Pigmented cosmetic dermatitis and coal tar dyes

Patch tests and photopatch tests with various cosmetics, coal tar dyes, perfumes, lanolin preparations and parabens-mix were performed in 53 patients with pigmented cosmetic dermatitis similar in clinical appearance to Riehl's melanosis. The results showed that coal tar dyes, particularly brilliant lake red R, were closely related to the cause of the disease. In patch testing and photopatch testing with coal tar dyes, the incidence of positive responses to the brilliant lake red R was found to be significantly higher than that to the other coal tar colors (22/38 = 57.9%). The relevance of ultraviolet light to the disease was found to be much less than the ratio expected (14/47 = 29.8%). A high incidence of positive responses to fragrances was also found, but it is considered to play a secondary role in the etiology of the disease.     

Discharge patterns evoked by depolarizing current injection in basal optic nucleus neurons of the pigeon

The nucleus of the basal optic root of the accessory optic system in birds is involved in optokinetic nystagmus, which stabilizes images on the retina by compensatory movements of the eyes. The present paper studies the physiological and morphological properties of basal optic neurons in the pigeon by using a brain slice preparation and intracellular recordings. Sixty-one cells examined could be categorized into six types based on their firing patterns in response to depolarizing current injection. Type I cells (54%) fire spontaneously and more spikes as current intensity is increased. Type II cells (15%) discharge regular spikes with similar interspike intervals. Type III cells (5%) show an early burst followed by tonic firing. Type IV cells (5%) fire regular bursts with similar interburst intervals. Type V cells (16%) fire a few spikes in a cluster only at onset of current application. Type VI cells (5%) produce a hump-like depolarization or a single spike depending on current intensities. Seventeen cells stained with Lucifer yellow have multipolar or piriform perikarya (15-28 microm) with two to eight primary dendrites. In some cases, an axon is observed to originate from the cell body, traveling dorsolaterally or dorsally. The physiological significance of these findings is discussed.     

Bioadhesive fluorescent microspheres as visible carriers for local delivery of drugs. II: Uptake of insulin-loaded PCEFB/PLGA microspheres by the gastrointestinal tract

Uptake of novel inherently fluorescent microspheres composed of a luminescent polyanhydride, poly[p-(carboxyethylformamido)- benzoic anhydride] (PCEFB), and poly(lactide-co-glycolide) (PLGA) (2:1, weight ratio) by the gastrointestinal tract was evaluated by fluorescent microscopy. Oral efficiency of the incorporated insulin also was determined by measuring reduction of plasma glucose levels after feeding diabetic rats with a single dose of the microspheres. We found that PCEFB/PLGA microspheres could adhere to the intestinal epithelium and traverse the absorptive cells. A large number of the spheres were observed in spleen, whereas few were detected in liver within the evaluated period of time. Apparent reduction of the plasma glucose levels was observed over a span of 6 h postfeeding. The unique properties of the delivery system such as biodegradability, bioadhesivity, and inherently luminescent characteristics render it an ideal “visible” tracer for monitoring oral fate of polymeric microspheres.     

骨髓基质细胞修复猪膝关节非负重区软骨与骨复合缺损的实验研究

目的 探讨猪骨髓基质细胞(bone marrow stromal cells,BMSC)复合聚羟基乙酸／聚乳酸(PGA／PIA)支架修复关节软骨与骨复合缺损的可行性。方法 杂交猪18只,抽取股骨骨髓,体外培养、扩增BMSC并分别经地塞米松诱导(A组)或地塞米松与转化生长因子β1(TGFβ1)联合诱导(B组),以免疫组织化学、逆转录-聚合酶链反应(RT-PCR)检测其软骨分化表型。其中有2只猪部分BMSC经绿色荧光蛋白(GFP)基因转染标记。诱导后的细胞分别接种到PGA／PLA支架,体外培养1周后植入猪自体股骨下端非负重面软骨及骨复合缺损处,单纯支架植入(C组)及空白不处理(D组)作为对照。上述动物分别于3(6只)、6(10只)个月时取材,进行大体观察、修复结果分级、组织学检查、葡糖氨基聚糖(GAG)含量测定及生物力学测定。含GFP标记细胞的2只猪7个月时取材,共聚焦显微镜观察植入细胞的分布。结果 诱导后BMSC均能表达软骨特征性的Ⅱ型胶原与聚集蛋白聚糖(aggrecan),两组细胞均与支架材料黏附良好。术后大体观察与组织学检查显示：A组缺损以不完全修复为主,多数缺损软骨修复不良,而骨缺损基本修复,组织学主要为纤维性软骨及松质骨;B组缺损以完全修复为主,组织学表现为透明软骨及松质骨,少部分标本修复组织中含有纤维性软骨;两对照组缺损主要由纤维性组织修复或无明显新生组织,软骨与骨缺损均明显存在。3个月时,A、B组软骨修复组织弹性模量分别达到正常关节软骨的30．37％及43．82％,6个月时达到正常的62．69％及80．27％。6个月时,A组软骨修复组织GAG含量达到正常的78．03％,B组与正常组间差异无显著意义。含GFP标记细胞的修复标本经共聚焦显微镜观察可见：新生的软骨陷窝及松质骨小梁内均含有荧光标记的细胞。结论BMSC在关节缺损内可分别向软骨细胞与成骨细胞分化,同时修复软骨与骨复合缺损,恢复关节正常结构;TGFβ1与地塞米松联合诱导可促进BMSC向软骨细胞分化,改善其修复关节缺损的效果。     

