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Apical cytoplasm

About: Apical cytoplasm is a research topic. Over the lifetime, 1080 publications have been published within this topic receiving 36131 citations.


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TL;DR: The present study suggests that LF in the nucleolus plays an important role in activation of ribosomal biogenesis preceding the cell differentiation and proliferation in the mouse uterus.
Abstract: Lactoferrin (LF) is known as an estrogen-inducible protein in the murine uterus. This study, employing immunoelectron microscopy with the pre-embedding methods, was carried out to elucidate temporal LF induction, the process of the induction and intracellular localization after 17βestradiol (E2) stimulation in the enodometrial epithelium of ovariectomized adult mice. By single i. p. injection of E2 (20μg/kg b. w.), LF was rapidly induced, even after 1 hr, and was exclusively localized in the nucleoli of surface and glandular epithelium. At 7 hr after E2 injection, strong immunostaining was recognized in the amorphous cytoplasm and in nucleoli, especially in the dense fibrillar component of the epithelium. From 13 hr to 23 hr after E2 administration, strong reaction was observed in the secretory pathway, i. e., cisternae of endoplasmic reticulum and the Golgi apparatus, and in vesicles and vacuoles in the apical cytoplasm, in addition to the nucleolar staining. LF-immunoreaction was also detected in the nucleoli and cytoplasm of stromal and muscle cells; it was demonstrated in the epithelium at the earliest period, subsequently in the stromal cells (7 hr), and finally in the muscle cells (13 hr). After three days of consecutive E2 stimulation, many secretory granules in the apical cytoplasm and apical cell membrane showed intense LF immunoreaction. The present study suggests that LF in the nucleolus plays an important role in activation of ribosomal biogenesis preceding the cell differentiation and proliferation in the mouse uterus.

5 citations

Journal ArticleDOI
30 Sep 2011
TL;DR: The results of this study suggest that basophilic cells and digestive cells in the digestive tubule are specialized in the extracellular and intracellular digestions, respectively.
Abstract: The anatomy and ultrastructure of the digestive diverticulum of Saxidomus purpuratus were described using light and electron microscopy. The digestive diverticulum of dark green color was situated on the gonad and connected to stomach by a primary duct. Digestive diverticulum is composed of numerous digestive tubules. The epithelial layer of digestive tubule, which is simple, is composed of basophilic cells and digestive cells. Basophilic cells are columnar in shape, and the electron density is higher than that of the digestive cell. The cytoplasm has a well-developed endoplasmic reticulum, tubular mitochondria, Golgi complex and membrane-bounded granules of high electron density. Digestive cells are columnar in shape, with development of microvilli on the free surface. Pinocytic vasicles, lysosomes and numerous mitochondria were observed in the apical cytoplasm of digestive cells. The results of this study suggest that basophilic cells and digestive cells in the digestive tubule are specialized in the extracellular and intracellular digestions, respectively.

