scholarly journals Bioreactor Platform for Biomimetic Culture and in situ Monitoring of the Mechanical Response of in vitro Engineered Models of Cardiac Tissue

2020 ◽  
Vol 8 ◽  
Author(s):  
Diana Massai ◽  
Giuseppe Pisani ◽  
Giuseppe Isu ◽  
Andres Rodriguez Ruiz ◽  
Giulia Cerino ◽  
...  
Keyword(s):  
Cardiac Tissue ◽  
Mechanical Response ◽  
In Situ Monitoring

scholarly journals Construction of a mammalian embryo model from stem cells organized by a morphogen signalling centre

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Peng-Fei Xu ◽  
Ricardo Moraes Borges ◽  
Jonathan Fillatre ◽  
Maraysa de Oliveira-Melo ◽  
Tao Cheng ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Tracking ◽  
Cardiac Tissue ◽  
Embryonic Stem ◽  
Mammalian Embryo ◽  
Wide Range ◽  
Vitro Model ◽  
Neurula Stage

AbstractGenerating properly differentiated embryonic structures in vitro from pluripotent stem cells remains a challenge. Here we show that instruction of aggregates of mouse embryonic stem cells with an experimentally engineered morphogen signalling centre, that functions as an organizer, results in the development of embryo-like entities (embryoids). In situ hybridization, immunolabelling, cell tracking and transcriptomic analyses show that these embryoids form the three germ layers through a gastrulation process and that they exhibit a wide range of developmental structures, highly similar to neurula-stage mouse embryos. Embryoids are organized around an axial chordamesoderm, with a dorsal neural plate that displays histological properties similar to the murine embryo neuroepithelium and that folds into a neural tube patterned antero-posteriorly from the posterior midbrain to the tip of the tail. Lateral to the chordamesoderm, embryoids display somitic and intermediate mesoderm, with beating cardiac tissue anteriorly and formation of a vasculature network. Ventrally, embryoids differentiate a primitive gut tube, which is patterned both antero-posteriorly and dorso-ventrally. Altogether, embryoids provide an in vitro model of mammalian embryo that displays extensive development of germ layer derivatives and that promises to be a powerful tool for in vitro studies and disease modelling.

scholarly journals Adequate UV Exposures for Healthy Life: In Situ Monitoring and Model Calculation of the Vitamin-D-Synthetic Capacity of Sunlight

2012 ◽  
Vol 7 (1) ◽  
pp. 98-103
Author(s):  
Irina Terenetskaya ◽  
Tetiana Orlova ◽  
Pavel Kapinos
Keyword(s):  
Vitamin D ◽  
Human Skin ◽  
Direct Calculation ◽  
Uv Spectra ◽  
In Situ Monitoring ◽  
Solar Uv ◽  
Vitro Model ◽  
Synthetic Capacity

Vitamin D which is formed upon UV solar radiation in human skin is essential in many physiological functions. To estimate beneficial vitamin-D-synthetic capacity of sunlight a bio-equivalent UV dosimeter that is based on the same molecular photochemistry from which vitamin D is photosynthesized in human skin has been developed. The examples of an in situ monitoring of the vitamin-D-synthetic capacity of sunlight using an in vitro model of vitamin D synthesis are presented, and various operational principles of the UV biodosimeter are discussed. In addition, reliable algorithm is presented for direct calculation of previtamin D3 accumulation using the photoreaction mathematical model with solar UV spectra as input data. Critical dependence of previtamin D3 accumulation on cloudiness and aerosols is demonstrated.

Dynamic mechanical response of brain tissue in indentation in vivo, in situ and in vitro

2011 ◽  
Vol 7 (12) ◽  
pp. 4090-4101 ◽  
Author(s):  
Thibault P. Prevost ◽  
Guang Jin ◽  
Marc A. de Moya ◽  
Hasan B. Alam ◽  
Subra Suresh ◽  
...  
Keyword(s):  
Brain Tissue ◽  
Mechanical Response ◽  
Dynamic Mechanical

scholarly journals In Situ Monitoring of Streptothricin Production by Streptomyces rochei F20 in Soil and Rhizosphere

2004 ◽  
Vol 70 (9) ◽  
pp. 5222-5228 ◽  
Author(s):  
Usanee Anukool ◽  
William H. Gaze ◽  
Elizabeth M. H. Wellington
Keyword(s):  
Stationary Phases ◽  
In Situ Monitoring ◽  
Dependent Manner ◽  
Rt Pcr ◽  
Transcript Accumulation ◽  
Reverse Transcription Pcr ◽  
Lower Population ◽  
Lower Population Density

