The role of acid phosphatase in the fusion of the secondary palate

Development ◽  
1968 ◽  
Vol 20 (1) ◽  
pp. 15-23
Author(s):  
D. Angelici ◽  
M. Pourtois
Keyword(s):  
Electron Microscopy ◽  
Acid Phosphatase ◽  
Epithelial Cells ◽  
Organ Culture ◽  
Fusion Process ◽  
Culture Methods ◽  
Secondary Palate ◽  
Subsequent Step ◽  
Cell Layers

Complete closure of the secondary palate must progress through two consecutive events: the converging movement of the palatal shelves and their subsequent fusion at the line of contact. Each step is indispensable in normal palatal development since, theoretically, a palatal cleft might be the consequence of a failure of either. Until recently, the mechanisms of shelf movement received most attention (Peter, 1924; Lazarro, 1940; Walker & Fraser, 1956; Larsson, 1960). However, recent investigations have focused on the subsequent step, properly referred to as fusion. These studies, based on organ culture methods (Pourtois, 1966) and electron microscopy (Mato, Aikawa & Katahira, 1966; Farbman, 1967; Smiley & Dixon, 1967), have emphasized the complexity of the fusion process. This process may be viewed as a sequence of four interdependent events: (1) differentiation of the cell layers at the edge of the shelves resulting in the formation of a ‘zone of stickiness’ (Pourtois, 1968); (2) fusion of these differentiated epithelial cells leading to the formation of a laminated wall of epithelium between the shelves; (3) rupture of that partition permitting contact between the elements of the mesenchyme from either side; and (4) finally, degeneration of the epithelial remains of the seam marking the completion of the fusion process.

Acid Phosphatase Localization in the Cataractous Rat Lens

1977 ◽  
Vol 35 ◽  
pp. 436-437
Author(s):  
N.J. Unakar ◽  
J. Tsui ◽  
J.R. Reddan
Keyword(s):  
Electron Microscopy ◽  
Wound Healing ◽  
Acid Phosphatase ◽  
Tissue Repair ◽  
Lysosomal Enzymes ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Probable Role

Lysosomal enzymes seem to play an important role in wound healing and tissue repair (1,2, and 3). In the present investigation we have shown the existence of acid phosphatase and lysosomes in lenticular tissue and have examined the probable role of this enzyme in the induction of galactose cataract. Experiments were performed on Sprague-Dawley rats (50g) fed for 4 days on a diet consisting of equal proportions (by wt.) of Purina Rat Chow and D-galactose. Animals fed Purina Rat Chow alone served as controls. Acid phosphatase was localized by two separate procedures (4 and 5). Lenses were processed for electron microscopy as previously described (3). Lenticular tissue of both controls (Figs. 1 and 2) and galactose fed animals exhibits the reaction product of acid phosphatase. However, the group fed galactose showed a much stronger reaction product compared to controls.

scholarly journals Intracellular pH regulates basolateral K+ and Cl- conductances in colonic epithelial cells by modulating Ca2+ activation.

1991 ◽  
Vol 98 (1) ◽  
pp. 183-196 ◽  
Author(s):  
D Chang ◽  
N L Kushman ◽  
D C Dawson
Keyword(s):  
Epithelial Cells ◽  
Intracellular Ph ◽  
Gain Control ◽  
Activation Process ◽  
Cytosolic Ph ◽  
Variable Gain ◽  
Ionic Conductances ◽  
Cell Layers ◽  
Conduction Properties

The role of intracellular pH as a modulator of basolateral K+ and Cl- conductances in epithelial cells was studied using digitonin-permeabilized colonic cell layers so that cytosolic pH could be clamped at specific values, while basolateral K+ and Cl- conductances were activated by stepwise increases in intracellular free Ca2+. Increasing the intracellular pH from 6.6 to 8.0 enhanced the sensitivity of both ionic conductances to intracellular Ca2+, but changing extracellular pH had no effect. Maximal K+ and Cl- currents activated by Ca2+ were not affected by changes in intracellular pH, suggesting that protons do not alter the conduction properties of the channels. Hill analysis of the Ca2+ activation process revealed that raising the cytosolic pH from 6.6 to 8.0 reduced the K1/2 for Ca2+ activation. In the absence of Ca2+, changes in intracellular pH did not have a significant effect on the basolateral K+ and Cl- conductances. These results are consistent with the notion that changes in cytosolic pH can modulate basolateral conductances by modifying the action of calcium, perhaps by acting at or near the activation site to provide a mechanism of variable "gain control."

