Differences in Optical Transport Properties between Human Meridian and Non-meridian

2007 ◽  
Vol 35 (05) ◽  
pp. 743-752 ◽  
Author(s):  
Hong-Qin Yang ◽  
Shu-Sen Xie ◽  
Song-Hao Liu ◽  
Hui Li ◽  
Zhou-Yi Guo
Keyword(s):  
Transport Properties ◽  
Light Propagation ◽  
Light Attenuation ◽  
Surrounding Tissue ◽  
Diffuse Light ◽  
Propagation Characteristics ◽  
Pericardium Meridian ◽  
Optical Transport ◽  
Objective Existence

This study is to present a new scheme for the detection of human meridian system non-invasively. The optical transport properties along the pericardium meridian and a non-meridian path about 1 cm away from the meridian were measured non- invasively on 20 healthy people in vivo. 633 nm, 658 nm and 785 nm red lasers were used for irradiation, and the diffuse light emittances at different points on meridian and non-meridian directions were collected respectively and compared. Our study suggested that the light propagation characteristics along both the meridian and non-meridian directions conformed to the Beer's exponential attenuation law. Statistical analysis of the results suggested that the optical properties of human meridian differ from those of the surrounding tissue ( p < 0.05), and the light attenuation is less when propagating along the pericardium meridian than along the non-meridian direction. These findings not only confirmed the objective existence of acupuncture meridians, but also shed new light on the understanding of meridians.

Nanorobots Sense Local Physiochemical Heterogeneities of Tumor Matrisome

2020 ◽  
Author(s):  
Debayan Dasgupta ◽  
Dharma Pally ◽  
Deepak K. Saini ◽  
Ramray Bhat ◽  
Ambarish Ghosh
Keyword(s):  
Cell Lines ◽  
Cancer Cell ◽  
Cancer Cell Lines ◽  
Adhesive Force ◽  
Surrounding Tissue ◽  
Quantitative Measurements ◽  
Malignant Breast Tumor ◽  
Malignant Breast ◽  
Cancer Dissemination

The dissemination of cancer is brought about by continuous interaction of malignant cells with their surrounding tissue microenvironment. Understanding and quantifying the remodeling of local extracellular matrix (ECM) by invading cells can therefore provide fundamental insights into the dynamics of cancer dissemination. In this paper, we use an active and untethered nanomechanical tool, realized as magnetically driven nanorobots, to locally probe a 3D tissue culture microenvironment consisting of cancerous and non-cancerous epithelia, embedded within reconstituted basement membrane (rBM) matrix. Our assay is designed to mimic the in vivo histopathological milieu of a malignant breast tumor. We find that nanorobots preferentially adhere to the ECM near cancer cells: this is due to the distinct charge conditions of the cancer-remodeled ECM. Surprisingly, quantitative measurements estimate that the adhesive force increases with the metastatic ability of cancer cell lines, while the spatial extent of the remodeled ECM was measured to be approximately 40 μm for all cancer cell lines studied here. We hypothesized and experimentally confirmed that specific sialic acid linkages specific to cancer-secreted ECM may be a major contributing factor in determining this adhesive behavior. The findings reported here can lead to promising applications in cancer diagnosis, quantification of cancer aggression, in vivo drug delivery applications, and establishes the tremendous potential of magnetic nanorobots for fundamental studies of cancer biomechanics.

scholarly journals In vivo multi-parametric manganese-enhanced MRI for detecting amyloid plaques in rodent models of Alzheimer’s disease

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Eugene Kim ◽  
Davide Di Censo ◽  
Mattia Baraldo ◽  
Camilla Simmons ◽  
Ilaria Rosa ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Plaques ◽  
Transgenic Animals ◽  
Surrounding Tissue ◽  
Rodent Models ◽  
Enhanced Mri ◽  
5Xfad Mice ◽  
Manganese Enhanced Mri

