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Allergy May 2024p-Phenylenediamine (PPD) is a potent contact allergen found in many hair colour products. However, not all individuals develop allergic contact dermatitis (ACD) although...
BACKGROUND
p-Phenylenediamine (PPD) is a potent contact allergen found in many hair colour products. However, not all individuals develop allergic contact dermatitis (ACD) although they are regularly exposed to PPD. It is unclear whether these asymptomatic individuals are true non-responders to PPD or whether they mount a response to PPD without showing any symptoms.
METHODS
Skin biopsies were collected from 11 asymptomatic hairdressers regularly exposed to PPD and from 10 individuals with known ACD on day 4 after patch testing with 1% PPD in petrolatum and petrolatum exclusively as control. RNA sequencing and confocal microscopy were performed.
RESULTS
T cell activation, inflammation and apoptosis pathways were up-regulated by PPD in both asymptomatic and allergic individuals. Compared to asymptomatic individuals with a negative patch test, individuals with a strong reaction to PPD strongly up-regulated both pro- and anti-inflammatory cytokines genes. Interestingly, PPD treatment induced significant up-regulation of several genes for chemokines, classical type 2 dendritic cell markers and regulatory T cell markers in both asymptomatic and allergic individuals. In addition, apoptosis signalling pathway was activated in both non-responders and allergic individuals.
CONCLUSION
This study demonstrates that there are no true non-responders to PPD but that the immune response elicited by PPD differs between individuals and can lead to either tolerance, subclinical inflammation or allergy.
Topics: Humans; Phenylenediamines; Dermatitis, Allergic Contact; Skin; Male; Adult; Female; Gene Expression Regulation; Immune Tolerance; Cytokines; Allergens; Middle Aged; Hair Dyes; Young Adult; Patch Tests; Apoptosis
PubMed: 38263750
DOI: 10.1111/all.16031 -
International Journal of Pharmaceutics Mar 2024The targeted choice of the emollient of a cream determines its physicochemical properties and clinical effectiveness. This work researched the effects of emollient...
The targeted choice of the emollient of a cream determines its physicochemical properties and clinical effectiveness. This work researched the effects of emollient properties on the final characteristics and potential performance of oil-in-water dermatological creams. Seven emollients with different chemical characteristics and structures (alkane, triglyceride, ether, silicone, vegetable oils, and mineral oil) were tested in a model formulation. Early stability, pH, droplet size distribution, rheology, tackiness, adhesivity, spreadability, tribology, and release profile of a lipophilic substance model (in Franz cells, through a synthetic membrane, for six hours) were assessed. The creams had acid epicutaneous pH and a "shear-thinning" "solid-like" viscoelastic behavior. Among the seven emollients' properties, polarity, density, and viscosity were the most influential. Droplet parameters were the most impacted, pH and release were moderately affected, and the textural properties were lowly to moderately impacted. The emollient substitution in the model formulation affected the experimental parameters differently, allowing formulation optimization and tailoring its potential therapeutic performance regarding drug release, coadjutant effects, and dwell time on the skin. By looking at the creams' characteristics, it was possible to select the best-suited emollients for releasing a lipophilic drug, applying on painful skin, and formulation in wash-off products or leave-on protective barrier creams.
Topics: Emollients; Mineral Oil; Plant Oils; Skin; Rheology
PubMed: 38253270
DOI: 10.1016/j.ijpharm.2024.123825 -
Journal of Chromatography. A Jan 2024An automated implementation for a subfractionation of mineral oil aromatic hydrocarbons (MOAH) into a mono-/di-aromatic fraction (MDAF) and a tri-/poly-aromatic fraction...
Advanced separation of mineral oil aromatic hydrocarbons by number of aromatic rings using donor-acceptor-complex chromatography to extend on-line coupled liquid chromatography-gas chromatography.
