Stroma

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Stroma

  • chloroplast stroma
  • connective tissue stroma
  • corneal stroma
  • desmoplastic stroma
  • endometrial stroma
  • fibrous stroma
  • hyalinized stroma
  • marrow stroma
  • myxoid stroma
  • surrounding stroma
  • tissue stroma
  • tumor stroma
  • tumour stroma

  • Terms modified by Stroma

  • stroma cell

  • Selected Abstracts


    Stroma remodelling during healing of corneal surface irregularities induced by PTK

    ACTA OPHTHALMOLOGICA, Issue 4 2007
    Marios Panagiotopoulos
    Abstract. Purpose:, To study the histopathology of the remodelling process in the stroma after excimer-laser-induced corneal irregular injuries. Methods:, Seven New Zealand white rabbits received in one eye a transepithelial plano photoablation (60 µm) and an additional plano ablation (25 µm). On the denuded stroma, an electron microscopy specimen grid was placed and another 25 µm ablation was applied to produce surface irregularities. Dichlorotriazinyl aminofluorescein (DTAF) was then applied for 45 seconds. Another seven right eyes of seven rabbits were ablated the same way but without using the grid, resulting in a plano ablation. All the rabbits were killed at weekly intervals after treatment. The harvested corneas from both eyes were further processed for haematoxylin-eosin staining and were also stained with monoclonal antibodies directed against Ki-67 antigen and ,-smooth muscle actin (,-SMA). All specimens were examined under light and fluorescence microscope. Results:, The corneal wounds were covered by epithelium during the first week. The 25 µm × 25 µm × 25 µm stromal irregularities were clearly discernible up to 3 weeks after treatment, during which time they melted and disappeared. A homogeneous zone was formed in which stroma cells laid down an initially disorganized stroma. This was sharply visible under a fluorescence microscope as a dark area between the dichlorotriazinyl aminofluorescein (DTAF) fluorescent stroma and autofluorescent epithelium. Very little response was seen in the plano-ablated wound microscopically and in terms of positive stained cells. Conclusion:, As the irregularities are flattened and the homogenous zone becomes repopulated with keratocytes forming extracellular matrix material (ECM), the cornea regains its previous architecture in both groups. The irregular wound surface promotes wound-healing reactivity, a process that allows the cornea to compensate for the irregularities and heal to a functional state. [source]


    Molecular characterization of regenerated cardiomyocytes derived from adult mesenchymal stem cells

    CONGENITAL ANOMALIES, Issue 1 2002
    Keiichi Fukuda
    ABSTRACT, We recently isolated a cardiomyogenic (CMG) cell line from murine bone marrow stroma, and in this paper characterize regenerated cardiomyocytes derived from adult mesenchymal stem cells at the molecular level. Stromal cells were immortalized, exposed to 5-azacytidine, and repeatedly screened for spontaneously beating cells. CMG cells began to beat spontaneously after 2 weeks, and beat synchronously after 3 weeks. They exhibited sinus-node-like or ventricular-cell-like action potentials. Analysis of the isoforms of contractile protein genes, such as of myosin and ,-actin, indicated that their phenotype was similar to that of fetal ventricular cardiomyocytes. The cells expressed Nkx2.5, GATA4, TEF-1, and MEF2-C mRNA before 5-azacytidine exposure, and MEF2-A and MEF2-D after exposure. CMG cells expressed ,1A, ,1B, and ,1D -adrenergic receptor mRNA prior to differentiation, and ,1, ,2 -adrenergic and M1, M2 -muscarinic receptors after acquiring the cardiomyocyte phenotype. Phenylephrine induced phosphorylation of ERK1/ 2, and the phosphorylation was inhibited by prazosin. Isoproterenol increased the cAMP level 38-fold and beating rate, cell motion, % shortening, and contractile velocity by 48%, 38%, 27%, and 51%, respectively, and the increases were blocked by CGP20712A (,1 -selective blocker). Car-bachol increased IP3 32-fold, and the increase was inhibited by AFDX116 (M2 -selective blocker). These findings demonstrated that the regenerated cardiomyocytes were capable of responding to adrenergic and muscarinic stimulation. This new cell line provides a model for the study of cardiomyocyte transplantation. [source]


    Incidence and cytological features of pulmonary hamartomas indeterminate on CT scan

    CYTOPATHOLOGY, Issue 3 2008
    A. Saqi
    Objective:, Pulmonary hamartomas have a characteristic heterogeneous radiological appearance. However, when composed predominantly of undifferentiated mesenchymal fibromyxoid component, their homogeneous appearance on computed tomography is indeterminate for malignancy. Rendering an accurate preoperative diagnosis in these cases can alter management. The aim of this study was to determine the incidence and accuracy of cytodiagnosis for hamartomas ,indeterminate' by imaging. Methods:, We retrospectively reviewed records for hamartomas diagnosed by transthoracic fine needle aspiration (FNA) including immediate impressions and final diagnoses. Cytological features evaluated included the presence of fibromyxoid stroma, bronchioloalveolar cell hyperplasia, fibroadipose tissue, cartilage and smooth muscle. Results:, Eighteen (1.3%) hamartomas were identified from 1355 transthoracic FNAs. The immediate impression was hamartoma in 13 (72%), carcinoid in one (6%), mucinous bronchioloalveolar carcinoma in two (11%) and non-diagnostic in two (11%). The final diagnosis of hamartoma in cases diagnosed as carcinoid, mucinous bronchioloalaveolar carcinoma and non-diagnostic on immediate impression was rendered following assessment of all cytological material. Conclusion:, Overall, FNAs are highly reliable for diagnosing hamartomas even when composed principally of undifferentiated mesenchymal fibromyxoid stroma, especially with the aid of all available preparations including Diff-Quik smears, Papanicolaou smears, ThinPreps and cell block material. [source]