ABSTRACT The onset of streptothricin (ST) biosynthesis in Streptomyces rochei F20 was studied by using reverse transcription-PCR (RT-PCR) to detect transcripts of ST genes during growth in liquid medium, soil, and the rhizosphere. In situ results correlated with those obtained in vitro, illustrating the growth phase-dependent manner of ST production by F20. Maximal transcription of ST resistance (sttR) and biosynthesis (sttA) genes occurred during the transition between the exponential and stationary phases of growth, when the specific growth rate (μ) started to decline. A higher level of gene expression of sttR versus sttA was observed in all experiments. In liquid culture, maximal transcript accumulation of the sttA gene was only ca. 40% that of the sttR gene. sttA and sttR mRNAs were detected in soil containing approximately 106 CFU of growing cells g of soil−1. sttR mRNA was detected in sterile and nonsterile rhizosphere colonized with growing mycelium of F20 at 1.2 × 106 and 4.0 × 105 CFU g of soil−1, respectively. However, neither sttR nor sttA transcripts were detected by RT-PCR in the rhizoplane, which supported a lower population density of F20 than the rhizosphere.

scholarly journals Application of image flow cytometry and photoacoustics for the characterization of red blood cell storage lesions

2021 ◽  
Author(s):  
Ruben N. Pinto
Keyword(s):  
Flow Cytometry ◽  
Structural Changes ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
In Situ Monitoring ◽  
Image Flow ◽  
Morphology Characterization

Significant functional/structural changes of red blood cells (RBCs) have been documented during its in vitro storage. Collectively termed as RBC storage lesions, changes include an increase in RBC oxygen saturation (SO2) and an increase in irreversibly damaged RBCs (spheroechinocytes). In this work, novel optical techniques are presented for determining the spheroechinocyte population as a function of storage time via automated image flow cytometry (IFC) morphology characterization, and the acquisition of RBC SO2 via an in situ photoacoustic (PA) method. Blood gas analysis (BGA) was used as the gold standard SO2 measure. Over the lifespan of seven blood bags, the IFC spheroechinocyte population – PA SO2 correlation was found to be strong (0.600.95) shows high potential for in situ monitoring of RBC storage lesions.

scholarly journals In situ detection of Esr proteins secretion during maize microspore embryogenesis and their secretion blockage show effects on the culture progression

2010 ◽  
Vol 37 (10) ◽  
pp. 985 ◽  
Author(s):  
Pilar S. Testillano ◽  
María-José Coronado ◽  
Anne-Marie Thierry ◽  
Elisabeth Matthys-Rochon ◽  
María C. Risueño
Keyword(s):  
Liquid Medium ◽  
Embryo Development ◽  
Secretory Pathway ◽  
Microspore Culture ◽  
Microspore Embryogenesis ◽  
In Situ Monitoring ◽  
Subcellular Localisation ◽  
Embryo Cells

In vitro plant cells in culture release proteins and carbohydrates, but the active molecules responsible for sustaining the switch in embryogenic development and progression have not yet been identified. In maize (Zea mays L.), the Esr genes encode for small hydrophilic proteins and are expressed in the restricted region of maize endosperm surrounding the embryo: the embryo surrounding region (ESR). In the present work, the possible influence of secreted molecules in the liquid medium during microspore-derived embryo development and specifically, the presence of Esr proteins, has been analysed in maize microspore cultures. The study has been conducted with in situ monitoring of the structural and cellular organisation of developing embryos and the subcellular localisation of the Esr proteins by immunofluorescence and immunogold labelling. The results obtained using confocal and electron microscopy revealed that Esr proteins were localised in elements of the secretory pathway and cell walls in microspore-derived embryo cells during early embryogenesis. Esr proteins were also detected in the liquid medium of maize microspore cultures and accumulated at 20 days of culture. Tunicamycin treatment to block protein glycosilation and, therefore, secretion inhibited microspore-derived embryo development, which was subsequently recovered by supplementation with medium containing all the secreted factors from a well developed microspore culture. Esr labelling was not present in non-developing microspore embryos of cultures treated with tunicamycin, whereas labelling was present again in the Golgi elements and secretory vesicles of embryo cells when development was restored. The results indicate that Esr proteins are part of the secreted proteins, which show a nursing or signalling role during in vitro embryo development in maize microspore embryogenesis cultures and provide new evidence for an endosperm-like function of microspore-derived embryo structures during the early stages.

scholarly journals Gap junction connexon configuration in rapidly frozen myocardium and isolated intercalated disks.