5 citations

Journal ArticleDOI
TL;DR: The failure of the digestive cells of the insects midgut may be regarded as a natural process of programmed cell death that may be under the influence of external conditions which probably accelerate the process, like the almost certain possibility of cell damage caused by food ingested by the insect.
Abstract: The individual cells of most tissues of an organism have a shorter life span than the organism itself. So, in order to maintain the organism’s integrity, a certain degree of cellular substitution must occur during life. Generally the substitution occurs by steam cells division, but in insects, mitosis is absent or is very rare in adulthood. In these cases a certain amount of undifferentiated cells are responsible for the replacement of the worn ones. The insects midgut is an example of this late condition. At least two types of cells are present in the adult: (1) the digestive, functional or differentiated cells and (2) the generative or undifferentiated cells (HL House 1965 In M Rockstein The Physiology of Insecta, vol. II, Academic Press, N.Y.) In the termites midgut the digestive cells are columnar and present short microvilli in the apical pole, supported by a microfibrilar cytoskeleton which continues into the terminal network (Fig. 1). Usually they have many folds of the plasmic membrane associated with mitochondria on the basal pole (Fig. 1). As these cells age, some deterioration may be observed, mainly in the apical zone. The aging of the cells is characterized by the loss of electron-density of the apical cytoplasm besides the appearance of large autophagic vacuoles and myelin figures (Figs 1, 2). The generative cells form nests inside the functional epithelium. The cells, in the nests sit over the epithelial basal lamina, but do not emerge into the epithelial surface. These cells are always differentiating since a digestive cell needs to be replaced. Then, they are transformed into functional or digestive ones. The process is marked by a straightening of some of the outer cells of the nest, by the development of their organelles, by the production of microvilli in the luminal surface and by appearance of invaginations of the plasmic membrane in the basal surface. In the replacement process, the cellular contacts between the digestive cells apparently become weak and the intercellular space appears enlarged. The damaged digestive cells are pushed up by the unclasping of the generative cells and are seen displayed parallel to the epithelial surface (Fig. 2) before being eliminated into the lumen. The cells undertaking the elimination process have nuclei parallel to the surface, desorganized microvilli (Figs 3, 4) and several types of autophagic structures, like myelin figures and dense lysosome-like granules (Figs 2, 3, 4). However, the mitochondria and the endoplasmic reticulum apparently remain intact, and the nuclei present a less condensed chromatin than the nuclei of normal cells. These cells are separated from the subjacent ones by membranes parallel to the epithelial surface (Fig. 2).The exact moment of the cellular elimination was not captured in the preparations, but cellular debris were observed in the lumen . The autophagic vacuoles present in the dying epithelial cells of the termite midgut are very similar to the apoptotic bodies (MJ Arends, AH Wyllie 1991, Int Rev Exp Pathol 32: 223-254) and they have already been described for the mature state of epithelial cells in other termites (AM CostaLeonardo 1995 Naturalia, in press). The failure of the digestive cells may be regarded as a natural process of programmed cell death that may be under the influence of external conditions which probably accelerate the process, like the almost certain possibility of cell damage caused by food ingested by the insect. In insects the generative cells do not divide, but in the studied neuter caste of termites some cell division was observed. However, this occurrence can not be considered an exception since the neuter caste in Isoptera is constituted by immature forms and not by adults. In termites the only adults are the alates, the reproductive forms.

5 citations

Journal Article
TL;DR: The cytologic features of a fine needle aspiration biopsy of lymph node metastases from a vulvar adenocarcinoma with apocrine differentiation are documented and correlated well with the histologic and histochemical features of the primary vulvar adsorption and its lymph nodes metastases.
Abstract: The cytologic features of a fine needle aspiration biopsy of lymph node metastases from a vulvar adenocarcinoma with apocrine differentiation are documented. Cytologic findings that suggested apocrine differentiation included extreme nuclear eccentricity, punctate eosinophilic cytoplasmic granules and moundlike protrusion of apical cytoplasm. The cytologic findings correlated well with the histologic and histochemical features of the primary vulvar adenocarcinoma and its lymph node metastases.

5 citations

Journal ArticleDOI
TL;DR: The general fine structure of intestinal cells and changes which occur in ultrastructure during development from fourth-stage to adult N. dubius are reported and pigment granules are prominent in intestinal cells.
Abstract: The general fine structure of intestinal cells and changes which occur in ultrastructure during development from fourth-stage to adult N. dubius are reported. In fourth-stage worms pigment granules are prominent in intestinal cells. In adults the number of pigment granules appears to be reduced and phagolysosomes containing membranous profiles and pigment material increase in number. Another reorganization of cell structure involves mitochondria which are randomly distributed in the cytoplasm of cells in fourth-stage worms, concentrated in the apical cytoplasm in worms in the molting process, and confined to the base of cells in adult worms. Other changes involved structure of the nucleus, rough endoplasmic reticulum and glycogen content of cells.

5 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202112
20205
20195
20188
20175
201615