A Technic for the Inoculation of Bacteria and Other Substances Into Living Cells

1911 ◽  
Vol 8 (3) ◽  
pp. 348-360 ◽  
Author(s):  
M. A. Barber
Keyword(s):  
Living Cells ◽  
Other Substances

scholarly journals The Expanding Role of Vesicles Containing Aquaporins

Cells ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 179 ◽  
Author(s):  
M Martinez-Ballesta ◽  
Paula Garcia-Ibañez ◽  
Lucía Yepes-Molina ◽  
Juan Rios ◽  
Micaela Carvajal
Keyword(s):  
Environmental Changes ◽  
Cell Communication ◽  
Membrane Vesicles ◽  
Living Cells ◽  
Biotechnological Applications ◽  
Future Perspectives ◽  
Physiological Processes ◽  
Communication Processes ◽  
Other Substances

In animals and plants, membrane vesicles containing proteins have been defined as key for biological systems involving different processes such as trafficking or intercellular communication. Docking and fusion of vesicles to the plasma membrane occur in living cells in response to different stimuli, such as environmental changes or hormones, and therefore play an important role in cell homeostasis as vehicles for certain proteins or other substances. Because aquaporins enhance the water permeability of membranes, their role as proteins immersed in vesicles formed of natural membranes is a recent topic of study. They regulate numerous physiological processes and could hence serve new biotechnological purposes. Thus, in this review, we have explored the physiological implications of the trafficking of aquaporins, the mechanisms that control their transit, and the proteins that coregulate the migration. In addition, the importance of exosomes containing aquaporins in the cell-to-cell communication processes in animals and plants have been analyzed, together with their potential uses in biomedicine or biotechnology. The properties of aquaporins make them suitable for use as biomarkers of different aquaporin-related diseases when they are included in exosomes. Finally, the fact that these proteins could be immersed in biomimetic membranes opens future perspectives for new biotechnological applications.

scholarly journals Croonian Lecture - The active and passive exchanges of inorganic ions through the surfaces of living cells and through living membranes generally

1946 ◽  
Vol 133 (871) ◽  
pp. 140-200 ◽  
Keyword(s):  
Cell Surface ◽  
Experimental Work ◽  
Diffusion Processes ◽  
Large Fraction ◽  
Inorganic Ions ◽  
Living Cells ◽  
Other Substances ◽  
Minor Part ◽  
Strong Electrolytes ◽  
A Minor

The main object of this paper is to discuss the large differences in concentration of individual ions between the interior of living cells and the fluids surrounding them, to bring out the point that such differences are normally, and perhaps always, brought about and also maintained by some special activity on the part of the cell, while diffusion processes are all the time tending to reduce them, and are, when maintained, expressions of steady states , differing in principle from equilibria by the necessity of energy being supplied for their maintenance. The pertinent facts are usually discussed under the heading ‘permeability’ (Wilbrandt 1938; Davson & Danielli 1943; Blinks 1942; Faraday Soc. Discussion 1937), but it will be shown below that, although permeability of the cell surface is of course a necessary corollary of the ion transport taking place, quantitative determinations of such permeabilities, in the generally accepted sense of the term, can be made only by means of isotopes and even then require special precautions and conditions which are difficult to realize and verify, because the exchanges normally taking place are largely brought about by active transport. The argument is concerned only with ions of strong electrolytes which are responsible in many cases for almost the whole of the osmotic pressure in organisms and cells, while in others they make up at least a large fraction. Other substances will be dealt with only incidentally and for the sake of comparison. Experimental results from the most diverse sources are brought together for discussion. The experiments carried out by myself and my associates make up only a minor part of the whole, and even some of these have been published before. Forced to leave Denmark about the middle of 1944 I had to discontinue experimental work, which had already suffered severely from the difficulties encountered. I have been fortunate in finding a refuge at the Institute of Physiology in Lund, and I wish to express my deep gratitude for the kindness shown me. Everything has been done to provide facilities and papers for my work, but many recent publications have proved inaccessible in Sweden.

scholarly journals On the determination of a coefficient by which the rate of diffusion of stain and other substances into living cells can be measured and by which bacteria and other cells may be differentiated

