Length, width, and volume changes in osmotically stressed myocytes

1986 ◽  
Vol 251 (6) ◽  
pp. H1373-H1378 ◽  
Author(s):  
K. P. Roos
Keyword(s):  
Optical Imaging ◽  
Cardiac Myocytes ◽  
Saline Solution ◽  
Rat Myocardium ◽  
Volume Changes ◽  
Load Bearing ◽  
Longitudinal Load ◽  
Length Width ◽  
Osmotic System ◽  
Cell Volumes

Sarcomere lengths, cell widths, and cell volumes were determined from photomicrographs and direct optical imaging of Ca2+-tolerant myocytes dispersed from collagenase-perfused whole rat myocardium. Individual unattached cells were examined at rest first in the normosmotic Ca2+-Tyrode saline solution and then in a sequence of hypotonic or hypertonic Tyrode solutions. Myocytes swell and shrink in hypotonic and hypertonic media but not as much as expected for an ideal uniform osmotic system. Furthermore, these changes were not proportional in the longitudinal and radial directions. These data suggest an 18% osmotically inactive volume and significant internal radial and longitudinal load-bearing structures within these cardiac myocytes.

Application of stereological analysis of cell volume to isolated myocytes in culture with and without adrenergic innervation

1990 ◽  
Vol 48 (3) ◽  
pp. 416-417
Author(s):  
Jane K. Rosenthal ◽  
Dianne L. Atkins ◽  
William J. Marvin ◽  
Penny A. Krumm
Keyword(s):  
Cardiac Myocytes ◽  
Structural Changes ◽  
Three Dimensional ◽  
Adrenergic Innervation ◽  
Culture Cell ◽  
Serial Sections ◽  
Newborn Rats ◽  
Primary Culture Cell ◽  
Biological Studies ◽  
Cell Volumes

To comprehend structural changes in cardiac myocytes accompanying adrenergic innervation, it is essential that a three dimensional analysis be performed. To date, biological studies which utilize stereological methods have been limited to cells in tissue and in organs. Our laboratory has utilized current stereological techniques for measuring absolute volumes of individual myocytes in primary culture. Cell volumes are calculated for two distinct groups of cells at 96 hours in culture: isolated myocytes and myocytes innervated with adrenergic neurons (Figure 1).Cardiac myocytes are cultured from the ventricular apices of newborn rats. Cells are plated directly onto tissue culture dishes with or without preplated explants from the paravertebral thoracolumbar sympathetic chain. On day four cultures are photographed and marked for one-to-one cell location. Following conventional fixation and embeddment in eponate-12, the cells are relocated and mounted for microtomy. The cells are completely sectioned at 120nm in their parallel orientation to the surface of the dish (Figure 2). Serial sections are collected on formvar coated slotted grids and are recorded in sequence.

scholarly journals Pressure- and Temperature-Induced Insertion of N2, O2 and CH4 to Ag-Natrolite

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4096
Author(s):  
Donghoon Seoung ◽  
Hyeonsu Kim ◽  
Pyosang Kim ◽  
Yongmoon Lee
Keyword(s):  
Unit Cell Volume ◽  
Molecular Size ◽  
Unit Cell ◽  
Volume Changes ◽  
Volume Increase ◽  
X Ray ◽  
Onset Pressure ◽  
Two Stages ◽  
Cell Volumes

This paper aimed to investigate the structural and chemical changes of Ag-natrolite (Ag16Al16Si24O80·16H2O, Ag-NAT) in the presence of different pressure transmitting mediums (PTMs), such as N2, O2 and CH4, up to ~8 GPa and 250 °C using in situ synchrotron X-ray powder diffraction and Rietveld refinement. Pressure-induced insertion occurs in two stages in the case of N2 and O2 runs, as opposed to the CH4 run. First changes of the unit cell volume in N2, O2 and CH4 runs are observed at 0.88(5) GPa, 1.05(5) GPa and 1.84(5) GPa with increase of 5.7(1)%, 5.5(1)% and 5.7(1)%, respectively. Subsequent volume changes of Ag-natrolite in the presence of N2 and O2 appear at 2.15(5) GPa and 5.24(5) GPa with a volume increase of 0.8(1)% and a decrease of 3.0(1)%, respectively. The bulk moduli of the Ag-NAT change from 42(1) to 49(7), from 38(1) to 227(1) and from 49(3) to 79(2) in the case of N2, O2 and CH4 runs, respectively, revealing that the Ag-NAT becomes more incompressible after each insertion of PTM molecules. The shape of the channel window of the Ag-NAT changes from elliptical to more circular after the uptake of N2, O2 and CH4. Overall, the experimental results of Ag-NAT from our previous data and this work establish that the onset pressure exponentially increases with the molecular size. The unit cell volumes of the expanded (or contracted) phases of the Ag-NAT have a linear relationship and limit to maximally expand and contract upon pressure-induced insertion.

