A Methodology for Quantifying Cell Density and Distribution in Multidimensional Bioprinted Gelatin-Alginate Constructs

2017 ◽  
Author(s):  
Houzhu Ding ◽  
Enyan Dai ◽  
Filippos Tourlomousis ◽  
Robert C. Chang
Keyword(s):  
Cell Density ◽  
Time Course ◽  
Density Ratio ◽  
Time Dependent ◽  
Control Group ◽  
3D Analysis ◽  
Cell Distribution ◽  
The Cross ◽  
Time Course Study ◽  
Cell Densities

Bioprinted tissue constructs are enabled by microextrusion-based co-printing of cells and hydrogel materials. In this paper, a gelatin-alginate hydrogel material formulation is implemented as the bio-ink towards a 3D cell-laden tissue construct. However, of fundamental importance during the printing process is the interplay between the various parameters that yield the final cell distribution and cell density at different dimensional scales. To investigate these effects, this study advances a multidimensional analytical framework to determine the spatial variations and temporal evolution of cell distribution and cell density within a bioprinted cell-laden construct. In the one dimensional (1D) analysis, the cell distribution and cross-sectional shape for a single printed fiber are observed to be dependent on the process temperature and material concentration parameters. This is illustrated by the reliable fabrication and image line profile analysis of the fiber prints. Round fiber prints with a measured width of 809.5±52.3 μm maintain dispersive cells with a degree of dispersion (Dd) at 96.8 % that can be achieved at high relative material viscosities under low temperature conditions (21 °C) or high material concentrations (10 % w/v gelatin). On the other hand, flat fiber prints with a measured width of 1102.2±63.6 μm coalesce cells towards the fiber midline with Dd = 76.3% that can be fabricated at low relative material viscosities under high temperature (24 °C) or low material concentrations (7.5 % w/v gelatin). In the 2D analysis, a printed grid structure yields differential cell distribution whereby differences in localized cell densities are observed between the strut and cross regions within the printed structure. At low relative viscosities, cells aggregate at the cross regions where two overlapping filaments fuse together, yielding a cell density ratio of 2.06±0.44 between the cross region and strut region. However, at high relative viscosities, the cell density ratio decreases to 0.96±0.03. In the 3D analysis, the cell density attributed to the different layers is studied as a function of printing time elapsed from the initial bio-ink formulation. Due to identifiable gravity and extrusion process-induced effects, the cell distribution within the original bio-ink cartridge or material reservoir is altered over time to yield initial quantitative increases in the cell density over the first several printed layers, followed by quantitative decreases in the subsequent printed layers. Finally, in the time-dependent analysis, the evolution of cell density and the emergence of material degradation effects is studied over a time course study. Variable initial cell densities (0.6 × 106 cells/ml, 1.0 × 106 cells/ml, and acellular control group) printed and cross-linked into cell-laden constructs for the 48 hr time course study exhibit a time-dependent increase in cell density owing to proliferation within the constructs that are presumed to accelerate the degradation rate.

A Methodology for Quantifying Cell Density and Distribution in Multidimensional Bioprinted Gelatin–Alginate Constructs

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Houzhu Ding ◽  
Filippos Tourlomousis ◽  
Robert C. Chang
Keyword(s):  
Cell Density ◽  
Time Course ◽  
Density Ratio ◽  
Control Group ◽  
3D Analysis ◽  
Cell Distribution ◽  
Material Degradation ◽  
The Cross ◽  
Time Course Study ◽  
Cell Densities

