Normal Volunteer Subjects Research Articles

Development of a Noninvasive Device to Predict Postoperative Ileus Using Acoustic Biomarkers

Abstract Purpose: For patients undergoing gastrointestinal surgery, postoperative ileus (POI) is difficult to predict and occurs at rates up to 30%. We hypothesized that discrete gastrointestinal acoustic biomarkers correlating to POI development may present in early postoperative hours. To test this hypothesis, we conducted a two-phase investigation to record and analyze intestinal sounds, then prospectively test the feasibility of predicting POI using a noninvasive device trained with an algorithm developed from Phase 1 results. Methods: In Phase 1, a library of intestinal sounds from normal volunteer subjects and patients undergoing intestinal resection were recorded. An acoustic biomarker most correlated with POI was identified and used to develop a predictive algorithm. In Phase 2, an autonomous, wearable device possessing listening and signal processing capability was developed and prospectively tested for prediction of POI in patients undergoing bowel resection. Results: In Phase 1, 30 patients undergoing resection were studied, 9 of whom developed POI, from which an acoustic biomarker was identified and analyzed. In Phase 2, prospective prediction of POI in 75 enrolled subjects undergoing bowel resection was assessed. POI was correctly predicted in 12 of 14 subjects who developed POI; prediction that POI would not occur was correct in 39 of 51 subjects. Sensitivity and specificity were 85.7% and 63.9%, respectively. Negative predictive value and accuracy were 95.1%, and 68%, respectively. Conclusions: Our study demonstrates feasibility of POI prediction based on gastrointestinal sounds using a noninvasive device. This device may help risk stratify patients likely to develop POI.

Is ketamine and lamotrigine interactions responsible for the sub-therapeutic effect of ketamine?

IntroductionThe immediate antidepressant effect of Ketamine has become a breakthrough in the treatment of depression. Cytochrome CYP3A4 and 2B6 primarily metabolize Ketamine.ObjectivesThe present study explores potential pharmacokinetic and pharmacodynamic interactions of Lamotrigine and Ketamine.MethodsA literature search was conducted using (“ketamine” OR “Lamotrigine” AND Interactions in PubMed, Embase, and PsycINFO. Our literature search resulted in 72 hits and result in qualified five studies.ResultsWe found five studies: one RCT study, a RCT, a crossover design, Two case reports, and one murine model study. In the first RCT conducted on 16 healthy normal volunteer subjects. lamotrigine significantly decreased ketamine-induced perceptual abnormalities (P < 0.001), positive (P < 0.001) and negative symptoms (P < 0.05), and learning and memory impairment (P < 0.05) which shows the counter effect of ketamine. Another study revealed Ketamine evoked increases in all the BPRS subscale scores, and all scores were lower after lamotrigine pretreatment. A case report from 2014 reports the failure of ketamine anesthesia in a patient with lamotrigine overdose. Another case report mentions that Lamotrigine reduced the craving in a patient with ketamine use disorder. A murine model study with lamotrigine showed improved PPI (Prepulse inhibition) ketamine-induced disruption. These results suggest that Lamotrigine may exert this effect via a glutamatergic system.ConclusionsThe literature review suggests that Lamotrigine interferes with glutamatergic neurotransmission reducing the effect of Ketamine. It is not clear how this may impact Ketamine’s antidepressant action. Future large scale and well-designed RCTs are required to confirm these findings.Conflict of interestNo significant relationships.

Thrombospondin 1 polymorphism associated with decreased expression and increased risk of pterygium

