Perfusion Measurement on Skin Model with Lasca Affected by Static and Mixed Scattering

2019 ◽  
Author(s):  
Tomi Smausz ◽  
Bence Kondasz
Keyword(s):  
Skin Model ◽  
Perfusion Measurement ◽  
Mixed Scattering

Optimization of Extraction Parameters of Reverse Iontophoretic Determination of Blood Glucose in an Artificial Skin Model

2020 ◽  
Vol 16 (6) ◽  
pp. 722-737
Author(s):  
Cigdem Yengin ◽  
Emrah Kilinc ◽  
Fatma Gulay Der ◽  
Mehmet Can Sezgin ◽  
Ilayda Alcin
Keyword(s):  
Ionic Strength ◽  
Body Fluids ◽  
Extraction Time ◽  
Artificial Skin ◽  
Dialysis Membrane ◽  
Skin Model ◽  
Non Invasive ◽  
Electrode Distance ◽  
Experimental Parameters

Background: Reverse İontophoresis (RI) is one of the promising non-invasive technologies. It relies on the transition of low magnitude current through the skin and thus glucose measurement becomes possible as it is extracted from the surface during this porter current flow. Objective: This paper deals with the development and optimization of an RI determination method for glucose. CE dialysis membrane based artificial skin model was developed and the dependence of RI extraction on various experimental parameters was investigated. Method: Dependence of RI extraction performance on noble electrodes (platinum, silver, palladium, ruthenium, rhodium) was checked with CA, CV and DPV, in a wide pH and ionic strength range. Optimizations on inter-electrode distance, potential type and magnitude, extraction time, gel type, membrane MWCO, usage frequency, pretreatment, artificial body fluids were performed. Results: According to the optimized results, the inter-electrode distance was 7.0 mm and silver was the optimum noble metal. Optimum pH and ionic strength were achieved with 0.05M PBS at pH 7.4. Higher glucose yields were obtained with DPV, while CA and CV achieved almost the same levels. During CA, +0.5V achieved the highest glucose yield and higher potential even caused a decrease. Glucose levels could be monitored for 24 hours. CMC gel was the optimum collection media. Pretreated CE membrane with 12kD MWCO was the artificial skin model. Pretreatment affected the yields while its condition caused no significant difference. Except PBS solution (simulated as artificial plasma), among the various artificial simulated body fluids, intestinal juice formulation (AI) and urine formulation U2 were the optimum extraction media, respectively. Conclusion: In this study, various experimental parameters (pretereatment procedure, type and MWCO values of membranes, inter-electrode distance, electrode material, extraction medium solvents, ionic strength and pH, collection medium gel type, extraction potential type and magnitude, extraction time and etc) were optimized for the non-invasive RI determination of glucose in a CE dialysis membrane-based artificial skin model and various simulated artificial body fluids.

scholarly journals Disinfectant effectiveness against SARS-CoV-2 and influenza viruses present on human skin: model-based evaluation

2021 ◽  
Author(s):  
Ryohei Hirose ◽  
Risa Bandou ◽  
Hiroshi Ikegaya ◽  
Naoto Watanabe ◽  
Takuma Yoshida ◽  
...  
Keyword(s):  
Human Skin ◽  
Influenza Viruses ◽  
Skin Model ◽  
Model Based

Clinical manifestations of VX poisoning following percutaneous exposure in the domestic white pig

2003 ◽  
Vol 22 (5) ◽  
pp. 255-261 ◽  
Author(s):  
R P Chilcott ◽  
C H Dalton ◽  
I Hill ◽  
C M Davidson ◽  
K L Blohm ◽  
...  
Keyword(s):  
Glucose Utilization ◽  
Clinical Manifestations ◽  
Lateral Diffusion ◽  
Nerve Agents ◽  
Application Site ◽  
Rodent Models ◽  
Skin Model ◽  
Exposed Skin ◽  
Percutaneous Exposure ◽  
Qualitative Relationship

Nerve agents are a class of organophosphorus chemicals that inhibit certain cholinesterase enzymes (ChE). If untreated, percutaneous exposure to nerve agents, such as VX (O-ethyl-S-[2(diisopropylamino)ethyl] methylphosphonothioate) can cause paralysis, apnoea and death. Much of the information concerning the percutaneous absorption and subsequent toxicity of nerve agents has been obtained using various rodent models. However, the most relevant ‘skin model’ is arguably the pig. Therefore, the purpose of this study was to examine the clinical manifestations of VX intoxication in the domestic white pig following a 2 LD50 (120 mg/kg) percutaneous challenge. There was a consistent onset of signs (where present) in each animal: mastication was followed by miosis, salivation, fasciculations and apnoea. Whilst ChE activity did not correlate with the onset of signs, there was a qualitative relationship in that mastication preceded substantial ChE inhibition, miosis lagged behind the linear decrease in acetylcholinesterase (AChE) activity and fasciculations and apnoea occurred after maximum ChE inhibition had been attained (5 / 10% of normal). These observations may be of use for the triage of patients exposed to VX. In comparison with similar studies with GD, VX did not affect glucose utilization. However, VX was similar to GD in that it caused a mild hyperkalaemia and hyperphosphataemia, although the significance of this observation was not clear. There was substantial lateral diffusion of the initial droplet of VX over the application site, indicating that, when decontaminating exposed skin, attention should also be directed to areas peripheral to the original site of exposure.