Bioprinted tissue constructs can be produced by microextrusion-based materials processing or coprinting of cells and hydrogel materials. In this paper, a gelatin–alginate hydrogel material formulation is implemented as the bio-ink toward a three-dimensional (3D) cell-laden tissue construct. However, of fundamental importance during the printing process is the interplay between the various parameters that yield the final cell distribution and cell density at different dimensional scales. To investigate these effects, this study advances a multidimensional analytical framework to determine both the spatial variations and temporal evolution of cell distribution and cell density within a bioprinted cell-laden construct. In the one-dimensional (1D) analysis, the cell distribution and single printed fiber shape in the circular cross-sectional view are observed to be dependent on the process temperature and material concentration parameters, along with the initial bio-ink cell densities. This is illustrated by reliable fabrication verified by image line profile analyses of structural fiber prints. Round fiber prints with width 809.5 ± 52.3 μm maintain dispersive cells with a degree of dispersion (Dd) at 96.8 ± 6.27% that can be achieved at high relative material viscosities under low temperature conditions (21 °C) or high material concentrations (10% w/v gelatin). On the other hand, flat fiber prints with width 1102.2 ± 63.66 μm coalesce cells toward the fiber midline with Dd = 76.3 ± 4.58% that can be fabricated at low relative material viscosities under high temperature (24 °C) or low material concentrations (7.5% w/v gelatin). A gradual decrement of Dd (from 80.34% to 52.05%) is observed to be a function of increased initial bio-ink cell densities (1.15 × 106–16.0 × 106 cells/ml). In the two-dimensional (2D) analysis, a printed grid structure yields differential cell distribution, whereby differences in localized cell densities are observed between the strut and cross regions within the printed structure. At low relative viscosities, cells aggregate at the cross regions where two overlapping filaments fuse together, yielding a cell density ratio of 2.06 ± 0.44 between the cross region and the strut region. However, at high relative viscosities, the cell density ratio decreases to 0.96 ± 0.03. In the 3D analysis, the cell density attributed to the different layers is studied as a function of printing time elapsed from the initial bio-ink formulation. Due to identifiable cell sedimentation, the dynamics of cell distribution within the original bio-ink cartridge or material reservoir yield initial quantitative increases in the cell density for the first several printed layers, followed by quantitative decreases in the subsequent printed layers. Finally, during incubation, the evolution of cell density and the emergence of material degradation effects are studied in a time course study. Variable initial cell densities (0.6 × 106 cells/mL, 1.0 × 106 cells/mL, and acellular control group) printed and cross-linked into cell-laden constructs for a 48 h time course study exhibit a time-dependent increase in cell density owing to proliferation within the constructs that are presumed to affect the rate of bio-ink material degradation.

scholarly journals SPARC Levels Modulate the Capacity of Mitomycin to Inhibit the Proliferation of Human Tenon’s Capsule Fibroblasts

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Yuanyuan Guo ◽  
Shouxiang Ni ◽  
Weiyan Zhou ◽  
Jiangping Hou ◽  
Jiaquan Shen
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Density ◽  
Collagen Gel ◽  
Reactive Oxygen ◽  
Control Group ◽  
Mrna Levels ◽  
Oxygen Species ◽  
Antifibrotic Effect ◽  
Cell Densities

Purpose. To evaluate the role of SPARC in the antiproliferation effect of MMC on human Tenon’s fibroblasts (HTF). Method. Sixteen PACG patients aged 59 ± 10 years (31–72 years), including 6 males and 10 females, were recruited. Tenon tissue was harvested during filtering surgery. Cell density was evaluated after MMC application with different concentrations and application times, by which the optimized MMC application modality was determined. MMC, si-SPARC, or SPARC protein was used when needed to evaluate the cell densities under different conditions, by which the role of SPARC in MMC-mediated antifibrotic process was identified. Results. Considering that the cell densities, as well as SPARC expression on mRNA and protein levels, are relatively stable when the MMC concentration is higher than 0.02% and exposure time longer than 90 s, we chose the MMC application pattern with 0.02% and 90 s as an optimized pattern for the downstream work. Compared to control, the si-SPARC and MMC downregulated the SPARC protein by 91% (P<0.01) and 65% (P<0.01) and mRNA by 96% (P<0.01) and 64% (P<0.01), respectively. MMC decreases the cell densities by 53.50% compared to control. si-SPARC + MMC dramatically deceased the cell density no matter compared to the control group (P<0.01) or MMC group (P<0.01); correspondingly, the relative collagen gel area in the MMC + si-SPARC group was higher than that in the MMC group or si-SPARC group (P<0.05). The reactive oxygen species expression in the MMC + si-SPARC group is higher than that in the MMC group (P<0.05). Conclusion. This study demonstrates that in HTF, (1) MMC downregulates the expression of SPARC in protein and mRNA levels; (2) SPARC depletion has synergistic effect on the antifibrotic effect of MMC; and (3) reactive oxygen species are the possible mediator in the antifibrotic effect of MMC and si-SPARC.