To assess the potential association of a thrombospondin 1 gene (THBS1) single-nucleotide polymorphism (rs1478604) with thrombospondin 1 (TSP-1) mRNA expression, as well as the risk of pterygium, in a pilot study. DNA and RNA were isolated from peripheral blood samples collected from normal volunteer subjects (n = 39). In addition, DNA was isolated from conjunctival tissue samples collected during pterygium excision surgeries (n = 42). Relative expression of TSP-1 mRNA was measured by quantitative RT-PCR, and rs1478604 genotype was determined using a TaqMan SNP genotyping assay. Genotype frequencies were compared with mRNA expression and between pterygium samples and normal controls. Expression of TSP-1 mRNA was significantly lower in the peripheral blood of normal subjects who were homozygous for the C allele of rs1478604 (CC) compared to TT and CT genotypes (p = 0.004). When we compared rs1478604 genotypes between normal and pterygium patients, we found that the CC genotype was also associated with an increased risk of pterygium compared to TT (odds ratio (OR) = 5.39, 95% CI [1.26-22.99], p = 0.028), CT (OR = 7.86, 95% CI [1.92-32.17], p = 0.003), and combined CT and TT genotypes (OR = 6.67; 95% CI = [1.75-25.37]; p = 0.003). We found that the C allele of rs1478604 was associated with both lower TSP-1 expression and higher risk of pterygium, possibly implicating TSP-1 in the pathogenesis of pterygium.

Benefits of Mainstreaming Herbal Medicine in the Philippine Healthcare System

Benefits of Mainstreaming Herbal Medicine in the Philippine Healthcare System

Differential diagnosis of schizophrenia and schizoaffective disorder from normal subjects using virtual reality

Dysfunction of allocentric and egocentric memories is one of the core features of psychiatric disorders. There are a few navigational studies on these memories in schizophrenia and bipolar disorders, but studies in schizoaffective disorder are lacking. Here, we aim to explore allocentric and egocentric navigation deficits in these subjects using our advanced recently developed virtual reality navigation task (VRNT). Twenty patients with schizophrenia and 20 with schizoaffective disorder were compared with 20 normal volunteer subjects on VRNTs consisting of a virtual neighbourhood (allocentric memory) and a virtual maze (egocentric memory). Compared with schizoaffective disorder and control subjects, patients with schizophrenia had the worst performance on both virtual neighbourhood and virtual maze tasks. The allocentric memory in both patients with schizophrenia and those with schizoaffective disorder was more impaired than the egocentric memory (p ˂ 0.001). However, the patients with schizoaffective disorder performed better in egocentric memory than those with schizophrenia, as they had fewer errors in the virtual maze. It was concluded that allocentric memory is more impaired than egocentric in both schizoaffective disorder and schizophrenia patients, whereas patients with schizoaffective disorder performed better in egocentric memory than patients with schizophrenia. It was also concluded that allocentric memory deficits can help differentiate patients with schizophrenia and schizoaffective disorder from healthy participants, whereas egocentric memory deficits can be used to distinguish them from each other.

Exploring the brain correlates of ideas of reference with a virtual reality paradigm in fMRI

Dysfunction of allocentric and egocentric memories is one of the core features of psychiatric disorders. There are a few navigational studies on these memories in schizophrenia and bipolar disorders, but studies in schizoaffective disorder are lacking. Here, we aim to explore allocentric and egocentric navigation deficits in these subjects using our advanced recently developed virtual reality navigation task (VRNT). Twenty patients with schizophrenia and 20 with schizoaffective disorder were compared with 20 normal volunteer subjects on VRNTs consisting of a virtual neighbourhood (allocentric memory) and a virtual maze (egocentric memory). Compared with schizoaffective disorder and control subjects, patients with schizophrenia had the worst performance on both virtual neighbourhood and virtual maze tasks. The allocentric memory in both patients with schizophrenia and those with schizoaffective disorder was more impaired than the egocentric memory (p ˂ 0.001). However, the patients with schizoaffective disorder performed better in egocentric memory than those with schizophrenia, as they had fewer errors in the virtual maze. It was concluded that allocentric memory is more impaired than egocentric in both schizoaffective disorder and schizophrenia patients, whereas patients with schizoaffective disorder performed better in egocentric memory than patients with schizophrenia. It was also concluded that allocentric memory deficits can help differentiate patients with schizophrenia and schizoaffective disorder from healthy participants, whereas egocentric memory deficits can be used to distinguish them from each other.

