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BACKGROUND: Use of artificial intelligence (AI), or machine learning, to assess dermoscopic images of skin lesions to detect melanoma has, in several retrospective studies, shown high levels of diagnostic accuracy on par with - or even outperforming - experienced dermatologists. However, the enthusiasm around these algorithms has not yet been matched by prospective clinical trials performed in authentic clinical settings. In several European countries, including Sweden, the initial clinical assessment of suspected skin cancer is principally conducted in the primary healthcare setting by primary care physicians, with or without access to teledermoscopic support from dermatology clinics. OBJECTIVES: To determine the diagnostic performance of an AI-based clinical decision support tool for cutaneous melanoma detection, operated by a smartphone application (app), when used prospectively by primary care physicians to assess skin lesions of concern due to some degree of melanoma suspicion. METHODS: This prospective multicentre clinical trial was conducted at 36 primary care centres in Sweden. Physicians used the smartphone app on skin lesions of concern by photographing them dermoscopically, which resulted in a dichotomous decision support text regarding evidence for melanoma. Regardless of the app outcome, all lesions underwent standard diagnostic procedures (surgical excision or referral to a dermatologist). After investigations were complete, lesion diagnoses were collected from the patients' medical records and compared with the app's outcome and other lesion data. RESULTS: In total, 253 lesions of concern in 228 patients were included, of which 21 proved to be melanomas, with 11 thin invasive melanomas and 10 melanomas in situ. The app's accuracy in identifying melanomas was reflected in an area under the receiver operating characteristic (AUROC) curve of 0.960 [95% confidence interval (CI) 0.928-0.980], corresponding to a maximum sensitivity and specificity of 95.2% and 84.5%, respectively. For invasive melanomas alone, the AUROC was 0.988 (95% CI 0.965-0.997), corresponding to a maximum sensitivity and specificity of 100% and 92.6%, respectively. CONCLUSIONS: The clinical decision support tool evaluated in this investigation showed high diagnostic accuracy when used prospectively in primary care patients, which could add significant clinical value for primary care physicians assessing skin lesions for melanoma.
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Intelligence artificielle , Dermoscopie , Mélanome , Applications mobiles , Soins de santé primaires , Tumeurs cutanées , Ordiphone , Humains , Mélanome/diagnostic , Mélanome/anatomopathologie , Tumeurs cutanées/diagnostic , Tumeurs cutanées/anatomopathologie , Tumeurs cutanées/imagerie diagnostique , Études prospectives , Femelle , Mâle , Adulte d'âge moyen , Sujet âgé , Adulte , Systèmes d'aide à la décision clinique , Suède , Sensibilité et spécificitéRÉSUMÉ
SwedAD, a Swedish nationwide registry for patients with atopic dermatitis receiving systemic pharmacotherapy, was launched on 1 September 2019. We describe here the establishment of a user-friendly registry to the benefit of patients with atopic dermatitis. By 5 November 2022, 38 clinics had recorded 931 treatment episodes in 850 patients with an approximate national coverage rate of 40%. Characteristics at enrolment included median Eczema Area and Severity Index (EASI) 10.2 (interquartile range 4.0, 19.4), Patient-Oriented Eczema Measure (POEM) 18.0 (10.0, 24.0), Dermatology Life Quality Index (DLQI) 11.0 (5.0, 19.0) and Peak Itch Numerical Rating Scale-11 (NRS-11) 6.0 (3.0, 8.0). At 3 months, median EASI was 3.2 (1.0, 7.3) and POEM, DLQI, and NRS-11 were improved. Regional coverage varied, reflecting the distribution of dermatologists, the ratio of public to private healthcare, and difficulties in recruiting certain clinics. This study highlights the importance of a nationwide registry when managing systemic pharmacotherapy of atopic dermatitis.