1984 ◽  
Vol 99 (2) ◽  
pp. 453-463 ◽  
Author(s):  
C R Green ◽  
N J Severs
Keyword(s):  
Gap Junctions ◽  
Gap Junction ◽  
Cardiac Tissue ◽  
Cell Biol ◽  
Junction Structure ◽  
Intercalated Disk ◽  
Hexagonal Arrays

By using two ultrarapid freezing techniques, we have captured the structure of rat and rabbit cardiac gap junctions in a condition closer to that existing in vivo than to that previously achieved. Our results, which include those from fully functional hearts frozen in situ in the living animal, show that the junctions characteristically consist of multiple small hexagonal arrays of connexons. In tissue frozen 10 min after animal death, however, unordered arrays are common. Examination of junction structure at intervals up to 40 min after death reveals a variety of configurations including dispersed and close-packed unordered arrays, and hexagonal arrays. By use of an isolated intercalated disk preparation, we show that the configuration of cardiac gap junctions in vitro cannot be altered by factors normally considered to induce functional uncoupling. These experiments demonstrate that, contrary to the conclusions of some earlier studies (Baldwin, K. M., 1979, J. Cell Biol., 82:66-75; Peracchia, C., and L. L. Peracchia, 1980, J. Cell Biol., 87:708-718), the arrangement of gap junction connexons, in cardiac tissue at least, cannot be used as a reliable guide to the functional state of the junctions.

scholarly journals THERMAL ACCLIMATION ALTERS BOTH ADRENERGIC SENSITIVITY AND ADRENOCEPTOR DENSITY IN CARDIAC TISSUE OF RAINBOW TROUT

1993 ◽  
Vol 181 (1) ◽  
pp. 27-48 ◽  
Author(s):  
J. E. Keen ◽  
D. M. Vianzon ◽  
A. P. Farrell ◽  
G. F. Tibbits
Keyword(s):  
Rainbow Trout ◽  
Cardiac Tissue ◽  
Radioligand Binding ◽  
Temperature Acclimation ◽  
Effect Of Temperature ◽  
Acclimation Temperature ◽  
Binding Studies ◽  
Tension Development

We examined the effect of temperature acclimation on the sensitivity of the rainbow trout heart to adrenaline and on the density of beta-adrenoceptors. The sensitivity of the heart was assessed using in situ working perfused heart and in vitro isometric ventricular strip preparations. When tested in situ and at acclimation temperature, hearts from fish acclimated to 8°C were approximately 10-fold more sensitive to adrenaline-supplemented perfusate than were hearts from fish acclimated to 18°C. The concentrations required for half-maximal stimulation (EC50) of myocardial power output were 1.9×10- 8 mol l-1 adrenaline and 1.7×10-7 mol l-1 adrenaline for hearts acclimated to 8°C and 18°C, respectively. In vitro, isometric ventricular strip preparations demonstrated a similar increase in adrenergic sensitivity with cold-acclimation. The EC50 values for maximal tension development were 2.7×10-7 mol l-1 adrenaline (8°C-acclimated) and 1.1×10-6 mol l-1 adrenaline (18°C-acclimated) when tested at acclimation temperature. This shift in adrenergic sensitivity was a function of the temperature acclimation because changes in bath temperature per se, either from 8°C to 18°C for 8°C- acclimated hearts or from 18°C to 8°C for 18°C-acclimated hearts, had no significant effect on the concentration-response curve for adrenaline. We conducted radioligand binding studies with [125I]iodocyanopindolol and propranolol to quantify the beta-adrenoceptor density (Bmax) of both homogenates and isolated sarcolemmal fractions of ventricles from rainbow trout acclimated to either 8°C or 18°C. The Bmax for isolated sarcolemmal fractions was significantly higher in the 8°C-acclimated group, but the Bmax of ventricular homogenates was not significantly different in the two acclimation groups. No significant differences in dissociation constant (Kd) were apparent in either the homogenates or sarcolemmal fractions. These results suggest that cardiac tissue from rainbow trout acclimated to 8°C has a greater cell surface adrenoceptor population available for beta-antagonist binding. This might explain the heightened cardiac sensitivity to adrenaline observed in situ and in vitro in 8°C-acclimated fish.

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