Mobile health architecture for obesity management using sensory and social data

Abstract One of the principal causes of several chronic diseases (e.g., diabetes, high cholesterol, and hypertension) is the obesity epidemic in high and middle income countries. Obesity also leads to an increasingly negative effect on public health resources. Therefore, obesity and overweight have to be monitored to mitigate and prevent the potential risks generated from the threat of related diseases and from reducing productivity experienced by businesses. A mobile-health monitoring system includes sensing, transmitting, storing, processing, and analyzing intensive, continuous, and heterogeneous medical data. However, current approaches are standalone mobile applications, augmented mobile applications, or mobile health systems. These approaches only consider simple activities (assess, detect, or control obesity) and rely on a mobile phone to perform complex processing operations on the collected data. Such complex operations need (1) efficient data mining techniques, (2) more memory consumption and processing time, and (3) long life mobile battery. In this work, we develop a new comprehensive mobile architecture for tackling the challenging issues of obesity control, monitoring, and prevention. We introduce a set of business requirements considering stakeholders, sensor devices, and architecture requirements to meet our architecture's objectives. Our architecture system can also help individuals track food intake, lifestyle, calories intake, calories consumption, and exercise activities. We analyze the data collected from continuous monitoring using non-invasive sensors, in addition to the data collected from social communities created to propagate awareness and share appropriate information about the obesity problem and its solution. We develop data mining algorithms and sentiment analysis algorithms and generate intelligent suggestions, warnings, and recommendations to control and mitigate the risk of obesity and its related diseases. We develop schemes for reducing data and saving energy, which minimize the amount of network traffic within the community of sensors. Moreover, we totally implement our architecture system as a collection of Web services organized by the model–view–controller design pattern to write, retrieve, and access data to and from the cloud storage firebase. We finally evaluate the efficacy and scalability of the implemented system using a comprehensive cloud database including entered data, calculated data, sensory data, and social data of 50 underweight, overweight, normal, and obese volunteer subjects. The obtained results show our architecture's objectives are fulfilled.

Interleukin 1 Receptor-Like 1 Protein (ST2) is a Potential Biomarker for Cardiomyopathy in Duchenne Muscular Dystrophy.

Duchenne muscular dystrophy (DMD) is a rare, fatal X-linked disorder characterized by the lack of dystrophin, a key sarcolemma muscle protein.Cardiac failure is a significant cause of death in DMD subjects. The purpose of our research was to identify potential cardiac serum biomarkers associated with DMD cardiomyopathy. This is an observational, case-controlled study using subjects from the CINRG DMD natural history study with cardiomyopathy (ejection fraction (EF) <55%; shortening fraction (SF) <28%), subjects without cardiomyopathy (EF≥55%; SF≥28%) compared to normal healthy volunteer subjects. The DMD with cardiomyopathy group had significantly lower average EF and SF (EF=45±10/SF=25±2%) than the DMD without cardiomyopathy group (EF=58±5% and SF=32±3%; p<0.01). Among a selected set of potential biomarkers for cardiomyopathy (MMP9, BNP, GAL3, CRP, LEP, TNC, TLR4 and ST2) we validated ST2 as significantly elevated in the serum of DMD cardiomyopathy group (35,798±4884pg/mL) compared to normal controls (9940±2680pg/mL; p<0.01; n=6). Matrix metallopeptidase 9 (MMP9) levels were found significantly increased in both DMD groups compared to controls (p<0.01). No significant differences were seen in BNP, GAL3, CRP, LEP, TNC or TLR4 levels. Increased ST2 levels were found in serum of DMD subjects compared to healthy volunteers and further elevated in DMD subjects with cardiomyopathy. Future studies correlating cardiomyopathy with ST2 levels may allow for improved non-invasive monitoring of cardiac disease in DMD subjects.

The flavor and acceptability of six different potassium-enriched (sodium reduced) iodized salts: a single-blind, randomized, crossover design.

