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Langmuir : the ACS Journal of Surfaces... Apr 2024Aqueous mixtures of oppositely charged polyelectrolytes and surfactants are useful in many industrial applications, such as shampoos and hair conditioners. In this work,...
Aqueous mixtures of oppositely charged polyelectrolytes and surfactants are useful in many industrial applications, such as shampoos and hair conditioners. In this work, we investigate the friction between biomimetic hair surfaces in the presence of adsorbed complexes formed from cationic polyelectrolytes and anionic surfactants in an aqueous solution. We apply nonequilibrium molecular dynamics (NEMD) simulations using the coarse-grained MARTINI model. We first developed new MARTINI parameters for cationic guar gum (CGG), a functionalized, plant-derived polysaccharide. The complexation of CGG and the anionic surfactant sodium dodecyl sulfate (SDS) on virgin and chemically damaged biomimetic hair surfaces was studied using a sequential adsorption approach. We then carried out squeeze-out and sliding NEMD simulations to assess the boundary lubrication performance of the CGG-SDS complex compressed between two hair surfaces. At low pressure, we observe a synergistic friction behavior for the CGG-SDS complex, which gives lower shear stress than either pure CGG or SDS. Here, friction is dominated by viscous dissipation in an interfacial layer comprising SDS and water. At higher pressures, which are probably beyond those usually experienced during hair manipulation, SDS and water are squeezed out, and friction increases due to interdigitation. The outcomes of this work are expected to be beneficial to fine-tune and screen sustainable hair care formulations to provide low friction and therefore a smooth feel and reduced entanglement.
PubMed: 38573738
DOI: 10.1021/acs.langmuir.3c03737 -
Clinical, Cosmetic and Investigational... 2024Noninfectious inflammatory dermatoses of the scalp are common, and their symptomsin particular, those affecting appearance, can have a psychological effect that may be...
Use of Topical Corticosteroids in the Treatment of Noninfectious Inflammatory Dermatoses of the Scalp: A Survey of Practicing Dermatologists and Dermatology Residents Using Delphi Methodology.
BACKGROUND
Noninfectious inflammatory dermatoses of the scalp are common, and their symptomsin particular, those affecting appearance, can have a psychological effect that may be disproportionate to their clinical severity. Effective, cosmetically acceptable treatments are important to manage these conditions. Topical corticosteroids form the cornerstone of acute treatment for many of these conditions. We surveyed practicing dermatologists and dermatology residents to determine the current clinical practice in prescribing topical corticosteroids for these disorders in their various preparation formats.
METHODS
A Delphi method was used, consisting of 2 questionnaire rounds. The first round contained 34 questions and was completed by 612 dermatologists and dermatology residents via email. The first round of responses was analyzed, and points that had > 70% agreement were used to form a second questionnaire of 21 statements. This second round was completed by 346 participants, and their responses were used to generate a final report. Participants were practicing in both public and private practices.
RESULTS
Clobetasol propionate 0.05% topical solution was considered to be the most appropriate treatment for noninfectious inflammatory scalp dermatoses in general, with 75.1% agreement in the second round of questionnaire. The main advantages of clobetasol propionate over other topical corticosteroids were reported as potency, effectiveness, and broad action spectrum (94.8% agreement). The preferred pharmaceutical format was the solution of clobetasol propionate.
CONCLUSION
Clobetasol propionate was the preferred topical treatment for the management of scalp dermatoses, usually as first-line treatment; solution was the preferred preparation.
PubMed: 38524395
DOI: 10.2147/CCID.S448016 -
Saudi Journal of Biological Sciences Apr 2024Cosmetic products may be exposed to microbial contamination during storage or transport, and to avoid the risk of microbial growth, manufacturers add preservative...