Blood Volume Changes during Three-Week Residence at High Altitude

1970 ◽  
Vol 16 (1) ◽  
pp. 7-14 ◽  
Author(s):  
L G Myhre ◽  
D B Dill ◽  
F G Hall ◽  
D K Brown
Keyword(s):  
Carbon Monoxide ◽  
Blood Cell ◽  
High Altitude ◽  
Cell Volume ◽  
Plasma Volume ◽  
Red Blood Cell ◽  
Hemoglobin Concentration ◽  
Red Cell ◽  
Volume Changes ◽  
Cell Volumes

Abstract Circulating red blood cell volumes were determined by the carbon monoxide method, and plasma volumes were calculated in four men 20, 29, 71, and 75 years old, and two women 29 years of age before, during, and after exposure to an altitude of 3800 m. In the four youngest subjects there were early increases in hemoglobin concentration during the first days at the stated altitude attributed to decreases in plasma volume. At the same time, hemoglobin concentration decreased and plasma volume increased in the oldest subject. Red cell volumes were slow to change, and it was concluded that 3 weeks or more of exposure to this altitude are required to affect significantly the red cell volume in man.

Thapsigargin inhibits Ca2+ uptake, and Ca2+ depletes sarcoplasmic reticulum in intact cardiac myocytes

1993 ◽  
Vol 265 (2) ◽  
pp. H517-H522 ◽  
Author(s):  
A. M. Janczewski ◽  
E. G. Lakatta
Keyword(s):  
Steady State ◽  
Sarcoplasmic Reticulum ◽  
Cardiac Myocytes ◽  
Ventricular Myocytes ◽  
Rat Myocardium ◽  
Half Time ◽  
Adult Rat ◽  
Time To Peak ◽  
Rapid Pacing ◽  
Ethanesulfonic Acid

We examined the effects of thapsigargin on Ca2+ accumulation by the sarcoplasmic reticulum (SR) and on electrically stimulated beats in single adult rat ventricular myocytes loaded with indo 1 and bathed in N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid buffer containing 1 mM Ca2+ at 23 degrees C. The SR Ca2+ content was assessed from the magnitude of intracellular Ca2+ (Ca2+i) transients and contractions elicited by rapid, brief applications of caffeine. After 20-30 min of exposure to 200 nM thapsigargin, the caffeine-dependent Ca2+i transients were abolished or markedly diminished (by 89 +/- 4%). The postrest potentiation of the Ca2+i transient and contraction, typical for rat myocardium, was abolished. Thapsigargin did not significantly change resting Ca2+i but diminished the amplitude of the steady-state Ca2+i transients by 73%, prolonged the time to peak by 24%, and prolonged the half-time (t1/2) of the Ca2+i transient decline by 42%. Progressive SR Ca2+ depletion by thapsigargin was strongly related (r = -0.78) to the prolongation of the t1/2 of relaxation of the steady-state Ca2+i transients, suggesting that the thapsigargin-dependent SR Ca2+ depletion results from an inhibition of the SR Ca2+ uptake. This interpretation was corroborated by comparison of the effects of thapsigargin with those of ryanodine (100 nM), which depletes SR of Ca2+ by accelerating the SR Ca2+ efflux but does not inhibit the SR Ca2+ pump. During rapid pacing (5 Hz), which raises Ca2+i and thus Ca2+ available for SR uptake, the caffeine-dependent SR Ca2+ release was restored in ryanodine-treated cells but not in the presence of thapsigargin.(ABSTRACT TRUNCATED AT 250 WORDS)

Crystallographic Data for the High-Pressure Phases CsClO4 IV and CsBF4 IV

1976 ◽  
Vol 31 (11) ◽  
pp. 1456-1458 ◽  
Author(s):  
P. W. Richter ◽  
E. Whalley ◽  
C. W. F. T. Pistorius
Keyword(s):  
High Pressure ◽  
Excellent Agreement ◽  
Atmospheric Pressure ◽  
Scheelite Structure ◽  
Volume Changes ◽  
Coordination Numbers ◽  
Tetrahedral Sites ◽  
Direct Measurements ◽  
Cation Coordination ◽  
Cell Volumes

The high-pressure phases CsClO4 IV and CsBF4 IV have been quenched to atmospheric pressure at 100°K. The powder patterns can be indexed on the basis of tetragonal cells with a0 = 12.965, 12.728 Å, c0 = 5.230, 5.126 Å, respectively, containing eight formula weights. The cell volumes are in excellent agreement with the values expected from direct measurements of the III (barite)/IV transition volume changes. Arguments are advanced to show that these high-pressure phases, slightly more densely packed than the scheelite structure, probably contain the large cations in eightfold sites, the smaller ones in tetrahedral sites, and have cation-cation coordination numbers of approximately eight

