Quantitative ultrastructure of gill epithelial cells in the larval lamprey Petromyzon marinus

1995 ◽  
Vol 52 (6) ◽  
pp. 1150-1164 ◽  
Author(s):  
Jon Mallatt ◽  
Steven J. Lampa ◽  
J. Franklin Bailey ◽  
Marc A. Evans ◽  
Wayne Tate

Cells and organelles in the respiratory epithelium of the sea lamprey (Petromyzon marinus) gill were measured in electron micrographs of plastic-embedded sections to provide baseline data for future quantitative studies of how toxicants affect gill morphology. Stereology was used, based on the [Formula: see text] method for determining cell volumes. The method was checked against unbiased methods and was shown to be accurate within 12%. We found that cells in the basal layer of the epithelium, basal cells, are smaller (averaging 338 μm3) and contain smaller volumes of most organelles, than cells in the superficial layer. These features suggest that basal cells are either undifferentiated or differentiating cells. The superficial layer contains larger, more specialized cells: presumed ion-uptake cells (817 μm3) and mucous-pavement cells (548 μm3). Ion-uptake cells contain the largest volume of mitochondria (270 μm3), consistent with the high energy demands of ion transport. Mucous-pavement cells contain the largest volume of secretory vesicles (55 μm3), presumably for coating the lamellae with protective mucus. A new cell type was discovered, with features intermediate between basal cells and mucous-pavement cells, suggesting that the former cells transform into the latter. Volumes of gill epithelial cells are independent of animal size.

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3325 ◽  
Author(s):  
Devi Paramitha ◽  
Stéphane Chabaud ◽  
Stéphane Bolduc ◽  
Hendra Hermawan

The use of ureteral stents to relieve urinary tract obstruction is still challenged by the problems of infection, encrustation, and compression, leading to the need for early removal procedures. Biodegradable ureteral stents, commonly made of polymers, have been proposed to overcome these problems. Recently, absorbable metals have been considered as potential materials offering both biodegradation and strength. This work proposed zinc-based absorbable metals by firstly evaluating their cytocompatibility toward normal primary human urothelial cells using 2D and 3D assays. In the 2D assay, the cells were exposed to different concentrations of metal extracts (i.e., 10 mg/mL of Zn–1Mg and 8.75 mg/mL of Zn–0.5Al) for up to 3 days and found that their cytoskeletal networks were affected but were recovered at day 3, as observed by immunofluorescence. In the 3D ureteral wall tissue construct, the cells formed a multilayered urothelium, as found in native tissue, with the presence of tight junctions at the superficial layer and laminin at the basal layer, indicating a healthy tissue condition even with the presence of the metal samples for up to 7 days of exposure. The basal cells attached to the metal surface as seen in a natural spreading state with pseudopodia and fusiform morphologies, indicating that the metals were non-toxic.


2020 ◽  
Vol 21 (19) ◽  
pp. 7230
Author(s):  
Yoichi Chiba ◽  
Ryuta Murakami ◽  
Koichi Matsumoto ◽  
Keiji Wakamatsu ◽  
Wakako Nonaka ◽  
...  

The choroid plexus plays a central role in the regulation of the microenvironment of the central nervous system by secreting the majority of the cerebrospinal fluid and controlling its composition, despite that it only represents approximately 1% of the total brain weight. In addition to a variety of transporter and channel proteins for solutes and water, the choroid plexus epithelial cells are equipped with glucose, fructose, and urate transporters that are used as energy sources or antioxidative neuroprotective substrates. This review focuses on the recent advances in the understanding of the transporters of the SLC2A and SLC5A families (GLUT1, SGLT2, GLUT5, GLUT8, and GLUT9), as well as on the urate-transporting URAT1 and BCRP/ABCG2, which are expressed in choroid plexus epithelial cells. The glucose, fructose, and urate transporters repertoire in the choroid plexus epithelium share similar features with the renal proximal tubular epithelium, although some of these transporters exhibit inversely polarized submembrane localization. Since choroid plexus epithelial cells have high energy demands for proper functioning, a decline in the expression and function of these transporters can contribute to the process of age-associated brain impairment and pathophysiology of neurodegenerative diseases.


