Fine-Structural Changes in Relation to Ion and Water Transport in the Rectal Papillae of the Blowfly, Calliphora

1967 ◽  
Vol 2 (1) ◽  
pp. 89-112 ◽  
Author(s):  
M. J. BERRIDGE ◽  
B. L. GUPTA
Keyword(s):  
Complex System ◽  
Water Transport ◽  
Structural Design ◽  
Structural Changes ◽  
Biological Tissues ◽  
Membrane Theory ◽  
Intercellular Spaces ◽  
Direct Response ◽  
Calliphora Erythrocephala ◽  
Double Membrane

The fine structure of the epithelial cells of the rectal papillae in the blowfly, Calliphora erythrocephala Meig., has been investigated to elucidate the possible mechanism of reabsorption of water and ions from the rectal lumen. To observe the variations in the structure of the epithelium in response to the absorptive processes the material was taken (a) from flies at the various stages of their first oviposition cycle, and (b) from freshly emerged imagoes starved for 2 days and injected into the rectum with solutions of various tonicities. It has been found that the complex system of intercellular spaces, formed by a prolific infolding of the lateral plasma membrane of the cells, shows a direct response to the conditions of supposedly maximal and minimal transport of fluid. These spaces are (a) grossly distended in the flies injected with hypotonic media, (b) highly dilated under normal conditions, and (c) completely collapsed in fasting and starved flies. These observations have been discussed in the light of the available theories to explain the mechanism of water transport in biological tissues. It is proposed that the structural design of the rectal papillae favours the application of double-membrane theory to explain the reabsorption of water against osmotic gradients as a consequence of an active transport of solutes into enclosed spaces.

The correlation of ethanol-induced depression of glucose and water transport with morphological changes in the hamster jejunum in vivo

1978 ◽  
Vol 56 (1) ◽  
pp. 123-131 ◽  
Author(s):  
J. E. Fox ◽  
T. F. McElligott ◽  
I. T. Beck
Keyword(s):  
Epithelial Cells ◽  
Light Microscopy ◽  
Glucose Transport ◽  
Water Transport ◽  
Structural Changes ◽  
Morphological Changes ◽  
Glucose Absorption ◽  
Intercellular Spaces ◽  
Lateral Intercellular Spaces

Glucose and water transport is depressed in the hamster jejunum in vivo by ethanol (4.8%) which also produced fluid-filled blebs at the tips of the villi. The epithelial cells over the blebs appeared stretched and cuboidal, the lateral intercellular spaces (LIS) were no longer recognizable, and the lacteals were closed. Forty-five minutes after discontinuation of the ethanol, water transport returned to normal while glucose transport remained depressed. At this time the villus structure had returned to normal. The blebs had disappeared, the LIS were again recognizable, and their appearance and number were similar to those in the control animals. Thus, the depression of water transport correlated with the obvious structural changes caused by ethanol; however, the depression of glucose absorption is associated with some effect of ethanol not evident by routine light microscopy.

Nickel oxide nanoparticles induce genotoxicity and cellular alterations in the ground beetle Blaps polycresta (Coleoptera: Tenebrionidae)

2021 ◽  
pp. 074823372110009
Author(s):  
Dalia Abdel Moneim Kheirallah ◽  
Awatef Mohamed Ali ◽  
Salah Eldein Osman ◽  
Amal Mohamed Shouman
Keyword(s):  
Nickel Oxide ◽  
Structural Changes ◽  
Ground Beetle ◽  
Biological Tissues ◽  
Treated Group ◽  
Sublethal Dose ◽  
Oxide Nanoparticles ◽  
Nickel Oxide Nanoparticles ◽  
Nio Nps ◽  
The Impact

Nickel nanoparticles (Ni-NPs) have advantageous applications in the industry; however, little is known of their adverse effects on biological tissues. In the present study, the ground beetle Blaps polycresta was employed as a sensitive indicator for nickel oxide nanoparticles (NiO-NPs) toxicity. Adult male beetles were injected with six dose levels of NiO-NPs (0.01, 0.02, 0.03, 0.04, 0.05, and 0.06 mg/g body weight). Mortality was reported daily over 30 days under laboratory conditions to establish an LD50. Nickel was detected in the testicular tissues of the beetles using X-ray analysis and transmission electronic microscopy. Beetles treated with the sublethal dose of 0.02 mg/g were selected to observe molecular, cellular, and subcellular changes. Gene transcripts of HSP70, HSP90, and MT1 were found to be increased >2.5-, 1.5-, and 2-fold, respectively, in the treated group compared with the controls. Decreased gene expression of AcPC01, AcPC02, and AcPC04 (≤1.5-, ≤2-, and < 2.5-fold, respectively, vs. controls) also were reported in the treated group. Under light microscopy, various structural changes were observed in the testicular tissues of the treated beetles. Ultrastructure observations using scanning and transmission electron microscopy showed severe damage to the subcellular organelles as well as deformities of the heads and flagella of the spermatozoa. Therefore, the present study postulated the impact of NiO-NPs in an ecological model.