AbstractAmyloid plaques are a hallmark of Alzheimer’s disease (AD) that develop in its earliest stages. Thus, non-invasive detection of these plaques would be invaluable for diagnosis and the development and monitoring of treatments, but this remains a challenge due to their small size. Here, we investigated the utility of manganese-enhanced MRI (MEMRI) for visualizing plaques in transgenic rodent models of AD across two species: 5xFAD mice and TgF344-AD rats. Animals were given subcutaneous injections of MnCl2 and imaged in vivo using a 9.4 T Bruker scanner. MnCl2 improved signal-to-noise ratio but was not necessary to detect plaques in high-resolution images. Plaques were visible in all transgenic animals and no wild-types, and quantitative susceptibility mapping showed that they were more paramagnetic than the surrounding tissue. This, combined with beta-amyloid and iron staining, indicate that plaque MR visibility in both animal models was driven by plaque size and iron load. Longitudinal relaxation rate mapping revealed increased manganese uptake in brain regions of high plaque burden in transgenic animals compared to their wild-type littermates. This was limited to the rhinencephalon in the TgF344-AD rats, while it was most significantly increased in the cortex of the 5xFAD mice. Alizarin Red staining suggests that manganese bound to plaques in 5xFAD mice but not in TgF344-AD rats. Multi-parametric MEMRI is a simple, viable method for detecting amyloid plaques in rodent models of AD. Manganese-induced signal enhancement can enable higher-resolution imaging, which is key to visualizing these small amyloid deposits. We also present the first in vivo evidence of manganese as a potential targeted contrast agent for imaging plaques in the 5xFAD model of AD.

scholarly journals Injectable non-leaching tissue-mimetic bottlebrush elastomers as an advanced platform for reconstructive surgery

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Erfan Dashtimoghadam ◽  
Farahnaz Fahimipour ◽  
Andrew N. Keith ◽  
Foad Vashahi ◽  
Pavel Popryadukhin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Reconstructive Surgery ◽  
Biomedical Applications ◽  
The Body ◽  
Surrounding Tissue ◽  
Curing Time ◽  
Materials Used ◽  
Significant Health

AbstractCurrent materials used in biomedical devices do not match tissue’s mechanical properties and leach various chemicals into the body. These deficiencies pose significant health risks that are further exacerbated by invasive implantation procedures. Herein, we leverage the brush-like polymer architecture to design and administer minimally invasive injectable elastomers that cure in vivo into leachable-free implants with mechanical properties matching the surrounding tissue. This strategy allows tuning curing time from minutes to hours, which empowers a broad range of biomedical applications from rapid wound sealing to time-intensive reconstructive surgery. These injectable elastomers support in vitro cell proliferation, while also demonstrating in vivo implant integrity with a mild inflammatory response and minimal fibrotic encapsulation.

In Vivo Laser Tissue Welding in the Rabbit Maxillary Sinus

2008 ◽  
Vol 22 (6) ◽  
pp. 625-628 ◽  
Author(s):  
Benjamin S. Bleier ◽  
James N. Palmer ◽  
Michael A. Gratton ◽  
Noam A. Cohen
Keyword(s):  
Intracranial Pressure ◽  
Maxillary Sinus ◽  
Skull Base ◽  
Thermal Injury ◽  
Surrounding Tissue ◽  
Csf Leak ◽  
Tissue Welding ◽  
Laser Tissue Welding ◽  
And Control

