ABOUT SOME PECULIARITIES OF THE PHYSIOLOGICAL HETEROGENEITY OF THE POPULATION OF SCENEDESMUS QUADRICAUDA (TURP.) BREB. IN THE PRESENCE OF LOW CONCENTRATIONS OF METALS

The structure of the laboratory population of green microalgae Scenedesmus quadricauda (Turp.) Breb (=Desmodesmus communis E. Hegew.) was studied at different stages of its growth (lag-phase, log-phase and stationary phase) at low concentrations of copper chloride and silver nitrate by the method microculture, allowing to monitor the state and development of single cells having different physiological status. The response of the culture of S. quadricauda - the change in the number of cells and the fractional composition (the fraction of dividing, «dormant» and dying cells) depended not only on the concentration of the toxicant in the medium, but also on the physiological state of the culture: the level of synchronization and the growth phase. Silver ions at low concentrations had a more pronounced toxic effect on the culture than copper ions at different phases of its development, especially at a concentration of 0.001 mg/l (10-9 M). The main mechanism of the toxic effect of metals is to inhibit the process of cell division. At low concentrations of toxicants, especially at a concentration of 0.001 mg/l, a «paradoxical» effect expressed in the predominance of the fraction of «dormant» cells was revealed. The temporary inhibition of the process of cell division can be regarded as a protective mechanism that allows preserving the integrity of the population and its ability to survive in a changing environment. The obtained data explain the effect of action of low concentrations of substances due to their inclusion in the cell, the subsequent accumulation in the cell and their low excretion.

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Efficacy of prayer in inducing immediate physiological changes: a systematic analysis of objective experiments

Journal of Complementary and Integrative Medicine ◽

10.1515/jcim-2020-0075 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Felix Chin ◽

Ryan Chou ◽

Muhammad Waqas ◽

Kunal Vakharia ◽

Hamid Rai ◽

...

Keyword(s):

Physiological State ◽

Experimental Studies ◽

Peripheral Resistance ◽

Pain Tolerance ◽

Physiological Status ◽

Physiological Changes ◽

Mental Functioning ◽

Baroreceptor Sensitivity ◽

Systematic Analysis ◽

Blood Marker

Abstract Objectives To assess the immediate impact of prayer on physiological state by systematically reviewing objective, controlled experimental studies in the literature. Content Experimental studies measuring objective physiological changes induced by prayer. Studies containing the keyword, “Prayer” anywhere in the title or abstract were curated from the following databases: Public/Publisher Medline (PubMed), Excerpta Medica Database (EMBASE) and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) in May 2019. Titles and abstracts were screened with the remaining 30 articles analyzed for inclusion. Only experimental studies were included. Summary Eight experimental studies were identified of which five investigated neurocognitive changes and three investigated systemic physiological changes during prayer. The five studies focusing on neuroactivity used functional MRI (fMRI), electroencephalography or SPECT imaging to obtain measurements. The remaining three studies analyzed an array of systemic physiological metrics, including blood pressure, heart rate, respiratory rate, peripheral resistance, baroreceptor sensitivity and/or cardiovascular rhythm variability during prayer. All studies aside from one saw objective changes during prayer. Neurocognitive changes were mainly associated with improved mental functioning, control and pain tolerance. Prayer was found to slow down physiological functions in two of the three vital-based studies, with the third reporting no change in physiological status. None of the studies measured blood marker changes. Outlook Experimental studies show prayer to induce healthy neurocognitive and physiological changes. Additional studies exploring objective measures from prayer are encouraged to provide practitioners with a more nuanced, scientific perspective when it comes to prescribing prayer as a complementary and alternative medicine (CAM) therapy.

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Extensive Regulation of Metabolism and Growth during the Cell Division Cycle

10.1101/005629 ◽

2014 ◽

Author(s):

Nikolai Slavov ◽

David Botstein ◽

Amy Caudy

Keyword(s):

