scholarly journals Compression-dependency of soft tissue bioimpedance for in-vivo and in-vitro tissue testing

2019 ◽  
Vol 6 (1) ◽  
pp. 22-32 ◽  
Author(s):  
Sepideh M. Moqadam ◽  
Parvind Grewal ◽  
Majid Shokoufi ◽  
Farid Golnaraghi
Keyword(s):  
Soft Tissue ◽  
Human Body ◽  
Tumor Detection ◽  
Membrane Capacitance ◽  
Electrical Impedance Spectroscopy ◽  
Tissue Impedance ◽  
Structure Variation ◽  
Extracellular Resistance

Abstract The present study determines the effect of compression over bioimpedance of healthy soft tissue (in-vitro and in-vivo). Electrical impedance spectroscopy (EIS) is a promising tissue characterization and tumor detection technique that uses tissue impedance or admittance to characterize tissue and identify tissue properties as well as cell structure. Variation in EIS measurements while applying pressure suggests that compression tends to affect soft tissue bioimpedance. Moreover, the displacements in tissue caused by applied compression may provide useful information about the structure and state of the tissue. Thus combining the changes to the electrical properties of tissue resulted by applied compression, with the changes in tissue displacements caused by applied compression, and consequently measuring the effect that electrical and mechanical properties have on each other, can be useful to identify tissue structure. In this study, multifrequency bioimpedance measurements were performed on in-vitro and in-vivo soft tissue at different pressure levels. Increasing compression on the in-vitro tissue results in an increase in both extracellular resistance and membrane capacitance while it causes a reduction in the intracellular resistance. However, as the compression over the in-vivo samples increases, the intracellular and extracellular resistance increase and the membrane capacitance decreases. The in-vivo measurements on human body are also tested on contra-lateral tissue sites and similar tissue impedance variation trends are observed in the contra-lateral sites of human body. The evidence from these tests suggests the possibility of using this EIS-Pressure combined measurement method to improve tumor detection in soft tissue. Based upon the observations, the authors envision developing an advanced model based upon the Cole model, which is dependent on tissue displacements.

Evaluation of 99mTc-Label led Vitamin K4 as an Agent for Testicular Imaging

1991 ◽  
Vol 30 (01) ◽  
pp. 35-39 ◽  
Author(s):  
H. S. Durak ◽  
M. Kitapgi ◽  
B. E. Caner ◽  
R. Senekowitsch ◽  
M. T. Ercan
Keyword(s):  
Soft Tissue ◽  
Room Temperature ◽  
Normal Subjects ◽  
Left Testis ◽  
Wide Range ◽  
Activity Ratios ◽  
The Right ◽  
Radioactivity Levels

Vitamin K4 was labelled with 99mTc with an efficiency higher than 97%. The compound was stable up to 24 h at room temperature, and its biodistribution in NMRI mice indicated its in vivo stability. Blood radioactivity levels were high over a wide range. 10% of the injected activity remained in blood after 24 h. Excretion was mostly via kidneys. Only the liver and kidneys concentrated appreciable amounts of radioactivity. Testis/soft tissue ratios were 1.4 and 1.57 at 6 and 24 h, respectively. Testis/blood ratios were lower than 1. In vitro studies with mouse blood indicated that 33.9 ±9.6% of the radioactivity was associated with RBCs; it was washed out almost completely with saline. Protein binding was 28.7 ±6.3% as determined by TCA precipitation. Blood clearance of 99mTc-l<4 in normal subjects showed a slow decrease of radioactivity, reaching a plateau after 16 h at 20% of the injected activity. In scintigraphic images in men the testes could be well visualized. The right/left testis ratio was 1.08 ±0.13. Testis/soft tissue and testis/blood activity ratios were highest at 3 h. These ratios were higher than those obtained with pertechnetate at 20 min post injection.99mTc-l<4 appears to be a promising radiopharmaceutical for the scintigraphic visualization of testes.

scholarly journals Quinolones for the Treatment ofNeisseria GonorrhoeaeandChlamydia Trachomatis