1909 ◽  
Vol 81 (546) ◽  
pp. 97-109 ◽  
Keyword(s):  
Living Cells ◽  
Other Substances

In former papers (3, 4, 5) it has been shown that when blood is spread upon a film of agar jelly which contains Unna’s stain and certain salts, the cells will absorb the stain, and that the absorption increases with the temperature and the time during which the cells have been resting on the film. The following facts have also been published:—(1) That alkalies , like heat and time , increase the diffusion of stain into the cells; (2) that acids and neutral salts delay the diffusion; and (3) that the staining of the nuclei of leucocytes is a sign of death. Soon after death the staining ceases, and the cells rupture or lose their stain. Evidence has also been given that these phenomena are due to the diffusion of stain into the jelly-like cytoplasm being hastened or delayed, as the case may be, by the agency of these factors, and that death, coincident with the staining of the nucleus, is followed by liquefaction of the cytoplasm and other changes which cause the cells to lose their stain and enter a phase which has been called the condition of achromasia (6).

scholarly journals Electrified water as a regulator of cell proliferation

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Yuri Pivovarenko
Keyword(s):  
Cell Proliferation ◽  
Electric Charge ◽  
Living Cells ◽  
Other Substances ◽  
Positively Charged ◽  
Charged Water

It was previously found that the electric charge of water determines its ability to interact with other substances, including biologically significant ones. It is shown here that the electric charge of water can also determine its ability to penetrate and accumulate in living cells. In particular, it has been shown that the high penetrating ability of positively charged water determines both its active penetration into cells and accumulation in them, which creates favourable conditions for cell proliferation. At the same time, it has been shown that the low penetrating ability of negatively charged water determines its ability to slow down cell proliferation. It also discusses how medics can obtain and use water at different charges.

scholarly journals ON THE ACTION OF COLCHICINE

1965 ◽  
Vol 122 (2) ◽  
pp. 361-384 ◽  
Author(s):  
Stephen E. Malawista
Keyword(s):  
Polymorphonuclear Leukocytes ◽  
Gouty Arthritis ◽  
Biological Properties ◽  
Living Cells ◽  
Dependent Manner ◽  
Melanocyte Stimulating Hormone ◽  
Chemical Agents ◽  
Other Substances ◽  
Synergism And Antagonism ◽  
Inflammatory Effect

The effect of colchicine was studied on the rapid, reversible darkening of frog skin under the influence of melanocyte-stimulating hormone (MSH). Darkening is due to dispersion of melanin granules in melanocytes and is thought to be accompanied by a gel-to-sol cytoplasmic transformation. After subsequent washing, the skin lightens, with aggregation of melanin granules and cytoplasmic gelation. Preincubation of skin with colchicine had the following effects: 1. Darkening induced by MSH was increased in comparison to control skins, and on removal of MSH, lightening was inhibited. Inhibition was a function of both concentration (1 x 10–5 to 9 x 10–5 M) and exposure time (2 to 30 minutes). Once established, inhibition was maintained throughout the remainder of the experiment. 2. The same effects were noted (a) when darkening was effected by agents other than MSH (ATP) 0.9 x 10–3 M; caffeine, 5.2 x 10–3 M; ethyl acetate, 0.8 x 10–2 M), and (b) when lightening was effected by addition of chemical agents (melatonin, 4.3 x 10–10 M; hydrocortisone, 1 x 10–3 M; norepinephrine, 1 x 10–3 M), instead of by washing. 3. Colchicine alone produced a gradual, irreversible, dosage-dependent darkening over several hours. This darkening was inhibited by melatonin, 4.3 x 10–10 M. The melanocyte model is used to construct a general theory of colchicine action on living cells, an action resulting in decreased protoplasmic viscosity. In this formulation colchicine lowers the potential limit of protoplasmic gelation, and does it rapidly, reversibly, in low concentration, in a dosage-dependent manner, and without killing the cell. The theory allows interpretation of "synergism" and "antagonism" to colchicine by other substances. It suggests a tentative approach to the understanding of colchicine action in acute gouty arthritis, where interference with ameboid activities of polymorphonuclear leukocytes is one possible aspect of the anti-inflammatory effect of colchicine. Finally, the colchicine-treated melanocyte is viewed as a good, live physical model that can be used to elucidate some fundamental biological properties.