Gene Expression ◽

Oxygen Consumption ◽

Cell Division ◽

Single Cell ◽

Single Cells ◽

Emergent Behavior ◽

Yeast Cells ◽

Physiological Data ◽

Synchronized Cultures ◽

Metabolic Cycle

Yeast cells grown in culture can spontaneously synchronize their respiration, metabolism, gene expression and cell division. Such metabolic oscillations in synchronized cultures reflect single-cell oscillations, but the relationship between the oscillations in single cells and synchronized cultures is poorly understood. To understand this relationship and the coordination between metabolism and cell division, we collected and analyzed DNA-content, gene-expression and physiological data, at hundreds of time-points, from cultures metabolically-synchronized at different growth rates, carbon sources and biomass densities. The data enabled us to extend and generalize our mechanistic model, based on ensemble average over phases (EAP), connecting the population-average gene-expression of asynchronous cultures to the gene-expression dynamics in the single-cells comprising the cultures. The extended model explains the carbon-source specific growth-rate responses of hundreds of genes. Our physiological data demonstrate that the frequency of metabolic cycling in synchronized cultures increases with the biomass density, suggesting that this cycling is an emergent behavior, resulting from the entraining of the single-cell metabolic cycle by a quorum-sensing mechanism, and thus underscoring the difference between metabolic cycling in single cells and in synchronized cultures. Measurements of constant levels of residual glucose across metabolically synchronized cultures indicate that storage carbohydrates are required to fuel not only the G1/S transition of the division cycle but also the metabolic cycle. Despite the large variation in profiled conditions and in the scale of their dynamics, most genes preserve invariant dynamics of coordination with each other and with the rate of oxygen consumption. Similarly, the G1/S transition always occurs at the beginning, middle or end of the high oxygen consumption phases, analogous to observations in human and drosophila cells. These results highlight evolutionary conserved coordination among metabolism, cell growth and division.

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Low concentrations of FA exhibits the Hormesis effect by affecting cell division and the Warburg effect

Ecotoxicology and Environmental Safety ◽

10.1016/j.ecoenv.2019.109576 ◽

2019 ◽

Vol 183 ◽

pp. 109576

Author(s):

Jieran An ◽

Fuhong Li ◽

Yujie Qin ◽

Hongmao Zhang ◽

Shumao Ding

Keyword(s):

Cell Division ◽

Warburg Effect ◽

Low Concentrations ◽

Hormesis Effect ◽

The Warburg Effect

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Laser-induced mass spectrometry for the determination of the physiological state of single cells

International Journal of Mass Spectrometry and Ion Physics ◽

10.1016/0020-7381(83)87079-x ◽

1983 ◽

Vol 48 ◽

pp. 265-268 ◽

Cited By ~ 4

Author(s):

B. Lindner ◽

U. Seydel

Keyword(s):

Mass Spectrometry ◽

Single Cells ◽

Physiological State

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A vena Coleoptile Segments: Hyperelongation Growth after Anaerobic Treatment

Zeitschrift für Naturforschung C ◽

10.1515/znc-1980-9-1022 ◽

1980 ◽

Vol 35 (9-10) ◽

pp. 794-804 ◽

Cited By ~ 9

Author(s):

A. Hager

Keyword(s):

Lactic Acid ◽

Anaerobic Treatment ◽

Positive Influence ◽

Elongation Growth ◽

Lag Phase ◽

Sodium Arsenate ◽

Anomalous Increase ◽

Control Value ◽

Low Concentrations ◽

Short Period

Abstract Avena sativa coleoptile segments show an anomalous increase in elongation growth following a short period of oxygen deprivation (tested between 0 and 60 min) lasting 20-30 min (Anaero-biosis-Aerobiosis transition effect = ANA effect). The increase in growth rate is 600% and is commensurate with that observable following an auxin treatment. This hyperelongation growth, in contrast to the auxin-induced growth, begins without a lag phase. The growth “burst” following anaerobiosis is similarly to auxin-induced elongation growth, and is suppressed increasingly by neutral or more alkaline buffers. Hyperelongation growth is suppressed by respiratory inhibitors and uncouplers. A complete inhibition is effected with KCN (0.5 mM) sodium azide (0.5 mM) and CCCP (1 μM); amytal (in the range 0.5 to 1 mM) and sodium arsenate (0.1 to 1 mM) are strong inhibitors. Some of these compounds (KCN, arsenate, amytal) cause a slight increase of the ANA effect in very low concentrations, which is probably due to the K+ or Na+ ions present; on their own, these ions have a strong positive influence on the ANA effect. During anaerobiosis the ATP level sinks around 75% and almost returns to the old value, following the supply of air, within one minute. The cell sap pH drops from 6.3 to 5.9 during anaerobiosis within 20 min. This lowering is mainly due to an increase in lactic acid concentration. Other acids such as citric, malic, and aspartic acids show insignificant changes in concentration. The NADH content increases during anaerobiosis, whereas that of NADPH drops almost as much. The mentioned changes in concentration of lactic acid, NADH and NADPH return to the control value within 20-30 min; thus the differences exist as long as hyperelongation growth is under way. Possible relationships between the mentioned chemical changes and hyperelongation growth are discussed. One of the possible explanations is the following: the lowering of the cytoplasmic pH (normally around pH 7) during anaerobiosis due to the formation of lactic acid causes an activation of H+-ATPases in the plasmalemma and ER, since their optimum activity occurs in a pH of 5.5 to 6.5. This activation causes a greater H+-excretion into the cell wall compartment, and thus hyperelongation growth following supply of air and of ATP.