Time-dependent porphyric response in mice subchronically exposed to arsenic

1995 ◽  
Vol 14 (6) ◽  
pp. 475-483 ◽  
Author(s):  
G. García-Vargas ◽  
ME Cebrián ◽  
A. Albores ◽  
CK Lim ◽  
Francesco De Matteis
Keyword(s):  
Drinking Water ◽  
Time Course ◽  
Sodium Arsenite ◽  
Time Dependent ◽  
Porphobilinogen Deaminase ◽  
Hepatic Enzyme ◽  
Sodium Arsenate ◽  
Similarities And Differences ◽  
Time Course Study ◽  
Increased Activity

1 A time-course study was carried out in mice subchroni cally exposed to As III (as sodium arsenite) or As V (as sodium arsenate), via drinking water, relating the pattern of urinary porphyrin excretion to the renal and hepatic enzyme activities of porphobilinogen deaminase (PBGD), uroporphyrinogen III synthetase (URO III-S), uropor phyrinogen decarboxylase (URO-D) and coproporphyrino gen oxidase (COPRO-O), as well as to the hepatic por phyrin accumulation in the treated animals. 2 A time-dependent, wave-like porphyric response was found in mice exposed to As V, and the increases seen in total urinary porphyrins (at 3 weeks of exposure) corre sponded to an increased activity of PBGD and Uro III-S in liver. 3 Significant decreases in renal URO-D and hepatic and renal COPRO-O activities were found in treated mice; these inhibitions were more pronounced in animals exposed to As III. 4 The combination of these enzymic effects may explain the time-dependent porphyric response of mice subchroni cally exposed to As. Finally, the relative magnitudes of URO-D and COPRO-O inhibitions may determine the pat tern of porphyrin concentration observed in urine and tis sues. 5 The decrease in renal URO-D activity may help to explain the inversion in the coproporphyrin/uroporphyrin ratio previously reported in humans chronically exposed to As; however, there were differences between the uri nary porphyrin profiles found in both species. The possi ble reasons for the similarities and differences are briefly discussed.

scholarly journals TIME COURSE STUDY OF COMBINED N-ACETYL-P-AMINOPHENOL AND DICLOPHENAC INDUCED-HEPATOTOXICITY AND OXIDATIVE STRESS IN WISTAR RATS

2021 ◽  
Vol 46 (2) ◽  
Author(s):  
O. A Dosumu ◽  
D. I. Akinloye ◽  
O. B. Onunkwor ◽  
F. C. Thomas ◽  
R. A. Adeyemo
Keyword(s):  
Oxidative Stress ◽  
Liver Damage ◽  
Wistar Rats ◽  
Time Course ◽  
Time Dependent ◽  
Control Group ◽  
Gamma Glutamyl Transferase ◽  
Dependent Manner ◽  
Glutamyl Transferase ◽  
And Oxidative Stress

The abuse of combined acetaminophen or N-acetyl-p-aminophenol (APAP) and diclofenac (DIC) due to their analgesics, anti-inflammatory and antipyretic properties is a predominant cause of hepatotoxicity and oxidative stress. This study investigated the time-course effects of APAP, DIC and their combination on biomarkers of hepatic function and oxidative stress in rats. Forty male Wistar rats were randomly divided into four groups of 10 animals each as follows; control (distilled water), APAP only, DIC only and APAP + DIC for 4 weeks. Indices of liver damage (serum ALT, alanine aminotransferase; AST, aspartate aminotransferase; ALP, alkaline phosphatase; GGT, gamma-glutamyl transferase and bilirubin) were measured. Oxidative stress biomarkers (MDA, malondialdehyde; NO, nitric oxide; CAT, Catalase activity; SOD, superoxide dismutase activity; GSH content, reduced glutathione), GR, glutathione reductase, and GST, glutathione-S-transferase) were also determined using spectrophotometric methods. Statistical analysis was done using one-way ANOVA with p < 0.05 considered significant. Acetaminophen and diclofenac caused marked liver damage as noted by time-dependent significant (p < 0.05) increased activities of serum ALT, AST, ALP, GGT, and bilirubin levels as well as significant (p < 0.05) increase in hepatic MDA and NO levels as compared to the control group. Hepatic GSH content, SOD, CAT, GPx, GST and GR activities were decreased significantly (p < 0.05) in all acetaminophen and diclofenac-treated groups compared to normal control in a time-dependent manner. These findings suggest that prolonged administration of diclofenac, acetaminophen or their combination may induce hepatotoxicity, oxidative stress and alteration of hepatic antioxidant status in a time-dependent manner.