    Increased Glycosaminoglycans Production in Sclerosing Basal Cell Carcinoma-Derived Fibroblasts and Stimulation of Normal Skin Fibroblast Glycosaminoglycans Production by a Cytokine-Derived from Sclerosing Basal Cell Carcinoma

    DERMATOLOGIC SURGERY, Issue 11 2000
    Ronald L. Moy MD
    Sclerosing basal cell carcinoma (S-BCC) is characterized by an abundant stroma. There is evidence that some tumor cells secrete cytokines that are mitogenic for stromal fibroblasts (FBs). From this study we report increased glycosaminoglycan (GAG) production by cultures of S-BCC FBs in comparison to cultures of nodular BCC (N-BCC) FBs and normal skin FBs. GAG production was measured by cetylpyridinium chloride precipitation of incorporated [3H]-glucosamine. The sclerosing BCC FBs demonstrated a significant increase in production of GAG over control FBs (P < .001) and over N-BCC FBs (P < .001). Values reported as a mean percentage ± SEM for GAG production by S-BCC over control normal skin FBs are 359 ± 28 and over N-BCC FBs are 266 ± 27. In additional experiments, cell extract dilutions from S-BCC tumor, normal dermis, and normal epidermis were incubated with cultures of normal skin FBs. S-BCC-conditioned media was also incubated with normal FBs and GAG production was measured. For both S-BCC extracts and conditioned media, a dose response curve was established showing increased GAG production by normal FBs in relation to increasing the concentration of S-BCC extract or conditioned media. When S-BCC extract was added to normal FBs there was increased GAG production in comparison to normal FBs incubated with dermal or epidermal extracts (P < .001) for both. Two growth factors, transforming growth factor-, (TGF-,) and platelet-derived growth factor (PDGF), already known to be mitogenic for FBs, were incubated with N-BCC and normal FBs in an effort to elucidate the potential cytokine(s) released by S-BCC, causing increased GAG production by surrounding FBs. Neither of these cytokines proved to be effective in promoting a significant increase in GAG production. Our findings support the hypothesis that BCCs release factors that alter stromal FB production of GAG. [source]


    Development of the corneal stroma, and the collagen,proteoglycan associations that help define its structure and function

    DEVELOPMENTAL DYNAMICS, Issue 10 2008
    Andrew J. Quantock
    Abstract The cornea of the eye is a unique, transparent connective tissue. It is comprised predominantly of collagen fibrils, remarkably uniform in diameter and regularly spaced, organized into an intricate lamellar array. Its establishment involves a precisely controlled sequence of developmental events in which the embryonic cornea undergoes major structural transformations that ultimately determine tissue form and function. In this article, we will review corneal developmental dynamics from a structural perspective, consider the roles and interrelationships of collagens and proteoglycans, and comment on contemporary concepts and current challenges pertinent to developmental processes that result in an optically clear, mature cornea. Developmental Dynamics 237:2607,2621, 2008. © 2008 Wiley-Liss, Inc. [source]


    Human primary corneal fibroblasts synthesize and deposit proteoglycans in long-term 3-D cultures

    DEVELOPMENTAL DYNAMICS, Issue 10 2008
    R. Ren
    Abstract Our goal was to develop a 3-D multi-cellular construct using primary human corneal fibroblasts cultured on a disorganized collagen substrate in a scaffold-free environment and to use it to determine the regulation of proteoglycans over an extended period of time (11 weeks). Electron micrographs revealed multi-layered constructs with cells present in between alternating parallel and perpendicular arrays of fibrils. Type I collagen increased 2,4-fold. Stromal proteoglycans including lumican, syndecan4, decorin, biglycan, mimecan, and perlecan were expressed. The presence of glycosaminoglycan chains was demonstrated for a subset of the core proteins (lumican, biglycan, and decorin) using lyase digestion. Cuprolinic blue,stained cultures showed that sulfated proteoglycans were present throughout the construct and most prominent in its mid-region. The size of the Cuprolinic-positive filaments resembled those previously reported in a human corneal stroma. Under the current culture conditions, the cells mimic a development or nonfibrotic repair phenotype. Developmental Dynamics 237:2705,2715, 2008. © 2008 Wiley-Liss, Inc. [source]


    Reciprocal chemokine receptor and ligand expression in the human placenta: Implications for cytotrophoblast differentiation

    DEVELOPMENTAL DYNAMICS, Issue 4 2004
    Penelope M. Drake
    Abstract At the onset of pregnancy, the human placenta, which forms the interface between the embryo/fetus and the mother, must rapidly develop into a life-sustaining organ. The many unusual processes entailed in placental development include the poorly understood phenomenon of maternal tolerance of the hemiallogeneic cells of the conceptus, including, most remarkably, placental trophoblasts that invade the uterine wall. To investigate whether this fetal organ exerts control over the maternal immune system at the level of leukocyte trafficking, we examined placental expression of chemokines, well-known cytokine regulators of leukocyte movements. In situ hybridization revealed abundant expression of 13 chemokines in the stromal but not the trophoblast compartment of chorionic villi. Potential roles for these molecules include recruitment of the resident macrophage (Hofbauer cell) population to the villi. In parallel, cytotrophoblast production of a panel of nine chemokine receptors was assessed by using RNase protection assays. The numerous receptors detected suggested the novel possibility that the paracrine actions of chemokine ligands derived from either the villous stroma or the decidua could mediate general aspects of placental development, with specific contributions to cytotrophoblast differentiation along the pathway that leads to uterine invasion. Developmental Dynamics 229:877,885, 2004. © 2004 Wiley-Liss, Inc. [source]


    Fine-needle aspiration diagnosis of a metastatic adult sclerosing rhabdomyosarcoma in a lymph node

