Derivation of a Liquid-to-Soild Ratio for ASTM Method D3987-85 for Soils Containing Chromite Ore Processing Residue Using Selected Unsaturated Zone Models

While most health-based cleanup levels for hexavalent chromium [Cr(VI)] in soil are established to protect the general population against cancer, the New Jersey Department of Environmental Protection (NJDEP) has established a Cr(VI) soil cleanup criterion to protect Cr(VI)-sensitive individuals against allergic contact dermatitis (ACD). For this criterion, exposure is assumed to occur when a Cr(VI)-sensitized individual contacts a puddle in which rainfall has dissolved Cr(VI) from the associated surface soils. To simulate the movement of Cr(VI) from surface soil into puddle water after rainfall events, this soil cleanup criterion requires that the Cr(VI) concentration extracted from soil using ASTM Method D3987-85 at a 2:1 liquid-to-solid ratio (LSR) be less than 25?mg/L. However, this LSR is based on several simplifying assumptions that may not be appropriate for many soil types. In this article, three unsaturated zone transport models—Chemflo, SWIM, and HYDROGEOCHEM—are evaluated for developing LSRs for sites with soil containing chromite ore processing residue (COPR). Based on this evaluation, SWIM was found to be the most appropriate model for simulating Cr(VI) transport into puddles because of its ability to simulate rainfall and evaporation rate changes during and following precipitation events. A more refined evaluation using only SWIM was performed to determine the effects of various factors on COPR-specific LSRs, including saturated hydraulic conductivity, daily rainfall rate, daily evaporation rate, and groundwater depth. The refined evaluation demonstrated that the LSR ranges from 1.4 to 30, with a mean of 7.4 and a median of 7.0. Thus, an LSR of 7:1 is the most appropriate to represent the puddle scenario at COPR sites.     

The important role of stratum corneum lipids for the cutaneous barrier function

The skin protects the body from unwanted influences from the environment as well as excessive water loss. The barrier function of the skin is located in the stratum corneum (SC). The SC consists of corneocytes embedded in a lipid matrix. This lipid matrix is crucial for the lipid skin barrier function. This paper provides an overview of the reported SC lipid composition and organization mainly focusing on healthy and diseased human skin. In addition, an overview is provided on the data describing the relation between lipid modulations and the impaired skin barrier function. Finally, the use of in vitro lipid models for a better understanding of the relation between the lipid composition, lipid organization and skin lipid barrier is discussed. This article is part of a Special Issue entitled The Important Role of Lipids in the Epidermis and their Role in the Formation and Maintenance of the Cutaneous Barrier. This article is part of a Special Issue entitled The Important Role of Lipids in the Epidermis and their Role in the Formation and Maintenance of the Cutaneous Barrier. Guest Editors: Kenneth R. Feingold and Peter Elias.     

Detection of endogenous and food-derived collagen dipeptide prolylhydroxyproline (Pro-Hyp) in allergic contact dermatitis-affected mouse ear

Generation of collagen dipeptides and deposition of orally administered prolylhydroxyproline (Pro-Hyp) in local inflammatory sites were examined in mice with hapten (2,4-dinitrofluorobenzene)-induced dermatitis in the ear. Pro-Hyp content in the hapten-treated ear was significantly higher in the chronic phase of contact dermatitis than the vehicle control. In contrast, hydroxyprolylglycine contents remained at lower levels in all cases compared to Pro-Hyp. Four hours after the ingestion of [¹³C₅,¹⁵N]Pro and [¹³C₅,¹⁵N]Pro-Hyp, labeled-Pro-Hyp and Pro, respectively, appeared only in the ear with dermatitis. Thus, Pro-Hyp is generated and degraded as part of the rapid synthesis and degradation of collagen in the ear with dermatitis. In addition to the endogenously generated Pro-Hyp, the orally administered Pro-Hyp was deposited in the ears.     

Stimulation of urinary copper excretion by trientine(R) in nickel-sensitive patients

Trientine^(R) is not an effective drug for the treatment of intractable hand dermatitis in nickel-sensitive patients. In a controlled, double-blind study this chelator, on oral administration, failed to stimulate nickel excretion. Early morning urine samples from two groups of nine patients were analyzed by atomic absorption spectrophotometry in a stabilized Temperature Platform Furnace equipped with Zeeman background correction. Group 1 patients received placebo for 6 wk, then a 4-wk rest before crossover. Group 2 received the drug in the first period. No difference in Ni levels between the placebo period and the drug period in either group was demonstrated, nor was there any significant improvement in the hand eczema. Copper was measured in the same urine samples using the same instrumentation, but with atomization off the wall. There was a considerable increase in copper excretion during the drug treatment period. Group 1 excreted a mean 538±378 (SD) μg/L, which represented a mean increase of 787±653 % (SD). Group 2 excreted a mean 960±410 (SD) μg/L; a mean difference of 630±398 % (SD). It was concluded that the use of Trientine^(R) in subjects of normal copper status should be carefully controlled and monitored.     