Sujet(s)
Eczéma atopique , Eczéma , Humains , Eczéma atopique/traitement médicamenteux , Suède , Indice de gravité de la maladie , Enregistrements , Qualité de vieRÉSUMÉ
This non-interventional, observational, longitudinal study describes treatment patterns of atopic dermatitis (AD) in Sweden. Data from 3 Swedish registries were merged, and included patients who received an AD diagnosis (during the period 1997 to 2019) and had AD treatment prescribed (during the period 2006 to 2020). Treatment persistence, treatment sequencing, time-to-event analysis, and 12-month prevalence were analysed. Overall, data for 99,885 patients with AD were included, of whom 4,086 (4.1%) received systemic treatments. Median persistence rates were 12.6 (95% CI 11.9, 13.4) months for methotrexate, 10.8 (9.1, 13.0) months for azathioprine, 5.6 (3.8, 6.2) months for mycophenolate, 5.1 (4.4, 5.7) months for alitretinoin and 3.4 (3.2, 3.7) months for cyclosporine. Median (Q1, Q3) time from first secondary care visit for AD to first systemic treatment was 5.8 (2.2, 11.0) years overall and 4.4 (1.3, 9.1) years in the Stockholm region. Methotrexate was a prominent first- and second-line treatment used during the period 2006 to 2020. Dupilumab was introduced during the study period and was increasingly used as first- or second-line therapy over time. The 12-month prevalence of AD generally remained steady, with a gradual increase observed over time for the overall population. A steep increase was observed in Stockholm from 2011. This study shows that a small proportion of patients with AD are offered systemic treatments in Sweden, with long periods in secondary care prior to systemic treatments and low persistence on systemic treatments. Regional differences highlight a need for national treatment guidelines.
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Eczéma atopique , Eczéma atopique/diagnostic , Eczéma atopique/traitement médicamenteux , Eczéma atopique/épidémiologie , Humains , Études longitudinales , Méthotrexate/usage thérapeutique , Études rétrospectives , Soins secondaires , Suède/épidémiologieRÉSUMÉ
Monitoring of low-molecular weight cancer biomarkers, such as tryptophan (Trp) and its derivative kynurenine (Kyn), might be advantageous to non-invasive skin cancer detection. Thus, we assessed several approaches of topical sampling of Trp and Kyn, in relation to phenylalanine (Phe) and tyrosine (Tyr), on the volar forearm of six healthy volunteers. The sampling was performed with three hydrogels (made of agarose or/and chitosan), hydrated starch films, cotton swabs, and tape stripping. The biomarkers were successfully sampled by all approaches, but the amount of collected Kyn was low, 20 ± 10 pmol/cm2. Kyn quantification was below LOQ, and thus, it was detected only in 20% of topical samples. To mitigate variability problems of absolute amounts of sampled amino acids, Tyr/Trp, Phe/Trp, and Phe/Tyr ratios were assessed, proving reduced inter-individual variation from 79 to 45% and intra-individual variation from 42 to 21%. Strong positive correlation was found between Phe and Trp, pointing to the Phe/Trp ratio (being in the 1.0-2.0 range, at 95% confidence) being least dependent on sampling materials, approaches, and sweating. This study leads to conclusion that due to the difficulty in quantifying less abundant Kyn, and thus the Trp/Kyn ratio, the Phe/Trp ratio might be a possible, alternative biomarker for detecting skin cancers.
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Marqueurs biologiques tumoraux , Tumeurs cutanées , Marqueurs biologiques , Volontaires sains , Humains , Cynurénine/métabolisme , Masse moléculaire , Phénylalanine , Tumeurs cutanées/diagnostic , Tryptophane/métabolisme , TyrosineRÉSUMÉ
The high-density microneedle array patch (HD-MAP) is a promising alternative vaccine delivery system device with broad application in disease, including SARS-CoV-2. Skin reactivity to HD-MAP applications has been extensively studied in young individuals, but not in the >65 years population, a risk group often requiring higher dose vaccines to produce protective immune responses. The primary aims of the present study were to characterise local inflammatory responses and barrier recovery to HD-MAPs in elderly skin. In twelve volunteers aged 69−84 years, HD-MAPs were applied to the forearm and deltoid regions. Measurements of transepidermal water loss (TEWL), dielectric permittivity and erythema were performed before and after HD-MAP application at t = 10 min, 30 min, 48 h, and 7 days. At all sites, TEWL (barrier damage), dielectric permittivity (superficial water);, and erythema measurements rapidly increased after HD-MAP application. After 7 days, the mean measures had recovered toward pre-application values. The fact that the degree and chronology of skin reactivity and recovery after HD-MAP was similar in elderly skin to that previously reported in younger adults suggests that the reactivity basis for physical immune enhancement observed in younger adults will also be achievable in the older population.