    DIAGNOSTIC CYTOPATHOLOGY, Issue 10 2010
    Richard L. Cantley M.D.
    Abstract Adult sclerosing rhabdomyosarcoma (ASRMS) is a rare variant of rhabdomyosarcoma with a characteristic histological appearance of small, round cells in a dense, hyalinized stroma. Although nodal metastases of soft-tissue sarcomas are considered uncommon, up to 5% overall are associated with lymph node metastases. Nonetheless, there is little literature on the cytologic characteristics of metastatic soft-tissue sarcomas in lymph nodes, and to our knowledge, there are no reports of nodal metastasis of ASRMS diagnosed by fine-needle aspiration (FNA) cytology. We report here a 55-year-old woman who presented with a right thigh mass and associated ipsilateral inguinal lymphadenopathy. Biopsy of the mass revealed a uniform population of small, round cells in a dense, sclerotic background. A diagnosis of ASRMS was rendered. Subsequently, the patient underwent FNA of an enlarged inguinal lymph node, which revealed an identical population of small, round cells in a dense, myxoid background. This case highlights the cytologic features of a rare form of rhabdomyosarcoma, and emphasizes the utility of FNA in the assessment of lymphadenopathy in the setting of a soft-tissue sarcoma. Diagn. Cytopathol. 2010;38:761,764. © 2010 Wiley-Liss, Inc. [source]


    Papanicolaou tests associated with cervical mucosal endometriosis: An analysis of cellular features and comparison to endocervical adenocarcinoma in situ

    DIAGNOSTIC CYTOPATHOLOGY, Issue 8 2010
    Charles V. Biscotti M.D.
    Abstract Endometrium directly sampled from endocervical mucosal endometriosis can mimic endocervical adenocarcinoma in situ (AIS) in Papanicolaou (Pap) tests. We analyzed a series of Pap tests to investigate the cellular features of mucosal endometriosis and to assess the utility of stroma and apoptotic bodies in the differential diagnosis with AIS. Pap test samples from patients known to have endocervical mucosal endometriosis were compared with samples containing AIS. Pap tests from patients with mucosal endometriosis had lesional cells in 13 (62%) cases which includes glandular and stromal cells (10 cases), stroma only (two cases), and glandular cells only (one case). Three (23%) cases had gland-stromal aggregates. Three (23%) cases had mitotic figures and two (15%) had apoptotic bodies. By comparison, only one (8%) AIS case had endometrial-type stroma. Seven (58%) AIS cases had apoptotic bodies and three (25%) had mitotic figures. We conclude that Pap tests from patients with mucosal endometriosis usually (62%) have lesional cells. These lesional cells almost always include stroma, which is useful in the differential diagnosis with AIS. We identified stroma significantly more often in endometriosis cases (92%) than in AIS cases (8%). Pathologists should look for endometrial stroma when considering an interpretation of directly sampled endometrium. In the absence of stroma, AIS should be considered. Diagn. Cytopathol. 2010;38:551,554. 2009 Wiley-Liss, Inc. [source]


    Mixed metaplastic carcinoma of the breast associated with pregnancy: Diagnostic dilemmas in fine-needle aspiration cytology

    DIAGNOSTIC CYTOPATHOLOGY, Issue 10 2009
    Lazaros Skagias M.D.
    Abstract Metaplastic carcinoma of the breast represents a rare entity characterized by the simultaneous presence of ductal, squamous, and/or mesenchymal components in several proportions. There are limitations in fine-needle aspiration diagnosis due to its pathological heterogeneity. When it develops under pregnancy and lactation influence, the cytologic evaluation appears to be more difficult and accurate diagnosis often proves challenging. We describe a case of mixed metaplastic carcinoma with dominant areas of squamous metaplasia, sarcomatoid stroma with spindle cells, and a minor component of cartilaginous metaplasia. We notify our experience in diagnostic approach of this entity focusing on differential diagnosis. Diagn. Cytopathol. 2009. © 2009 Wiley-Liss, Inc. [source]


    Cytohistologic correlations in schwannomas (neurilemmomas), including "ancient," cellular, and epithelioid variants

    DIAGNOSTIC CYTOPATHOLOGY, Issue 8 2006
    Jerzy Klijanienko M.D.
    Abstract Schwannoma accounts for one of the most common benign mesenchymal neoplasms of soft tissues. Although it is well defined in the cytology literature, particular histologic subtypes such as "ancient," cellular and epitheliod variants could be a source of diagnostic difficulties. We have reviewed cytology aspirates and corresponding histologic sections from 34 schwannomas diagnosed at Institut Curie. Histologically, 24 cases were classic, 5 were "ancient," 4 were cellular, and 1 was epithelioid schwannomas. No example of melanotic schwannoma was recorded. Original cytologic diagnosis was schwannoma in 13 (38.2%) cases, benign soft tissue tumor in 11 (32.4%), pleomorphic adenoma in 2 (6%) cases, angioma in 1 (2.9%) case, nodular fasciitis in 1 (2.9%) case, suspicious in 3 (8.8%) cases, and not satisfactory in 3 (8.8%) cases. There were no major differences between classical, "ancient," cellular, and epithelioid variants on cytology smears. Myxoid stroma, mast cells, and intranuclear inclusions were limited to classical subtype. Similarly, cyto-nuclear atypia was more frequent in classical subtype than in other subtypes. Schwannoma should be differentiated from well-differentiated malignant peripheral nerve sheath tumor, neurofibroma, and pleomorphic adenoma, in the last instance particularly for head and neck lesions. Diagn. Cytopathol. 2006;34:517,522. © 2006 Wiley-Liss, Inc. [source]