1989 ◽  
Vol 94 (3) ◽  
pp. 403-413 ◽  
Author(s):  
J. Taylor-Papadimitriou ◽  
M. Stampfer ◽  
J. Bartek ◽  
A. Lewis ◽  
M. Boshell ◽  
...  

The luminal and basal epithelial cells in the human mammary gland can be distinguished in tissue sections on the basis of the pattern of keratins they express. Moreover, the invasive cells in primary carcinomas show a keratin profile that corresponds to that of the dominant luminal cell (7, 8, 18, 19). When homogeneous populations of luminal epithelial cells from milk or from breast cancer metastases are cultured the profile of keratin expression seen in vivo is maintained. We have therefore used monospecific antibodies reactive with individual keratins to examine the phenotype of cells cultured in three different media from reduction mammoplasty tissue that contains both luminal and basal cells. The phenotype of cells cultured from primary breast cancers in one of these media (MCDB170) has also been examined. In characterizing cell phenotypes, antibodies to a polymorphic epithelial mucin (PEM) expressed in vivo by luminal cells, and to smooth muscle (a) actin, expressed in vivo by basal cells, have also been used. Our results show that proliferation of different cell phenotypes is selected for in different media. In milk mix (MX) developed for growth of luminal cells from milk, only the luminal cell phenotype proliferates (for only 1 or 2 passages). In medium MCDB 170, which was developed for long-term growth of human mammary epithelial cells from reduction mammoplasty organoids, cells from the basal layer proliferate, while in MM medium the basal phenotype dominates, but a few cells with the luminal phenotype are found. Around passage 3, in medium MCDB 170, most cells senesce and a subpopulation of cells proliferates on further passage. These cells retain expression of the basal epithelial keratins but also express some features characteristic of luminal epithelial cells, suggesting that the basal layer may contain a stem cell that can develop along the luminal lineage. In culture, however, they do not express keratin 19, which in vivo is a feature of the fully differentiated luminal cell. The cells cultured from primary breast cancer in medium MCDB 170 have a similar keratin profile to that of the normal cells cultured in this medium. They do not express keratin 19, even though the invasive cells in primary cancers homogeneously express this keratin in vivo. The invasive phenotype, which in its keratin profile corresponds to the differentiated luminal cell and that of the metastatic cancer lines, cannot be cultured from primary breast cancers using MX, which supports proliferation of the corresponding normal cell.