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The molecular composition of human skin is altered due to diseases, which can be utilized for non-invasive sampling of biomarkers and disease diagnostics. For this to succeed, it is crucial to identify a sampling formulation with high extraction efficiency and reproducibility. Highly hydrated skin is expected to be optimal for increased diffusion of low-molecular-weight biomarkers, enabling efficient extraction as well as enhanced reproducibility as full hydration represents a well-defined endpoint. Here, the aim was to explore water-based formulations with high water activities, ensuring satisfactory skin hydration, for non-invasive sampling of four analytes that may serve as potential biomarkers, namely tryptophan, tyrosine, phenylalanine, and kynurenine. The included formulations consisted of two hydrogels (chitosan and agarose) and two different liquid crystalline cubic phases based on the polar lipid glycerol monooleate, which were all topically applied for 2 h on 35 healthy subjects in vivo. The skin status of all sampling sites was assessed by electrical impedance spectroscopy and transepidermal water loss, enabling explorative correlations between biophysical properties and analyte abundancies. Taken together, all formulations resulted in the successful and reproducible collection of the investigated biomarkers. Still, the cubic phases had an extraction capacity that was approximately two times higher compared to the hydrogels.
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The AWARE (A World-wide Antihistamine-Refractory chronic urticaria patient Evaluation) study investigated outcomes in patients with chronic urticaria refractory to H1-antihistamine. The objective of the current study was to analyse the effects of treatment on patients' symptoms and quality of life for a period of up to 2 years. Over the 2 years, there was clear improvement in the high rates of disease burden from baseline, as evidenced by lower scores for disease severity scales, better quality of life, and a decreasing rate of medical resource utilization. However, this is the result of treatment adherence to the guidelines in highly specialized Scandinavian urticaria centres, and has its basis in the relatively low treatment intensity and control at enrolment. There is a need for greater adherence to the treatment guidelines and better management of antihistamine-refractory chronic urticaria.
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Urticaire chronique , Urticaire , Maladie chronique , Urticaire chronique/diagnostic , Urticaire chronique/traitement médicamenteux , Études de suivi , Antihistaminiques des récepteurs H1/effets indésirables , Humains , Qualité de vie , Urticaire/induit chimiquement , Urticaire/diagnostic , Urticaire/traitement médicamenteuxRÉSUMÉ
SIGNIFICANCE: Tissue simulating phantoms are an important part of validating biomedical optical techniques. Tissue pathology in inflammation and oedema involves changes in both water and hemoglobin fractions. AIM: We present a method to create solid gelatin-based phantoms mimicking inflammation and oedema with adjustable water and hemoglobin fractions. APPROACH: One store-bought gelatin and one research grade gelatin were evaluated. Different water fractions were obtained by varying the water-to-gelatin ratio. Ferrous stabilized human hemoglobin or whole human blood was added as absorbers, and the stability and characteristics of each were compared. Intralipid® was used as the scatterer. All phantoms were characterized using spatial frequency domain spectroscopy. RESULTS: The estimated water fraction varied linearly with expected values (R2 = 0.96 for the store-bought gelatin and R2 = 0.99 for the research grade gelatin). Phantoms including ferrous stabilized hemoglobin stayed stable up to one day but had methemoglobin present at day 0. The phantoms with whole blood remained stable up to 3 days using the store-bought gelatin. CONCLUSIONS: A range of physiological relevant water fractions was obtained for both gelatin types, with the stability of the phantoms including hemoglobin differing between the gelatin type and hemoglobin preparation. These low-cost phantoms can incorporate other water-based chromophores and be fabricated as thin sheets to form multilayered structures.