BackgroundHypertension is a serious public health problem. Potassium-enriched salt is suggested as a tool for lowering blood pressure. However, its flavor and taste acceptability is essential for population-based salt reduction strategy and needs to be well-understood. This trial assessed the flavor and taste acceptability of six different potassium-enriched iodized salts in the general population.MethodsWe conducted this crossover trial from May to June 2016, enrolling 100 normal volunteer subjects aged 11 to 64 years. We compared regular sodium chloride salt (placebo) with six different potassium-enriched (sodium reduced) iodized salt (experiment), including 0 %, 5 %, 10 %, 15 %, 20 %, 25 %, and 30 %. The participants served as their own control and received a placebo and a sequence of the experiments. They tasted the two salts sequentially and stated their preference and acceptance. Each subject received all salts.ResultsMore than 80 % of participants who either did not distinguish between the two salts even in high potassium-enriched salts or preferred potassium-enriched salt (P < 0.001). The number of participants who preferred the flavor of potassium-enriched salt was greater than the number of subjects who preferred the flavor of regular sodium chloride.ConclusionOur findings indicated that the six different potassium-enriched salts had a public acceptability of at least 80 % among normal subjects from the general population. Although the acceptability of the potassium-enriched salts by a more general population group would require to be confirmed, universal use of this salt may help us achieve the target of 30 % relative reduction in mean population intake of sodium by 2025.

Functional neuroimaging of acute oculomotor deficits in concussed athletes.

In the pursuit to better understand the neural underpinnings of oculomotor deficits following concussion we performed a battery of oculomotor tests while performing simultaneous functional magnetic resonance imaging (fMRI). Based on the increasing evidence that concussion can disrupt multiple brain functional networks, including the oculomotor control networks, a series of classic saccadic and smooth pursuit tasks were implemented. Nine concussed athletes were tested within seven days of injury along with nine age and sex matched healthy normal volunteers. Both behavioral and fMRI data revealed differential results between the concussed and normal volunteer groups. Concussed subjects displayed longer latency time in the saccadic tasks, worse position errors, and fewer numbers of self-paced saccades compared to normal volunteer subjects. Furthermore, the concussed group showed recruitment of additional brain regions and larger activation sites as evidenced by fMRI. As a potential diagnostic and management tool for concussion, oculomotor testing shows promise, and here we try to understand the reasons for this disrupted performance with the aide of advanced neuroimaging tools.

Increase in skin surface elasticity in normal volunteer subjects following the use of copper oxide impregnated socks.

Copper is an essential mineral involved in the formation and stabilisation of extracellular skin proteins. As copper can be absorbed through intact skin, we reasoned that using socks containing copper-impregnated fibres may have an effect on skin elasticity. A double blind, placebo controlled study was conducted in which one group of healthy volunteers (n = 32) wore socks with fibres containing microscopic copper oxide particles and the other group wore identical socks without copper oxide (n = 28). The socks were worn for at least 10 h a day for 4 weeks. Skin elasticity measurements were taken from three separate test sites on the side of the ankle using a Cutometer at baseline and after 2 and 4 weeks of product use. There was an increase in the mean net skin elasticity (R5) of 6.4% (P = 0.6) and 31.4% (P = 0.004) after 2 and 4 weeks respectively, in the group of individuals that used the copper oxide containing socks, but no increase in the group of individuals that used the control socks. Similarly, there was an increase in the mean biological elasticity (R7 values) of 3% (P = 0.55) and 20.7% (0.014) after 2 and 4 weeks, respectively, only in the group of individuals that used the copper oxide containing socks. The differences between treatments (i.e. socks used) were statistically significant at 4 weeks (P = 0.0058 and P = 0.0327 for R5 and R7, respectively). Using copper oxide containing socks results in an increase in skin elasticity of the feet.

A novel electrodiagnostic assessment of the laryngeal closure reflex

We describe a novel, clinically applicable conduction study of the laryngeal nerves. Seventeen normal volunteer subjects were included. Activation of the sensory territory of the superior laryngeal nerve was performed by administration of low level brief electrical stimuli. The laryngeal closure reflex (LCR) evoked by this stimulus was recorded by needle electrodes. Mean minimal latencies were calculated for each response, and proposed values for the upper limit of normal were determined. Uniform, consistent early ipsilateral responses and late bilateral responses, which exhibit greater variation in latency and morphology, were recorded. Significant side-to-side differences in latencies were observed, consistent with the length discrepancy between right and left recurrent laryngeal nerves. This technique yields clear, quantifiable data regarding neurologic integrity of laryngeal function, heretofore unobtainable in the clinical setting. This study may yield clinically relevant information regarding severity and prognosis in patients with laryngeal neuropathic injury.

