Guide for medical professionals (i.e. dermatologists) for the management of Rhododenol‐induced leukoderma

Because some users develop depigmentation after the use of melanogenesis‐inhibiting products containing the quasi‐drug ingredient Rhododenol, Japanese Dermatological Association (JDA) established a Special Committee on the Safety of Cosmetics Containing Rhododenol on July 17, 2013 and management guide for dermatologists has been updated on the website in order to delineate the diagnostic criteria for Rhododenol‐induced leukoderma and provides a broad guide for standard treatment based on current knowledge. This guide is produced on the basis of the guide (version 7) updated on June 20, 2014 in the website. Rhododenol‐induced leukoderma refers to depigmentation of varying severity that develops after the use of cosmetics containing Rhododenol, mainly at the site of use. In most cases, repigmentation of part or all the affected area is evident after discontinuation. Histopathologically cellular infiltration around the hair follicles and melanophages are present in most cases. The number of melanocytes in the lesion is declined but not totally absent in most cases. Rhododenol itself is a good substrate for tyrosinase, resulting in the formation of Rhododenol metabolites (e.g., Rhododenol quinone). Melanocytes are damaged by Rhododenol metabolites during the subsequent metabolic process. The continued use of cosmetics containing Rhododenol thus induces tyrosinase activity‐dependent cytotoxicity in melanocytes in the epidermis at application sites, resulting in decreasing the amount of melanin produced by melanocytes; the addition of some other factor to this process is believed to subsequently cause the decrease or disappearance of melanocytes themselves from the epidermis.     

Evaluation of microwave-assisted ultraviolet digestion method for rice and wheat for subsequent spectrometric determination of As,Cd, Hg and Pb

The aim of this study was to optimize a sample preparation method for rice and wheat using microwave-assisted ultraviolet digestion (MW-UV) for subsequent determination of toxic elements. Cadmium and Pb were determined by sector-field inductively coupled plasma mass spectrometry (SF-ICP-MS), while As and Hg were determined by chemical vapor generation coupled to atomic absorption spectrometry (CVG-AAS). A systematic evaluation of the microwave heating program, nitric acid concentrationand sample mass was performed to optimize the MW-UV digestion method for rice and wheat samples. The relationship between nitric acid concentration and sample mass was monitored by determination of the residual carbon content (RCC) and residual acidity (RA) in order to obtain a high efficiency of digestion. The MW-UV method was successful at digesting up to 1100 mg of rice and wheat using 4 mol L⁻¹ HNO₃ with RCC and RA lower than 1.5 %, and 10 %, respectively. Recovery results ranging from 88 % to 117 % and agreement with certified reference values (t-test, 95 % confidence level) were obtained after digestion using the MW-UV method for spiked samples and certified reference materials (peach leaves-NIST 1547 and tomato leaves-NIST 1573), respectively. The optimized method was suitable for analysis of toxic elements in rice and wheat in compliance with the maximum levels reported in official directives.     

Laser vaccine adjuvants: Light-augmented immune responses

Adjuvants are essential for ensuring the efficacy of modern vaccines. Considering frequent local and systemic adverse reactions, research into the development of safer and more effective adjuvants is being actively conducted. In recent years, the novel concept of laser vaccine adjuvants, which use the physical energy of light, has been developed. For long, light has been known to affect the physiological functions in living organisms. Since the development of lasers as stable light sources, laser adjuvants have evolved explosively in multiple ways over recent decades. Future laser adjuvants would have the potential not only to enhance the efficacy of conventional vaccine preparations but also to salvage candidate vaccines abandoned during development because of insufficient immunogenicity or owing to their inability to be combined with conventional adjuvants. Furthermore, the safety and efficacy of non-invasive laser adjuvants make them advantageous for vaccine dose sparing, which would be favorable for the timely and equitable global distribution of vaccines. In this review, we first describe the basics of light–tissue interactions, and then summarize the classification of lasers, the history of laser adjuvants, and the mechanisms by which different lasers elicit an immune response.     