scholarly journals Effects of resistance training at different intensities of load on cross-education of muscle strength

2021 ◽  
Author(s):  
Danyelle Cristina Silva Pelet ◽  
Fábio Lera Orsatti
Keyword(s):  
Resistance Training ◽  
Muscle Strength ◽  
Time Course ◽  
Dynamic Strength ◽  
Elbow Flexion ◽  
Load Resistance ◽  
Control Group ◽  
Cross Education ◽  
Lower Load ◽  
The Cross

The objectives of this study were 1) to compare the extent of cross-transfer of high- versus low-load unilateral resistance training performed with external pacing of the movement (URTEP) and 2) to compare the time course of the two approaches. Fifty subjects were randomized to one of the following three groups: G80 [two sets at 80% and two sets at 40% of one maximum repetition (1RM), 1 concentric second and 3 eccentric seconds controlled by a metronome]; G40 (four sets at 40% of 1 RM, 1s and 3s controlled by a metronome); or CG (control group). At week 1, the G80 increased the elbow flexion 1RM (P<0.05) in contralateral arm. At week 4, both G80 and G40 increased the elbow flexion 1RM (P<0.05) in contralateral arm. However, a greater 1RM gain was observed in the G80 than in the G40 (P< .05). Thus, although higher-load URTEP seems to enhance the cross-education effect when compared to lower-load URTEP, the cross-education of dynamic strength can be achieved in the two approaches after four weeks. Many patients would benefit from cross-education of muscle strength through URPEP, even who are unable to exercise with high loads and in short periods of immobilization. Novelty bullets: (1) Unilateral resistance training promotes cross-education of dynamic muscle strength. (2) However, higher-load resistance training enhances the effects of cross-education of muscle strength.

USING THE KAZAKH WHITE-HEADED BREED TO INCREASE BEEF IN THE FLAT PROVINCE OF DAGESTAN

2020 ◽  
Author(s):  
М.М. САДЫКОВ ◽  
М.П. АЛИХАНОВ ◽  
А.Г. СИМОНОВ ◽  
Г.А. СИМОНОВ
Keyword(s):  
Growth And Development ◽  
Live Weight ◽  
Control Group ◽  
Beef Production ◽  
Daily Growth ◽  
Carcass Yield ◽  
Breeding Stock ◽  
Fattening Period ◽  
The Cross ◽  
Experimental Group