Comparison of 24-hour urinary citrate excretion in stone formers and healthy volunteers.

Low urinary citrate excretion is a risk factor in stone formers (SF). This study aimed to measure the urinary citrate excretion in SF and healthy volunteers at our center from 12 June 2008 to 20 August 2009. There were 28 SF patients (18 males and ten females) and 27 (18 males and nine females) age-matched healthy adult volunteers who participated in this study. Both groups had a similar living environment, extrinsic factors, diet and genetic descent. After collecting 24-h urine, citrate was measured using an enzymatic kit. Routine urinalysis and 24-h creatinine and uric acid were also performed. There was a significant difference in urinary citrate excretion level among SF (mean 310, SD 260 mg/L) and normal volunteer subjects (mean 800, SD 300 mg/L). By applying the previously defined normal values (320 mg/24 h) of urinary citrate in the local population, 43% of the SF in our study group was hypocitric, and none among the controls. We conclude that prevalence of hypocitraturia in stone formers was higher than that in healthy volunteers in our population.

Surgery and Brain Atrophy in Cognitively Normal Elderly Subjects and Subjects Diagnosed with Mild Cognitive Impairment

Structural magnetic resonance imaging is used to longitudinally monitor the progression of Alzheimer disease from its presymptomatic to symptomatic phases. Using magnetic resonance imaging data from the Alzheimer's Disease Neuroimaging Initiative, we tested the hypothesis that surgery would impact brain parameters associated with progression of dementia. Brain images from the neuroimaging initiative database were used to study normal volunteer subjects and patients with mild cognitive impairment for the age group 55 to 90 inclusive. We compared changes in regional brain anatomy for three visits that defined two intervisit intervals for a surgical cohort (n = 41) and a propensity matched nonsurgical control cohort (n = 123). The first interval for the surgical cohort contained the surgical date. Regional brain volumes were determined with Freesurfer and quantitatively described with J-image software (University of California at San Francisco, San Francisco, California). Statistical analysis used Repeated Measures ANCOVA (SPSS, v.18.0; Chicago, IL). We found that surgical patients, during the first follow-up interval (5-9 months), but not subsequently, had increased rates of atrophy for cortical gray matter and hippocampus, and lateral ventricle enlargement, as compared with nonsurgical controls. A composite score of five cognitive tests during this interval showed reduced performance for surgical patients with mild cognitive impairment. Elderly subjects after surgery experienced an increased rate of brain atrophy during the initial evaluation interval, a time associated with enhanced risk for postoperative cognitive dysfunction. Although there was no difference in atrophy rate by diagnosis, subjects with mild cognitive impairment suffered greater subsequent cognitive effects.

Clinical and radiographic evaluation of the shoulder of spinal cord injured patients undergoing rehabilitation program

Clinical and radiographic evaluation of the shoulders of tetraplegic and paraplegic patients who attend rehabilitation program. The objective of this study is to establish the usefulness of radiography as a trial exam for shoulder pain in spinal cord injured patients. Hospital das Clinicas-UNICAMP. Campinas, Sao Paulo, Brazil. Thirty-two shoulders of 16 patients were evaluated by clinical exam and radiography. Patients were divided into two groups: paraplegic and tetraplegic. A control group of 16 normal volunteer subjects was selected. Shoulder pain was reported in 88.89% of tetraplegic and 42.85% of paraplegic. The time of injury ranged from 1.5-22 years (mean 7.88 years); patients had a mean age of 34.68 years (range, 21-57 years). The acromioclavicular joint (ACJ) space ranged from 0.03-0.7 cm on the right side and 0.15-0.7 cm on the left side, with a mean of 0.37 and 0.41 cm, respectively. No correlation was found between shoulder pain and gender, age or time since injury. There was a trend to correlation between shoulder pain and type of injury with tetraplegic having a tendency to pain symptoms. On average, tetraplegic had smaller ACJ. The small number of patients in this study did not allow us to confirm the hypothesis that X-ray finding may indicate risk for shoulder pain in spinal cord injury patients. A work with a greater number of subjects could demonstrate association between shoulder pain and the reduced acromioclavicular distance, making plain radiography a trial exam for spinal cord-injured patients.