The Selection of a Pharmaceutical Salt—The Effect of the Acidity of the Counterion on Its Solubility and Potential Biopharmaceutical Performance

A roadmap for the selection of a pharmaceutical salt form for a development candidate is presented. The free base of the candidate did not have sufficient chemical stability for development. The initially selected salt form turned out to be undevelopable because it was unstable during scale-up synthesis and storage. The rationale for the new solid form screening and the criteria for selection are discussed. Before the final selection, the pH solubility profiles of the 2 new salts, a benzoate and a besylate, were compared. Atypical solubility behavior was observed for the benzoate salt in hydrochloric acid with and without normal saline. A scheme is proposed illustrating how the pKas of the counterion and active pharmaceutical ingredient, the medium composition, and final pH affect the solubility and solution equilibria of the 2 selected salt forms. This scheme also includes the equilibria between solution and solid phases in different pH ranges. The pharmaceutical importance of this research is that it sheds light on how the acidity of the counterion can affect the solubility of the selected salt form in the gastric environment. With a well-designed formulation strategy, this property potentially can be translated to optimal biopharmaceutical performance of the drug product.     

Bottom-Up and Top-Down Approaches to Explore Sodium Dodecyl Sulfate and Soluplus on the Crystallization Inhibition and Dissolution of Felodipine Extrudates

The objectives of this study were to explore sodium dodecyl sulfate (SDS) and Soluplus on the crystallization inhibition and dissolution of felodipine (FLDP) extrudates by bottom-up and top-down approaches. FLDP extrudates with Soluplus and SDS were prepared by hot melt extrusion, and characterized by polarized light microscopy, differential scanning calorimetry, and fourier transform infrared spectroscopy. Results indicated that Soluplus inhibited FLDP crystallization, and the whole amorphous solid dispersions (ASDs) were binary FLDP-Soluplus (1:3) and ternary FLDP-Soluplus-SDS (1:2:0.15～0.3 and 1:3:0.2～0.4) extrudates. Internal SDS (5%-10%) decreased glass transition temperatures of FLDP-Soluplus-SDS ternary ASDs without presenting molecular interactions with FLDP or Soluplus. The enhanced dissolution rate of binary or ternary Soluplus-rich ASDs in the nonsink condition of 0.05% SDS was achieved. Bottom-up approach indicated that Soluplus was a much stronger crystal inhibitor to the supersaturated FLDP in solutions than SDS. Top-down approach demonstrated that SDS enhanced the dissolution of Soluplus-rich ASDs via wettability and complexation with Soluplus to accelerate the medium uptake and erosion kinetics of extrudates, but induced FLDP recrystallization and resulted in incomplete dissolution of FLDP-rich extrudates. In conclusion, top-down approach is a promising strategy to explore the mechanisms of ASDs' dissolution, and small amount of SDS enhances the dissolution rate of polymer-rich ASDs in the nonsink condition.     

Osmolyte taurine induction in UVA exposed human retinal pigment epithelial cells

Aim: To explore the osmolytes expression in ultraviolet (UVA) stressed human retinal pigment epithelial cells.

Methods: Osmolyte transporters and vascular endothelial growth factor (VEGF) messenger RNA (mRNA) were determined by real time polymerase chain reaction (PCR). Osmolyte uptake was measured by radioimmunoassay. VEGF concentrations were determined by immunoassay and enzyme-linked immunosorbent assay (ELISA). Osmolyte taurine transporter (TAUT) were silenced by siRNA technology.

Results: Hypertonicity accelerated osmolyte betaine uptake, myoinositol uptake, and taurine uptake, compared to normotonic stress. UVA irradiation also accelerated osmolyte transporters expression and osmolytes uptake. Especially, osmolyte taurine remarkably inhibited VEGF release induced by UVA irradiation. VEGF in the UVA stressed retinal pigment epithelial cell supernatant was accumulated slow after taurine preincubation. VEGF expression increased significantly in UVA-stressed cells after TAUT silencing. Moreover, taurine reduced the VEGF level in human ocular aqueous humor.