Изучены рост и развитие бычков — помесей красной степной с казахской белоголовой породой в равнинной провинции Дагестана. Установлено, что помесный молодняк, по сравнению с чистопородным скотом красной степной породы, имеет более высокую живую массу при рождении на 1,8 кг, или 7,3%. При отъеме в 8-месячном возрасте помеси имели живую массу 210 кг против 187,6 кг у красного степного молодняка, что на 22,4 кг, или 11,9% выше. В 12-, 15- и 18-месячном возрасте живая масса помесных бычков равнялась 291,8 кг, 359,7 и 436,6 кг, соответственно, или на 28 кг, 36 и 45,8 кг больше по сравнению с красным степным скотом. Среднесуточные приросты помесных бычков за период выращивания и откорма составили 760 г, что выше на 12,1% по сравнению с чистопородным красным степным молодняком. После заключительного откорма и убоя помесные бычки дали тяжеловесные туши с хорошим поливом. По массе парной туши они превосходили чистопородных аналогов на 31,3 кг, или 15,6% с преимуществом выхода туши на 2,4%. Убойный выход у бычков опытной группы составил 58,7%, контрольной — 55,8%. От помесных бычков были получены тяжеловесные шкуры массой 27,1 кг, от чистопородных — 21,6 кг, преимущество по этому показателю имели помесные животные 5,5 кг, или 25,4%. Для увеличения производства говядины в равнинной провинции Дагестана рекомендуем скрещивание коров красной степной породы с быками казахской белоголовой породы. The growth and development of bulls of red steppe crossbreeds with the Kazakh white-headed breed in the flat province of Dagestan were studied. It was found that young crossbreed animals in comparison with purebred red steppe cattle have a higher live weight at birth by 1,8 kg or 7,3%. When weaning at 8 months of age, cross-bred bulls had a live weight of 210 kg against 187,6 kg in red steppe young, which is 22,4 kg, or 11,9% higher. At 12, 15 and 18 months of age, the live weight of crossbred bulls was 291,8 kg, 359,7 and 436,6 kg, respectively, or 28 kg, 36 and 45,8 kg more than the red steppe cattle. The average daily growth of cross-bred bulls during the growing and fattening period was 760 g compared to 678 g, that is, they were 12,1% higher compared to purebred red steppe young. After the final fattening and slaughter, the cross-bred bulls gave heavy carcasses with good watering. By weight of the paired carcass, they were superior to purebred counterparts by 31,3 kg or 15,6% with an advantage of 2,4% carcass yield. The slaughter yield of bulls in the experimental group was 58,7%, 55,8% in the control group, respectively, with an advantage in favor of crossbreeds of 2,9%. Heavy skins weighing 27,1 kg were obtained from crossbreed bulls, 21,6 kg from purebred ones, and crossbreed animals of 5,5 kg or 25,4% had an advantage in this indicator. Studies have shown that in order to increase beef production in the lowland province of Dagestan, it is necessary to use crossbreeding of the breeding stock of the red steppe breed with bulls of the Kazakh white-headed breed.

Time course study of blood pressure in children over a three-year period. Bogalusa Heart Study

Hypertension ◽  
1980 ◽  
Vol 2 (4) ◽  
pp. 102-108 ◽  
Author(s):  
A. W. Voors ◽  
L. S. Webber ◽  
G. S. Berenson
Keyword(s):  
Blood Pressure ◽  
Time Course ◽  
Bogalusa Heart Study ◽  
Heart Study ◽  
Time Course Study

scholarly journals On the Role of Bilateral Brain Hypofunction and Abnormal Lateralization of Cortical Information Flow as Neural Underpinnings of Conventional Metaphor Processing Impairment in Schizophrenia: An fMRI and EEG Study

2021 ◽  
Author(s):  
Przemysław Adamczyk ◽  
Martin Jáni ◽  
Tomasz S. Ligeza ◽  
Olga Płonka ◽  
Piotr Błądziński ◽  
...  
Keyword(s):  
Information Flow ◽  
Language Processing ◽  
Time Course ◽  
Figurative Language ◽  
Neural Circuits ◽  
Effective Connectivity ◽  
Brain Regions ◽  
Blood Oxygenation ◽  
Control Group ◽  
Metaphor Processing

AbstractFigurative language processing (e.g. metaphors) is commonly impaired in schizophrenia. In the present study, we investigated the neural activity and propagation of information within neural circuits related to the figurative speech, as a neural substrate of impaired conventional metaphor processing in schizophrenia. The study included 30 schizophrenia outpatients and 30 healthy controls, all of whom were assessed with a functional Magnetic Resonance Imaging (fMRI) and electroencephalography (EEG) punchline-based metaphor comprehension task including literal (neutral), figurative (metaphorical) and nonsense (absurd) endings. The blood oxygenation level-dependent signal was recorded with 3T MRI scanner and direction and strength of cortical information flow in the time course of task processing was estimated with a 64-channel EEG input for directed transfer function. The presented results revealed that the behavioral manifestation of impaired figurative language in schizophrenia is related to the hypofunction in the bilateral fronto-temporo-parietal brain regions (fMRI) and various differences in effective connectivity in the fronto-temporo-parietal circuit (EEG). Schizophrenia outpatients showed an abnormal pattern of connectivity during metaphor processing which was related to bilateral (but more pronounced at the left hemisphere) hypoactivation of the brain. Moreover, we found reversed lateralization patterns, i.e. a rightward-shifted pattern during metaphor processing in schizophrenia compared to the control group. In conclusion, the presented findings revealed that the impairment of the conventional metaphor processing in schizophrenia is related to the bilateral brain hypofunction, which supports the evidence on reversed lateralization of the language neural network and the existence of compensatory recruitment of alternative neural circuits in schizophrenia.