Numerical analysis of non-aligned inputs M-type micromixers with different shaped obstacles for biomedical applications

2021 ◽  
pp. 095440892110516
Author(s):  
Muhammad Irfan ◽  
Imran Shah ◽  
Usama M Niazi ◽  
Muhsin Ali ◽  
Sadaqat Ali ◽  
...  
Keyword(s):  
Structural Design ◽  
Biomedical Applications ◽  
Structural Changes ◽  
Nanoparticle Synthesis ◽  
Fluid Mixing ◽  
The Novel ◽  
Flow Conditions ◽  
Mixing Index ◽  
Mixing Performance ◽  
Passive Micromixer

Fluid mixing in lab-on-a-chip devices at laminar flow conditions result in a low mixing index. The reason is dominant diffusion over the convection process. The mixing index can be improved by certain changes in the micromixer structural design like introducing obstacles in the path of fluid flow. These obstacles will make dominant the advection process over the diffusion process. The main contribution of this work is based on proposing the novel hybrid type micromixer design for enhancing the mixing quality. Three non-aligned M-type and non-aligned M-type with obstacles passive type micromixers are analyzed by COMSOL5.5. These designs are hybrid types because different structural changes are combined in a single design for mixing improvement. First of all the straight non-aligned inlets, M-type passive micromixer (SMTM) is analyzed. It is observed that mixing performance is improved because of M-shaped mixing units and non-aligned inlets. This improvement is deemed to be not enough so different shaped obstacles are introduced in the micromixer design. These designs based on obstacles are named horizontal rectangular M-type micromixer, square M-type micromixer, and vertical rectangular M-type micromixer. The mixing index for SMTM, square M-type micromixer, horizontal rectangular M-type micromixer, and vertical rectangular M-type micromixer at Reynolds number Re = 60 is respectively given by 71.1%, 83.21%, 84.45%, and 89.99%. The mixing index of vertical rectangular M-type micromixer was 59.34% − 87.65% for Re = 0.5–100. Vertical rectangular M-type micromixer is concluded with the better-mixing capability design among the proposed ones. Based on these simulation results, the vertical rectangular M-type micromixer design can be utilized for mixing purposes in biomedical applications like nanoparticle synthesis and biomedical sample preparation for drug delivery.

scholarly journals Mitonucleons formed during differentiation of Ishikawa endometrial cells generate vacuoles that elevate monolayer syncytia: Differentiation of Ishikawa domes, Part 1

2016 ◽  
Author(s):  
Honoree Fleming
Keyword(s):  
Cell Death ◽  
Structural Changes ◽  
Apical Membrane ◽  
Signet Ring Cells ◽  
Double Membrane ◽  
Endometrial Cells ◽  
Endometrial Epithelial Cell ◽  
Signet Ring ◽  
Endogenous Biotin ◽  
Cell Profile

In 1998, we published a paper (Fleming et.al, 1998) describing some aspects of Ishikawa endometrial epithelial cell differentiation from monolayer cells into cells forming fluid-filled hemispheres called domes. The process begins with the dissolution of membranes within discrete regions of the monolayer. Nuclei from fused cells aggregate and endogenous biotin in particulate structures assumed to be mitochondria increase throughout the resulting syncytium. Endogenous biotin is also the distinguishing feature of a membrane that surrounds aggregates of multiple nuclei in a structure called a mitonucleon. The current paper includes additional observations on structural changes accompanying Ishikawa differentiation. Vacuoles form in the heterochromatin of the mitonucleon and within the biotin-containing double membrane surrounding heterochromatin. With the formation of vacuoles, the mitonucleon can be seen to rise along with the apical membrane of the syncytium in which it formed. The small vacuoles that form within the heterochromatin result in structures similar to “cells with optically clear nuclei” found in some cancers. The second larger vacuole that forms within the membrane surrounding the heterochromatin transforms the cell profile to one that resembles “signet ring” cells also observed in some cancers. Eventually the membrane surrounding the massed heterochromatin, generated three to four hours earlier, is breached and previously aggregated nuclei disaggregate. During this process heterochromatin in the mitonucleons undergoes changes usually ascribed to cells undergoing programmed cell death such as pyknosis and DNA fragmentation (Fleming, 2016b). The cells do not die, instead chromatin filaments appear to coalesce into a chromatin mass that gives rise to dome-filling nuclei by amitosis during the final three to four hours of the 20 hour differentiation (Fleming, 2016c).