Background One of the challenges in the current expansion of endoscopic sinonasal surgery is the ability to adequately reconstruct the skull base. Laser tissue welding (LTW) uses laser energy coupled to a biological solder to produce tissue bonds with burst thresholds exceeding human intracranial pressure. This technology could be used to reduce the rate of postoperative cerebrospinal fluid (CSF) leak. We performed this study to determine whether LTW can create durable tissue bonds in sinonasal mucosa that support normal wound healing and produce minimal collateral thermal injury. Methods Bilateral maxillary sinus mucosal incisions were made in 20 New Zealand white rabbits and one side was repaired using LTW. Burst pressure thresholds were measured on postoperative days 0, 5, and 15 and were compared with control using a two- way ANOVA and a post hoc Tukey test. Welds were examined histologically for thermal injury, inflammation, and fibroplasia and graded on a 4-point scale by three blinded observers. Results The burst pressures of the LTW group were significantly higher than control on postoperative day 0 (120.85 mm Hg, N = 4, SD = 47.84 versus 7.85 mm Hg, N = 4, SD = 0.78), and day 5 (132.56 mm Hg, N = 8, SD = 24.02 versus 41.7 mm Hg, N = 8, SD = 7.2; p < 0.05). By postoperative day 15 there was no significant difference between LTW (169.64 mm Hg, N = 8, SD = 18.49) and control (160.84 mm Hg, N = 8, SD = 14.16) burst thresholds. There was no evidence of thermal injury to the surrounding tissue in any group as well as no difference between experimental group and control with respect to inflammation or fibroplasia. Conclusion This is the first in vivo study showing that LTW is capable of producing tissue bonds exceeding human intracranial pressure with negligible thermal injury in sinonasal tissue. Welding can be performed endoscopically using a fiberoptic cable and may be useful in CSF leak and skull base repair.

670 Delayed Enzymatic Debridement of Burn Wounds using the Proteolytic Gel SN514

2021 ◽  
Vol 42 (Supplement_1) ◽  
pp. S191-S192
Author(s):  
Angela R Jockheck-Clark ◽  
Randolph Stone ◽  
Michelle Holik ◽  
Lucy Schaffer ◽  
Shanmugasundaram Natesan ◽  
...  
Keyword(s):  
Burn Injury ◽  
Vehicle Control ◽  
Surrounding Tissue ◽  
Burn Wound ◽  
Burn Wounds ◽  
Delayed Treatment ◽  
Medical Evacuation ◽  
Contamination Levels

Abstract Introduction Thermal burns account for 5–10% of casualties sustained in present-day conflicts and are expected to be one of the most common wounds to occur in future conflicts. In prolonged field care (PFC) situations, medical evacuation could be delayed for days. During this time, burn wounds can become infected, detrimentally impact neighboring tissue, and cause systemic immune responses. Therefore, it is essential to test and evaluate non-surgical debridement agents that could be implemented prior to reaching a Role 3 military treatment facility. This work details how the proprietary proteolytic gel SN514 impacts burn debridement when applied within a PFC-like timeline. SN514 contains an enzyme formulation that is thermostable, easy to apply, and selectively degrades non-viable tissue in vitro and in vivo. Methods Deep-partial thickness contact burns were created using an established porcine model and covered with gauze or an antimicrobial incise drape. Four days later, the burns were treated with one of five treatments: 0.2% SN514, 0.8% SN514, a vehicle control, gauze, or an antimicrobial silver dressing. Treatments were re-applied every 24 hours for 72 to 96 hours. The effects of the treatment regiments were compared histologically. Biopsies were also taken to monitor bacterial contamination levels. Results Burns treated with SN514 were partially debrided and visually distinct from those treated with gauze, the silver dressing, or the vehicle control. Preliminary analyses suggest that SN514-treated burns that had been covered with “dry” gauze had a much lower debridement efficiency than those treated with the incise drape. This suggests that SN514 debridement efficiency may depend on the presence of a moist eschar. Preliminary analyses also suggest that there was little difference in burn wound bacterial counts among the five treatment groups. Conclusions SN514 is able to debride burns that experienced delayed treatment, without any evidence of harm to the surrounding tissue or evidence of exacerbating the original burn injury. SN514-treated wounds displayed little to no blood loss and did not increase burn wound infection levels compared to wounds treated with gauze or an antimicrobial silver dressing.