Neurovascular changes after four-layer compression bandaging in people with chronic venous leg ulcers

2007 ◽  
Vol 22 (2) ◽  
pp. 49-55 ◽  
Author(s):  
R Ogrin ◽  
P Darzins ◽  
Z Khalil
Keyword(s):  
Wound Healing ◽  
Wound Repair ◽  
Statistical Significance ◽  
Sensory Nerve ◽  
Compression Therapy ◽  
Clinical Problem ◽  
Leg Ulcers ◽  
Venous Leg Ulcers ◽  
Perfusion Measurement ◽  
Compression Bandaging

Objectives: Venous leg ulcers represent a major clinical problem, with poor rates of healing. Ideal treatment is compression bandaging. The effect of compression on neurovascular tissues involved in wound repair is unclear. This study aims to assess the effect of four-layer compression therapy (40 mmHg) on neurovascular function and wound healing in people with chronic venous leg ulcers – 15 people (55 years or older) with venous leg ulcers for more than six weeks. Methods: Basal microvascular perfusion measurement (MPM), oxygen tension (tc pO2) measured at sensor temperatures of 39°C and 44°C and sensory nerve function using electrical cutaneous perception thresholds (ECPT) at 5, 250 and 2000 Hz (corresponding to C, A δ and A β fibres) were assessed adjacent to the ulcer site, and at a mirror location on the non-ulcerated limb. Testing was undertaken before and after therapy for 5–12 weeks of four-layer compression bandaging. Results: There was significant improvement in tc pO2 at 44°C and ECPT at 2000 Hz ( P<0.05) compared with pre-intervention. Changes in basal MPM, tc pO2 at 39°C and ECPT at 5 and 250 Hz after compression therapy did not reach statistical significance. Conclusion: Four-layer compression bandaging in people with venous leg ulcers improved some components of neurovascularture in people with chronic venous leg ulcers. Whether this improvement has contributed to wound healing in this study requires further investigation.

Basic Red 51, a permitted semi-permanent hair dye, is cytotoxic to human skin cells: Studies in monolayer and 3D skin model using human keratinocytes (HaCaT)

2014 ◽  
Vol 227 (2) ◽  
pp. 139-149 ◽  
Author(s):  
Thalita B. Zanoni ◽  
Manoela Tiago ◽  
Fernanda Faião-Flores ◽  
Silvia B. de Moraes Barros ◽  
Aalt Bast ◽  
...  
Keyword(s):  
Human Skin ◽  
Human Keratinocytes ◽  
Skin Model ◽  
Hair Dye ◽  
Skin Cells ◽  
Human Skin Cells ◽  
3D Skin

scholarly journals Development and Evaluation of a Topical Anti-Inflammatory Preparation Containing Dodonaea polyandra Extract

2015 ◽  
Vol 18 (4) ◽  
pp. 578 ◽  
Author(s):  
Bradley S Simpson ◽  
Xianling Luo ◽  
Jiping Wang ◽  
Yunmei Song ◽  
David Claudie ◽  
...  
Keyword(s):  
Phase Separation ◽  
Human Skin ◽  
Dosage Form ◽  
Interleukin 1 ◽  
In Vitro Release ◽  
Skin Inflammation ◽  
Skin Model ◽  
Inflammation Model ◽  
Anti Inflammatory

Purpose: We have previously reported that the Australian Northern Kaanju (Kuuku I’yu) medicinal plant Dodonaea polyandra has anti-inflammatory activity. This is attributed largely to the presence of clerodane diterpenoids contained within the leaf resin. We envisaged developing a topical preparation to treat indications relating to skin inflammation. However, it was unknown whether the resin could be incorporated into a suitable dosage form while retaining the therapeutic value demonstrated in previous work. Therefore, the following study was undertaken to assess parameters of safety and efficacy for a prototype formulation containing the leaf resin extracted from D. polyandra. Methods: Using the assessment criteria of optimum appearance, tactile feeling, spreadability and odour, 78 different formulations were developed. Formulation stability was assessed using a centrifugal test with preparations displaying phase separation further modified or re-formulated. A prototype formulation containing 5% w/w plant resin was selected and subjected to in vitro release studies. This was quantified through HPLC analysis using two major bioactive diterpenoids as reference. The prototype formulation was tested for efficacy in a TPA-induced acute murine skin inflammation model as well as a 3D human skin model for irritancy/toxicity (Epiderm™). Results: The prototype resin cream was a chartreuse-coloured homogenous semisolid preparation that was readily spreadable upon contact with skin with no sensation of tackiness, residual greasiness, or irritation. The optimized cream showed no phase separation after 30 min centrifugation at 825 g. In the TPA-induced inflammation model, the resin formulation significantly reduced ear thickness and interleukin-1 beta levels in mouse ear tissue. The 5% w/w resin cream formulation showed no irritancy in a 3D human skin model. Conclusions: Our results demonstrate that bioactive resin from D. polyandra can be formulated into a stable and non-irritant semi-solid dosage form and reduce parameters of acute skin inflammation in vivo. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

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