    Uterine adenosarcoma detected by Papanicolaou smear: A Case report,

    DIAGNOSTIC CYTOPATHOLOGY, Issue 7 2006
    F.R.C.P.C., Sylvia Pasternak M.D.
    Abstract Adenosarcoma is a rare uterine biphasic tumor composed of benign epithelial elements and a sarcomatous stroma. Although it is well described histologically, its cytological features are rarely mentioned in the literature. We describe a case of uterine adenosarcoma that was first detected by Papanicolau (Pap) smear. Numerous crowded clusters of spindle cells were present within a bloody background, as well as a few smaller, dyscohesive groups with cells showing high N:C ratio and oval to round nuclei with coarse chromatin and small nucleoli. A few nuclear grooves were identified. Adenosarcomas are rare lesions but should be considered in the differential diagnosis when spindled cells are noted in a pap smear. Diagn. Cytopathol. 2006;34:495,498. © 2006 Wiley-Liss, Inc. [source]


    Nodular fasciitis of parotid region: A pitfall in the diagnosis of pleomorphic adenomas on fine-needle aspiration cytology

    DIAGNOSTIC CYTOPATHOLOGY, Issue 3 2005
    Ph.D., Reda S. Saad M.D.
    Abstract Fine-needle aspiration cytology (FNAC) is routinely employed for the preoperative diagnosis of salivary gland lesions. Although most cases show morphologic features characteristic of specific entities, some lesions can be diagnostically challenging. We report two parotid aspirates, initially diagnosed as pleomorphic adenoma on FNA. The patients, a 33-yr-old white man, and a 24-yr-old white woman, presented with indurated lesions arising in the parotid gland region. The aspirates from both patients were markedly hypercellular. Smears showed a mixture of spindle cells with a well-demarcated cytoplasm showing occasional long cytoplasmic process; and cells with abundant cytoplasm with round to oval eccentric nuclei, giving the impression of plasmacytoid cells of pleomorphic adenoma. The nuclear chromatin was evenly distributed and finely granular with one or two occasional small nucleoli. Intermingled with the tumor cells were scattered neutrophils, eosinophils, and macrophages. Aggregates of spindle cells were also seen embedded in a mucoid background with occasional small tufts of a fibrillar mucoid stroma. These fibrillar tufts were magenta red in the Diff-Quik stain, giving the impression of matrix of pleomorphic adenoma. Both cases were later diagnosed on histologic examination as nodular fasciitis. Nodular fasciitis should be considered in the differential diagnosis of a mass arising in association with the parotid gland. Diagn. Cytopathol. 2005;33:191,194. © 2005 Wiley-Liss, Inc. [source]


    Clear-cell adenocarcinoma of the female genital tract: Presence of Hyaline stroma and tigroid background in various types of cytologic specimens

    DIAGNOSTIC CYTOPATHOLOGY, Issue 6 2005
    Surapan Khunamornpong M.D.
    Abstract Hyaline basement membrane-like stromal material and tigroid background are distinctive cytologic features observed in Diff-Quik (DQ)- or Giemsa-stained smears of clear-cell adenocarcinoma (CCA) of the female genital tract. However, it is uncertain how often these features are present in different types of cytologic specimens, and which type of preparation is optimal for this diagnosis. We therefore reviewed the cytologic features of CCA in three types of specimens, including 15 scrape cytology specimens, 7 fine-needle aspiration (FNA) specimens, and 15 peritoneal cytology specimens, with emphasis on the features observed in DQ-stained smears. The cell morphology in scrape cytology specimens and FNA specimens was comparable, whereas in peritoneal cytology specimens, the cytoplasm was better preserved. Most tumor cells had fragile cytoplasm containing variable amounts of fine vacuoles, and round nuclei with distinct or prominent nucleoli. Hyaline stroma was present in 93% of scrape cytology specimens, 71% of FNA specimens, and 80% of peritoneal cytology specimens. Tigroid background was observed in 47% of scrape cytology specimens, 43% of FNA specimens, but in none of the peritoneal cytology specimens. Formation of a tigroid background may be prevented by the abundant fluid content in peritoneal cytology specimens. Hyaline stroma and tigroid background were uncommonly seen in scrape smears from other types of primary ovarian tumors, mainly juvenile granulosa cell tumor and yolk sac tumor. However, the additional presence of papillary structures allows CCA to be readily distinguished from these other tumors. We propose that scrape cytology offers the best approach for the intraoperative cytologic diagnosis of CCA. Diagn. Cytopathol. 2005;32:336,340.© 2005 Wiley-Liss, Inc. [source]


    Sclerosing lobular hyperplasia of the breast: Fine-needle aspiration cytology findings,A case report

    DIAGNOSTIC CYTOPATHOLOGY, Issue 5 2004
    Nirupma Panikar M.D.
    Abstract Sclerosing lobular hyperplasia (SLH) is an uncommon benign lesion seen in the juvenile breast. It presents as a palpable, firm, circumscribed nodular lump in the breast of a young woman. Histologically, it is characterised by prominent lobular hyperplasia and sclerosis of the intralobular connective tissue. We discuss the cytomorphology and differential diagnosis. A 16-yr-old female patient presented with a painless, firm, nodular, mobile mass in the right breast measuring 4 × 4 cm. The clinical and radiological diagnosis was fibroadenoma. Fine-needle aspiration smears showed round to oval ductal epithelial cells in flat sheets and round clusters with an acinar arrangement. A few bare nuclei were seen dispersed in a clean background but no stroma was visualised. A combination of clinical findings, imaging, and cytological features of SLH can help to differentiate this condition from other palpable juvenile breast diseases. Diagn. Cytopathol. 2004;31:340,341. © 2004 Wiley-Liss, Inc. [source]


    Fine-needle aspiration cytology of pseudoangiomatous stromal hyperplasia of the breast

    DIAGNOSTIC CYTOPATHOLOGY, Issue 5 2004
    Philip C.W. Lui M.B.B.S.
    Abstract Pseudoangiomatous stromal hyperplasia (PASH) is an uncommon lesion usually found in premenopausal women. Histologically, it is characterized by complex, anatomosing, empty slit-like spaces in a dense collagenous stroma. These pseudoangiomatous spaces are lined by monomorphic spindle cells of myofibroblastic differentiation. Cytological features of PASH are rarely discussed and reported, and may pose diagnostic challenge to surgical pathologists. Two cases of PASH are reported with emphasis on the FNAC features and cytologic differentiation from other benign fibroepithelial lesions. Diagn. Cytopathol. 2004;30:353,355. © 2004 Wiley-Liss, Inc. [source]


