vitro, their entrapment by hemocytes, and nodule formation. A model system consisting of an isolated hemocyte protein (47 KDa), isolated hemocyte tyrosinase, isolated hemocytes, tyrosine, and E. coli was used to obtain these results. The 47 kDa polypeptide has the ability to form adducts with tyrosine derivatives generated by the action of tyrosinase and to attach to the E. coli surface. The latter process takes place independently of tyrosinase activity. When the E. coli-47KDa protein complex was overlaid on hemocyte monolayers followed by tyrosine and tyrosinase or vice versa, the bacteria were entrapped by hemocytes. The same results were obtained when the monolayers were overlaid with 47 KDa protein, followed by E. coli-47 KDa protein complex and then tyrosine and tyrosinase. The same experimental procedure in test tubes resulted in nodule formation. These results permit us to propose that the most likely explanation for the entrapment of E. coli to hemocytes and the formation of nodules is the production of E. coli-47 KDa complexes, and their crosslinking through a quinone intermediate generated by the action of tyrosinase on hemocytes.

A defense mechanism in the cuticle of developing C. capitata was demonstrated using an in vitro system consisting of isolated cuticular tyrosinase from C. capitata, cuticular tyrosinase-free proteins, tyrosine, and E. coli. The simultaneous presence of the above components resulted in the formation of large immobilized E. coli aggregates. By contrast, omission of any of the above components failed to produce such aggregates. In other words, E. coli retained their mobility and viability. The results indicate that certain cuticular proteins are responsible for the nonself-recognition, since they are able to bind to the E. coli surface in vitro, and a reactive tyrosine derivative is generated by the action of cuticular tyrosinase for the immobilization and probably killing of E. coli. Based on these studies the most likely explanation for the nonself-recognition and immobilization and/or killing of bacteria is the production of E. coli-protein complexes and their crosslinking through quinone intermediate.