An automated implementation for a subfractionation of mineral oil aromatic hydrocarbons (MOAH) into a mono-/di-aromatic fraction (MDAF) and a tri-/poly-aromatic fraction (TPAF) is presented, which is highly demanded by the European Food Safety Authority (EFSA) respecting the genotoxic and carcinogenic potential of MOAH. For this, donor-acceptor-complex chromatography (DACC) was used as a selective stationary phase to extend the conventional instrumental setup for the analysis of mineral oil hydrocarbons via on-line coupled liquid chromatography-gas chromatography-flame ionization detection (LC-GC-FID). A set of six new internal standards was introduced for the verification of the MOAH fractionation and a quantification of MDAF and TPAF, respectively. The automated DACC approach was applied to representative petrochemical references as well as to food samples, such as rice and infant formula, generally showing well conformity with results obtained by state-of-the-art analysis using two-dimensional GC (GCxGC). Relative deviations of DACC/LC-GC-FID compared to GCxGC-FID methods regarding the ≥ 3 ring MOAH content ranged between -50 and +6 % (median: -2 %, all samples, only values above limit of quantification). However, crucial deviations mainly result from "border-crossing" substances, e.g., dibenzothiophenes or partially hydrogenated MOAH. These substances can cause overestimations of ≥ 3 ring MOAH fraction during GCxGC analysis due to co-elution, which is mostly avoided using the DACC approach. Furthermore, the DACC approach can help to minimize underestimations of toxicologically relevant ≥ 3 ring MOAH caused by an unavoidable loss of MOAH during epoxidation, since natural olefins, such as terpenes, predominantly elute in MDAF, which was exemplarily shown for an olive oil and a terpene reference. The presented approach can be implemented easily in existing LC-GC-FID setup for an automated and advanced screening of MOAH to lower the need for elaborate GCxGC analysis also in routine environments.
Topics: Humans; Mineral Oil; Food Contamination; Hydrocarbons, Aromatic; Chromatography, Gas; Chromatography, Liquid; Hydrocarbons; Terpenes
PubMed: 38176352
DOI: 10.1016/j.chroma.2023.464600 -
Chemical Senses Jan 2024Although studies have shown that olfaction may contribute to the perception of tastant, literature is scarce or circumstantial, especially in humans. This study aims to...
Although studies have shown that olfaction may contribute to the perception of tastant, literature is scarce or circumstantial, especially in humans. This study aims to (i) explore whether humans can perceive solutions of basic prototypical tastants through orthonasal and retronasal olfaction and (ii) to examine what volatile odor compounds (VOCs) underlie this ability. Solutions of 5 basic tastants (sucrose, sodium chloride, citric acid, monosodium glutamate [MSG], quinine) dissolved in water, and 2 fatty acids (oleic and linoleic acid) dissolved in mineral oil were prepared. Triangle discrimination tests were performed (n = 41 in duplicate) to assess whether the tastant solutions can be distinguished from blanks (solvents) through ortho- and retronasal olfaction. Participants were able to distinguish all tastant solutions from blank through orthonasal olfaction. Only sucrose, sodium chloride, oleic acid, and linoleic acid were distinguished from blank by retronasal olfaction. Ethyl dichloroacetate, methylene chloride, and/or acetone were identified in the headspace of sucrose, MSG, and quinine solutions but not in the headspace of water, sodium chloride, and citric acid solutions. Fat oxidation compounds such as alcohols and aldehydes were detected in the headspace of the oleic and linoleic acid solutions but not the mineral oil. We conclude that prototypical tastant solutions can be discriminated from water and fatty acid solutions from mineral oil through orthonasal olfaction. Differences in the volatile headspace composition between blanks and tastant solutions may have facilitated the olfactory discrimination. These findings can have methodological implications for future studies assessing gustatory perception using these prototypical taste compounds.