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Gélatine , Eau , Gélatine/composition chimique , Hémoglobines , Humains , Inflammation , Microdialyse , Fantômes en imagerieRÉSUMÉ
BACKGROUND: The high-density microarray patch (HD-MAP) promises to be a robust vaccination platform with clear advantages for future global societal demands for health care management. The method of action has its base not only in efficient delivery of vaccine but also in the reliable induction of a local innate physical inflammatory response to adjuvant the vaccination process. The application process needs to induce levels of reactivity, which are acceptable to the vaccine, and from which the skin promptly recovers. MATERIALS AND METHODS: 1 × 1 cm HD-MAP patches containing 5000, 250-µm long microprojections were applied to the skin in 12 healthy volunteers. The return of skin barrier function was assessed by transepidermal water loss (TEWL) and reaction to topical histamine challenge. RESULTS: Skin barrier recovery by 48 h was confirmed for all HD-MAP sites by recovered resistance to the effects of topical histamine application. CONCLUSIONS: Our previous observation, that the barrier disruption indicator TEWL returns to normal by 48 h, is supported by this paper's demonstration of return of skin resistance to topical histamine challenge in twelve healthy subjects.
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Peau , Perte insensible en eau , Volontaires sains , Humains , Ponctions , Vaccination , Perte insensible en eau/physiologieRÉSUMÉ
Borrelia-specific antibodies in serum did not contribute to the diagnosis of Borrelia arthritis or Borrelia-associated dermatitis in a young woman with ongoing treatment with rituximab due to multiple sclerosis. The diagnosis was confirmed by the detection of Borrelia-DNA in a skin punch biopsy. The patient history did not reveal any tick exposure. She had suffered for several months from fluctuating pain and swelling of the right knee as well as skin involvement with redness and oedema around the ankle of the same leg. Monoarthritis was confirmed by a rheumatologist. Knee puncture was performed but the synovial fluid was only sufficient for microscopic examination of crystals. Neither monosodium urate crystals nor calcium pyrophosphate crystals were found. Borrelia serology in blood revealed borderline levels of immunoglobulin (Ig)M and IgG, respectively. Treatment with doxycycline resulted in resolution of the joint and skin manifestations within a month. This case highlights that Borrelia-specific antibody levels cannot be reliably interpreted in patients who have received B-cell depleting therapy. Under these circumstances, detection of the bacterial genome in different body fluids, such as in the skin, can be a useful complement to the diagnosis of Lyme disease. In this young female, the diagnosis would certainly have been further delayed without the detection of Borrelia-DNA in the skin.
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BACKGROUND: The efficiency of transdermal drug delivery may be increased by pretreating the skin with microneedles, but distinct effects of microneedles and the microneedle-enhanced delivery of vasoactive drugs on the skin microvasculature are still not well investigated. MATERIALS AND METHODS: In eight healthy human subjects, we measured the microvascular response to microneedle-induced microtraumas in the skin microvasculature using polarized light spectroscopy imaging (Tissue Viability imaging, TiVi). The microvascular response was assessed for up to 48 hours for three microneedle sizes (300 µm, 500 µm, and 750 µm) and for different pressures and application times. RESULTS: In our results, microneedle application increased the local red blood cell (RBC) concentration for up to 24 hours dependent on the needle lengths, applied time, and force. CONCLUSION: Optimization of microneedles size, pressure, and application time should be taken into account for future protocols for drug delivery and experimental provocations.
