Structure of the midgut epithelium in four diplopod species: histology, histochemistry and ultrastructure

Abstract The middle region of the digestive system of millipedes, the midgut, is responsible for all processes connected with digestion, but also takes part in homeostasis maintenance thanks to the ability to activate many mechanisms which neutralize changes occurring at different levels of the animal’s body. Numerous millipede species are treated as bioindicators of the natural environment and they are exposed to different stressors which originate from external environment. To obtain all data on the functioning of midgut of millipedes as the barrier against stressors, it is necessary to have a precise and general description of the midgut epithelium. Members from four millipede orders were selected for the studies: Polydesmus angustus (Polydesmida), Epibolus pulchripes (Spirobolida), Unciger transsilvanicus (Julida) and Glomeris tetrasticha (Glomerida). The structure and ultrastructure of their midgut epithelial cells (the digestive, secretory and regenerative cells) were documented using transmission electron microscopy and histochemical methods. The obtained results have been compared and discussed to previous ones, to present the general and structural organization of the midgut in Diplopoda. Our studies revealed that the ultrastructure of all cells which form the midgut epithelium in millipedes is general for all the species studied up to now and it resembles the cell ultrastructure observed in Chilopoda and Hexapoda, including the digestive, secretory and stem cells.

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Autophagy and Apoptosis in the Midgut Epithelium of Millipedes

Microscopy and Microanalysis ◽

10.1017/s143192761900059x ◽

2019 ◽

Vol 25 (4) ◽

pp. 1004-1016 ◽

Cited By ~ 4

Author(s):

M.M. Rost-Roszkowska ◽

J. Vilimová ◽

K. Tajovský ◽

A. Chachulska-Żymełka ◽

A. Sosinka ◽

...

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Light Microscope ◽

Fluorescence Microscope ◽

Midgut Epithelium ◽

Digestive Cells ◽

Histochemical Methods ◽

Transmission Electron ◽

Regenerative Cells ◽

Residual Bodies

AbstractThe process of autophagy has been detected in the midgut epithelium of four millipede species: Julus scandinavius, Polyxenus lagurus, Archispirostreptus gigas, and Telodeinopus aoutii. It has been examined using transmission electron microscopy (TEM), which enabled differentiation of cells in the midgut epithelium, and some histochemical methods (light microscope and fluorescence microscope). While autophagy appeared in the cytoplasm of digestive, secretory, and regenerative cells in J. scandinavius and A. gigas, in the two other species, T. aoutii and P. lagurus, it was only detected in the digestive cells. Both types of macroautophagy, the selective and nonselective processes, are described using TEM. Phagophore formation appeared as the first step of autophagy. After its blind ends fusion, the autophagosomes were formed. The autophagosomes fused with lysosomes and were transformed into autolysosomes. As the final step of autophagy, the residual bodies were detected. Autophagic structures can be removed from the midgut epithelium via, e.g., atypical exocytosis. Additionally, in P. lagurus and J. scandinavius, it was observed as the neutralization of pathogens such as Rickettsia-like microorganisms. Autophagy and apoptosis ca be analyzed using TEM, while specific histochemical methods may confirm it.

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Ultrastructure of two Types of Endocrine Cells in the Midgut Epithelium of Spodoptera Exiqua Hűbner, 1808 (Insecta, Lepidoptera, Noctuidae)

Zoologica Poloniae ◽

10.2478/v10049-008-0003-6 ◽

2008 ◽

Vol 53 (1-4) ◽

pp. 27-35 ◽

Cited By ~ 3

Author(s):

Magdalena Rost-Roszkowska ◽

Agata Chechelska ◽

Maciej Frądczak ◽

Katarzyna Salitra

Keyword(s):

Electron Microscope ◽

Endocrine Cells ◽

Larval Instar ◽

Midgut Epithelium ◽

Transmission Electron ◽

Regenerative Cells ◽

Apical Membranes ◽

Columnar Cells ◽

Lepidoptera Noctuidae ◽

Midgut Lumen

Ultrastructure of two Types of Endocrine Cells in the Midgut Epithelium ofSpodoptera ExiquaHűbner, 1808 (Insecta, Lepidoptera, Noctuidae)Midgut epithelium of Lepidoptera consists of four types of cells: columnar, goblet, endocrine and regenerative. Among endocrine cells two types have been distinguished: "open" and "closed". In all five larval instars ofSpodoptera exiqua(Lepidoptera, Noctuidae) only "open" endocrine cells were observed, which means that their apical membranes contact with the midgut lumen and form microvilli like columnar cells of epithelial character. Among them granular and vesicular cells are distinguishable. The number of vesicular endocrine cells increases distinctly in the 5thlarval instar. The structure of endocrine cells in the midgut epithelium ofS. exiquaand their differentiation from the regenerative cells, studied in transmission electron microscope, are described.