1993 ◽  
Vol 1 (2) ◽  
pp. 108-113 ◽  
Author(s):  
Sebastian Faro
Keyword(s):  
Urinary Tract ◽  
Soft Tissue ◽  
Chlamydia Trachomatis ◽  
Urinary Tract Infections ◽  
Single Agent ◽  
Moderate Activity ◽  
Sexually Transmitted ◽  
Tract Infections

The most commonly sexually transmitted bacteria areNeisseria gonorrhoeaeandChlamydia trachomatis.The quinolones ofloxacin and ciprofloxacin have been shown to have activity against both of these bacteria in vitro and in vivo. Ofloxacin is particularly well suited for the treatment ofN. gonorrhoeaeandC. trachomatiscervical infection, which can be considered the earliest manifestation of pelvic inflammatory disease (PID). Not only can ofloxacin be effectively used as a single agent, it is also useful in treating urinary tract infections caused by Enterobacteriaceae. Although it has moderate activity against anaerobes in general, ofloxacin does have activity against the anaerobes commonly isolated from female patients with soft tissue pelvic infections. Thus, ofloxacin has the potential for being utilized to treat early salpingitis.

scholarly journals A multi-center comparison of dual energy X-ray absorptiometers: In vivo and in vitro soft tissue measurement

1997 ◽  
Vol 51 (5) ◽  
pp. 312-317 ◽  
Author(s):  
CD Economos ◽  
ME Nelson ◽  
MA Fiatarone ◽  
GE Dallal ◽  
SB Heymsfield ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Dual Energy ◽  
X Ray

From local to global matrix organization by fibroblasts: a 4D laser-assisted bioprinting approach

2021 ◽  
Author(s):  
Camille Douillet ◽  
Marc Nicodeme ◽  
Loïc Hermant ◽  
Vanessa Bergeron ◽  
Fabien Guillemot ◽  
...  
Keyword(s):  
High Resolution ◽  
Soft Tissue ◽  
Dynamic Properties ◽  
Unmet Need ◽  
Specific Pattern ◽  
Matrix Remodeling ◽  
Collagen Gels ◽  
Lattice Contraction

Abstract Fibroblasts and myofibroblasts play a central role in skin homeostasis through dermal organization and maintenance. Nonetheless, the dynamic interactions between (myo)fibroblasts and the extracellular matrix (ECM) remain poorly exploited in skin repair strategies. Indeed, there is still an unmet need for soft tissue models allowing to study the spatial-temporal remodeling properties of (myo)fibroblasts. In vivo, wound healing studies in animals are limited by species specificity. In vitro, most models rely on collagen gels reorganized by randomly distributed fibroblasts. But biofabrication technologies have significantly evolved over the past ten years. High-resolution bioprinting now allows to investigate various cellular micropatterns and the emergent tissue organizations over time. In order to harness the full dynamic properties of cells and active biomaterials, it is essential to consider “time” as the 4th dimension in soft tissue design. Following this 4D bioprinting approach, we aimed to develop a novel model that could replicate fibroblast dynamic remodeling in vitro. For this purpose, (myo)fibroblasts were patterned on collagen gels with laser-assisted bioprinting (LAB) to study the generated matrix deformations and reorganizations. First, distinct populations, mainly composed of fibroblasts or myofibroblasts, were established in vitro to account for the variety of fibroblastic remodeling properties. Then, LAB was used to organize both populations on collagen gels in even isotropic patterns with high resolution, high density and high viability. With maturation, bioprinted patterns of fibroblasts and myofibroblasts reorganized into dispersed or aggregated cells, respectively. Stress-release contraction assays revealed that these phenotype-specific pattern maturations were associated with distinct lattice tension states. The two populations were then patterned in anisotropic rows in order to direct the cell-generated deformations and to orient global matrix remodeling. Only maturation of anisotropic fibroblast patterns, but not myofibroblasts, resulted in collagen anisotropic reorganizations both at tissue-scale, with lattice contraction, and at microscale, with embedded microbead displacements. Following a 4D bioprinting approach, LAB patterning enabled to elicit and orient the dynamic matrix remodeling mechanisms of distinct fibroblastic populations and organizations on collagen. For future studies, this method provides a new versatile tool to investigate in vitro dermal organizations and properties, processes of remodeling in healing, and new treatment opportunities.