Cosmetic products may be exposed to microbial contamination during storage or transport, and to avoid the risk of microbial growth, manufacturers add preservative compounds as a protection for the product from spoilage. The Microbial Challenge test is a procedure to evaluate the preservative efficacy by challenging the product with testing microorganisms to determine the quality of preservation. In this study, thirty-two cosmetics products used for body and skin care were collected from markets and pharmacies in Mecca region, these products are subjected to microbiological analysis, results show that most samples are contaminated except six samples. Non contaminated samples were subjected to European Pharmacopeia 7.0 standards. Results show that two samples, foaming gel and body and face cream are failed to demonstrate the required microbiocidal effect against the test species, results recorded 1.21 x 10 and 6.80 x 10 (CFU/ml) respectively at the second day of incubation, other products: shower gel, hand wash, body lotion and shampoo demonstrate that required microbiocidal effect against the test species during day 2, 7, 14 until day 28th. The microbial count number is less than 10 during all incubation periods. To prevent contamination in cosmetics, manufacturers are required to add a good preservative system to the products and examine them before sale. Due to the high percentage of microbial contamination in cosmetics in Mecca region and for consumers safety, this study is prepared.
PubMed: 38440744
DOI: 10.1016/j.sjbs.2024.103965 -
Veterinary Journal (London, England :... Apr 2024Malassezia are members of the mycobiome of dogs and cats. In the presence of an underlying disease, these yeasts can proliferate, attach to the skin or mucosa to induce... (Review)
Review
Malassezia are members of the mycobiome of dogs and cats. In the presence of an underlying disease, these yeasts can proliferate, attach to the skin or mucosa to induce a secondary Malassezia dermatitis, otitis externa or paronychia. Since allergic dermatitis is one of the most common underlying causes, diagnostic investigation for allergy is often indicated. Cats may suffer from various other underlying problems, especially where Malassezia dermatitis is generalised. Malassezia dermatitis in dogs and cats is chronic, relapsing and pruritic. Direct cytology from dermatological lesions and the ear canal, showing "peanut-shaped" budding yeasts, facilitates a rapid and reliable diagnosis. Topical treatment includes antiseptic and antifungal azole-based products. Systemic treatment with oral antifungals is indicated only in severe or refractory disease. Identification and treatment of the underlying cause is essential for an optimal response. In this evidence-based narrative review, we discuss the clinical presentation of Malassezia dermatitis in dogs and cats, underlying comorbidities, and diagnostic considerations. Treatment is discussed in light of emerging evidence of antifungal resistance and the authors' clinical experience.
Topics: Animals; Cats; Dogs; Malassezia; Dermatomycoses; Cat Diseases; Antifungal Agents; Dog Diseases; Neoplasm Recurrence, Local; Dermatitis
PubMed: 38431127
DOI: 10.1016/j.tvjl.2024.106084 -
Medical Mycology Case Reports Mar 2024Tinea capitis is a chronic fungal infection of the scalp occurring commonly in children of school age, especially in developing countries. It is caused primarily by the...
Tinea capitis is a chronic fungal infection of the scalp occurring commonly in children of school age, especially in developing countries. It is caused primarily by the dermatophyte members of genera and . Here we report presence of free-living mycelial stage of dermatophytes, a stage of fungal growth which form in culture medias, around affected hairs and skin scrapings of scalp lesions in a 3-year-old boy presenting with alopecia and multiple scaly, non-erythematous plaques. On direct microscopy examination using 10 % potassium hydroxide, the fungal hyphae and arthrospores were detected in ectothrix form. In addition, we also observed numerous multicellular, thick-walled spindle-shaped macroconidia around hairs and skin scrapings. To our knowledge this is the first study reporting dermatophyte's macroconidia directly seen on clinical samples. Species level identification of the dermatophyte isolate growing on Mycosel™ agar was confirmed by PCR-sequencing of internal transcribed spacer of ribosomal RNA as The patient was successfully treated with systemic itraconazole combined with topical ketoconazole shampoo.
PubMed: 38369987
DOI: 10.1016/j.mmcr.2024.100629 -
Heliyon Feb 2024An extraction-free methodology is proposed for quantifying urea in cosmetics, which relies on urea-mediated decrease of methyl red decoloration by sodium hypochlorite....