scholarly journals Improvement of business processes in modern shipping companies in the field of international sea fright transportation

2021 ◽  
Vol 2021 (1) ◽  
pp. 1-12
Author(s):  
Zoryana Dvulit ◽  
◽  
Olena Tymoshchuk ◽  
Olha Levchenko ◽  
◽  
...  
Keyword(s):  
International Trade ◽  
Water Transport ◽  
Business Process ◽  
Structural Changes ◽  
Process Management ◽  
Business Processes ◽  
Successful Implementation ◽  
Shipping Company ◽  
Current Trends ◽  
Systemic Problems

In a market economy, there are a significant number of shipping companies that compete with each other and fight for maximum profits in a highly competitive environment. Competitive advantages lie in the plane of organization of the fleet, which relate mainly to the management of shipping companies. Operators of shipping companies establish tactical and strategic cooperation with freight forwarders and other participants in the logistics chain for the successful implementation of business processes and subprocesses. The study of the water transport of Ukraine from 2002 to 2020 revealed that in this period there were significant structural changes in freight turnover and traffic, which indicates the presence of serious systemic problems in management. If current trends continue, the national economy may lose such a strategically important sector. The shortcomings in the field of international maritime transport are caused, among other things, by inefficient management of business processes of Ukrainian shipping companies. The business process of a shipping company is a set of interdependent tasks and works aimed at creating a product or service to meet the needs of their customers. The business processes of shipping companies are due to the characteristics of staff and the processes of international trade. Thus, the personnel of shipping companies, concentrated in the operational units, provide a range of services that ensure the movement of goods and passengers with the required level of quality. The complex of such services is described by many business processes and represents the main processes of the shipping company. Improving the business processes of these companies must be viewed through the prism of the field of logistics, the main factors in the development of which are staff and international trade trends. Research and study of international experience in the field of business process management and its implementation in the activities of shipping companies of Ukraine to some extent will improve the declining trends in freight traffic and water transport, which have been observed in recent years.

scholarly journals CONTRAST BETWEEN THE ENVIRONMENTAL pH DEPENDENCIES OF PROPHASING AND NUCLEAR MEMBRANE FORMATION IN INTERPHASE-METAPHASE CELLS

1973 ◽  
Vol 58 (3) ◽  
pp. 608-617 ◽  
Author(s):  
Yoshitaka Obara ◽  
Hiroshi Yoshida ◽  
Lee S. Chai ◽  
Herbert Weinfeld ◽  
Avery A. Sandberg
Keyword(s):  
Structural Changes ◽  
Chinese Hamster ◽  
Binucleate Cell ◽  
M Cells ◽  
M Cell ◽  
Metaphase Chromosomes ◽  
Membrane Formation ◽  
Interphase Cell ◽  
Double Membrane ◽  
Mononucleate Cell

In Chinese hamster Don cells, fusion of an interphase cell with a metaphase cell resulted either in prophasing of the interphase nucleus, including loss of the nuclear envelope (NE), or in the formation of a double membrane around the metaphase chromosomes. Only one of these phenomena occurred in a given interphase-metaphase (I–M) binucleate cell. At pH 7.4, there was about an equal probability that either event could occur amongst the population of I–M cells. The effect of pH changes in the medium containing the fused cells was examined. At pH 6.6, prophasing was the predominant event; at pH 8.0, membrane formation predominated. It was found that the rate of progression of a mononucleate cell from G2 to metaphase was appreciably faster at pH 6.6 than at pH 8.0. Conversely, the progression from metaphase to G1 was faster at pH 8.0 than at pH 6.6. These results with the mononucleate cells strengthen the hypothesis that structural changes in I–M cells are reflections of normal mitotic phenomena. Additional evidence for this hypothesis was produced by electron microscope examination after direct fixation in chrom-osmium. The double membrane around the chromosomes of the I–M cell was indistinguishable from the normal NE. The results obtained by varying the pH of the medium containing the fused cells provide an indication that disruption or formation of the NE of Don cells depends on the balance reached between disruptive and formative processes.