X-Ray Emission Microanalysis of Proteins and Sulphur in Rat Plantar Epidermis

1968 ◽  
Vol 3 (4) ◽  
pp. 563-572
Author(s):  
R. T. SIMS ◽  
T. HALL
Keyword(s):  
Stratum Corneum ◽  
Unit Area ◽  
Skin Surface ◽  
Albino Rats ◽  
Paraffin Sections ◽  
Volume Changes ◽  
Mass Unit ◽  
X Ray ◽  
Stratum Spinosum ◽  
Cell Volumes

The distributions of proteins and protein-bound sulphur have been studied by X-ray emission microanalysis in the plantar epidermis of six albino rats. Plantar skin was fixed in 10% formaldehyde for 24 h and 5-µ paraffin sections obtained. Discrete and continuous measurements of the relative concentrations (mass/unit area) of proteins and sulphur were made along lines of scan perpendicular to the skin surface. The concentrations of proteins and sulphur almost double from the stratum basale across the stratum spinosum. There is a sharp twofold increase in their concentrations across the stratum granulosum to the stratum corneum where they become constant. The sulphur:protein ratio is constant across all layers of the epidermis. Rough estimates of cell volumes give a ratio of 1:9:7.5 for the cells of the strata basale, granulosum and corneum respectively. Cell volume changes cannot be responsible for the changes in concentration so it is concluded that epidermal cells synthesize and accumulate proteins throughout their migration to the stratum corneum. The observations are regarded as circumstantial evidence for the incorporation of keratohyalin granules into cornified cells.

scholarly journals Combination ipilimumab and radiosurgery for brain metastases: tumor, edema, and adverse radiation effects

2018 ◽  
Vol 129 (6) ◽  
pp. 1397-1406 ◽  
Author(s):  
Kevin Diao ◽  
Shelly X. Bian ◽  
David M. Routman ◽  
Cheng Yu ◽  
Paul E. Kim ◽  
...  
Keyword(s):  
Brain Metastases ◽  
Cox Proportional Hazards Model ◽  
Volume Reduction ◽  
Local Failure ◽  
Control Group ◽  
Volume Changes ◽  
Edema Volume ◽  
Relative Safety ◽  
Length Width ◽  
The Mean

OBJECTIVETumor and edema volume changes of brain metastases after stereotactic radiosurgery (SRS) and ipilimumab are not well described, and there is concern regarding the safety of combination treatment. The authors evaluated tumor, edema, and adverse radiation-induced changes after SRS with and without ipilimumab and identified associated risk factors.METHODSThis single-institution retrospective study included 72 patients with melanoma brain metastases treated consecutively with upfront SRS from 2006 to 2015. Concurrent ipilimumab was defined as ipilimumab treatment within 4 weeks of SRS. At baseline and during each follow-up, tumor and edema were measured in 3 orthogonal planes. The (length × width × height/2) formula was used to estimate tumor and edema volumes and was validated in the present study for estimation of edema volume. Tumor and edema volume changes from baseline were compared using the Kruskal-Wallis test. Local failure, lesion hemorrhage, and treatment-related imaging changes (TRICs) were analyzed with the Cox proportional hazards model.RESULTSOf 310 analyzed lesions, 91 were not treated with ipilimumab, 59 were treated with concurrent ipilimumab, and 160 were treated with nonconcurrent ipilimumab. Of 106 randomly selected lesions with measurable peritumoral edema, the mean edema volume by manual contouring was 7.45 cm3 and the mean volume by (length × width × height)/2 formula estimation was 7.79 cm3 with R2 = 0.99 and slope of 1.08 on line of best fit. At 6 months after SRS, the ipilimumab groups had greater tumor (p = 0.001) and edema (p = 0.005) volume reduction than the control group. The concurrent ipilimumab group had the highest rate of lesion response and lowest rate of lesion progression (p = 0.002). Within the concurrent ipilimumab group, SRS dose ≥ 20 Gy was associated with significantly greater median tumor volume reduction at 3 months (p = 0.01) and 6 months (p = 0.02). The concurrent ipilimumab group also had the highest rate of lesion hemorrhage (p = 0.01). Any ipilimumab was associated with higher incidence of symptomatic TRICs (p = 0.005). The overall incidence of pathologically confirmed radiation necrosis (RN) was 2%. In multivariate analysis, tumor and edema response at 3 months were the strongest predictors of local failure (HR 0.131 and HR 0.125) and lesion hemorrhage (HR 0.225 and HR 0.262). Tumor and edema response at 1.5 months were the strongest predictors of TRICs (HR 0.144 and HR 0.297).CONCLUSIONSThe addition of ipilimumab improved tumor and edema volume reduction but was associated with a higher incidence of lesion hemorrhage and symptomatic TRICs. There may be a radiation dose-response relationship between SRS and ipilimumab when administered concurrently. Early tumor and edema response were excellent predictors of subsequent local failure, lesion hemorrhage, and TRICs. The incidence of pathologically proven RN was low, supporting the relative safety of ipilimumab in radiosurgery treatment.

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