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Aiguilles , Absorption cutanée , Administration par voie cutanée , Systèmes de délivrance de médicaments , Humains , Peau/métabolismeRÉSUMÉ
The development of microarray patches for vaccine application has the potential to revolutionise vaccine delivery. Microarray patches (MAP) reduce risks of needle stick injury, do not require reconstitution and have the potential to enhance immune responses using a fractional vaccine dose. To date, the majority of research has focused on vaccine delivery with little characterisation of local skin response and recovery. Here we study in detail the immediate local skin response and recovery of the skin post high density MAP application in 12 individuals receiving 3 MAPs randomly assigned to the forearm and upper arm. Responses were characterised by clinical scoring, dermatoscopy, evaporimetry and tissue viability imaging (TiVi). MAP application resulted in punctures in the epidermis, a significant transepidermal water loss (TEWL), the peak TEWL being concomitant with peak erythema responses visualised by TiVi. TEWL and TiVi responses reduced over time, with TEWL returning to baseline by 48 h and erythema fading over the course of a 7 day period. As MAPs for vaccination move into larger clinical studies more variation of individual subject phenotypic or disease propensity will be encountered which will require consideration both in regard to reliability of dose delivery and degree of inherent skin response.
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Épiderme , Érythème , Patch transdermique/effets indésirables , Vaccination/effets indésirables , Vaccins , Adolescent , Adulte , Sujet âgé , Épiderme/immunologie , Épiderme/anatomopathologie , Érythème/étiologie , Érythème/immunologie , Érythème/anatomopathologie , Humains , Mâle , Adulte d'âge moyen , Vaccins/administration et posologie , Vaccins/immunologieRÉSUMÉ
Actinic keratosis is the most common actinic lesion in fair-skinned populations. It is accepted as an indicator of actinic skin damage and as an occasional precursor of squamous cell carcinoma. The aim of this study was to investigate, in a cohort of patients with a diagnosis of actinic keratosis, the relative risk of developing skin cancer during a follow-up period of 10 years. This registry-based cohort study compared a cohort of 2,893 individuals in south-eastern Sweden, who were diagnosed with actinic keratosis during the period 2000 to 2004, with a matched-control cohort of 14,668 individuals without actinic keratosis during the same inclusion period. The subjects were followed for 10 years to identify skin cancer development in both cohorts. Hazard ratios with 95% confidence intervals (95% CI) were used as risk measures. Individuals in the actinic keratosis cohort had a markedly higher risk for all skin cancer forms compared with the control cohort (hazard ratio (HR) 5.1, 95% CI 4.7-5.6). The relative risk was highest for developing squamous cell carcinoma (SCC) (HR 7.7, 95% CI 6.7-8.8) and somewhat lower for basal cell carcinoma (BCC) (HR 4.4, 95% CI 4.1-5.0) and malignant melanoma (MM) (HR 2.7 (2.1-3.6). Patients with a diagnosis of actinic keratosis were found to be at increased risk of developing SCC, BCC and MM in the 10 years following diagnosis of actinic keratosis. In conclusion, a diagnosis of actinic keratosis, even in the absence of documentation of other features of chronic sun exposure, is a marker of increased risk of skin cancer, which should be addressed with individually directed preventive advice.
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Carcinome basocellulaire/épidémiologie , Carcinome épidermoïde/épidémiologie , Kératose actinique/diagnostic , Mélanome/épidémiologie , Tumeurs cutanées/épidémiologie , Sujet âgé , Sujet âgé de 80 ans ou plus , Études cas-témoins , Femelle , Études de suivi , Humains , Incidence , Mâle , Adulte d'âge moyen , Enregistrements , Facteurs de risque , Suède/épidémiologieRÉSUMÉ
BACKGROUND: Hyaluronic acid (HA), a large glycosaminoglycan involved in proliferation, migration, and tissue repair, is suggested to be an important factor for keratinocyte activation and re-epithelialization. The experimental hypothesis of this study was that HA accelerates re-epithelialization, and we aimed to investigate the effect of exogenous intradermal HA during deep dermal, incisional wound healing in vivo in humans, the primary endpoint being re-epithelialization. METHODS: A total of 8 standardized deep dermal incisional wounds (depth 1.6 mm, width 1.8 mm) per subject were induced in 10 healthy volunteers. Two of the wound sites per subject were pretreated with injections of HA and 2 with saline solution. At 2 time points (24 hours and 14 days), 2 biopsies for each treatment group (one for histology and one for proteomics) were taken. Skin erythema was measured at 24-hour intervals for 14 days as a surrogate measurement of inflammation. RESULTS: At 24 hours, 8 of 9 wounds pretreated with HA showed complete re-epithelization, whereas none of the wounds pretreated with saline had re-epithelized. Wounds pretreated with HA also showed a 10-fold regulation of 8 identified proteins involved in wound healing compared to wounds treated with saline solution. No difference in inflammation, as measured as erythema, could be seen between any of the groups. CONCLUSIONS: We conclude that HA accelerates re-epithelialization and stimulates an altered protein expression in vivo in human deep dermal incisional skin wounds, but has no effect on the inflammation process as measured by erythema.