Topics: Humans; Smell; Sodium Chloride; Sodium Glutamate; Quinine; Mineral Oil; Taste; Water; Sucrose; Citric Acid; Linoleic Acids
PubMed: 38175732
DOI: 10.1093/chemse/bjad054 -
Contact Dermatitis Mar 2024After almost three-quarters of a century during which contact dermatologists have often struggled to comprehend the relationship between metal allergy and failure of... (Review)
Review
After almost three-quarters of a century during which contact dermatologists have often struggled to comprehend the relationship between metal allergy and failure of metal-alloy containing implant, it is possible to say that a relationship does exist, particularly for cobalt and chromium, but also for nickel. There is still debate as to whether allergy develops as a consequent of failure but thenceforth contributes to it, or whether sensitisation starts first and induces failure secondarily-opinion probably favours the first. Metal-on-polypropylene articulations were associated with few metal allergic problems but now are less favoured by orthopaedists due to plastic wear products causing osteolysis and pseudotumour formation through local inflammation. New metal alloys are regularly being introduced such that interested dermatologists need to stay on top of the situation. The jury is still out as to whether the recent favouring of titanium-containing alloys will confirm them to be more inert allergenically. Case reports do show some clinical reactions to titanium-containing implants and patch test series have inferred sometimes quite a high background rate of allergy, but interpretation must be tempered by the awareness that titanium salts on patch testing have a tendency to cause irritant reactions. Blood monitoring of metal ion values is now recommended in certain situations after joint replacement and increasing levels may be an indication that allergy with joint failure can develop, in which case patch testing is indicated, and suggested series are available. Predictive patch testing, whilst generally not recommended in the past, has been introduced into some protocols often by non-dermatologists, such that it is now needed for temporo-mandibular joint and Nuss bar insertion, and it can be anticipated that this may become more commonplace in the future. One of the major current deficits for patch testers is standardised guidance on which preparation or preparations to use for suspected titanium allergy. One suggestion is 0.5% titanium sulphate in petrolatum, though experience in at least one centre suggests the use of a battery of titanium salts might be desirable.
Topics: Humans; Titanium; Salts; Dermatitis, Allergic Contact; Alloys; Metals; Hypersensitivity
PubMed: 38148670
DOI: 10.1111/cod.14481 -
Tropical Doctor Apr 2024Gastrointestinal foreign bodies present a common clinical challenge. We present an unusual case of a 58-year-old construction worker who ingested liquid concrete that...
Gastrointestinal foreign bodies present a common clinical challenge. We present an unusual case of a 58-year-old construction worker who ingested liquid concrete that risked solidifying in his stomach. Gastroscopy revealed only partial solidification and pyloric obstruction, which were successfully resolved through endoscopic fragmentation and mechanical removal. To protect the gastric mucosa during elimination, liquid paraffin and a cellulose-based formula were administered. Complete gastrointestinal evacuation was achieved within 3 days, with no complications observed. This case emphasises the urgency of the early removal of concrete.
Topics: Humans; Middle Aged; Stomach; Upper Gastrointestinal Tract; Gastroscopy; Foreign Bodies; Mineral Oil
PubMed: 38146189
DOI: 10.1177/00494755231220095 -
Zhonghua Wei Chang Wai Ke Za Zhi =... Dec 2023This study aimed to investigate the viability and safety of a novel defecator in managing rectal fecal impaction. In a descriptive case series, this new defecator was...
This study aimed to investigate the viability and safety of a novel defecator in managing rectal fecal impaction. In a descriptive case series, this new defecator was administered to constipated individuals among the ages of 18 and 80 years who met the diagnostic criteria for rectal fecal impaction and were identified with acute rectal fecal impaction through CT scans. The contraindications for this defecator included: (1) Anal stenosis, acute intestinal obstruction, and intestinal perforation; (2) Concomitant rectal malignant tumors; (3) Coagulation dysfunction, low platelet counts, gastrointestinal bleeding, or other bleeding risks; (4) Patients with severe underlying conditions affecting the heart, brain, lungs, or other systems; (5) Individuals with mental health disorders. Based on these criteria, clinical data from 42 patients with rectal fecal impaction who underwent treatment with the new defecator at Deyang People's Hospital between July 2020 and April 2023 were retrospectively analyzed.The defecator comprises three components: a head, a spiral rod, and a handle, constructed from disposable stainless steel wire. The treatment procedure involves the following steps: The patient assumes a flexed, supine position on their left side with their buttocks slightly protruding from the bed's edge. A transparent sealing bag is affixed to the buttocks, centered around the anus. With gloved hands inserted through the bag's entrance, a cotton ball soaked in liquid paraffin lubricates the anal canal and the head of the defecator's spiral rod. The defecator is then slowly rotated and inserted into the anus, with careful attention to any changes in resistance. Once the spiral rod is fully inserted, the patient is instructed to inhale and defecate while the defecator is slowly withdrawn, carrying the dislodged fecal matter, and depositing it into the sealed bag. This operation is repeated 2 to 3 times, followed by the injection of either 100 ml of 36°C normal saline or 60 ml of liquid paraffin into the rectum. After a 5 to 8-minute wait, the patient assumes a squatting position to expel any remaining feces from the rectum. The study assessed the operation time, single treatment success rate, pain levels during treatment, and the occurrence of complications. All 42 patients successfully underwent treatment with the new defecator device, achieving a single treatment success rate of 100%. The average operation time was 11.0 minutes (range: 9.0 to 13.3 minutes). During treatment, 20 cases (47.6%) reported moderate to severe anal pain, with 1 case (2.4%) experiencing anal fissure bleeding, and 6 cases (14.3%) reporting discomfort such as palpitations and sweating. No serious complications, including rectal perforation, were observed in any case. The new defecator device demonstrates ease of use and safety, making it a feasible option for treating acute rectal fecal impaction.