Capillaries demonstrate changes in membrane potential in response to pharmacological stimuli

1998 ◽  
Vol 274 (1) ◽  
pp. H60-H65 ◽  
Author(s):  
Eugene D. McGahren ◽  
James M. Beach ◽  
Brian R. Duling
Keyword(s):  
Endothelial Cells ◽  
Membrane Potential ◽  
Fluorescence Emission ◽  
Cheek Pouch ◽  
Surrounding Tissue ◽  
Hamster Cheek Pouch ◽  
Capillary Membrane ◽  
Resistance Vessels ◽  
Capillary Endothelial Cells

It has been proposed that capillaries can detect changes in tissue metabolites and generate signals that are communicated upstream to resistance vessels. The mechanism for this communication may involve changes in capillary endothelial cell membrane potentials which are then conducted to upstream arterioles. We have tested the capacity of capillary endothelial cells in vivo to respond to pharmacological stimuli. In a hamster cheek pouch preparation, capillary endothelial cells were labeled with the voltage-sensitive dye di-8-ANEPPS. Fluorescence from capillary segments (75–150 μm long) was excited at 475 nm and recorded at 560 and 620 nm with a dual-wavelength photomultiplier system. KCl was applied using pressure injection, and acetylcholine (ACh) and phenylephrine (PE) were applied iontophoretically to these capillaries. Changes in the ratio of the fluorescence emission at two emission wavelengths were used to estimate changes in the capillary endothelial membrane potential. Application of KCl resulted in depolarization, whereas application of the vehicle did not. Application of ACh and PE resulted in hyperpolarization and depolarization, respectively. The capillary responses could be blocked by including a receptor antagonist (atropine or prazosin, respectively) in the superfusate. We conclude that the capillary membrane potential is capable of responding to pharmacological stimuli. We hypothesize that capillaries can respond to changes in the milieu of surrounding tissue via changes in endothelial membrane potential.

scholarly journals Fatty acid is a potential agent for bone tissue induction: In vitro and in vivo approach

2017 ◽  
Vol 242 (18) ◽  
pp. 1765-1771 ◽  
Author(s):  
Guinea BC Cardoso ◽  
Erivelto Chacon ◽  
Priscila GL Chacon ◽  
Pedro Bordeaux-Rego ◽  
Adriana SS Duarte ◽  
...  
Keyword(s):  
Stem Cells ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Bone Tissue ◽  
In Vivo Studies ◽  
Surrounding Tissue ◽  
Bone Induction ◽  
Acid Addition

Our hypothesis was to investigate the fatty acid potential as a bone induction factor. In vitro and in vivo studies were performed to evaluate this approach. Oleic acid was used in a 0.5 wt.% concentration. Polycaprolactone was used as the polymeric matrix by combining solvent-casting and particulate-leaching techniques, with a final porosity of 70 wt.%, investigated by SEM images. Contact angle measurements were produced to investigate the influence of oleic acid on polycaprolactone chains. Cell culture was performed using adipocyte-derived stem cells to evaluate biocompatibility and bioactivity properties. In addition, in vivo studies were performed to evaluate the induction potential of oleic acid addition. Adipocyte-derived stem cells were used to provide differentiation after 21 days of culture. Likewise, information were obtained with in vivo data and cellular invagination was observed on both scaffolds (polycaprolactone and polycaprolactone /oleic acid); interestingly, the scaffold with oleic acid addition demonstrated that cellular migrations are not related to the surrounding tissue, indicating bioactive potential. Our hypothesis is that fatty acid may be used as a potential induction factor for bone tissue engineering. The study’s findings indicate oleic acid as a possible agent for bone induction, according to data on cell differentiation, proliferation, and migration. Impact statement The biomaterial combined in this study on bone regeneration is innovative and shows promising results in the treatment of bone lesions. Polycaprolactone (PCL) and oleic acid have been studied separately. In this research, we combined biomaterials to assess the stimulus and the speed of bone healing.

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