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BACKGROUND: In the light of increasing skin cancer incidences worldwide, preventive measures to promote sun protection in individuals with risky sun habits have continued relevance and importance. AIM: To report the long-term effect of individualised sun protection advice given in primary health care (PHC), on sun habits and sun protection behaviour. DESIGN & SETTING: In 2005, 309 PHC patients were enrolled in a randomised controlled study performed in a Swedish PHC setting. METHOD: At baseline, the study participants completed a Likert scale-based questionnaire, mapping sun habits, propensity to increase sun protection, and attitudes towards sun exposure, followed by randomisation into three intervention groups, all receiving individualised sun protection advice: in Group 1 (n = 116) by means of a letter, and in Group 2 (n = 97) and 3 (n = 96) communicated personally by a GP. In Group 3, participants also underwent a skin ultraviolet-sensitivity phototest, with adjusted sun protection advice based on the result. A repeated questionnaire was administered after 3 and 10 years. RESULTS: Statistically significant declines were observed in all groups for sun exposure mean scores over time. When using a cumulative score, according to the Sun Exposure and Protection Index (SEPI), significantly greater decrease in SEPI mean score was observed in Groups 2 and 3 (GP), compared to Group 1 (letter); P<0.01. The addition of a phototest did not enhance the effect of the intervention. CONCLUSION: Individualised sun protection advice mediated verbally by the GP can lead to sustained improvement of sun protective behaviour.
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BACKGROUND: Capillary refill (CR) time is traditionally assessed by 'naked-eye' inspection of the return to original colour of a tissue after blanching pressure. Few studies have addressed intra-observer reliability or used objective quantification techniques to assess time to original colour. This study compares naked-eye assessment with quantified CR (qCR) time using polarisation spectroscopy and examines intra-observer and interobserver agreements in using the naked eye. METHOD: A film of 18 CR tests (shown in a random fixed order) performed in healthy adults was assessed by a convenience sample of 14 doctors, 15 nurses and 19 secretaries (Department of Emergency Medicine, Linköping University, September to November 2017), who were asked to estimate the time to return to colour and characterise it as 'fast', 'normal' or 'slow'. The qCR times and corresponding naked-eye time assessments were compared using the Kruskal-Wallis test. Three videos were shown twice without observers' knowledge to measure intra-observer repeatability. Intra-observer categorical assessments were compared using Cohen's Kappa analysis. Interobserver repeatability was measured and depicted with multiple-observer Bland-Altman plotting. Differences in naked-eye estimation between professions were analysed using ANOVA. RESULTS: Naked-eye assessed CR time and qCR time differ substantially, and agreement for the categorical assessments (naked-eye assessment vs qCR classification) was poor (Cohen's kappa 0.27). Bland-Altman intra-observer repeatability ranged from 6% to 60%. Interobserver agreement was low as shown by the Bland-Altman plotting with a 95% limit of agreement with the mean of ±1.98 s for doctors, ±1.6 s for nurses and ±1.75 s for secretaries. The difference in CR time estimation (in seconds) between professions was not significant. CONCLUSIONS: Our study suggests that naked-eye-assessed CR time shows poor reproducibility, even by the same observers, and differs from an objective measure of CR time.