蒲螨与人类疾病

蒲螨为一类农业害螨,部分种类可暂时性或偶然地侵袭人体。该文简要介绍了蒲螨的生物学、生态学、引起人体皮炎的蒲螨种类、皮炎的发生特点以及蒲可寄生人体内引起的疾病。并提出治疗方法和除螨措施。     

综述与专论: 低功率光照疗法对机体免疫应答的影响

最近几年,采用红至红外波长(600～1 100 nm)的低功率光照(low-dose light,LDL)疗法对组织代谢系统、神经系统、血液循环系统和免疫系统等方面的调节效应已经引起了广泛关注．同时,生物能学和光生物学基础研究的发展推动了低功率光照在疾病治疗领域的革新．有报道指出,巨噬细胞、肥大细胞、中性粒细胞和淋巴细胞等免疫细胞能响应低功率光照,产生细胞因子和保护性的蛋白质分子来缓解一些疾病的进程．因此,本文将从分子、细胞和组织水平对低功率光照改善的一些疾病的免疫学现象及机制进行归纳总结．     

Dermal toxicology of Lyngbya majuscula, from Moreton Bay, Queensland, Australia

Lyngbya majuscula is a filamentous marine cyanobacterium with a worldwide distribution in temperate and tropical regions to a depth of 30 m. Over 70 chemicals have been isolated and characterised from this organism, many of which are biologically active. Previously, L. majuscula has been reported as implicated in negative health outcomes only in Hawaii and Okinawa. Recently large blooms of L. majuscula have occurred with increasing repetition in the Moreton Bay region as well as other areas along the Australian coastline.Lyngbya toxin A (LA) and debromoaplysiatoxin (DAT) were found in samples of L. majuscula collected from Eastern Moreton Bay and North Deception Bay, Queensland, Australia, respectively. Samples of L. majuscula were also obtained from West Maui, Hawaii and the freshwater Lyngbya wollei from Florida. A quantitative measure of the irritant effects of the chemicals found in L. majuscula was made using a mouse ear swelling test. The relative toxicities of two purified toxins, LA and DAT, were examined. These were found to produce swelling to a similar extent. The time course of inflammation and histopathological results were also similar for the two purified toxins. Less than 1 μg per ear of either toxin or a mixture (1:1) of the two toxins caused a measurable increase in ear thickness. When toxins were combined (1:1) there was an additive, not synergistic effect. Increases in ear thickness occurred within 15 min. Crude extracts of L. majuscula from Moreton Bay were also applied to mice ears. The effect of crude extracts from Eastern Moreton Bay was not fully explained by the measured LA content, suggesting other toxin(s) and/or modulating factors were present. The toxic effects of L. majuscula containing DAT from North Deception Bay were explained by the concentrations measured. Some samples of L. majuscula containing no measurable quantities of LA or DAT were found to exert an inflammatory response. This response had a different time course to the response produced by LA or DAT.     

广西部分地区稻田皮炎的调查研究

广西各地稻田皮为存在已久。１９８４－１９９０年，经调查及实验研究，证实流行于上林、横县、宁明、龙州、天等、田阳、都安等县的稻田皮炎，其病原为包氏毛毕吸虫尾蚴，本虫的自然终宿主为家鸭，中间宿主是椭圆卜螺和小土蜗。皮炎的发生常与养鸭习惯、季节性、稻田种类及施肥等因素有关。每年的４－９月份为广西稻田皮炎发病季节，其中４－５月份为广西稻皮炎发病季节，其中４－５月份为发病高峰。     

The basidiomycetous yeasts Cryptococcus diffluens and C. liquefaciens colonize the skin of patients with atopic dermatitis

Our previous research showed that lipophilic yeasts, Malassezia species, colonize the skin of patients with atopic dermatitis (AD) at a high frequency. In this study, we found that two basidiomycetous yeasts, Cryptococcus diffluens and C. liquefaciens, colonize the skin significantly more frequently in AD patients than in healthy subjects. Transparent dressings were applied to the skin of 36 AD patients and 30 healthy subjects and then transferred onto Sabouraud dextrose agar. Colonies recovered from the medium were identified by DNA sequence analysis of internal transcribed spacer regions and the D1/D2 26S rRNA gene. C. diffluens and C. liquefaciens were isolated from 42% (15/36) and 33% (12/36) of AD patients and from 20% (6/30) and 20% (6/30) of healthy subjects, respectively. In addition, fungal DNA was extracted directly from the dressings and amplified in a specific nested PCR assay. C. diffluens and C. liquefaciens DNA were detected in dressings from 97% (35/36) and 86% (31/36) of the AD patients and 47% (14/30) and 37% (11/30) of the healthy subjects, respectively. These findings show that Malassezia spp. are not the only yeasts that colonize the skin of AD patients; Cryptococcus spp. also are present in a high proportion of patients. The role of these microorganisms in AD is as yet unknown, but the current findings, in combination with previous results, indicate that C. diffluens, C. liquefaciens, M. globosa, and M. restricta together colonize the skin surface of AD patients at a high frequency.