An extraction-free methodology is proposed for quantifying urea in cosmetics, which relies on urea-mediated decrease of methyl red decoloration by sodium hypochlorite. The method is applied directly to the cosmetic formulation and the resulting color intensity is captured by a smartphone camera. We demonstrate a linear relationship between color intensity and urea concentration in O/W emulsions and a shampoo. This quantification methodology is fully validated by determining its technical characteristics in an O/W cosmetic emulsion: The standard curve is linear over 2.5-30.0 % w/w urea (R ≥ 0.985). The coefficient of variation (CV %) on all quality control levels is ≤ 12.54 % for intermediate precision, indicating acceptable precision. Bias is up to ±4.93 % in the emulsion, indicating acceptable accuracy and a countable matrix effect. The proposed analysis setup in combination with a standard addition methodology is applied to verify urea content in purpose-made emulsions: bias is ≤±10.9 %, even in the presence of interfering ammonia. We finally demonstrate that the camera-captured color intensity of an O/W emulsion is proportional to different colorant concentrations in the formulation. This opens the route for further applications of the proposed setup to other ingredients capable of generating a colored product upon suitable reaction inside the formulation matrix.
PubMed: 38333856
DOI: 10.1016/j.heliyon.2024.e25503 -
International Journal of Women's... Jun 2023Black haircare is an estimated $2.51-billion-dollar industry. Black women spend 9 times more on ethnic hair products than non-Black consumers. The haircare industry has...
BACKGROUND
Black haircare is an estimated $2.51-billion-dollar industry. Black women spend 9 times more on ethnic hair products than non-Black consumers. The haircare industry has adapted to these market trends by developing products catering to the needs of "natural hair," referring to curly to tightly coiled hair texture that has not been chemically straightened with a relaxer. Anecdotally, natural haircare products are relatively expensive.
OBJECTIVE
We aimed to investigate texture-based price differences for haircare products targeting coily/curly compared to straight hair types.
METHODS
Data were collected in August 2022 from 6 brands available on www.amazon.com. After stratifying the data by manufacturer, hair texture, and average price/oz, we used 2 sample -test with equal variances to examine cost differences.
RESULTS
Overall, there was a significant difference in average price/oz between all coily/curly and straight hair products, with coily/curly hair products being more expensive. When stratified by manufacturer, one leading US manufacturer sold coily/curly hair products at a higher price ($0.66/oz ±$0.05) compared with straight hair products ($0.46/oz ±$0.04), = 2.8967, < 0.0134.
LIMITATIONS
A small sample size of only shampoos and conditioners were analyzed, which may not represent the number of haircare products that consumers use.
CONCLUSION
Pricing policies should ensure that all individuals have access to effective, affordable haircare products. Dermatologists should also be cognizant of pricing differences to direct patients with natural hair to fairly priced products.
PubMed: 38323221
DOI: 10.1097/JW9.0000000000000089 -
The Science of the Total Environment Mar 2024Among personal care products, quaternium-15 is prominently featured as a preservative in items such as shampoos, soaps, shaving products, and cosmetics. The widespread...
Among personal care products, quaternium-15 is prominently featured as a preservative in items such as shampoos, soaps, shaving products, and cosmetics. The widespread use of these products in people's daily routines contributes to quaternium-15 release into aquatic ecosystems. In this context, the primary aim of the study was to assess the physiological and cellular responses of the digestive gland and gills in Mytilus galloprovincialis to quaternium-15 exposure. Cell viability and the ability of digestive gland cells to regulate their volume were evaluated. Additionally, the expression of the genes involved in oxidative stress response was assessed to further substantiate the compound's harmful effects. Results indicated a significant decrease in both the viability of digestive gland cells and their RVD (regulatory volume decrease) capacity when exposed to a hypotonic solution. Furthermore, impairment of digestive gland cell function was corroborated by the modulation of oxidative stress-related gene expression, including SOD, Cat, as well as Hsp70 and CYP4Y1. Similar gene expression alterations were observed in the gills, reflecting impaired functionality in this vital organ as well. In summary, the outcomes of the study provide conclusive evidence of the toxicity of quaternium-15. This underscores the urgent need to further investigate the toxicological effects of this contaminant on aquatic ecosystems and emphasises the necessity of limiting the use of products containing quaternium-15.