scholarly journals NF-κB and FosB mediate inflammation and oxidative stress in the blast lung injury of rats exposed to shock waves

2021 ◽  
Author(s):  
Hong Wang ◽  
Wenjuan Zhang ◽  
Jinren Liu ◽  
Junhong Gao ◽  
Le Fang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lung Injury ◽  
Shock Waves ◽  
Time Dependent ◽  
Inflammatory Factors ◽  
Control Group ◽  
Dependent Manner ◽  
Total Antioxidant ◽  
Blast Lung Injury ◽  
And Oxidative Stress

Abstract Blast lung injury (BLI) is the major cause of death in explosion-derived shock waves; however, the mechanisms of BLI are not well understood. To identify the time-dependent manner of BLI, a model of lung injury of rats induced by shock waves was established by a fuel air explosive. The model was evaluated by hematoxylin and eosin staining and pathological score. The inflammation and oxidative stress of lung injury were also investigated. The pathological scores of rats’ lung injury at 2 h, 24 h, 3 days, and 7 days post-blast were 9.75±2.96, 13.00±1.85, 8.50±1.51, and 4.00±1.41, respectively, which were significantly increased compared with those in the control group (1.13±0.64; P&lt;0.05). The respiratory frequency and pause were increased significantly, while minute expiratory volume, inspiratory time, and inspiratory peak flow rate were decreased in a time-dependent manner at 2 and 24 h post-blast compared with those in the control group. In addition, the expressions of inflammatory factors such as interleukin (IL)-6, IL-8, FosB, and NF-κB were increased significantly at 2 h and peaked at 24 h, which gradually decreased after 3 days and returned to normal in 2 weeks. The levels of total antioxidant capacity, total superoxide dismutase, and glutathione peroxidase were significantly decreased 24 h after the shock wave blast. Conversely, the malondialdehyde level reached the peak at 24 h. These results indicated that inflammatory and oxidative stress induced by shock waves changed significantly in a time-dependent manner, which may be the important factors and novel therapeutic targets for the treatment of BLI.

scholarly journals Clinical Value and Time Course of Pericoronary Fat Inflammation in Patients with Angiographically Nonobstructive Coronaries: A Preliminary Report

2021 ◽  
Vol 10 (8) ◽  
pp. 1786
Author(s):  
Valeria Pergola ◽  
Marco Previtero ◽  
Annagrazia Cecere ◽  
Vittorio Storer ◽  
Teresa Castiello ◽  
...  
Keyword(s):  
Cardiac Troponin ◽  
Preliminary Report ◽  
Time Course ◽  
Coronary Artery Stenosis ◽  
High Sensitivity ◽  
Control Group ◽  
Clinical Value ◽  
Coronary Ct ◽  
Electrocardiographic Changes ◽  
Acute Event

The introduction of high-sensitivity cardiac troponin allowed identifying a proportion of subjects with chest pain and electrocardiographic changes suggestive of myocardial infarction showing <50% coronary artery stenosis. PFAI is a coronary CT marker proved to predict outcome in ischemic heart disease. Based on CMR findings, patients were divided into myocarditis (n = 15), MINOCA (n = 14) and TTS (n = 9) groups. The aim was to estimate the value of pFAI in these groups compared to 12 controls. To evaluate the coronary inflammation “time course,” 20 patients underwent CMR and coronary CT scan within 8 days from the onset, the others within 60 days. There were higher values of pFAI in myocarditis (−86.45 HU), MINOCA (−84.63 HU) and TTS (−84.79 HU) compared to controls (−96.02 HU; p = 0.0077). Among patients who underwent CT within 8 days from onset, the MINOCA had a significantly higher pFAI value (−76.91 HU) compared to the control group (−96.02 HU; p = 0.0001). In the group that underwent CT later than 8 days, elevated pFAI values persisted only in the myocarditis and TTS groups, and there was no difference between MINOCA and controls. Our study shows that in patients with a diagnosis of MINOCA, there is acute coronary inflammation, which is more evident within one week from the acute event but tends to disappear with time.

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