Topic
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 thyroid gland of silver eels, specimens of the Anguilla japonica before breeding migration was examined with the electron microscope, and the rough-surfaced endoplasmic reticulum is well developed throughout.
Abstract: The thyroid gland of silver eels, specimens of the Anguilla japonica before breeding migration was examined with the electron microscope. The apical surface of the follicle cell is irregular in outline and microvilli are scarce. Though the rough-surfaced endoplasmic reticulum is well developed throughout, especially at the basal part of the cytoplasm, the cisterna of this structure is not so largely vacuolated but flattend, and the cytoplasm looks relatively compact as compared with that of the higher vertebrate. There are three kinds of vesicles or granules in the apical cytoplasm of the follicle cell; (1) less-dense small vesicles, (2) large less-dense or moderately dense droplet and (3) large or small dark granules. Small less-dense vesicles and some of the dark granules are considered to be derived from the Golgi region. A central flagellum is observed in a few follicle cells. The fine structure of the pericapillary region is similar to that of the higher vertebrate, though the pericapillary space with connective tissue cells and fibrils is relatively thicker and the endothelial pores are not observed. Numerous pinocytotic vesicles are found in the endothelial cell.
20 citations
TL;DR: The morphoogical changes that the ductuli efferentes undergo during the seasonal breeding cycle of the ground squirrel Citellus lateralis were examined by means of electron microscopy and a dramatic increase in dense inclusions representing deposits of lipofuchsin was seen.
Abstract: The morphological changes that the ductuli efferentes undergo during the seasonal breeding cycle of the ground squirrel Citellus lateralis were examined by means of electron microscopy. At the time of spermatogenetic activity the epithelium of the ductuli was composed of highly differentiated principal and ciliated cells. Distinctive cytological features of these cells during this period were the presence of a heterogeneous collection of numerous membrane-bound granules in principal cells and large accumulations of glycogen in ciliated cells. Structurally these cells were specialized for movement of luminal contents and its modification by absorption and possible secretion. With the onset of testicular regression, profound changes occurred in both cell types. Initially the lumen of the ductuli became occluded by masses of apical cytoplasm protruded from principal and ciliated cells as well as by degenerating cells which had been sloughed from the epithelium. This leads eventually, by the time of complete testicular regression, to reduced ductuli containing cells smaller in size with fewer organelles than those present during the period of spermatogenesis. The membrane-bound granules in principal cells and the accretions of glycogen in ciliated cells had now virtually disappeared. There was, however, a dramatic increase in dense inclusions representing deposits of lipofuchsin. As yet the cellular mechanisms controlling and effecting these dramatic changes in morphological appearance are unknown.
20 citations
TL;DR: The combination of centrifugation assisted cell culture infection and cycloheximide treatment of Vero cell coverslip cultures provided the highest inclusion numbers with all chlamydial strains, and the use of Iscove's modified Dulbecco's medium instead of Eagle's minimal essential medium significantly increased Chlamydia suis inclusion counts.
Abstract: Porcine Chlamydiaceae were cultivated under various culture conditions and we compared their growth characteristics with those of ruminant and avian strains. The combination of centrifugation assisted cell culture infection and cycloheximide treatment of Vero cell coverslip cultures provided the highest inclusion numbers with all chlamydial strains. Interestingly, the use of Iscove's modified Dulbecco's medium instead of Eagle's minimal essential medium significantly increased Chlamydia suis inclusion counts. C. suis and Chlamydophila pecorum inclusion numbers were markedly increased in CaCo cells, compared with Vero cells. This accelerated growth of porcine Chlamydiaceae under certain cultivation conditions may be helpful for the propagation of low chlamydial numbers or for their isolation from field samples. The intracellular distribution of porcine Chlamydiaceae in polarised CaCo cells clearly demonstrated differences between the chlamydial strains: C. pecorum 1710S inclusions were predominantly localised in the apical cytoplasm, C. suis S45 inclusions, however, were mostly situated in lower cytoplasmatic compartments. These findings might reflect biological differences in vivo.
19 citations
TL;DR: It was concluded that urine formation by tubular secretion may occur in cells with different types of basilar cell membrane specializations.
Abstract: The tubules in the aglomerular kidney of Nerophis ophidion are composed of cells showing different types of specializations of their plasma membrane. All cells possess a luminal brush border composed of microvilli, and show presence of vesicles with 100 A thick “unit” membranes — some containing electron dense material —, tubular elements, multivesicular bodies, and plasma membrane invaginations in their apical cytoplasm. These features suggest an absorptive function of the cells. The apical portions of the cells are supplied with typical cilia.
19 citations
TL;DR: Results indicate that the disruption of MF, rather than MT, contributes to the transformation of the uterine luminal cell surface during the lead up to blastocyst attachment.
19 citations