Conclusion: The inhibition of VEGF by osmolyte taurine plays the crucial role in retina adaption to UVA irradiation.     

地面水背景下眼部紫外线暴露强度分析

目的探讨水面反射对眼部紫外线暴露量的影响,为眼部紫外线防护提供依据。方法采用自制旋转式眼部紫外线暴露模型于2017年8月期间在辽宁省沈阳地区某公园的水面和木板两种不同地面背景,同时进行眼部紫外线暴露强度监测。结果无论紫外线A段(UVA)还是紫外线B段(UVB)其眼部暴露强度均为地面水背景下高于木板背景。水面、木板背景下眼部UVA暴露最大值日间变化均呈双峰分布,2者峰值相差479μW/cm2(上午)、526μW/cm2(下午);眼部UVB暴露最大值的日间变化双峰不明显,水面、木板背景下眼部UVB暴露最大值的峰值差值为14μW/cm2。不同方位眼部紫外线暴露强度多数为地面水背景高于木板背景。结论地面水背景下的眼部紫外线暴露强度高于木板背景下的眼部紫外线暴露强度。     

黄芩素对UVB诱导HaCaT细胞光老化及相关p38信号通路的影响

目的:研究黄芩素对中波紫外线(UVB)诱导人皮肤角质形成细胞(HaCaT)光老化及相关p38丝裂原活化蛋白激酶(p38MAPK)信号通路的影响。方法:选择1×10~(-11),1×10~(-10),1×10~(-9),1×10~(-8),1×10~(-7),1×10~(-6),1×10~(-5),1×10~(-4),1×10~(-3)mol·L~(-1)9种浓度黄芩素作用于HaCaT细胞,噻唑蓝(MTT)法筛选出最佳有效浓度。经预实验筛选出辐射强度为0.5 mW·cm~(-2)的UVB,辐射时间为5 min建立光老化模型,筛选出最佳有效浓度作用于光老化模型,另设空白组MTT法检测各组细胞活性。超氧化物歧化酶(SOD),谷胱甘肽过氧化物酶(GSH-Px),过氧化氢酶(CAT)及丙二醛(MDA)试剂盒检测SOD,GSH-Px,CAT活性及MDA含量。实时定量荧光定量聚合酶连式反应(RT-PCR)及蛋白免疫印迹法(Western blot)分别检测各组细胞中mRNA及蛋白表达。结果:筛选出1×10~(-7),1×10~(-6),1×10~(-5)mol·L~(-1)黄芩素为最佳有效浓度;与空白组比较,UVB组对HaCaT细胞无明显的增殖作用。与UVB组比较,1×10~(-7),1×10~(-6),1×10~(-5)mol·L~(-1)黄芩素组对光老化模型无明显增殖作用。与空白组比较,UVB组SOD,GSH-Px及CAT活性明显的降低,MDA含量显著升高(P0.01);与UVB组比较,1×10~(-7),1×10~(-6),1×10~(-5)mol·L~(-1)黄芩素组SOD,GSH,CAT活性明显升高,MDA含量明显降低(P0.05,P0.01)。与空白组比较,UVB组肿瘤坏死因子-α(TNF-α)mRNA及TNF-α,磷酸化p38(p-p38)蛋白表达显著升高(P0.01);与UVB组比较,1×10~(-7),1×10~(-6),1×10~(-5)mol·L~(-1)黄芩素组TNF-αmRNA及TNF-α,p-p38蛋白表达明显降低(P0.05,P0.01)。结论:黄芩素对UVB诱导HaCaT细胞光老化保护作用主要是通过提高氧化酶活性以及阻断p38MAPK信号通路,抑制炎症因子产生。