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Action capillaire , Biais de l'observateur , Statistiques comme sujet/normes , Analyse de variance , Compétence clinique/normes , Compétence clinique/statistiques et données numériques , Volontaires sains/statistiques et données numériques , Hémodynamique/physiologie , Humains , Reproductibilité des résultats , Statistiques comme sujet/méthodes , SuèdeSujet(s)
Interventions chirurgicales de cytoréduction , Hyperthermie provoquée , Tumeurs du rein/thérapie , Tumeurs du péritoine/thérapie , Canaux de Wolff/anatomopathologie , Antinéoplasiques immunologiques/usage thérapeutique , Bévacizumab/usage thérapeutique , Femelle , Humains , Adulte d'âge moyen , Résultat thérapeutiqueRÉSUMÉ
Skin microdialysis (SMD) is a versatile sampling technique that can be used to recover soluble endogenous and exogenous molecules from the extracellular compartment of human skin. Due to its minimally invasive character, SMD can be applied in both clinical and preclinical settings. Despite being available since the 1990s, the technique has still not reached its full potential use as a tool to explore pathophysiological mechanisms of allergic and inflammatory reactions in the skin. Therefore, an EAACI Task Force on SMD was formed to disseminate knowledge about the technique and its many applications. This position paper from the task force provides an overview of the current use of SMD in the investigation of the pathogenesis of chronic inflammatory skin diseases, such as atopic dermatitis, chronic urticaria, psoriasis, and in studies of cutaneous events during type 1 hypersensitivity reactions. Furthermore, this paper covers drug hypersensitivity, UVB-induced- and neurogenic inflammation, and drug penetration investigated by SMD. The aim of this paper is to encourage the use of SMD and to make the technique easily accessible by providing an overview of methodology and applications, supported by standardized operating procedures for SMD in vivo and ex vivo.
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OBJECTIVE: To describe the effect of low ambient temperature on skin temperature and capillary refill (CR) time in forehead, sternum and finger pulp. METHODS: An observational, nonrandomized experimental study on 15 healthy subjects (6 females) in a cold room (8°C). Outcome measures were skin temperature and quantified CR test after application of a standardized blanching pressure (9 N/cm2 ) using digital photographic polarization spectroscopy to generate CR times. RESULTS: The finger pulp showed marked temperature fall and prolonged CR times (>10 seconds). The CR registrations of the forehead and sternum were more comparable to curves observed in a control material at room temperature, and skin temperature falls were less marked. CR times were not prolonged in forehead measurements. At the sternum, some individuals showed CR times beyond guideline recommendations despite only a marginal reduction in skin temperature. CONCLUSIONS: Low ambient temperature is a strong independent factor for CR time at peripheral sites. Reservation about sternum as a site of measurement is warranted since cold provocation produced prolonged CR times in some individuals. We found that the forehead is the most thermostable of the 3 sites and thus the preferred site to avoid ambient temperature artifact in measuring CR time.
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Vaisseaux capillaires/physiologie , Température cutanée , Température , Adulte , Sujet âgé , Femelle , Doigts/vascularisation , Front/vascularisation , Humains , Cinétique , Mâle , Adulte d'âge moyen , Sternum/vascularisationRÉSUMÉ
To use Bioengineering methodology is used to achieve, at five anatomical sites, a detailed, quantitative assessment of the return of blood content to the blanched area, during the Capillary Refill (CR) test. An observational, non-randomized, experimental study on 23 healthy subjects (14 females) was performed in our climate controlled skin physiology laboratory. Our main outcome measures were based on the chronological assessment and quantification of red blood cell concentration (RBC) after the release of blanching pressure in the CR test, using Tissue Viability Imaging (TiVi), a digital photographic technique based on polarisation spectroscopy. TiVi enabled collection of detailed data on skin RBC concentration during the CR test. The results were shown as curves with skin blood concentration (TiVi-value) on the y-axis and the time on the x-axis. Quantitative CR responses showed site and temperature variability. We also suggest possible objective endpoint values from the capillary refill curve. Detailed data on skin RBC concentration during the CR test is easily obtained and allows objective determination of end points not possible to achieve by naked eye assessment. These findings have the potential to place the utility of the CR test in a clinical setting in a new light. Picture: Regular photograph and TiVi Image showing CR test and corresponding graph for the CR response.