N tau-methylhistidine release: contributions of rat skeletal muscle, GI tract, and skin

1982 ◽  
Vol 243 (4) ◽  
pp. E293-E297 ◽  
Author(s):  
S. J. Wassner ◽  
J. B. Li
Keyword(s):  
Skeletal Muscle ◽  
Gastrointestinal Tract ◽  
Soft Tissue ◽  
Fractional Catabolic Rate ◽  
Gi Tract ◽  
Rat Skeletal Muscle ◽  
Catabolic Rate ◽  
Total Body

The relative contributions of skeletal muscle, gastrointestinal tract, and skin to urinary N tau-methylhistidine (MH) excretion were estimated during in vitro studies using the rat hemicorpus preparation. After 0.5 h of perfusion, MH release into the perfusate was linear for 3 h and averaged 29.8 nmol . h-1 . 100 g hemicorpus-1. In vivo, 24-h urinary MH excretion averaged 37.3 nmol . h-1 . 100 g body wt-1. The ratio of soft tissue to skin weight is equal (3.2:1) in the whole rat and in the hemicorpus. The gastrointestinal tract released 16.0 nmol . h-1 . 100 g body wt-1 or approximately 41% of the total urinary MH excretion. Preparations perfused with or without skin showed modest differences in the rate of MH release that were not statistically significant. Skeletal muscle contains 89.8% of total body MH content, whereas gastrointestinal tract and skin contain 3.8 and 6.4%, respectively. Gastrointestinal tract actomyosin turns over rapidly with a fractional catabolic rate of 24%/day versus 1.4%/day for skeletal muscle actomyosin.

scholarly journals Building an experimental model of the human body with non-physiological parameters

TECHNOLOGY ◽  
2017 ◽  
Vol 05 (01) ◽  
pp. 42-59 ◽  
Author(s):  
Joseph M. Labuz ◽  
Christopher Moraes ◽  
David R. Mertz ◽  
Brendan M. Leung ◽  
Shuichi Takayama
Keyword(s):  
Human Body ◽  
Rational Design ◽  
Distribution Systems ◽  
Cell Metabolism ◽  
Natural Experiments ◽  
Empirical Observation ◽  
Model Complex ◽  
Blood Volumes

New advances in engineering and biomedical technology have enabled recent efforts to capture essential aspects of human physiology in microscale, in-vitro systems. The application of these advances to experimentally model complex processes in an integrated platform — commonly called a ‘human-on-a-chip (HOC)’ — requires that relevant compartments and parameters be sized correctly relative to each other and to the system as a whole. Empirical observation, theoretical treatments of resource distribution systems and natural experiments can all be used to inform rational design of such a system, but technical and fundamental challenges (e.g. small system blood volumes and context-dependent cell metabolism, respectively) pose substantial, unaddressed obstacles. Here, we put forth two fundamental principles for HOC design: inducing in-vivo-like cellular metabolic rates is necessary and may be accomplished in-vitro by limiting O2 availability and that the effects of increased blood volumes on drug concentration can be mitigated through pharmacokinetics-based treatments of solute distribution. Combining these principles with natural observation and engineering workarounds, we derive a complete set of design criteria for a practically realizable, physiologically faithful, five-organ millionth-scale ([Formula: see text]) microfluidic model of the human body.

scholarly journals Tissue-engineered Oral Mucosa

2012 ◽  
Vol 91 (7) ◽  
pp. 642-650 ◽  
Author(s):  
K. Moharamzadeh ◽  
H. Colley ◽  
C. Murdoch ◽  
V. Hearnden ◽  
W.L. Chai ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Soft Tissue ◽  
Oral Mucosa ◽  
Dental Materials ◽  
Three Dimensional ◽  
Bacterial Invasion ◽  
Graft Material ◽  
Oral Diseases

Advances in tissue engineering have permitted the three-dimensional (3D) reconstruction of human oral mucosa for various in vivo and in vitro applications. Tissue-engineered oral mucosa have been further optimized in recent years for clinical applications as a suitable graft material for intra-oral and extra-oral repair and treatment of soft-tissue defects. Novel 3D in vitro models of oral diseases such as cancer, Candida, and bacterial invasion have been developed as alternatives to animal models for investigation of disease phenomena, their progression, and treatment, including evaluation of drug delivery systems. The introduction of 3D oral mucosal reconstructs has had a significant impact on the approaches to biocompatibility evaluation of dental materials and oral healthcare products as well as the study of implant-soft tissue interfaces. This review article discusses the recent advances in tissue engineering and applications of tissue-engineered human oral mucosa.