Author(s):  
D. Kuznetsova

Purpose: to study the clinical and echographic manifestation of endometritis.Materials and methods. Clinical and echographic research was carried out on 19 red-and-white cows, in the conditions of the agricultural farm of the Druzhba breeding plant, Pavlovsky district, Voronezh region on the 30-32th day after calving using the Easi-Scan scanner from BCF Technology Ltd, Scotland. Before ultrasound examination to establish the diagnosis, all animals were examined, transrectal palpation of the uterus. Simultaneously with the ultrasound examination, a cytological study of the uterine mucosa was carried out. For this purpose, a probe was constructed from a metal catheter intended for artificial insemination of cows with sequins by the deep cervical method with rectal fixation of the cervix; a cytobrush of the Juno probe was attached to the tip of the instrument. To confirm the diagnosis, a laboratory study of cervical mucus was additionally carried out by the express method according to Whiteside, modified by N. I. Polyantsev and Yu. N. Popov.Results. According to the results of rectal examination and ultrasound diagnostics, the cows were divided into three groups: clinically healthy, animals with clinically pronounced chronic endometritis and with latent endometritis. In the group of healthy animals, individual superficial and vacuolated intermediate cells (6.17 ± 0.51) and single neutrophils (2.31 ± 0.32) were detected in smears. In the group of clinically healthy cows, no gram-positive coccobacillary microorganisms and cells of the basal layer of the uterine mucosa were detected. In the second group, in animals with clinically pronounced chronic endometritis, a large number of segmented neutrophils, lymphocytes and a large number of cocci were detected in smears. Thus, in one visual field, the number of gram-positive cocobacillary microorganisms fluctuated on average 764.45 ± 4.56 microbial bodies, while the number of neutrophils increased in comparison with clinically healthy animals by 20.84 times and averaged 48.14 ± 2 in the group. , 91, the percentage of the score averaged around 12.1%. Simultaneously with an increase in the number of leukocytes in animals, the number of epithelial cells of the uterine mucosa increased by 2.21 times, while individual basal cells were detected simultaneously with superficial and intermediate cells (0.75 ± 0.48). In smears obtained from animals of the third group of cows, there was a significant decrease in the number of coccobacillary microorganisms to 75-360 in one visual field in comparison with similar results in the group with a clinically pronounced form of chronic endometritis. The indicator for segmented neutrophils was 8.05 times higher than in clinically healthy cows, while in relation to clinically sick cows by 61.4% and amounted to 18.60 ± 2.23. In terms of the number of superficial, vacuolated intermediate and basal cells in sick animals with chronic clinically pronounced endometritis and latent endometritis, no significant changes were revealed (1.08 times), while in relation to clinically healthy animals, these indicators were 2.38 times higher. The degree of variation in the number of epithelial cells in the group of cows with latent chronic endometritis was insignificant, which indicates the stability of the trait.Conclusion. Ultrasound scanning allows you to identify the latent form of endometritis and establish degenerative changes in the tissues of the uterus. Ultrasound examination in cows in establishing a diagnosis - endometritis should be the decisive diagnostic method.


Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1945
Author(s):  
Sheyla González ◽  
Maximilian Halabi ◽  
David Ju ◽  
Matthew Tsai ◽  
Sophie X. Deng

The Notch signaling pathway plays a key role in proliferation and differentiation. We investigated the effect of Jagged 1 (Jag1)-mediated Notch signaling activation in the human limbal stem/progenitor cell (LSC) population and the stratification of the limbal epithelium in vitro. After Notch signaling activation, there was a reduction in the amount of the stem/progenitor cell population, epithelial stratification, and expression of proliferation markers. There was also an increase of the corneal epithelial differentiation. In the presence of Jag1, asymmetric divisions were decreased, and the expression pattern of the polarity protein Par3, normally present at the apical-lateral membrane of basal cells, was dispersed in the cells. We propose a mechanism in which Notch activation by Jag1 decreases p63 expression at the basal layer, which in turn reduces stratification by decreasing the number of asymmetric divisions and increases differentiation.


Biomedicines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 489
Author(s):  
Hilary Y. Liu ◽  
Jenna R. Gale ◽  
Ian J. Reynolds ◽  
John H. Weiss ◽  
Elias Aizenman

Zinc is a highly abundant cation in the brain, essential for cellular functions, including transcription, enzymatic activity, and cell signaling. However, zinc can also trigger injurious cascades in neurons, contributing to the pathology of neurodegenerative diseases. Mitochondria, critical for meeting the high energy demands of the central nervous system (CNS), are a principal target of the deleterious actions of zinc. An increasing body of work suggests that intracellular zinc can, under certain circumstances, contribute to neuronal damage by inhibiting mitochondrial energy processes, including dissipation of the mitochondrial membrane potential (MMP), leading to ATP depletion. Additional consequences of zinc-mediated mitochondrial damage include reactive oxygen species (ROS) generation, mitochondrial permeability transition, and excitotoxic calcium deregulation. Zinc can also induce mitochondrial fission, resulting in mitochondrial fragmentation, as well as inhibition of mitochondrial motility. Here, we review the known mechanisms responsible for the deleterious actions of zinc on the organelle, within the context of neuronal injury associated with neurodegenerative processes. Elucidating the critical contributions of zinc-induced mitochondrial defects to neurotoxicity and neurodegeneration may provide insight into novel therapeutic targets in the clinical setting.


Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 641
Author(s):  
Vânia Pôjo ◽  
Tânia Tavares ◽  
Francisco Xavier Malcata

One of the main goals of Mankind is to ensure food system sustainability—including management of land, soil, water, and biodiversity. Microalgae accordingly appear as an innovative and scalable alternative source in view of the richness of their chemical profiles. In what concerns lipids in particular, microalgae can synthesize and accumulate significant amounts of fatty acids, a great fraction of which are polyunsaturated; this makes them excellent candidates within the framework of production and exploitation of lipids by various industrial and health sectors, either as bulk products or fine chemicals. Conventional lipid extraction methodologies require previous dehydration of microalgal biomass, which hampers economic feasibility due to the high energy demands thereof. Therefore, extraction of lipids directly from wet biomass would be a plus in this endeavor. Supporting processes and methodologies are still limited, and most approaches are empirical in nature—so a deeper mechanistic elucidation is a must, in order to facilitate rational optimization of the extraction processes. Besides circumventing the current high energy demands by dehydration, an ideal extraction method should be selective, sustainable, efficient, harmless, and feasible for upscale to industrial level. This review presents and discusses several pretreatments incurred in lipid extraction from wet microalga biomass, namely recent developments and integrated processes. Unfortunately, most such developments have been proven at bench-scale only—so demonstration in large facilities is still needed to confirm whether they can turn into competitive alternatives.


2002 ◽  
Vol 13 (3) ◽  
pp. 162-165 ◽  
Author(s):  
Rodrigo de Castro Albuquerque ◽  
Ricardo Santiago Gomez ◽  
Rodrigo Aliprandi Dutra ◽  
Wallison Arthuso Vasconcellos ◽  
Renato Santiago Gomez ◽  
...  

The purpose of the present study was to evaluate the influence of short course topical application of carbamide peroxide on proliferating cell nuclear antigen (PCNA) immunohistochemical expression in the oral tongue mucosa of rats. Twelve male Wistar rats were submitted to topical application of 10% carbamide peroxide on one side of the dorsal tongue once a week for three consecutive weeks. Only distilled water was applied on the control side. The animals were killed on days 0, 10, and 20 after the last application. The tongue was fixed in buffered formalin for 24 h and embedded in paraffin. Tissue blocks (3 µm) were subjected to the biotin-streptavidin amplified system for identification of PCNA. The percentage of epithelial-positive basal cells in each side of the tongue mucosa was calculated. The results demonstrated that topical application of 10% carbamide peroxide increases PCNA immunohistochemical expression on the basal layer of the oral mucosa epithelium of rats on day 0 after treatment. In conclusion, short-course use of carbamide peroxide induces transient epithelial cell proliferation of the oral mucosa of rats.


2015 ◽  
Vol 27 (4) ◽  
pp. 497-503 ◽  
Author(s):  
Jason B. Pieper ◽  
Adam W. Stern ◽  
Suzette M. LeClerc ◽  
Karen L. Campbell

Forty-seven canine cutaneous epithelial tumors and cysts were examined to determine coordinate expression of cytokeratins 7 (CK7) and 14 (CK14), vimentin, and Bcl-2 using commercially available antibodies. Within non-affected normal skin adjacent to tumors or cysts, CK7 expression was observed in luminal cells in apocrine glands; CK14 expression was observed in the stratum basale, stratum spinosum, stratum granulosum, basal layer of outer root sheath, sebaceous glands, and myoepithelial cells of apocrine glands; vimentin expression was observed in dermal papilla and scattered non-epithelial cells within the epidermis; and Bcl-2 expression was observed in scattered non-epithelial cells in the epidermis and some apocrine glands. The pattern of expression of CK7 and CK14 in cases of adenocarcinoma of the apocrine gland of the anal sac (CK7+/CK14–) and hepatoid gland tumors (CK7–/CK14+) may prove useful for diagnostic purposes. Loss of expression of CK14 and vimentin, identifying myoepithelial cells, was observed in apocrine and ceruminous adenocarcinomas. Differences in patterns of expression of Bcl-2 were observed between infundibular keratinizing acanthomas compared to trichoepitheliomas.


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