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Capillary Force Driven Single-Cell Spiking Apparatus for Studying Circulating Tumor Cells

Volume 10: Micro- and Nano-Systems Engineering and Packaging ◽

10.1115/imece2018-87109 ◽

2018 ◽

Author(s):

Jacob Amontree ◽

Kangfu Chen ◽

Jose Varillas ◽

Z. Hugh Fan

Keyword(s):

Single Cell ◽

Tumor Cells ◽

Circulating Tumor Cells ◽

Single Cells ◽

Lymphoblastic Leukemia ◽

Surface Membrane ◽

Critical Element ◽

Cell Capture ◽

Biomedical Sciences ◽

Low Concentrations

The characterization of single cells within heterogeneous populations has great impact on both biomedical sciences and cancer research. By investigating cellular compositions on a broad scale, pertinent outliers may be lost in the sample set. Alternatively, an investigation focused on the behavior of specific cells, such as circulating tumor cells (CTCs), will reveal genetic biomarkers or phenotypic characteristics associated with cancer and metastasis. On average, CTC concentration in peripheral blood is extremely low, as few as one to two per billion of healthy blood cells. Consequently, the critical element lacking in many methods of CTC detection is accurate cell capture efficiency at low concentrations. To simulate CTC isolation, researchers usually spike small amounts of tumor cells to healthy blood for separation. However, spiking tumor cells at extremely low concentrations is challenging in a standard laboratory setting. We report our study on an innovative apparatus and method designed for low-cost, precise, and replicable single-cell spiking (SCS). Our SCS method operates solely from capillary aspiration without the reliance on external laboratory equipment. To ensure that our method does not affect the viability of each cell, we investigated the effects of surface membrane tensions induced by aspiration. Finally, we performed affinity-based CTC isolation using human acute lymphoblastic leukemia cells (CCRF-CEM) spiked into healthy whole blood with the SCS technique. The results of the isolation experiments demonstrate the reliability of our method in generating low-concentration cell samples.

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The use of N-methylprotoporphyrin dimethyl ester to inhibit ferrochelatase in Rhodopseudomonas sphaeroides and its effect in promoting biosynthesis of magnesium tetrapyrroles

Biochemical Journal ◽

10.1042/bj2080479 ◽

1982 ◽

Vol 208 (2) ◽

pp. 479-486 ◽

Cited By ~ 12

Author(s):

J D Houghton ◽

C L Honeybourne ◽

K M Smith ◽

H D Tabba ◽

O T G Jones

Keyword(s):

Dimethyl Ester ◽

Cell Suspensions ◽

Maximum Effect ◽

Lag Phase ◽

Rhodopseudomonas Sphaeroides ◽

Normal Cells ◽

Low Concentrations ◽

Cytochrome Content ◽

Monomethyl Ester ◽

Substrate Addition

N-Methylprotoporphyrin dimethyl ester inhibits ferrochelatase in isolated membranes of Rhodopseudomonas sphaeroides at low concentrations (around 10 nm). Full inhibition developed after a short lag phase. The inhibition was non-competitive with porphyrin substrate. Addition of inhibitor to growing cultures of Rps. sphaeroides caused a decrease (near 40%) in cytochrome content and a severe inhibition of ferrochelatase; the excretion of haem into the medium by cell suspensions was also severely inhibited. The addition of N-methylprotoporphyrin dimethyl ester to suspensions of photosynthetically competent Rps. sphaeroides Ga caused excretion of Mg-protoporphyrin monomethyl ester. When added to mutants V3 and O1, magnesium divinylphaeoporphyrin a5 monomethyl ester and 2-devinyl-2-hydroxyethylphaeophorbide a were excreted, with maximum effect at around 3 microM-inhibitor in the medium. The results are interpreted to suggest that the inhibitor decreases concentration of intracellular haem, which normally controls the activity of 5-aminolaevulinate synthetase. Unregulated activity of this enzyme leads to overproduction of protoporphyrin, which is diverted to the bacteriochlorophyll pathway. Further control operates at magnesium protoporphyrin ester conversion in normal cells.