Structural changes in acclimated and unacclimated leaves during freezing and thawing

2004 ◽  
Vol 31 (1) ◽  
pp. 29 ◽  
Author(s):  
Marilyn C. Ball ◽  
Martin J. Canny ◽  
Chen X. Huang ◽  
Roger D. Heady
Keyword(s):  
Low Temperatures ◽  
Structural Changes ◽  
Living Cells ◽  
Evolutionary Significance ◽  
Intercellular Spaces ◽  
Freezing And Thawing ◽  
Specific Expansion ◽  
Intracellular Ice ◽  
Leaf Tissues ◽  
Leaf Survival

Freeze-induced damage to leaf tissues was studied at different states of acclimation to low temperatures in snow gum, Eucalyptus pauciflora Sieber ex Sprengel. Intact, attached leaves of plants grown under glasshouse or field conditions were frozen at natural rates (frost-freezing) and thawed under laboratory conditions. Leaves were cryo-fixed unfrozen, during frost-freezing or after thawing for observation in a cryo-scanning electron microscope. Frost-freezing in unacclimated tissues caused irreversible tissue damage consistent with tissue death. Intracellular ice formed in the cambium and phloem, killing the cells and leaving persistent gaps between xylem and phloem. Many other cells were damaged by frost-freeze-induced dehydration and failed to resorb water from thawed extracellular ice, leaving substantial amounts of liquid water in intercellular spaces. In contrast, acclimated leaves showed reversible tissue displacements consistent with leaf survival. In these leaves during freezing, massive extracellular ice formed in specific expansion zones within the midvein. On thawing, water was resorbed by living cells, restoring the original tissue shapes. Possible evolutionary significance of these expansion zones is discussed. Acclimated leaves showed no evidence of intracellular freezing, nor tissue lesions caused by extracellular ice. While the observations accord with current views of freeze-sensitivity and tolerance, cryo-microscopy revealed diverse responses in different tissue types.

scholarly journals Effects of Zn and Cd accumulation on structural and physiological characteristics of barley plants

2007 ◽  
Vol 19 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Balaji B. Maruthi Sridhar ◽  
Fengxiang X. Han ◽  
Susan V. Diehl ◽  
David L. Monts ◽  
Yi Su
Keyword(s):  
Structural Changes ◽  
Metal Accumulation ◽  
Morphological Changes ◽  
Dry Weight ◽  
Vascular Bundles ◽  
Fresh Weight ◽  
Intercellular Spaces ◽  
Cd Accumulation ◽  
Potted Plants ◽  
High Concentrations

The objectives of this study were to identify the structural changes caused by Zn and Cd accumulation in shoots and roots of barley (Hordeum vulgare) plants; and to correlate metal accumulation with anatomical, physiological and morphological changes. Potted plants were exposed to metal treatments of Zn and Cd for 19 and 16 d respectively. Leaves, stems and roots were harvested to identify structural changes and analyze metal accumulation. Barley effectively accumulated Zn (up to 11283 mg kg-1) and Cd (up to 584 mg kg-1) in the shoots. Microscopic structural changes, such as a decrease in intercellular spaces, breakdown of vascular bundles, and shrinkage of palisade and epidermal cells, occurred in leaves, stems and roots of plants treated with high concentrations of Zn. Zinc accumulation also resulted in a significant decrease in water content, fresh weight, dry weight and plant height. Cadmium only caused structural changes in roots at the higher concentrations. Barley plants were able to accumulate significant amounts of Zn and Cd without exhibiting symptoms of phytotoxicity when the metal concentrations were relatively low.

On Monitoring Structural Changes of Anisotropic Tissues by Means of Statistical Analysis of Ultrasonic Images

1993 ◽  
Vol 15 (4) ◽  
pp. 324-334
Author(s):  
C. Pecorari
Keyword(s):  
Structural Changes ◽  
Early Stage ◽  
Three Dimensional ◽  
Biological Tissues ◽  
Small Time ◽  
Image Texture ◽  
Structural Variations ◽  
Geometrical Properties ◽  
The Time Domain ◽  
Ultrasonic Images

An investigation into statistical properties of ultrasonic image texture from three-dimensional clusters of anisotropic scatterers is carried out. The structural properties of the clusters are modeled after those of soft biological tissues, such as skeletal muscle tissues, both in their healthy condition and at the early stage of degenerative diseases. The average axial autocorrelation function of the intensity of the image texture is used to characterize and monitor changes of the geometrical properties of the tissue components. A distinct local increase of the autocorrelation is observed within a range of small time shifts, and it is explained in terms of the structure of the time-domain backscattered signal from each individual scatterer. It is shown that such an increase is sensitive to structural variations of the cluster similar to those occurring at the early stage of several muscular diseases.

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