Topics: Humans; Rectum; Fecal Impaction; Retrospective Studies; Mineral Oil; Anal Canal; Pain
PubMed: 38110281
DOI: 10.3760/cma.j.cn441530-20230720-00008 -
Journal of Pharmaceutical Sciences May 2024Although laurocapram (Azone) significantly enhances the skin permeation of drugs, its development was hindered by its skin irritation. We then developed an Azone-mimic...
Although laurocapram (Azone) significantly enhances the skin permeation of drugs, its development was hindered by its skin irritation. We then developed an Azone-mimic ionic liquid (IL-Azone), composed of less irritating cationic ε-caprolactam and anionic myristic acid. IL-Azone dissociates to the original cation and anion in the presence of water in the formulation. We tried to select a formulation suitable for IL-Azone in the present study. Each formulation contained 5 % of either Azone or IL-Azone along with the model drug antipyrine, and skin permeation experiments of the drug were conducted. The results revealed that IL-Azone did not enhance skin permeation when combined with most formulations tested. However, a notable and rapid enhancement in skin permeation was observed when combined with white petrolatum. This effect could be attributed to the minimal water content in white petrolatum, which prevented IL-Azone degradation. Furthermore, its permeation-enhancing effects from IL-Azone in white petrolatum were more pronounced and rapid than Azone. The rapid onset observed with IL-Azone can be attributed to its degradation into its original components at the interface between the stratum corneum and the living epidermis, which results in a shorter lag time before achieving a steady-state concentration in the SC compared to Azone.
Topics: Skin Absorption; Ionic Liquids; Skin; Petrolatum; Water; Administration, Cutaneous; Azepines
PubMed: 38103688
DOI: 10.1016/j.xphs.2023.12.007 -
Scientific Reports Dec 2023It is uncertain whether hydrocolloid dressings, a more costly intervention than offering standard care with petrolatum, is superior to prevent pressure ulcers among... (Randomized Controlled Trial)
Randomized Controlled Trial
It is uncertain whether hydrocolloid dressings, a more costly intervention than offering standard care with petrolatum, is superior to prevent pressure ulcers among hospitalized high-risk adults. Randomized, parallel-group, open-label, superiority trial with an active control group, blinded for investigators, event validators, and analysts (December 1, 2015 to December 12, 2017). Eligible patients were ≥ 18 years of age with intact skin judged as high-risk for skin ulcers (Braden scale), admitted to surgical or medical wards of two tertiary-level hospitals. Participants were randomized (1:1) to protection with hydrocolloid dressings or petrolatum. The primary outcome was the first occurrence of pressure ulcers (with post-injury photographs adjudicated by three judges) under intention-to-treat analysis. Based on prior cost analysis, and the available resources (assumed incidence of 6 ulcers/1000 patient-days in controls), inclusion of up to 1500 participants allowed to surpass a one-sided superiority threshold > 5% based on a target efficacy > 40% for dressings. We planned an economic analysis using a decision tree model based on the effectiveness of the study results from a perspective of the third payer of health care. After inclusion of 689 patients (69 events), the trial was stopped for futility after a planned interim analysis (conditional power < 0.1 for all scenarios if the trial was completed). Pressure ulcers had occurred in 34 (10.2%) patients in the intervention group [9.6 per 1000 patient-days] and 35 (9.9%) participants in the control group [7.9 per 1000 patient-days], HR = 1.07 [95% CI 0.67 to 1.71]. The estimated incremental cost for dressings (a dominated strategy) was USD 52.11 per patient. Using hydrocolloid dressings was found similar to petrolatum for preventing pressure ulcers among hospitalized high-risk patients. As it conveys additional costs, and in this study was unlikely to demonstrate enough superiority, this strategy did not overcome conventional skin care.Trial registration: ClinicalTrials.gov identifier (NCT number): NCT02565745 registered on December 1, 2015.