Development of Fieldable Lab-on-a-Chip Systems for Detection of a Broad Array of Targets From Toxicants to Biowarfare Agents

2013 ◽  
Vol 4 (2) ◽  
Author(s):  
Jill Grimme ◽  
Travis King ◽  
Kyoo Dong Jo ◽  
Don Cropek ◽  
Aaron T. Timperman
Keyword(s):  
Synthetic Biology ◽  
Environmental Changes ◽  
Lab On A Chip ◽  
Living Cells ◽  
Cell Organelle ◽  
Trace Level ◽  
Hardware System ◽  
Recent Advances ◽  
Broad Array ◽  
Other Substances

In today's world, there is an ever growing need for lightweight, portable sensor systems to detect chemical toxicants and biological toxins. The challenges encountered with such detection systems are numerous, as there are a myriad of potential targets in various sample matrices that are often present at trace-level concentrations. At ERDC-CERL, the Lab-on-a-Chip (LoaC) group is working with a number of academic and small business collaborators to develop solutions to meet these challenges. This report will focus on recent advances in three distinct areas: (1) the development of a flexible platform to allow fieldable LoaC analyses of water samples, (2) cell-, organelle-, and synthetic biology-based toxicity sensors, and (3) nanofluidic/microfluidic interface (NMI) sample enrichment devices. To transition LoaC-based sensors from the laboratory bench to the field, a portable hardware system capable of operating a wide variety of microfluidic chip-based assays has been developed. As a demonstration of the versatility of this approach assays for the separation and quantitation of anionic contaminants (i.e., perchlorate), quantitation of heavy metals (Pb and Cd), and cell-based toxicity sensors have been developed and demonstrated. Sensors harboring living cells provide a rapid means of assessing water toxicity. Cell-based sensors exploit the sensitivity of a living cell to discrete changes in its environment to report the presence of toxicants. However, this sensitivity of cells to environmental changes also hinders their usability in nonlaboratory settings. Therefore, isolating intact organelles (i.e., mitochondria) offers a nonliving alternative that preserves the sensitivity of the living cells and allows the electrochemical reporting of the presence of a contaminant. Pursuing a synthetic biology approach has also allowed the development of nonliving reporting mechanisms that utilize engineered biological pathways for novel sensing and remediation applications. To help overcome the challenges associated with the detection of target species at trace-level concentrations, NMIs are being developed for the enrichment of charged species in solution. NMI concentrators can be classified as either electroosmotic flow or electrophoresis-dominant devices. Further advances in electrophoresis-dominant concentrators will aid in the analysis of samples that contain proteins and other substances prone to surface adsorption. These recent advances illustrate how LoaC systems provide a suitable platform for development of fieldable sensors to detect a broad range of chemical/biological pollutants and threats.

Fluorescence ratio imaging of dynamic intracellular ionic signals

1988 ◽  
Vol 46 ◽  
pp. 42-43
Author(s):  
R. Y. Tsien ◽  
A. Minta ◽  
M. Poenie ◽  
J.P.Y. Kao ◽  
A. Harootunian
Keyword(s):  
Binding Sites ◽  
Living Cells ◽  
Molecular Engineering ◽  
Ph Indicators ◽  
Highly Sensitive ◽  
Fluorescence Ratio Imaging ◽  
Ratio Imaging ◽  
Technical Advances ◽  
Indicator Dyes ◽  
Fluorescein Dyes

Recent technical advances now enable the continuous imaging of important ionic signals inside individual living cells with micron spatial resolution and subsecond time resolution. This methodology relies on the molecular engineering of indicator dyes whose fluorescence is strong and highly sensitive to ions such as Ca2+, H+, or Na+, or Mg2+. The Ca2+ indicators, exemplified by fura-2 and indo-1, derive their high affinity (Kd near 200 nM) and selectivity for Ca2+ to a versatile tetracarboxylate binding site3 modeled on and isosteric with the well known chelator EGTA. The most commonly used pH indicators are fluorescein dyes (such as BCECF) modified to adjust their pKa's and improve their retention inside cells. Na+ indicators are crown ethers with cavity sizes chosen to select Na+ over K+: Mg2+ indicators use tricarboxylate binding sites truncated from those of the Ca2+ chelators, resulting in a more compact arrangement of carboxylates to suit the smaller ion.