    Fine-needle aspiration cytology of giant cell fibroblastoma: Case report and review of the literature

    DIAGNOSTIC CYTOPATHOLOGY, Issue 6 2002
    Lester J. Layfield M.D.
    Abstract Giant cell fibroblastoma is an uncommon soft tissue neoplasm occurring in childhood. It appears to be the juvenile form of dermatofibrosarcoma protuberans, with which it shares some histologic, cytogenetic, and immunohistochemical features. We report, to our knowledge, the second description of the cytologic features of giant cell fibroblastoma. The present case represents a recurrent lesion in the soft tissues of the scrotum of a 17-yr-old male. The aspirate produced moderately cellular smears containing mononuclear cells, usually lying singly, but occasionally forming clusters. The majority of the individual cells possessed scanty bipolar cytoplasm or were devoid of cytoplasm. The nuclei were bland, with small nucleoli. Nuclear membranes frequently contained notches, creases, or folds. Small fragments of metachromatic stroma were present in the background and were often associated with small aggregates of cells. Rare multinucleated giant cells containing bland oval or basillary-shaped nuclei were admixed with the spindle-cell component. Necrosis and mitotic figures were not a component of the smears. Surgical resection of the mass confirmed the diagnosis of giant cell fibroblastoma. We review the characteristic cytologic features of giant cell fibroblastoma and compare them with other soft tissue tumors in the differential diagnosis. Diagn. Cytopathol. 2002;26:398,403. © 2002 Wiley-Liss, Inc. [source]


    SOLITARY PEDUNCULATED GASTRIC GLAND HETEROTOPIA TREATED BY ENDOSCOPIC POLYPECTOMY: REPORT OF A CASE

    DIGESTIVE ENDOSCOPY, Issue 1 2001
    Kazuo Kitabayashi
    The patient, a 68-year-old woman with a long-standing history of schizophrenia, was admitted to our hospital complaining of vomiting which had lasted approximately 3 weeks. Endoscopic examination of the stomach revealed a solitary pedunculated submucosal tumor, of approximately 2 cm in diameter, on the anterior wall of the upper body, close to the greater curvature. The lesion was endoscopically excised using a polypectomy snare without any complication. Microscopic examination was compatible with the diagnosis of gastric gland heterotopia showing submucosal proliferation of pseudopyloric glands, fundic glands and foveolar epithelium with fibromuscular stromal framework. The proliferating foveolar epithelium and fibromuscular stroma were in continuity with the overlaying gastric mucosa and muscularis mucosae, respectively. The lesion was entirely covered by normal gastric epithelium. No atypical cells were revealed in the lesion. The clinical significance of gastric gland heterotopia is unclear because of its controversial histogenesis and carcinogenetic potential. We herein report a rare case of solitary pedunculated gastric gland heterotopia with some review of scientific reports. [source]


    2-Amino-1-methyl-6-phenylimidazo[4,5- b]pyridine (PhIP),induced mutagenesis in cultured Big BlueÔ rat mammary epithelial and fibroblast cells

    ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 2-3 2002
    Heather M. McDiarmid
    Abstract Epithelial cells are the primary site of carcinogenesis in most tissues, including the mammary gland. As an alternative to the study of mutation induction in whole tissues in vivo, we have established Big BlueÔ transgenic rat cell lines from the mammary epithelium (BBR/ME) and the mammary stroma (BBR/MFib), to permit a comparison of their mutagenic responses to carcinogens. We previously demonstrated their responsiveness to the alkylating agent N -ethyl- N -nitrosourea (ENU) (McDiarmid H et al. [2001]: Mutat Res 497:39,47). Here, we examined the responses of cultured epithelial and stromal cells to the protein pyrolysis product and mammary carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5- b]pyridine (PhIP). Rat hepatic S9 was used as a source of bioactivation enzymes. Mutant induction (cII locus) and clonogenic survival were measured as a function of PhIP concentration. PhIP mutagenicity was observed in the fibroblast cells, but the greater toxicity of PhIP to the epithelial cells prevented a definitive evaluation of mutagenicity. Since PhIP may be detoxified by conjugation with glutathione, we measured glutathione levels and glutathione- S -transferase expression and activities in both cell lines. The epithelial cells had higher glutathione- S -transferase enzyme activity and protein expression than did the fibroblast cell line. Because the epithelial cells were more sensitive to toxicity, glutathione conjugation evidently plays only a minor role in PhIP toxicity and mutagenicity in our cell lines. Environ. Mol. Mutagen. 39:245,253, 2002. © 2002 Wiley-Liss, Inc. [source]


    Histologic and morphologic effects of valproic acid and oxcarbazepine on rat uterine and ovarian cells

    EPILEPSIA, Issue 1 2010
    Ali Cansu
    Summary Purpose:, To determine the histologic and morphologic effects of valproic acid (VPA) and oxcarbazepine (OXC) on rat uterine and ovarian cells. Methods:, Fifty-six female prepubertal Wistar rats (21,24 days old and weighing between 47.5 and 58.1 g) were divided equally into four groups, which were given drinking water (controls), 300 mg/kg/day of VPA, 100 mg/kg/day of OXC or VPA + OXC via gavage, for 90 days. Ovaries and uteri of rats on proestrous and diestrous phases of estrous cycle were extirpated and placed in a fixation solution. The tissue specimens were assessed with apoptosis (TUNEL) staining protocols, eosinophil counting, and electron microscopic techniques. Results:, In uteri, apoptosis in stroma, mitochondrial swelling, and cristolysis were observed in the VPA group, and OXC led to negative effects on epithelial cell and intracellular edema. In ovaries, both drugs increased apoptosis and intracytoplasmic edema. Organelle structure disruption was also observed in the OXC group. More conspicuous degenerative modifications were determined in the VPA + OXC group. In uteri, the number of TUNEL-positive luminal epithelial cells was 7.20 ± 1.32 in controls, and significantly increased to 29.60 ± 1.58, 34.20 ± 2.53, and 54.80 ± 2.04 in VPA, OXC, and VPA + OXC groups, respectively (p < 0.001). The highest number of TUNEL-positive glandular epithelium cells was observed in the VPA + OXC group; however, the number of TUNEL-positive stroma cells was highest in the VPA group. The highest number of eosinophils in stroma was in the VPA group. Conclusion:, VPA and OXC trigger apoptotic and degenerative effects on rat uterine and ovarian cells. VPA also prevents implantation of embryo to the uterus and causes abortion via endometrial eosinophil infiltration. [source]