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Ultrastructure of the midgut epithelium in three species of Macrobiotidae (Tardigrada: Eutardigrada: Parachela)

Zoological Journal of the Linnean Society ◽

10.1093/zoolinnean/zlz052 ◽

2019 ◽

Author(s):

M Rost-Roszkowska ◽

K Janelt ◽

I Poprawa

Keyword(s):

Lipid Droplets ◽

Digestive System ◽

Midgut Epithelium ◽

Middle Region ◽

Reserve Material ◽

Digestive Cells ◽

Intracellular Digestion ◽

Carnivorous Species ◽

Males And Females ◽

Anterior Ring

Abstract Three species of Macrobiotidae, Macrobiotus polonicus, Macrobiotus diversus and Macrobiotus pallarii, were selected for analysis of the fine structure of the midgut epithelium. They are gonochoric and carnivorous species that live in wet terrestrial and freshwater environments. The ultrastructure of the midgut epithelium of the investigated Macrobiotidae species was analysed in both males and females. Their digestive system is composed of fore- and hindguts that are covered by a cuticle, and the middle region, termed the midgut. It is lined with a simple epithelium that is formed by digestive cells that have a distinct brush border. Crescent-shaped cells that form an anterior ring in the border between the fore- and midgut were detected. The ultrastructure of the intestinal epithelium of the examined species differs slightly depending on sex. The digestive cells of the posterior segment of the intestine contain numerous lipid droplets, which are the reserve material. We concluded that the digestive cells of the Macrobiotidae midgut are responsible for its intracellular digestion owing to endocytosis. They also participate in the extracellular digestion owing to merocrine secretion (exocytosis). However, the midgut is not the main organ that accumulates reserve material. Additionally, the midgut epithelium does not participate in oogenesis.

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Effects of the pseudomonad phytotoxin coronatine on tomato leaf structure and ultrastructure

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100140683 ◽

1995 ◽

Vol 53 ◽

pp. 862-863

Author(s):

D.A. Palmer ◽

C.L. Bender

Keyword(s):

Pseudomonas Syringae ◽

Membrane Integrity ◽

Leaf Tissue ◽

Cell Number ◽

Cell Ultrastructure ◽

Response To Treatment ◽

Prominent Symptom ◽

Chlorophylls A And B ◽

Cell Dimensions ◽

Structure And Ultrastructure

Coronatine is a non-host-specific phytotoxin produced by several members of the Pseudomonas syringae group of pathovars. The toxin acts as a virulence factor in P. syringae pv. tomato, allowing the organism to multiply to a higher population density and develop larger lesions than mutant strains unable to produce the toxin. The most prominent symptom observed in leaf tissue treated with coronatine is an intense spreading chlorosis; this has been attributed to a loss of chlorophylls a and b in tobacco. Coronatine's effects on membrane integrity and cell ultrastructure have not been previously investigated. The present study describes changes in tomato leaves in response to treatment with purified coronatine, infection by a coronatine-producing strain of P. syringae pv. tomato, and infection by a cor" mutant.In contrast to H2O-treated tissue, coronatine-treated tissue showed a diffuse chlorosis extending approximately 5 mm from the inoculation site. Leaf thickness, cell number, and cell dimensions were similar for both healthy and coronatine-treated, chlorotic tissue; however, the epidermal cell walls were consistently thicker in coronatine-treated leaves (Figs, la and lb).

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Cis-Diamminedichloroplatinum (II) Ototoxicity in the Guinea Pig

Otolaryngology ◽

10.1177/019459988108900424 ◽

1981 ◽

Vol 89 (4) ◽

pp. 638-645 ◽

Cited By ~ 83

Author(s):

Scott A. Estrem ◽

Richard W. Babin ◽

Jai H. Ryu ◽

Kenneth C. Moore

Keyword(s):

Electron Microscopy ◽

Hair Cells ◽

Supporting Cell ◽

Cell Ultrastructure ◽

Outer Hair Cells ◽

Detectable Change ◽

Supporting Cells ◽

Apical Portion ◽

Ultrastructural Evidence ◽

Transmission Electron

Cochleas from 12 guinea pigs were evaluated using light, scanning, and transmission electron microscopy after systemic administration of cis-diamminedichloroplatinum (cis-DDP). Administration of cis-DDP resulted in loss of the Preyer reflex and degeneration of outer hair cells (OHC) with increased dose. The OHC degeneration was most pronounced in the basal turns of the cochlea with greatest severity in the inner row. Ultrastructural evidence of OHC degeneration included dilatation of the parietal membranes, softening of the cuticular plate, increased vacuolization and increased numbers of lysosome-like bodies in the apical portion of the cell. Supporting cells appeared more sensitive than OHC. Alteration of supporting cell ultrastructure preceded detectable change in OHC. Injury to the supporting cells was noted with intracellular vesiculation and increased autophagocytosis.

