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Intermediate Cells (intermediate + cell)
Selected AbstractsImmunohistochemical evidence for hepatic progenitor cells in liver diseasesLIVER INTERNATIONAL, Issue 5 2002Jianyou Tan Abstract:, Background/Aim: Proliferative bile ductular reactions occur in a variety of liver diseases in humans. It is a matter of debate whether such reactions result from progenitor cell proliferation with biliary and hepatocytic differentiation, versus biliary metaplasia of damaged hepatocytes. We investigated bile ductular reactions in liver diseases, paying particular attention to the presence of cells with intermediate (hepatocytic/biliary) features (oval-like cells). Methods: Five specimens each were selected of submassive hepatic necrosis and cirrhosis due to hepatitis B, hepatitis C, autoimmune hepatitis, alcohol injury, primary biliary cirrhosis and primary sclerosing cholangitis. Immunohistochemical stains were performed for biliary markers (cytokeratins [CKs] 7 and 19), as well as hepatocytic markers (HepParl and alpha-fetoprotein[AFP]) in sequential sections. The degree of staining of each cell type (biliary, hepatocytic, intermediate) was graded semiquantitatively. Results: Hepatocytes always stained diffusely for HepParl, occasionally for CK7, and rarely for CK19. Biliary cells were always diffusely positive for CK7 and CK19, and rarely for HepParl. Intermediate cells were identified in all cases and showed widespread staining for both HepParl and CK7, and less commonly for CK19. AFP was not expressed in any cell type. The morphologic and immunohistochemical features of bile ductular reactions were similar in the different diseases. Conclusions: Proliferating hepatic parenchymal cells with intermediate (hepatocytic/biliary) morphologic features and combined immunophenotype can be identified in a variety of acute and chronic liver diseases. The similarity of bile ductular reactions among chronic hepatitic, alcoholic and biliary diseases suggests that they result from proliferation of oval-like progenitor cells. [source] Epithelial stem cell-related alterations in Trichinella spiralis -infected small intestineCELL PROLIFERATION, Issue 3 2009R. Walsh Objectives:, Infection of mice with the parasite Trichinella spiralis leads to small intestinal inflammation, characterized by changes in mucosal architecture and subpopulations of epithelial cells. This model has been used to explore changes in the epithelial proliferative cell population and expression of transforming growth factor-beta (TGF-,). Materials and methods:, Histochemical and immunohistochemical studies were undertaken in duodenal samples. Location and number of Ki-67-positive cells were assessed using Score and Wincrypts program. Changes in mRNA transcripts were studied by real-time RT-PCR. Results:,T. spiralis infection induced an increase in total number of proliferative (Ki-67-positive) cells per half crypt on day 2 post-infection. Transcription of Math1, a transcription factor required for secretory cell differentiation in the intestine, was up-regulated on days 6,18 post-infection. At these time points, numbers of Paneth cells at the crypt base were also increased and the epithelial proliferative zone was shifted up the crypt-villus axis. Transcription of TGF-, isoforms within the small intestine was up-regulated on days 6 and 12 post-infection, but anti-TGF-, antibody treatment had no effect on T. spiralis -induced changes in mucosal architecture or increase in Paneth/intermediate cells. Conclusions:,T. spiralis infection promotes an initial increase in small intestinal epithelial proliferation and subsequent cell differentiation along the secretory cell lineage. The resulting increase in numbers of Paneth cells at the crypt base causes the proliferative zone to move up the crypt-villus axis. Further studies are required to determine the significance of an increase in the expression of TGF-, transcripts. [source] Cytohormonal and morphological alterations in cervicovaginal smears of postmenopausal women on hormone replacement therapyDIAGNOSTIC CYTOPATHOLOGY, Issue 10 2006Sanjay Gupta M.D. Abstract The objective of the study was to study the cytohormonal and morphological alterations in cervicovaginal smears associated with the use of hormone replacement therapy (HRT) and to assess the utility of vaginal cytology in determining the response to HRT. Ninety postmenopausal women (30 on estrogen,progesterone combination (HRT) for 1 to 24 mo (user 1), 30 on estrogen therapy (ERT) for 1 to 44 mo (user 2), and 30 not on any hormones (nonusers)) were included in the cross-sectional study. Their lateral vaginal wall smears and cervical smears were examined for hormonal and morphological assessments, respectively. The smear pattern showed predominance of parabasal cells in 46.6% of nonusers, while none of the users had >70% parabasal cells. A high percentage (>70%) of intermediate cells was found in 46.6% of users and only in 16.6% of nonusers. A high maturation value (MV) was found in more than 75% of users but in only 16.6% of nonusers. The women with high MV (>50) were significantly less symptomatic than did nonusers. Atrophic changes were present in cervical smears of 14/20 (46.6%) nonusers when compared with 1/60 (1.66%) users. Atypical squamous cells of undetermined significance (ASC-US) were diagnosed in seven users and three nonusers. It persisted on follow-up in four users and one nonuser. Histology revealed one mild dysplasia among users. Lactobacilli were more frequently observed in users. The cytohormonal pattern on vaginal smears correlates well with the response to hormonal therapy and clinical symptoms. Awareness of the morphological alterations associated with the use of replacement hormones would enable the cytologists to reduce the false-positive diagnoses while evaluating postmenopausal smears. Diagn. Cytopathol. 