Application of FRAP and digitized fluorescence microscopy to problems in cell membrane dynamics

1988 ◽  
Vol 46 ◽  
pp. 118-119
Author(s):  
K. Jacobson ◽  
A. Ishihara ◽  
B. Holifield ◽  
F. Zhang
Keyword(s):  
Fluorescence Microscopy ◽  
Cell Biology ◽  
Extended Period ◽  
Dynamic Structure ◽  
Living Cells ◽  
Membrane Dynamics ◽  
Molecular Cell Biology ◽  
Image Averaging ◽  
Single Living Cells ◽  
Single Living

Our laboratory is concerned with understanding the dynamic structure of the plasma membrane with particular reference to the movement of membrane constituents during cell locomotion. In addition to the standard tools of molecular cell biology, we employ both fluorescence recovery after photo- bleaching (FRAP) and digitized fluorescence microscopy (DFM) to investigate individual cells. FRAP allows the measurement of translational mobility of membrane and cytoplasmic molecules in small regions of single, living cells. DFM is really a new form of light microscopy in that the distribution of individual classes of ions, molecules, and macromolecules can be followed in single, living cells. By employing fluorescent antibodies to defined antigens or fluorescent analogs of cellular constituents as well as ultrasensitive, electronic image detectors and video image averaging to improve signal to noise, fluorescent images of living cells can be acquired over an extended period without significant fading and loss of cell viability.

Multimode light microscopy and fluorescence-based reagents as tools for the study of chemical and molecular dynamics of living cells and tissues

1992 ◽  
Vol 50 (1) ◽  
pp. 418-419
Author(s):  
D. L. Taylor
Keyword(s):  
Living Cells ◽  
Cellular Level ◽  
Molecular Techniques ◽  
Cellular Functions ◽  
Macromolecular Assemblies ◽  
Cell Functions ◽  
Molecular Events ◽  
Yield Information ◽  
Full Knowledge ◽  
Structural Methods

Cells function through the complex temporal and spatial interplay of ions, metabolites, macromolecules and macromolecular assemblies. Biochemical approaches allow the investigator to define the components and the solution chemical reactions that might be involved in cellular functions. Static structural methods can yield information concerning the 2- and 3-D organization of known and unknown cellular constituents. Genetic and molecular techniques are powerful approaches that can alter specific functions through the manipulation of gene products and thus identify necessary components and sequences of molecular events. However, full knowledge of the mechanism of particular cell functions will require direct measurement of the interplay of cellular constituents. Therefore, there has been a need to develop methods that can yield chemical and molecular information in time and space in living cells, while allowing the integration of information from biochemical, molecular and genetic approaches at the cellular level.

4-dimensional, high-resolution imaging of living cells

1992 ◽  
Vol 50 (1) ◽  
pp. 416-417
Author(s):  
Shinya Inoué
Keyword(s):  
Light Microscope ◽  
Living Cells ◽  
Live Cells ◽  
Video Tape ◽  
Active Living ◽  
High Resolution Imaging ◽  
3 Dimensional ◽  
Dynamic Architecture ◽  
Resolution Imaging ◽  
Disk Memory

This paper reports progress of our effort to rapidly capture, and display in time-lapsed mode, the 3-dimensional dynamic architecture of active living cells and developing embryos at the highest resolution of the light microscope. Our approach entails: (A) real-time video tape recording of through-focal, ultrathin optical sections of live cells at the highest resolution of the light microscope; (B) repeat of A at time-lapsed intervals; (C) once each time-lapsed interval, an image at home focus is recorded onto Optical Disk Memory Recorder (OMDR); (D) periods of interest are selected using the OMDR and video tape records; (E) selected stacks of optical sections are converted into plane projections representing different view angles (±4 degrees for stereo view, additional angles when revolving stereos are desired); (F) analysis using A - D.

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