Topics: Adult; Humans; Bandages, Hydrocolloid; Pressure Ulcer; Patients; Petrolatum
PubMed: 38062132
DOI: 10.1038/s41598-023-47483-0 -
Investigative Radiology Jul 2024Optical fluorescence imaging can track the biodistribution of fluorophore-labeled drugs, nanoparticles, and antibodies longitudinally. In hybrid computed...
OBJECTIVES
Optical fluorescence imaging can track the biodistribution of fluorophore-labeled drugs, nanoparticles, and antibodies longitudinally. In hybrid computed tomography-fluorescence tomography (CT-FLT), CT provides the anatomical information to generate scattering and absorption maps supporting a 3-dimensional reconstruction from the raw optical data. However, given the CT's limited soft tissue contrast, fluorescence reconstruction and quantification can be inaccurate and not sufficiently detailed. Magnetic resonance imaging (MRI) can overcome these limitations and extend the options for tissue characterization. Thus, we aimed to establish a hybrid CT-MRI-FLT approach for whole-body imaging and compared it with CT-FLT.
MATERIALS AND METHODS
The MRI-based hybrid imaging approaches were established first by scanning a water and coconut oil-filled phantom, second by quantifying Cy7 concentrations of inserts in dead mice, and finally by analyzing the biodistribution of AF750-labeled immunoglobulins (IgG, IgA) in living SKH1 mice. Magnetic resonance imaging, acquired with a fat-water-separated mDixon sequence, CT, and FLT were co-registered using markers in the mouse holder frame filled with white petrolatum, which was solid, stable, and visible in both modalities.
RESULTS
Computed tomography-MRI fusion was confirmed by comparing the segmentation agreement using Dice scores. Phantom segmentations showed good agreement, after correction for gradient linearity distortion and chemical shift. Organ segmentations in dead and living mice revealed adequate agreement for fusion. Marking the mouse holder frame and the successful CT-MRI fusion enabled MRI-FLT as well as CT-MRI-FLT reconstructions. Fluorescence tomography reconstructions supported by CT, MRI, or CT-MRI were comparable in dead mice with 60 pmol fluorescence inserts at different locations. Although standard CT-FLT reconstruction only considered general values for soft tissue, skin, lung, fat, and bone scattering, MRI's more versatile soft tissue contrast enabled the additional consideration of liver, kidneys, and brain. However, this did not change FLT reconstructions and quantifications significantly, whereas for extending scattering maps, it was important to accurately segment the organs and the entire mouse body. The various FLT reconstructions also provided comparable results for the in vivo biodistribution analyses with fluorescent immunoglobulins. However, MRI additionally enabled the visualization of gallbladder, thyroid, and brain. Furthermore, segmentations of liver, spleen, and kidney were more reliable due to better-defined contours than in CT. Therefore, the improved segmentations enabled better assignment of fluorescence signals and more differentiated conclusions with MRI-FLT.
CONCLUSIONS
Whole-body CT-MRI-FLT was implemented as a novel trimodal imaging approach, which allowed to more accurately assign fluorescence signals, thereby significantly improving pharmacokinetic analyses.
Topics: Animals; Mice; Magnetic Resonance Imaging; Tissue Distribution; Tomography, X-Ray Computed; Phantoms, Imaging; Whole Body Imaging; Multimodal Imaging; Tomography, Optical; Imaging, Three-Dimensional
PubMed: 38038691
DOI: 10.1097/RLI.0000000000001052