Increased Nitric Oxide Concentrations in the Small Airway of Older Normal Subjects

There is a paucity of normal-age stratified data for fraction of exhaled nitric oxide (Feno). Our goal was to obtain normal data for large-airway nitric oxide flux (J'awno) and small-airway and/or alveolar nitric oxide concentration (Cano) in nonsmoking, healthy, adult subjects of various ages. In 106 normal volunteer subjects (60 women) aged 55 ± 20 years (mean ± SD), Feno (parts per billion [ppb]) was measured at 50, 100, 150, and 200 mL/s and J'awno (nL/s) and Cano (ppb) were calculated using a two-compartment model with correction for axial nitric oxide (NO) back diffusion. Fourteen older normal subjects were also treated with inhaled corticosteroid (540 μg budesonide bid) for 14 days. We studied 34 younger normal subjects (17 women) aged 18 to 39 years (younger), 26 middle-aged normal subjects (22 women) aged 40 to 59 years (middle-aged), and 46 older normal subjects (21 women) aged 60 to 86 years (older). Feno at 50 mL/s in the younger group was 21 (14-28) ppb (median, 1-3 interquartile); in the middle-aged group it was 22 (18-30) ppb, and in the older group it was 27 (21-33) ppb, (analysis of variance [ANOVA]) P = .02. For Feno, the younger vs older groups was (Mann-Whitney) P = .03, and Feno in the combined younger and middle-aged groups was 21 (15-29) ppb vs 27 (21-33) ppb, P = .006 for the older group. Corrected J'awno in the younger group was 1.5 (1.0-2.1) nL/s; in the middle-aged group it was 1.4 (1.0-2.0) nL/s, and in the older group it was 1.8 (1.2-2.4) nL/s, (ANOVA) P = .3. Corrected Cano in the younger group was 1.9 (0.8-3.0) ppb; in the middle-aged group it was 2.8 (0.8-5.1) ppb, and in the older group it was 3.9 (1.4-6.6) ppb, (ANOVA) P = .02. Cano in the younger vs older groups was P = .003, and the combined younger and middle-aged group result was 2.0 (0.8-3.8) vs 3.9 (1.4-6.6), P = .01 in the older group. There was no change in NO gas exchange with inhaled corticosteroids. In nonsmoking healthy subjects with normal spirometry, Feno at 50 mL/s and Cano increased significantly with age ≥ 60 years, whereas J'awno did not. We suspect the increase in Cano was due to a decrease in capillary blood volume with reduced NO diffusion, which is also reflected in increased Feno. Inhaled budesonide had no anti-NO-mediated inflammatory effect. Age-matched control subjects will be needed in NO comparative studies. ClinicalTrials.gov; No.: NCT00576069 and NCT00568347; URL: www.clinicaltrials.gov.

Phase 1 Clinical Testing of HQK-1001, a Novel Oral Fetal Globin Gene Inducer

Development of non-cytotoxic, orally-active therapeutics, which induce fetal globin production, would be beneficial for treatment of beta-thalassemias and hemoglobinopathies. The short-chain fatty acids (SCFA) butyrate and phenylbutyrate are active fetal globin inducers, but their clinical application has been limited by inhibition of erythropoiesis and unfavorable PK profiles. HQK-1001 is a SCFA which stimulates fetal globin gene expression in reporter gene assays, erythroid progenitors, transgenic mice, and anemic baboons. HQK-1001 also stimulates human erythroid progenitor (BFU-E) proliferation by a mean of 30% above controls, and increased red blood cell counts in phlebotomized baboons. HQK-1001 has demonstrated a wide safety margin in pre-clinical toxicology testing, with no significant adverse effects in sub-chronic (6-month) studies and negative mutagenicity testing. Based on these pre-clinical data, a placebo-controlled, randomized, blinded, single-dose escalating Phase 1 trial was conducted to evaluate HQK-1001 at 4 dose levels ranging from 2 to 20 mg/kg in 32 normal volunteers. The drug was welltolerated, with no significant adverse events. Pharmacokinetic analyses showed low intersubject variability, a linear increase in Cmax and AUC with increasing dose, and T½ of 11 hours, indicating suitability for once-daily dosing. Administration under fed conditions demonstrated equivalent AUC to fasting conditions. In a subsequent 14-day Phase 1 dosing study in 41 normal subjects, the drug was also well-tolerated, with no significant adverse effects at the studied dose levels (5, 10 and 15 mg/kg). F-reticulocytes increased in subjects treated with 5 to 10 mg/kg doses. Absolute reticulocytes increased significantly above baseline (p <0.02 – 0.002) following 14-day dosing at all dose levels, while no significant change occurred in placebo controls. These first-in-human clinical studies demonstrating safety of HQK-1001 in 73 normal volunteer subjects and an improved pharmacologic profile over prior SCFAs indicate that HQK-1001 merits further clinical investigation in anemic patients with beta-globin gene disorders.