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The model of regional social-economical system in condition of little forecasted external environment for informational advancing system (for example of Bryansk rigion)

Bulletin of Bryansk state technical university ◽

10.12737/22722 ◽

2015 ◽

Vol 2015 (1) ◽

pp. 73-78 ◽

Cited By ~ 3

Author(s):

Дмитрий Аксененко ◽

Dmitriy Aksenenko ◽

Андрей Аверченков ◽

Andrey Averchenkov ◽

Елена Аверченкова ◽

...

Keyword(s):

External Environment ◽

System Model ◽

Economical System ◽

Different Levels

Base characteristics of regional social-economical system model in condition of little forecasted external environment are in this article. Creation of informational advancing system is the goal of this model. Informational advancing system helps to make management decides for different levels of region authorities.

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Structure and ultrastructure of oogenic stage in short mackerel Rastrelliger brachysoma (Teleostei: Scombidae)

Journal of Morphological Sciences ◽

10.4322/jms.096915 ◽

2017 ◽

Vol 34 (01) ◽

pp. 023-030

Author(s):

S. Senarat ◽

J. Kettratad ◽

W. Jiraungkoorskul

Keyword(s):

Lipid Droplets ◽

Growth Stage ◽

Secondary Growth ◽

Cytoplasmic Organelles ◽

Transmission Electron ◽

Candidate Species ◽

Vitellogenic Stage ◽

Epithelial Compartment ◽

Vitelline Envelope ◽

Structure And Ultrastructure

Abstract Introduction: Structure, ultrastructural features and degeneration of oogenesis were first investigated in female Rastrelliger brachysoma as new candidate species for aquaculture by transmission electron microscopy. Materials and Methods: Specimens were naturally collected during the breeding season from Samut Songkhram Province, Thailand. Results: The ultrastructure of female oogenesis was principally divided into five stages based on the nuclear characterization and cytoplasmic organelles; (i) oogonium; (ii) previtellogenic; (iii) lipid and cortical alveolar; (iv) early and (v) late vitellogenic stages. Initially, oogonium was present within cell nest in the epithelial compartment. Its cell was supported by prefollicular cells. The multiple nucleoli in previtellogenic stage, referring to primary growth stage were the first to appear and they were scattered around the peripheral of nuclear membrane with the increasing number of cytoplasmic organelles. Some microvilli of granulosa cell initially protruded into the vitelline envelope. A simple layer of flattened granulosa and theca cells was also observed. The lipid and cortical alveolar stage under secondary growth oocyte was accumulated with two inclusions; the lipid droplets and cortical alveoli in the ooplasm. Another characterization, the increasing of numerous microvilli was also detected in the vitelline envelope. Finally, in the vitellogenic stage, a massive uptake and processing of proteins into yolk platelets due to embedding of the numerous microvilli in the largest vitelline envelope was observed. Oocyte degeneration in R. brachysoma was novel found especially oogonial and previtellogenic stages. Conclusion: Five oogenic stages of this fish are found with the changing of the arrangement of nucleus, cytoplasmic organelles and follicular complex, which will be applied to further studies.

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In Vitro Cytotoxicity Induced by the Bufadienolides 1α,2α-Epoxyscillirosidine and Lanceotoxin B on Rat Myocardial and Mouse Neuroblastoma Cell Lines

Toxins ◽

10.3390/toxins11010014 ◽

2019 ◽

Vol 11 (1) ◽

pp. 14 ◽

Cited By ~ 2

Author(s):

Danielle Henn ◽

Annette Venter ◽

Christo Botha

Keyword(s):