2006;34:676,681. © 2006 Wiley-Liss, Inc. [source] On the dynamics of breast tumor development in women carrying germline BRCA1 and BRCA2 mutationsINTERNATIONAL JOURNAL OF CANCER, Issue 8 2008Richard Simon Abstract We used mathematical models to analyze the age-incidence curve of breast carcinoma for individuals carrying a germline mutation in the BRCA1 or BRCA2 gene locus. Although many genomic abnormalities have been identified in breast tumors, we found that a two-stage model fit the data well. A one-hit model was not, however, consistent with the data. The results supported the hypothesis that the first hit represents loss of the wild type BRCA1 or BRCA2 allele as this occurs at a rate very similar to that for loss of the wild-type RB allele in retinoblastoma. Loss of the wild-type BRCA1 or BRCA2 allele appears to destabilize the genome as the second event occurs at a much higher rate. The second event is "rate limiting" in the sense that its occurrence is constrained by the limited number of intermediate cells with doubly mutated BRCA1 or BRCA2 alleles. The second event may not be unique, however. Loss of the wild-type BRCA allele appears to result in an increased rate for subsequent genomic events. A second event increasing proliferation of the partially malignant intermediate clone may lead inexorably to production and selection of cells with additional mutations in genes that facilitate tumor progression. © 2007 Wiley-Liss, Inc. [source] Gut-associated cells of derocheilocaris remanei (crustacea, mystacocarida)JOURNAL OF MORPHOLOGY, Issue 3 2002Isabel Fernández Abstract The gut-associated cells (GA-cells) of the mystacocarid Derocheilocaris remanei were investigated by transmission electron microscopy. These cells are characterized by a dense cytoplasm, the presence of clear vesicles adjacent to the gut epithelium, glycogen, and lipid droplets. GA-cells envelop the midgut and hindgut and send blunt cytoplasmic extensions to the gut epithelium through its basal lamina. The GA-cells also extend dorsolateral projections to the body wall by means of intermediate cells. In addition to a mechanical function of suspending and stabilizing the gut, these cells may affect the flow of the hemocoelic fluid and may be implicated in the processes of transport, assimilation, and storage of nutrients. J. Morphol. 251:276,283, 2002. © 2002 Wiley-Liss, Inc. [source] Activity of Azole Fungicides and ABC Transporter Modulators on Mycosphaerella graminicolaJOURNAL OF PHYTOPATHOLOGY, Issue 6 2002I. STERGIOPOULOS The antimicrobial activity of the azole fungicides cyproconazole and propiconazole as single active ingredients and in mixtures with the ATP-Binding Cassette (ABC) transporter modulators rhodamine 6G, quercetin, quinidine, and verapamil and the strobilurin kresoxim-methyl was assessed against the wheat pathogen Mycosphaerella graminicola. Interactions amongst these compounds were evaluated on germination and germ tube growth of pycnidiospores using the Colby and Wadley method. Water agar proved to be the best test medium since all pycnidiospores germinated within 24 h of incubation and apical germ tube growth dominated over bud formation by intermediate cells. Analysis with the Colby method revealed that interactions between the compounds in all mixtures tested on germination of pycnidiospores were additive. With regard to germ tube growth, mixtures of cyproconazole and verapamil or kresoxim-methyl displayed a synergistic interaction. Analysis of mixtures of cyproconazole and kresoxim-methyl with the Wadley method revealed that the interaction between the two compounds was purely additive. These results indicate that the Colby method overestimated the interaction between these two compounds in a mixture. [source] Cytologic, hormonal, and ultrasonographic correlates of the menstrual cycle of the New World monkey Cebus apellaAMERICAN JOURNAL OF PRIMATOLOGY, Issue 3 2005R.E. Ortiz Abstract Few reports on the reproductive physiology of Cebus apella have been published. In this study we characterized menstrual cycle events by means of vaginal cytology, ultrasonography (US), and hormonal measurements in serum during three consecutive cycles in 10 females, and assessed the probability that ovulation would occur in the same ovary in consecutive cycles in 18 females. The lengths and phases of the cycles were determined according to vaginal cytology. Taking