    Splenic stromal cells mediate IL-7 independent adult lymphoid tissue inducer cell survival

    EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 2 2010
    Tie Zheng Hou
    Abstract Lymphoid tissue inducer cells (LTi) play an important role in the development of lymphoid tissue in embryos. Adult CD4+CD3, LTi-like cells present a similar phenotype and gene expression to their embryonic counterpart and have important roles in CD4+ T-cell memory and lymphoid tissue recovery following viral infection. However, adult LTi-like cells are heterogeneous populations and the factors that regulate their survival and accumulation within secondary lymphoid organs remain unclear, in particular whether the T-zone stroma is involved. Here we report the identification and characterization of a distinct subset of podoplanin+ murine splenic stromal cells that support adult LTi-like cell survival. We have identified and isolated CD45,podoplanin+ stromal cell populations which have a similar but distinct phenotype to T-zone reticular cells in LN. CD45,podoplanin+ fibroblast-like cells mediate LTi-like cell survival in vitro; surprisingly this was not dependent upon IL-7 as revealed through blocking Ab experiments and studies using LTi-like cells unable to respond to , chain cytokines. Our findings show that adult LTi-like cells require extrinsic signals from podoplanin+ splenic stromal cells to survive and suggest that IL-7 is not necessary to mediate their survival in the adult spleen. [source]


    The most C-terminal tri-glycine segment within the polyglycine stretch of the pea Toc75 transit peptide plays a critical role for targeting the protein to the chloroplast outer envelope membrane

    FEBS JOURNAL, Issue 7 2006
    Amy J. Baldwin
    The protein translocation channel at the outer envelope membrane of chloroplasts (Toc75) is synthesized as a larger precursor with an N-terminal transit peptide. Within the transit peptide of the pea Toc75, a major portion of the 10 amino acid long stretch that contains nine glycine residues was shown to be necessary for directing the protein to the chloroplast outer membrane in vitro[Inoue K & Keegstra K (2003) Plant J34, 661,669]. In order to get insights into the mechanism by which the polyglycine stretch mediates correct targeting, we divided it into three tri-glycine segments and examined the importance of each domain in targeting specificity in vitro. Replacement of the most C-terminal segment with alanine residues resulted in mistargeting the protein to the stroma, while exchange of either of the other two tri-glycine regions had no effect on correct targeting. Furthermore, simultaneous replacement of the N-terminal and middle tri-glycine segments with alanine repeats did not cause mistargeting of the protein as much as those of the N- and C-terminal, or the middle and C-terminal segments. These results indicate that the most C-terminal tri-glycine segment is important for correct targeting. Exchanging this portion with a repeat of leucine or glutamic acid also caused missorting of Toc75 to the stroma. By contrast, its replacement with repeats of asparagine, aspartic acid, serine, and proline did not largely affect correct targeting. These data suggest that relatively compact and nonhydrophobic side chains in this particular region play a crucial role in correct sorting of Toc75. [source]


    Importance of Cryphonectria parasitica stromata production and intermediate-pigmented isolates in spread of Cryphonectria hypovirus 1 on grafted American chestnut trees

    FOREST PATHOLOGY, Issue 5 2008
    E. P. Hogan
    Summary Large, surviving American chestnut trees, grafted in 1980, were inoculated in 1982 and 1983 with four ,white' European (French and Italian) hypovirulent strains of Cryphonectria parasitica infected with Cryphonectria hypovirus 1 (CHV1). Spread of Italian CHV1-Euro7, indicated by nucleotide sequence analysis of CHV1 isolates, and a high level of blight control, occurred on these trees for over 20 years. However, the means by which CHV1 spreads and the possible role of stromata production in that spread are unknown. In this study, 249 C. parasitica isolates were recovered from stromata excised from natural cankers on the grafted trees and plated on an agar medium; 5.2% of the stromata yielded white phenotype isolates, 9.2% yielded intermediate-pigmented isolates (30,70% pigmentation) and the remainder were normal-pigmented isolates. For comparison, cankers artificially established on blight-free, forest-clear-cut American chestnut trees, following inoculation with three Italian white hypovirulent strains, were evaluated in a similar manner. Of 241 C. parasitica isolates recovered from stromata, 66.4% had a white colony phenotype, 19.1% had an intermediate-pigmented phenotype and the remainder were normal-pigmented isolates. For single conidia collected from stromata and plated, nearly equal frequencies of only white and intermediate-pigmented colony phenotypes were obtained. Following dsRNA extraction and electrophoresis, 21 of 33 intermediate-pigmented isolates were positive for CHV1. Some normal pigmented isolates also were positive for CHV1. Single-sporing a CHV1-positve, normal-pigmented, natural-canker, stroma isolate (Str 1) from the grafts resulted in several deeply red-orange pigmented (JR) isolates as well as some white isolates. The dsRNA in the JR isolate was extracted and cDNAs made by reverse transcriptase-polymerase chain reaction (RT-PCR) for part of a region (p29) in ORF A. Nucleotide sequencing indicated 100% identity to CHV1 present in the inoculated Italian white strain, Ep 47. The results indicate that stromata production on the grafted trees may contribute to CHV1 spread, and the presence of CHV1 in intermediate-pigmented isolates and some normal pigmented isolates indicates these isolates, often overlooked, may be important in CHV1 spread and the high level of blight control on the grafted trees. [source]