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Emergent multicellular life cycles in filamentous bacteria owing to density-dependent population dynamics

Journal of The Royal Society Interface ◽

10.1098/rsif.2011.0102 ◽

2011 ◽

Vol 8 (65) ◽

pp. 1772-1784 ◽

Cited By ~ 19

Author(s):

Valentina Rossetti ◽

Manuela Filippini ◽

Miroslav Svercel ◽

A. D. Barbour ◽

Homayoun C. Bagheri

Keyword(s):

Cell Division ◽

Population Growth ◽

Generation Time ◽

Single Cells ◽

Bacterial Species ◽

Life Forms ◽

Life Cycles ◽

Morphological Properties ◽

Filamentous Bacteria ◽

Growth Phases

Filamentous bacteria are the oldest and simplest known multicellular life forms. By using computer simulations and experiments that address cell division in a filamentous context, we investigate some of the ecological factors that can lead to the emergence of a multicellular life cycle in filamentous life forms. The model predicts that if cell division and death rates are dependent on the density of cells in a population, a predictable cycle between short and long filament lengths is produced. During exponential growth, there will be a predominance of multicellular filaments, while at carrying capacity, the population converges to a predominance of short filaments and single cells. Model predictions are experimentally tested and confirmed in cultures of heterotrophic and phototrophic bacterial species. Furthermore, by developing a formulation of generation time in bacterial populations, it is shown that changes in generation time can alter length distributions. The theory predicts that given the same population growth curve and fitness, species with longer generation times have longer filaments during comparable population growth phases. Characterization of the environmental dependence of morphological properties such as length, and the number of cells per filament, helps in understanding the pre-existing conditions for the evolution of developmental cycles in simple multicellular organisms. Moreover, the theoretical prediction that strains with the same fitness can exhibit different lengths at comparable growth phases has important implications. It demonstrates that differences in fitness attributed to morphology are not the sole explanation for the evolution of life cycles dominated by multicellularity.

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Differential Expression of Proteins and Genes in the Lag Phase of Lactococcus lactis subsp. lactis Grown in Synthetic Medium and Reconstituted Skim Milk

Applied and Environmental Microbiology ◽

10.1128/aem.72.2.1173-1179.2006 ◽

2006 ◽

Vol 72 (2) ◽

pp. 1173-1179 ◽

Cited By ~ 27

Author(s):

Nadja Larsen ◽

Mette Boye ◽

Henrik Siegumfeldt ◽

Mogens Jakobsen

Keyword(s):

Gene Expression ◽

Cell Division ◽

Lactococcus Lactis ◽

Stationary Phases ◽

Polyacrylamide Gel Electrophoresis ◽

Synthetic Medium ◽

Skim Milk ◽

Elongation Factor ◽

Nucleotide Metabolism ◽

Lag Phase

ABSTRACT We investigated protein and gene expression in the lag phase of Lactococcus lactis subsp. lactis CNRZ 157 and compared it to the exponential and stationary phases. By means of two-dimensional polyacrylamide gel electrophoresis, 28 highly expressed lag-phase proteins, implicated in nucleotide metabolism, glycolysis, stress response, translation, transcription, cell division, amino acid metabolism, and coenzyme synthesis, were identified. Among the identified proteins, >2-fold induction and down-regulation in the lag phase were determined for 12 proteins in respect to the exponential phase and for 18 proteins in respect to the stationary phase. Transcriptional changes of the lag-phase proteins in L. lactis were studied by oligonucleotide microarrays. Good correlation between protein and gene expression studies was demonstrated for several differentially expressed proteins, including nucleotide biosynthetic enzymes, adenylosuccinate synthase (PurA), IMP dehydrogenase (GuaB), and aspartate carbamoyl transferase (PyrB); heat-shock protein DnaK; serine hydroxymethyl transferase (GlyA); carbon catabolite control protein (CcpA); elongation factor G (FusA); and cell division protein (FtsZ).

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