the first day of endometrial bleeding as the first day of the cycle, the mean cycle length ± SEM was 19.5±0.4 days, with follicular and luteal phases lasting 8.2±0.2 and 11.3±0.4 days, respectively. The follicular phase included menstruation and the periovulatory period, which was characterized by the presence of a large number of superficial eosinophilic cells in the vaginal smear. The myometrium, endometrium, and ovaries were clearly distinguished on US examination. During each menstrual cycle a single follicle was recruited at random from either ovary. The follicle grew from 3 mm to a maximum diameter of 8,9 mm over the course of 8 days, in association with increasing estradiol (E2) serum levels (from 489±41 to 1600±92 pmol/L). At ovulation, the mean diameter of the dominant follicle usually decreased by >20%, 1 day after the maximum E2 level was reached. Ovulation was associated with an abrupt fall in E2, a decreased number of eosinophilic cells, the presence of leukocytes and intermediate cells in the vaginal smear, and a progressive increase in progesterone (P) levels that reached a maximum of 892±65 nmol/L on days 3,6 of the luteal phase. The menstrual cycle of Cebus apella differs in several temporal and quantitative aspects from that in humans and Old World primates, but it exhibits the same correlations between ovarian endocrine and morphologic parameters. Am. J. Primatol. 66:233,244, 2005. © 2005 Wiley-Liss, Inc. [source] Light and Electron Microscope Studies on the Nasopharynx and Nasopharyngeal Tonsil of the HorseANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2 2001P Kumar Light and electron microscope studies were conducted on the nasopharynx and the nasopharyngeal tonsil of 15 young horses. The nasopharynx and nasopharyngeal tonsil was lined with pseudostratified columnar ciliated epithelium and goblet cells. The lymphoepithelium of the nasopharyngeal tonsil was folded forming crypts, the mucosa of which was modified into follicle associated epithelium characterized by stratified cuboidal epithelium, loss of cilia, absence of goblet cells and infiltration of lymphocytes. The lamina propria mucosae of the nasopharyngeal tonsil contained well-developed lymphoid tissue and clusters of seromucus acini. Scanning electron-microscopy revealed a dense mat of cilia covering the nasopharynx and nasopharyngeal tonsil. The follicle-associated epithelium consisted of different populations of microvillus cells in addition to M cells with very short microvilli and a few squamous and intermediate cells. Microvillus cells in the deeper part of the FAE had larger microvilli and their cytoplasm contained a dense population of mitochondria, smooth and rough endoplasmic reticulum, Golgi complexes and lysosomes. The flat surfaced M cell had a more electron-dense cytoplasm and contained small supranuclear vacuoles in addition to the organelles seen in microvillus cells. [source] Localization of sphingomyelin during the development of dorsal and tail epidermis of miceBRITISH JOURNAL OF DERMATOLOGY, Issue 5 2001Y. Yoshida Background The water permeability barrier of the stratum corneum seems to be regulated primarily by lamellar bodies situated between the corneocytes; the lamellar bodies originate largely from polar lipid precursors, mainly sphingomyelin (SM), provided by the cells of the stratum granulosum via exocytosis of their lamellar body content. Objectives The aim of our study was to evaluate the cellular distribution of SM during development of the epidermis. Methods In this study, we investigated the expression and localization of SM in both adult and fetal mouse skin by a cytochemical detection method, immunofluorescence microscopy and immunoelectron microscopy, using anti-SM antibody, a specific binding protein to SM (lysenin), and Nile red stain. In addition, we measured transepidermal water loss to estimate the barrier function of the fetal skin. Results We observed that SM was widely distributed from the basal layer to the granular layer in the adult mouse epidermis. An intense cytochemical reaction for SM was observed on embryonic day E14·5 of gestation just before the differentiation of the granular and squamous cells from the intermediate cells. The immunofluorescence indicating SM was detected in two regions, i.e. the most superficial zone of the granular layer and the upper spinous layer after the cell differentiation at the late gestational age. This distribution was not detected by conventional lipid staining, such as with Nile red stain. Immunoelectron microscopy revealed that SM was mainly localized in the intercellular spaces of the adult mouse epidermis and in the intracellular vesicles without a complete lamellar structure in the cytoplasm of epidermal cells of E14·5 fetuses. It is well known that the formation of the structurally mature cornified cell envelope occurs at E15·5 of development. The skin of fetuses at E16·5 showed a definite barrier function. Conclusions These findings suggest that SM dynamics is related to the formation of the lipid envelope, cell differentiation, and epidermal barrier function during development. [source] | |||||||||||||