scholarly journals KIM-1 Mediates High Glucose-Induced Autophagy and Apoptosis in Renal Tubular Epithelial Cells

2016 ◽  
Vol 38 (6) ◽  
pp. 2479-2488 ◽  
Author(s):  
Rong Gou ◽  
Juntong Chen ◽  
Shifeng Sheng ◽  
Ruiqiang Wang ◽  
Yudong Fang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Flow Cytometry ◽  
Epithelial Cells ◽  
High Glucose ◽  
Kidney Injury ◽  
Tubular Epithelial Cells ◽  
Renal Tubular Epithelial Cells ◽  
Normal Glucose ◽  
Renal Tubular

Background/Aim: To investigate the role of kidney injury molecular 1 (KIM-1) in high glucose-induced autophagy and apoptosis in renal tubular epithelial cells. Methods: Human renal tubular epithelial cells (HK2) were treated with normal glucose (NG, D -glucose 5.6 mmol/L), high glucose (HG, 30 mmol/L), high osmotic (HO, D-glucose 5.6 mmol/L + D-mannitol 24.4 mmol/L), HG + KIM-1 siRNA, HG + siRNA control. The expressions of KIM-1 and microtubule-associated protein 1 light chain 3II (LC3II) were measured by western blot as well as real time PCR; the number of autophagosome was detected by electron microscopy; and the level of apoptosis was analyzed by flow cytometry. Results: In the HG group, the expressions of KIM-1 and LC3II were increased markedly, which was accompanied by more autophagosome and higher level of apoptosis compared with NG group. Silencing of KIM-1 by siRNA inhibited the increases in the levels of LC3II, autophagosome and apoptosis. Conclusion: KIM-1 may mediate high glucose-induced autophagy and apoptosis in renal tubular epithelial cells.

DC-HEATING-INDUCED ANTIBAND FORMATION AND SUBSEQUENT STEP WANDERING ON Si(111) STUDIED BY IN-SITU REM

1999 ◽  
Vol 06 (06) ◽  
pp. 977-984 ◽  
Author(s):  
MASASHI DEGAWA ◽  
HIROKI MINODA ◽  
YASUMASA TANISHIRO ◽  
KATSUMICHI YAGI
Keyword(s):  
Electron Microscopy ◽  
Present Report ◽  
Current Direction ◽  
Vicinal Surfaces ◽  
Step Bunching ◽  
Subsequent Step ◽  
Step Down ◽  
Scanning Electron

Direct current fed through a Si crystal with (111) vicinal surfaces induces step bunching and wandering which depend on the temperature and the current direction. In the present report in-situ reflection electron microscope studies of antiband formation and the growth of step wandering are presented together with supplemental observations by scanning electron microscopy and optical microscopy. Observations were for the temperature range (about 1000–1180°C) where the step-down current induces step wandering and the step-up current induces step bunching and antiband formation and subsequent step wandering. An important role of antiband formation for step wandering in the step-up current regions is presented.

scholarly journals Role of the Campylobacter jejuni Cj1461 DNA Methyltransferase in Regulating Virulence Characteristics

2008 ◽  
Vol 190 (19) ◽  
pp. 6524-6529 ◽  
Author(s):  
Joo-Sung Kim ◽  
Jiaqi Li ◽  
If H. A. Barnes ◽  
David A. Baltzegar ◽  
Mohanasundari Pajaniappan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Epithelial Cells ◽  
Mutant Strain ◽  
Campylobacter Jejuni ◽  
Dna Methyltransferase ◽  
Wild Type ◽  
Less Invasive ◽  
Human Epithelial Cells ◽  
Methyltransferase Gene

ABSTRACT Mutation of the cj1461 predicted methyltransferase gene reduced the motility of Campylobacter jejuni 81-176. Electron microscopy revealed that the mutant strain had flagella but with aberrant structure. The Δcj1461 mutant was sevenfold more adherent to but 50-fold less invasive of INT-407 human epithelial cells than the wild type.

scholarly journals Functional analysis of the baculovirus per os infectivity factors 3 and 9 by imaging the interaction between fluorescently labelled virions and isolated midgut cells

