Skin problems after a tsunami

BACKGROUND: On December 26, 2004, the biggest earthquake for 40 years, measuring 9.0 on the Richter scale, triggered a tsunami that pounded the coastal areas of South Asia and East Africa. The effects of the tsunami on skin conditions have not been evaluated. OBJECTIVE: To determine the influence of the tsunami on skin conditions by evaluating the skin problems of patients presenting at hospitals after the tsunami. METHODS: Between 5 and 25 January 2005, two dermatologists evaluated patients who complained of skin problems at an outpatient clinic and emergency room of a general hospital in Banda Aceh, Aceh Province, Indonesia. RESULTS: The total number of patients that presented during the study period was 235 (131 males and 104 females), and they had a total of 265 skin problems. In terms of age distribution, most subjects were in their fourth decade (23.0%), followed by the third (22.6%) and fifth decade (16.6%). The most prevalent skin problems were infections-infestations (32.5%), followed by eczemas (29.8%) and traumatic skin disorders (29.4%). In males, traumatic skin disorders were most common. The great majority of infection-infestation cases involved superficial fungal infections. Contact dermatitis accounted for three-quarters of eczema cases, and mainly involved the arms (40.0%) and legs (27.1%). The majority of traumatic skin disorders were lacerations, punctures and penetrations, and the feet (44.7%) and hands (18.8%) were most frequently affected. CONCLUSIONS: Unhygienic conditions, exposure to a hazardous environment and contact with various objects during and after the tsunami probably increased the prevalence of infections-infestations, traumatic skin disorders and contact dermatitis. To prevent these problems and associated secondary bacterial infections, health-related education and early medical management are required.     

Pesticide assessment: Protecting public health on the home turf

Pesticide regulation is examined in the context of Health Canada’s Pest Management Regulatory Agency’s assessment of the chlorophenoxy herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) for turf. 2,4-D is the most common herbicide used to kill weeds in grass.The medical literature does not uniformly indicate harms from herbicides. However, the balance of epidemiological research suggests that 2,4-D can be persuasively linked to cancers, neurological impairment and reproductive problems. These may arise from 2,4-D itself, from breakdown products or dioxin contamination, or from a combination of chemicals.Regulators rely largely on toxicology, but experiments may not replicate exposures from 2,4-D application to lawns because environmental breakdown products (eg, 2,4-dichlorophenol) may not accumulate and selected herbicides are possibly less contaminated. Dioxins are bioaccumulative chemicals that may cause cancer, harm neurological development, impair reproduction, disrupt the endocrine system and alter immune function. No dioxin analyses were submitted to the Pest Management Regulatory Agency, and the principal contaminants of 2,4-D are not among the 17 congeners covered in pesticide regulation. Independent assessment of all dioxins is needed, in tissues and in the environment.The 2,4-D assessment does not approach standards for ethics, rigour or transparency in medical research. Canada needs a stronger regulator for pesticides. Potentially toxic chemicals should not be registered when more benign solutions exist, risks are not clearly quantifiable or potential risks outweigh benefits. Until landscaping pesticides are curtailed nationally, local bylaws and Quebec’s Pesticide Code are prudent measures to protect public health. Physicians have a role in public education regarding pesticides.     

成纤维细胞的力学生物学(下)

一、肌腱内成纤维细胞的力学生物学反应 肌腱内的成纤维细胞可以合成胶原蛋白及其他一些大分子。成纤维细胞可以将这些分子排列成组织性较高的单元，并使纤维的方向与张力方向平行。无论是培养的肌腱还是独立的成纤维细胞都可以对力做出相应的反应。     

Lipoteichoic acid induces secretion of interleukin-8 from human blood monocytes: a cellular and molecular analysis.

Invasion by gram-positive and gram-negative bacterial organisms is characterized immunopathologically by the activation of mononuclear phagocytic cells, leading to the elaboration of macrophage-derived regulatory and chemotactic factors, and the resultant influx of inflammatory leukocytes. Little is known regarding the mechanisms by which gram-positive organisms initiate macrophage activation and subsequent inflammation. In this investigation, we postulated that lipoteichoic acid (LTA) purified from two different gram-positive bacterial species was an important signal for the expression of chemotactic cytokines from human peripheral blood monocytes (PBM). In initial experiments, we demonstrated that cell-associated interleukin-8 (IL-8) was expressed by mononuclear phagocytes present in inflamed areas of endocardium in cases of acute Staphylococcus aureus endocarditis. We next demonstrated that LTA purified from either Staphylococcus aureus or Streptococcus pyogenes induced the time- and dose-dependent expression of IL-8 mRNA and protein from human PBM. The expression of IL-8 mRNA from LTA- but not lipopolysaccharide (LPS)-treated PBM was superinduced by concomitant treatment with cycloheximide, indicating that the expression of IL-8 mRNA from LTA-treated PBM was negatively controlled by repressor proteins. Furthermore, mRNA stability studies indicated that IL-8 mRNA was less stable in the presence of LTA than in the presence of LPS. Our findings indicate that LTA can induce the secretion of the polymorphonuclear leukocyte chemotactic factor IL-8 and that LTA may be an important cellular mediator of inflammatory cell recruitment that characterizes immune responses to gram-positive bacterial infections.