Mutagenicity of textile dye products

Within an EU-funded research project, 281 textile dye products in use at nine textile finishing companies from eight European countries were assessed for potential mutagenic properties. Most of the dyes belonged to the so-called existing substances. Data sources considered were data published in the literature, unpublished industrial data provided by dye producing companies, and laboratory testing. Data on mutagenicity are virtually absent for many of the dyes. Unpublished test results performed on behalf of the dye manufacturing industry proved to be an important data source that is not accessible under usual circumstances. Four dye stuffs contained in seven dye products in use at the textile finishing companies were judged to be mutagenic, based on published data from the literature. Mutagenicity testing using Salmonella typhimurium, strains TA98 and TA100, revealed positive results for about 28% (15 out of 53) of the dye products investigated. Upon further testing with the mouse lymphoma assay (L5178Y/TK(+/-)) 67% (6 out of 9) of Ames-positive dyes proved to be mutagenic in this mammalian cell test. All data sources combined led to an overall assessment of 14 dye products out of 281 being mutagenic. For 16 there is a suspicion of mutagenicity due to positive responses in one test but 71 of the dye products are without any data on mutagenicity. This paper describes the data aggregation process, evaluation criteria and the overall assessment, and exemplifies controversial evaluations.     

Allergic contact dermatitis from dyes in wigs following diphencyprone treatment

Objectives:  To investigate symptoms from the eyes and airways, elicited by perfume and fragrance products and associations between such symptoms and skin prick test reactivity, metacholine bronchial hyperreactivity (BHR), contact allergy, and eczema in a population based sample.
Methods:  A questionnaire on mucosal symptoms elicited by fragrance products was mailed to 1189 persons who had participated in a Danish population‐based study of allergic diseases in 1997/98. The study included measurement of BHR, skin prick testing, patch testing and history of hand eczema.
Results:  The response rate to the questionnaire was 80%. Symptoms from the eyes or airways elicited by fragrance products were reported by 42%. There were no significant associations between these symptoms and skin prick test reactivity. Positive and independent statistical significant associations were found between BHR, perfume contact allergy and hand eczema, and symptoms from the eyes and airways elicited by fragrance products, also when adjusting for nickel contact allergy, age, gender psychological vulnerability, educational level and social class.
Conclusions:  Individuals with BHR, hand eczema and/or perfume contact allergy, as opposed to those without, are more frequently and more severely bothered from the eyes or airways after volatile exposure to fragrance products. The lack of association with skin prick test reactivity indicates that IgE mediated allergic mechanisms do not play a major role in the development of these symptoms. Having hand eczema has the greatest impact on reporting mucosal symptoms elicited by fragrance products.     

Transplantation of autologous dorsal root ganglia into the peroneal nerve of adult rats: uni- and bidirectional axonal regrowth from the grafted DRG neurons

Previous studies have demonstrated that transplanted dorsal root ganglion neurons (DRGNs) can survive and differentiate in a variety of orthotopic and heterotopic locations. In order to develop strategies aimed at restoring the sensory function following traumatic injury to the spinal cord and to its peripheral sensory connections, we have transplanted adult autologous dorsal root ganglia (DRGs) into the peroneal nerve of adult rats. Twelve female Sprague-Dawley rats were used. A segment of the peroneal nerve was isolated by double transection and ligature to prevent undesirable reinnervation. The left fifth cervical (C5) DRG was removed from its normal location and inserted into the midportion of the isolated nerve segment. One month after the grafting procedure, a morphological study included axonal retrograde labeling with True Blue (TB) and/or Diamidino Yellow (DY) applied on each cut end of the nerve segment, cell counting, and cell measurement after staining with cresyl violet. Compared to the C5 ganglion maintained in situ, the mean number of surviving DRGNs in the transplant was 1381, corresponding to a survival rate of 20%. Both singly (TB or DY) and doubly (TB + DY) stained DRGNs were encountered. The proportion of surviving neurons that appeared to be doubly labeled was 23%. These neurons were considered as having grown two opposite axonal projections, one into the "central" part of the nerve segment and a second one into its "peripheral" part. The present results give new insights and interesting prospects concerning the possibilities of reconstructing the sensory circuitry after central and/or peripheral injuries.