Preliminary studies on the relationship among peel force, quantitative measures of skin damage and subjective discomfort

The ability to anticipate skin damage and subject/patient discomfort due to the removal of adhesive materials without human testing is currently limited. While standardized laboratory methods have been developed, their ability to model and predict the interaction with relevant living substrate is imperfect. The aim of this study was to assess the adhesion of various materials as a function of time using the abdomen as the body site, and determine if a relationship existed with skin damage and subject discomfort. Strips of six different materials used in medical devices and known to have different adhesive properties in the laboratory setting were tested in this study. The strips were adhered to the abdomens of normal volunteer subjects for varying periods of time. Peel force was measured under conditions developed to lessen the influence of skin elasticity. Disturbance of the skin barrier was assessed by measuring transepidermal water loss; erythema by reflectance L*a*b* measurements; skin cells removal by quantitation of dyed cells adhering to the test strips; and discomfort using subject self-assessment. When measured at times from 30 min to 72 h after application, the peel force was highest for materials at 30 min. The peel force for one of the six materials, designated F, was clearly higher than the others at time points from 30 min to 48 h after application. Interestingly, this material caused less disruption to the skin barrier and was reported to cause less discomfort. In this system, there was not a correspondence between adhesion as measured by peel force and skin damage or self-report of discomfort. Further investigations will be required to establish the predictive value of other biophysical measurements and discomfort.

Objective and Subjective Measurements of Cutaneous Inflammation after a Novel Hyaluronic Acid Injection

Hyaluronic acid (HA) dermal fillers are commonly used to minimize the appearance of facial lines and wrinkles. However, after the injection of HA, there is normally a mild inflammatory reaction. All published studies to date have measured this unwanted side effect by subjective means only. The primary objective was to determine the magnitude and duration of the inflammation induced by injection of a novel HA using objective and subjective means. The study was an open study in 25 normal volunteer subjects. All subjects had a single injection and were assessed objectively using an erythema meter and infrared thermometer and subjectively using established clinical scales. The erythema meter and the infrared thermometer objectively measured the mild cutaneous inflammation, which was transitory in nature. These objective measurements correlated well with the subjective clinical scores. The results of this study show that the erythema meter and the infrared thermometer are effective tools to objectively measure mild inflammation post-HA injection.

Objective and Subjective Measurements of Cutaneous Inflammation after a Novel Hyaluronic Acid Injection

BACKGROUND Hyaluronic acid (HA) dermal fillers are commonly used to minimize the appearance of facial lines and wrinkles. However, after the injection of HA, there is normally a mild inflammatory reaction. All published studies to date have measured this unwanted side effect by subjective means only. OBJECTIVE The primary objective was to determine the magnitude and duration of the inflammation induced by injection of a novel HA using objective and subjective means. MATERIALS AND METHODS The study was an open study in 25 normal volunteer subjects. All subjects had a single injection and were assessed objectively using an erythema meter and infrared thermometer and subjectively using established clinical scales. RESULTS The erythema meter and the infrared thermometer objectively measured the mild cutaneous inflammation, which was transitory in nature. These objective measurements correlated well with the subjective clinical scores. CONCLUSIONS The results of this study show that the erythema meter and the infrared thermometer are effective tools to objectively measure mild inflammation post-HA injection.