    Rat choroid plexuses contain myeloid progenitors capable of differentiation toward macrophage or dendritic cell phenotypes

    GLIA, Issue 3 2006
    Serge Nataf
    Abstract The interface between the blood and the cerebrospinal fluid (CSF) is formed by the choroid plexuses (CPs), which are specialized structures located within the brain ventricles. They are composed of a vascularized stroma surrounded by a tight epithelium that controls molecular and cellular traffic between the blood and the CSF. Cells expressing myeloid markers are present within the choroidal stroma. However, the exact identity, maturation state, and functions of these CP-associated myeloid cells are not fully clarified. We show here that this cell population contains immature myeloid progenitors displaying a high proliferative potential. Thus, in neonate rats and, to a lesser extent, in adult rats, cultured CP stroma cells form large colonies of macrophages, in response to M-CSF or GM-CSF, while, under the same conditions, peripheral blood monocytes do not. In addition, under GM-CSF treatment, free-floating colonies of CD11c+ monocytic cells are generated which, when restimulated with GM-CSF and IL-4, differentiate into OX62+/MHC class II+ dendritic cells. Interestingly, in CP stroma cultures, myeloid cells are found in close association with fibroblastic-like cells expressing the neural stem-cell marker nestin. Similarly, in the developing brain, macrophages and nestin+ fibroblastic cells accumulate in vivo within the choroidal stroma. Taken together, these results suggest that the CP stroma represents a niche for myeloid progenitors and may serve as a reservoir for brain macrophages. © 2006 Wiley-Liss, Inc. [source]


    Severe alterations of endothelial and glial cells in the blood-brain barrier of dystrophic mdx mice

    GLIA, Issue 3 2003
    Beatrice Nico
    Abstract In this study, we investigated the involvement of the blood-brain barrier (BBB) in the brain of the dystrophin-deficient mdx mouse, an experimental model of Duchenne muscular dystrophy (DMD). To this purpose, we used two tight junction markers, the Zonula occludens (ZO-1) and claudin-1 proteins, and a glial marker, the aquaporin-4 (AQP4) protein, whose expression is correlated with BBB differentiation and integrity. Results showed that most of the brain microvessels in mdx mice were lined by altered endothelial cells that showed open tight junctions and were surrounded by swollen glial processes. Moreover, 18% of the perivascular glial endfeet contained electron-dense cellular debris and were enveloped by degenerating microvessels. Western blot showed a 60% reduction in the ZO-1 protein content in mdx mice and a similar reduction in AQP4 content compared with the control brain. ZO-1 immunocytochemistry and claudin-1 immunofluorescence in mdx mice revealed a diffuse staining of microvessels as compared with the control ones, which displayed a banded staining pattern. ZO-1 immunogold electron microscopy showed unlabeled tight junctions and the presence of gold particles scattered in the endothelial cytoplasm in the mdx mice, whereas ZO-1 gold particles were exclusively located at the endothelial tight junctions in the controls. Dual immunofluorescence staining of ,-actin and ZO-1 revealed colocalization of these proteins. As in ZO-1 staining, the pattern of immunolabeling with anti,,-actin antibody was diffuse in the mdx vessels and pointed or banded in the controls. ,-actin immunogold electron microscopy showed gold particles in the cytoplasms of endothelial cells and pericytes in the mdx mice, whereas ,-actin gold particles were revealed on the endothelial tight junctions and the cytoskeletal microfilaments of pericytes in the controls. Perivascular glial processes of the mdx mice appeared faintly stained by anti-AQP4 antibody, while in the controls a strong AQP4 labeling of glial processes was detected at light and electron microscope level. The vascular permeability of the mdx brain microvessels was investigated by means of the horseradish peroxidase (HRP). After HRP injection, extensive perivascular areas of marker escape were observed in mdx mice, whereas HRP was exclusively intravascularly localized in the controls. Inflammatory cells, CD4-, CD8-, CD20-, and CD68-positive cells, were not revealed in the perivascular stroma of the mdx brain. These findings indicate that dystrophin deficiency in the mdx brain leads to severe injury of the endothelial and glial cells with disturbance in ,-actin cytoskeleton, ZO-1, claudin-1, and AQP4 assembly, as well as BBB breakdown. The BBB alterations suggest that changes in vascular permeability are involved in the pathogenesis of the neurological dysfunction associated with DMD. GLIA 42:235,251, 2003. © 2003 Wiley-Liss, Inc. [source]


    Bone marrow and tumour stroma: an intimate relationship

    HEMATOLOGICAL ONCOLOGY, Issue 4 2006
    Natalie C Direkze
    Abstract In recent years the bone marrow has become recognized as a potential source of cells for non-haematopoietic wound healing, in some instances demonstrating surprising plasticity in providing new epithelial cells. On the other hand, the contribution of bone marrow derived cells to fibrosis and blood vessel formation is more widely acknowledged. Tumour stroma has a vital role to play in determining cancer growth and spread, and there is a growing realization that the bone marrow has a significant input into this desmoplastic response. This review focuses on the contribution of bone marrow cells to tumour stroma, highlighting the bone marrow as a potential new portal through which to direct anti-tumour therapies. Copyright © 2006 John Wiley & Sons, Ltd. [source]