Cell Lines ◽

Neuroblastoma Cell ◽

Cell Types ◽

Cell Ultrastructure ◽

In Vitro Cytotoxicity ◽

Cytoplasmic Material ◽

Mouse Neuroblastoma ◽

Transmission Electron ◽

Half Maximal Effective Concentration

Consumption of bufadienolide-containing plants are responsible for many livestock mortalities annually. Bufadienolides are divided into two groups; non-cumulative bufadienolides and cumulative bufadienolides. Cumulative bufadienolides are referred to as neurotoxic, as the chronic intoxication with this type of bufadienolide results in a paretic/paralytic syndrome known as ‘krimpsiekte’. The in vitro cytotoxicity of a non-cumulative bufadienolide, 1α,2α-epoxyscillirosidine, and a cumulative bufadienolide, lanceotoxin B, were compared using the MTT ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction) assay after exposing rat myocardial (H9c2) and mouse neuroblastoma (Neuro-2a) cell lines. The effect of these two bufadienolides on cell ultrastructure was also investigated using transmission electron microscopy (TEM). H9c2 cells exhibited greater cytotoxicity when exposed to 1α,2α-epoxyscillirosidine, compared to lanceotoxin B. In contrast, Neuro-2a cells were more susceptible to lanceotoxin B. The EC50 (half maximal effective concentration) of lanceotoxin B exposure of Neuro-2a cells for 24–72 h ranged from 4.4–5.5 µM compared to EC50s of 35.7–37.6 µM for 1α,2α-epoxyscillirosidine exposure of Neuro-2a cells over the same period. 1α,2α-Epoxyscillirosidine induced extensive vacuolization in both cell types, with swollen RER (rough endoplasmic reticulum) and perinuclear spaces. Lanceotoxin B caused swelling of the mitochondria and sequestration of cytoplasmic material within autophagic vesicles. These results corroborate the notion that cumulative bufadienolides are neurotoxic.

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TrkB-Targeted Therapy for Mucoepidermoid Carcinoma

Biomedicines ◽

10.3390/biomedicines8120531 ◽

2020 ◽

Vol 8 (12) ◽

pp. 531

Author(s):

Vivian P. Wagner ◽

Manoela D. Martins ◽

Esra Amoura ◽

Virgilio G. Zanella ◽

Rafael Roesler ◽

...

Keyword(s):

Cell Migration ◽

Cell Lines ◽

Mucoepidermoid Carcinoma ◽

Combined Treatment ◽

Cell Ultrastructure ◽

Ultrastructural Changes ◽

Migration And Invasion ◽

Limiting Factor ◽

Transmission Electron

The brain-derived neurotrophic factor (BDNF)/tyrosine receptor kinase B (TrkB) pathway was previously associated with key oncogenic outcomes in a number of adenocarcinomas. The aim of our study was to determine the role of this pathway in mucoepidermoid carcinoma (MEC). Three MEC cell lines (UM-HMC-2, H253 and H292) were exposed to Cisplatin, the TrkB inhibitor, ANA-12 and a combination of these drugs. Ultrastructural changes were assessed through transmission electron microscopy; scratch and Transwell assays were used to assess migration and invasion; and a clonogenic assay and spheroid-forming assay allowed assessment of survival and percentage of cancer stem cells (CSC). Changes in cell ultrastructure demonstrated Cisplatin cytotoxicity, while the effects of ANA-12 were less pronounced. Both drugs, used individually and in combination, delayed MEC cell migration, invasion and survival. ANA-12 significantly reduced the number of CSC, but the Cisplatin effect was greater, almost eliminating this cell population in all MEC cell lines. Interestingly, the spheroid forming capacity recovered, following the combination therapy, as compared to Cisplatin alone. Our studies allowed us to conclude that the TrkB inhibition, efficiently impaired MEC cell migration, invasion and survival in vitro, however, the decrease in CSC number, following the combined treatment of ANA-12 and Cisplatin, was less than that seen with Cisplatin alone; this represents a limiting factor.

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Does strategic planning help firms translate slack resources into better performance?

Journal of Management & Organization ◽

10.1017/jmo.2017.84 ◽

2018 ◽

Vol 26 (4) ◽

pp. 395-407 ◽

Cited By ~ 1

Author(s):

Jinyu Guo ◽

Bo Zhou ◽

Haili Zhang ◽

Chunjia Hu ◽

Michael Song

Keyword(s):

Firm Performance ◽

Strategic Planning ◽

External Environment ◽

Organizational Slack ◽

Low Levels ◽

Using Data ◽

The Impact ◽

Performance Research ◽

Practical Implications ◽

Different Levels

AbstractIs organizational slack good or bad for firm performance? Research addressing this question has obtained mixed results. Such studies have focused mainly on the impact of environmental conditions on the slack–performance relationship. In this study, instead of focusing on the uncontrollable external environment, we consider actions determined by firms internally, in particular strategic planning. Using data from 183 US firms, we explore the connection between organizational slack and firm performance with different levels of strategic planning. The results suggest that at low levels of strategic planning the slack–performance relationship is linear, while at high levels of strategic planning this relationship is inverse U shaped. We discuss the theoretical and practical implications of these findings.

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