2020 ◽  
Vol 101 (7) ◽  
pp. 778-784
Author(s):  
Bob Boogaard ◽  
Jan W. M. van Lent ◽  
Monique M. van Oers
Keyword(s):  
Functional Analysis ◽  
Epithelial Cells ◽  
Confocal Microscopy ◽  
Spodoptera Exigua ◽  
Oral Infection ◽  
Fusion Process ◽  
Insect Larvae ◽  
Two Phase ◽  
Brush Borders

Baculovirus occlusion-derived viruses (ODVs) contain ten known per os infectivity factors (PIFs). These PIFs are crucial for midgut infection of insect larvae and form, with the exception of PIF5, an ODV entry complex. Previously, R18-dequenching assays have shown that PIF3 is dispensable for binding and fusion with midgut epithelial cells. Oral infection nevertheless fails in the absence of PIF3. PIF9 has not been analysed in much depth yet. Here, the biological role of these two PIFs in midgut infection was examined by monitoring the fate of fluorescently labelled ODVs when incubated with isolated midgut cells from Spodoptera exigua larvae. Confocal microscopy showed that in the absence of either PIF3 or PIF9, the ODVs bound to the brush borders, but the nucleocapsids failed to enter the cells. Finally, we discuss how the results obtained for PIF3 with dequenching assays and confocal microscopy can be explained by a two-phase fusion process.

The Ultrastructure of Monkey Gingival Epithelium

1967 ◽  
Vol 25 ◽  
pp. 16-17
Author(s):  
C.N. Sun
Keyword(s):  
Epithelial Cells ◽  
Macaca Nemestrina ◽  
Stratum Granulosum ◽  
Solution Ph ◽  
Gingival Epithelial Cells ◽  
Stratum Spinosum ◽  
Cell Layers ◽  
Gingival Epithelium ◽  
The Individual ◽  
Different Thickness

The present study demonstrates the ultrastructure of the gingival epithelium of the pig tail monkey (Macaca nemestrina). Specimens were taken from lingual and facial gingival surfaces and fixed in Dalton's chrome osmium solution (pH 7.6) for 1 hr, dehydrated, and then embedded in Epon 812.Tonofibrils are variable in number and structure according to the different region or location of the gingival epithelial cells, the main orientation of which is parallel to the long axis of the cells. The cytoplasm of the basal epithelial cells contains a great number of tonofilaments and numerous mitochondria. The basement membrane is 300 to 400 A thick. In the cells of stratum spinosum, the tonofibrils are densely packed and increased in number (fig. 1 and 3). They seem to take on a somewhat concentric arrangement around the nucleus. The filaments may occur scattered as thin fibrils in the cytoplasm or they may be arranged in bundles of different thickness. The filaments have a diameter about 50 A. In the stratum granulosum, the cells gradually become flatted, the tonofibrils are usually thin, and the individual tonofilaments are clearly distinguishable (fig. 2). The mitochondria and endoplasmic reticulum are seldom seen in these superficial cell layers.

Effect of Calcium on the Growth and Differentiation of Cultured Rat Esophageal Epithelial Cells

1982 ◽  
Vol 40 ◽  
pp. 132-133
Author(s):  
W.T. Gunning ◽  
M.R. Marino ◽  
M.S. Babcock ◽  
G.D. Stoner
Keyword(s):  
Epithelial Cells ◽  
Cell Types ◽  
Replication Rate ◽  
Enzymatic Dissociation ◽  
Growth Assay ◽  
Epidermal Growth ◽  
Fetal Bovine ◽  
Esophageal Epithelial Cells ◽  
Cellular Replication

The role of calcium in modulating cellular replication and differentiation has been described for various cell types. In the present study, the effects of Ca++ on the growth and differentiation of cultured rat esophageal epithelial cells was investigated.Epithelial cells were isolated from esophagi taken from 8 week-old male CDF rats by the enzymatic dissociation method of Kaighn. The cells were cultured in PFMR-4 medium supplemented with 0.25 mg/ml dialyzed fetal bovine serum, 5 ng/ml epidermal growth factor, 10-6 M hydrocortisone 10-6 M phosphoethanolamine, 10-6 M ethanolamine, 5 pg/ml insulin, 5 ng/ml transferrin, 10 ng/ml cholera toxin and 50 ng/ml garamycin at 36.5°C in a humidified atmosphere of 3% CO2 in air. At weekly intervals, the cells were subcultured with a solution containing 1% polyvinylpyrrolidone, 0.01% EGTA, and 0.05% trypsin. After various passages, the replication rate of the cells in PFMR-4 medium containing from 10-6 M to 10-3 M Ca++ was determined using a clonal growth assay.

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