    Adipokines in liver diseases,

    HEPATOLOGY, Issue 3 2009
    Fabio Marra
    Adipokines are polypeptides secreted in the adipose tissue in a regulated manner. While some of these molecules are expressed only by adipocytes, resident and infiltrating macrophages and components of the vascular stroma markedly contribute to expression of other adipokines. As a result, adipose tissue inflammation is associated with a modification in the pattern of adipokine secretion. Leptin, adiponectin, and resistin are the best-studied molecules in this class, but cytokines such as tumor necrosis factor or interleukin-6 are also secreted at high levels by the adipose tissue. Several other molecules have been recently identified and are actively investigated. Adipokines interfere with hepatic injury associated with fatty infiltration, differentially modulating steatosis, inflammation, and fibrosis. Several studies have investigated plasma levels of adiponectin in patients with nonalcoholic fatty liver disease, to establish correlations with the underlying state of insulin resistance and with the type and severity of hepatic damage. Hepatitis C is another disease where adipokines may represent a link between viral infection, steatosis, and metabolic disturbances. Identification of the mediators secreted by expanded adipose tissue and their pathogenic role is pivotal in consideration of the alarming increase in the prevalence of obesity and of the detrimental role that this condition exerts on the course of liver diseases. (HEPATOLOGY 2009.) [source]


    Autocrine motility factor enhances hepatoma cell invasion across the basement membrane through activation of ,1 integrins

    HEPATOLOGY, Issue 1 2001
    Takuji Torimura
    Autocrine motility factor/phosphohexose isomerase (AMF/PHI) is a cytokine that is linked to tumor invasion and metastasis. In hepatocellular carcinoma (HCC) tissues, hepatoma cells produce AMF/PHI and its receptor, Mr 78,000 glycoprotein (gp78), is strongly detected in hepatoma cells invading into the stroma and tumor thrombi in the portal vein. Here, we investigated the mechanism of hepatoma cell invasion through Matrigel induced by AMF/PHI using 3 hepatoma cell lines. Production of AMF/PHI, phosphorylation of MEK1/2, and Rho activity were investigated by immunoblotting. Expression of AMF/PHI and gp78 was observed by confocal fluorescence microscopy. The influence of AMF/PHI on activated integrin ,1 subunit expression was evaluated by flow cytometry. Changes in invasion, adhesion, and motility induced by AMF/PHI were evaluated using chemoinvasion, adhesion, and phagokinetic track motility assays. The effect of AMF/PHI on matrix metalloproteinase (MMP) secretion was evaluated by gelatin zymography. Hepatoma cells produced AMF/PHI and expressed gp78. Although AMF/PHI was ubiquitously detected, gp78 was strongly expressed in migrating cells. AMF/PHI induced up-regulation of activated integrin ,1 subunit expression. AMF/PHI stimulated hepatoma cell invasion through Matrigel, and stimulated the adhesion, motility, and MMP-2 secretion of hepatoma cells. The latter effects were suppressed by the function-blocking antibody for integrin ,1 subunit. AMF/PHI also enhanced Rho activity and the phosphorylation of MEK1 and MEK 2. Our results indicate that AMF/PHI enhances hepatoma cell invasion through Matrigel in an autocrine manner by stimulating the adhesion, motility, and MMP-2 secretion of these cells through activation of ,1 integrins. [source]


    Expression of matrix metalloproteinases MMP-2, MMP-9 and their tissue inhibitors TIMP-1 and TIMP-2 in the epithelium and stroma of salivary gland pleomorphic adenomas

    HISTOPATHOLOGY, Issue 3 2009
    Xiaojun Zhang
    Aims:, The balance between matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) is involved in the morphogenesis of normal salivary gland as well as in the mechanisms of tumour invasion and metastasis. The role of MMPs and TIMPs in pleomorphic adenoma has not been elucidated sufficiently. Our aim was to analyse the mRNA and protein expression of MMP-2, MMP-9, TIMP-1 and TIMP-2 in the epithelium and stroma of pleomorphic adenoma and to evaluate their roles. Methods and results:, In each sample from six patients, cells from the epithelium and stroma were obtained by laser microdissection. The mRNA expression of MMPs and TIMPs was determined by real-time quantitative reverse transcriptase-polymerase chain reaction and protein expression was confirmed by immunohistochemistry. Results showed that mRNA expression of MMPs and TIMPs was significantly higher in stroma than in epithelium in most patients. MMPs and TIMPs were immunoreactive mainly in epithelium rather than in stroma. Conclusions:, Our results provide preliminary evidence that stromal myoepithelium may be the primary source of MMPs and that the stroma has the potential to play a more important role than ductal epithelium in biological behaviour of pleomorphic adenomas. These findings seem worthy of further investigation. [source]


    Stromal cells promote bone invasion by suppressing bone formation in ameloblastoma

    HISTOPATHOLOGY, Issue 4 2008
    G S A Sathi
    Aims:, To study the stromal variation and role of stromal,tumour cell interaction in impaired bone formation as well as enhanced bone resorption in ameloblastoma. Methods and results:, Four types of stroma were observed histologically; fibrous, desmoplastic, myxoid and myxoid with hyalinization. Osteoblast and osteoclast were counted using haematoxylin and eosin sections and immunohistochemistry with CD68. After histomorphometric analysis, only fibrous and myxoid types of stroma were distinctly identified. Secreted frizzled-related peptide (sFRP)-2, transforming growth factor-beta 1 and receptor activator of nuclear factor-,B ligand (RANKL) revealed strong expression in myxoid type compared with the normal stroma. Bone morphogenetic protein (BMP)-2 was negative in myxoid type, but positive in normal stroma. Fibrous-type stroma showed weak expression of all antigens except RANKL compared with myxoid type. Conclusions:, The results suggest that stroma does not act only in bone resorption, but also in the suppression of new bone formation. sFRP-2 is the main factor for impaired bone formation. The expression of markers related to osteoclastogenesis and suppression of osteoblast formation is higher in myxoid-type than in fibrous-type stroma. Tumour cells create a favourable environment for impaired bone formation by secreting sFRP-2 as well as bone resorption by secreting RANKL and interleukin-6. [source]