Controlled implant/soft tissue interaction by nanoscale surface modifications of 3D porous titanium implants

Nanoscale ◽  
2015 ◽  
Vol 7 (21) ◽  
pp. 9908-9918 ◽  
Author(s):  
Elisabeth Rieger ◽  
Agnès Dupret-Bories ◽  
Laetitia Salou ◽  
Marie-Helene Metz-Boutigue ◽  
Pierre Layrolle ◽  
...  
Keyword(s):  
Surface Modification ◽  
Soft Tissue ◽  
Surface Modifications ◽  
Porous Titanium ◽  
Titanium Implants ◽  
Tissue Response ◽  
Soft Tissue Response ◽  
Modification Of Titanium

Nanoscale surface modification of titanium microbeads can control the soft tissue response in vitro and in vivo.

MDM2 inhibitor AMG-232 and radiation therapy in treating patients with soft tissue sarcoma with wild-type TP53: A phase IB study (NRG-DT001).

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. TPS11076-TPS11076 ◽  
Author(s):  
Meng XU WELLIVER ◽  
Brian Andrew Van Tine ◽  
Peter Houghton ◽  
Michelle A. Rudek ◽  
Raphael E. Pollock ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Soft Tissue ◽  
Dose Level ◽  
P53 Gene ◽  
Tp53 Gene ◽  
Wild Type ◽  
P53 Activation ◽  
Level 1

TPS11076 Background: Over-expression of mdm2 is a major block to p53 activation in soft tissue sarcoma (STS). AMG-232 specifically inhibits human MDM2-p53 interactions in vitro and in vivo, thereby activating p53. Resistance mechanisms to MDM2 inhibition by AMG-232 is through accumulation of MDM2 and MDMX. However, DNA damaging agents, such as radiotherapy (RT), promote MDMX degradation and lead to sustained p53 activation, which is critically important for radiation-induced tumor cell killing in STS. Indeed, preclinical studies reveal that AMG-232 synergizes with RT in vitro and in vivo when treating STS with wild type (WT) P53 gene . Since a majority of STS harbor WT TP53 gene and RT is part of the standard of care in treating STS; it is the next rational step to test the safety and efficacy of combination of AMG-232 and RT followed by surgery. In this clinical trial, we hypothesize that preoperative AMG-232 plus RT is safe and well tolerated in 2 separate cohorts: (A) extremity and body wall; (B) abdomen/pelvis/retroperitoneum. Methods: A key feature of this trial is to incorporate TP53 NGS sequencing result as one of the eligibility criteria. Adult patients with pathologically proven grade 2-3 STS with size ≥ 5 cm are eligible to enroll if there is a planned definitive surgical resection of the primary tumor. There must be sufficient tissue to submit to central laboratory for NGS sequencing of the TP53 gene, which is an integral biomarker. Only those with tumors harboring WT p53 gene will be allowed to continue protocol treatment. The primary objective is to evaluate the safety and tolerability of AMG-232 in combination with standard-dose RT in STS in two separate cohort; as well as to determine the maximum tolerated dose (MTD) and recommended phase II dose (RP2D) of AMG-232 in combination with RT. We define DLT as grade 4-5 toxicities attributable to AMG-232 for up to 4 weeks after the completion of combination treatment (prior to surgery) as well as any AMG-232 related grade 3 toxicity that should lead to > 2 weeks treatment delay or ≥ two dose reductions. There are 3 dose levels for AMG-232: dose level 1 is 120 mg daily for 3 days per week; dose level 2 is 120 mg daily 4 days per week and dose level 5 is 120 mg daily 5 days a week. If patients did not tolerate dose level 1, AMG-232 will be de-escalated to a lower level, which is 120 mg daily 2 days a week. The trial was open since 11/2017; 3 patients have been enrolled to cohort A and 2 patients in cohort B at dose level 1. The first patient has a tumor with WT p53 gene and has completed protocol treatment safely. Clinical trial information: NCT03217266.

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