Topics: Humans; Animals; Mytilus; Ecosystem; Oxidative Stress; Digestion; Water Pollutants, Chemical; Gills; Biomarkers; Methenamine
PubMed: 38309339
DOI: 10.1016/j.scitotenv.2024.170568 -
BMC Infectious Diseases Jan 2024Head lice are a main public health problem and the most important human ectoparasites and the use of pediculicides is the most common way to control it. One of the...
BACKGROUND
Head lice are a main public health problem and the most important human ectoparasites and the use of pediculicides is the most common way to control it. One of the possible causes of treatment failure is the lack of improper application of pediculicide. The aim of this study was to assess the effect of education on efficacy of 1% permethrin or 4% dimeticone lotion to treat head lice infestation.
METHODS
This quasi-experimental study included 100 individuals with head lice infestation from comprehensive urban health centers in Ardabil as the intervention group, and 400 individuals from East Azerbaijan and West Azerbaijan provinces as the control group, from April to March 2019. The data collection tools included a demographic questionnaire and an examination recording sheet, which documented the presence of adult lice or nits. Due to the inability to perform random assignment and control for numerous observed covariates, propensity score matching (PSM) was used.
RESULTS
The outcome of treatment included elimination of head lice infestation on is 7, and in the case of recurrence, it was considered on days 14 and 30 after treatment. The results showed that the educational intervention program had a significant positive effect on the efficacy of both treatments. The likelihood of improvement was approximately three times greater in the intervention group compared to the control group.
CONCLUSION
Participants who received the training intervention (OR = 3.29; CI 95%: 2.21-4.88) were more likely to have a successful treatment than control group. In the case of providing proper training on the use of pediculicides and observing hygiene tips to patients with pediculosis, could help to successful treatment of pediculosis.
Topics: Animals; Adult; Humans; Lice Infestations; Permethrin; Propensity Score; Dimethylpolysiloxanes; Pediculus; Insecticides
PubMed: 38291370
DOI: 10.1186/s12879-024-09029-1 -
Journal of Clinical and Investigative... Jul 2023Seborrheic dermatitis (SD) is an inflammatory disease that has a papulosquamous morphology in areas rich in sebaceous glands such as the scalp, face, and body folds....
BACKGROUND
Seborrheic dermatitis (SD) is an inflammatory disease that has a papulosquamous morphology in areas rich in sebaceous glands such as the scalp, face, and body folds. Petaloid SD is an uncommon presentation found in patients with dark skin (Fitzpatrick Skin type V-VI). This form of SD can appear as pink or hypopigmented polycyclic coalescing rings or scaly macules and patches in the typical areas SD appears, which can mimic other conditions including lupus erythematosus. There is significant disproportion in the representation of darker skin types in dermatological textbooks and scarce literature on petaloid SD. This case demonstrates the presentation of the petaloid SD in an African American patient to contribute to the limited literature on dermatological conditions within this population.
CASE REPORT
A 25-year-old African American female with a history of mild hidradenitis suppurativa and asthma who presented with asymptomatic hypopigmented rashes throughout her face, scalp, and chest. She was diagnosed with the petaloid form SD and treated with ketoconazole shampoo once weekly, ketoconazole cream 1-2x daily, and hydrocortisone 2.5% ointment twice daily as needed. At six-week post-treatment follow-up, the patient's rashes significantly improved.
CONCLUSIONS
The petaloid form of SD is commonly experienced in dark-skinned patients. While common treatments for SD are effective in this form of SD, special consideration of skin types, skincare habits, and haircare in the African American population should be explored. This case report demonstrates how this uncommon skin condition presents in patients of Fitzpatrick skin type V-VI and a successful treatment course.
PubMed: 38249156
DOI: 10.13188/2373-1044.1000086