Microcystin-LR Removal from Water via Enzymatic Linearization and Ultrafiltration

Microcystin-LR (MC-LR) is a toxin produced by cyanobacteria that can bloom in freshwater supplies. This study describes a new strategy for remediation of MC-LR that combines linearization of the toxin using microcystinase A, MlrA, enzyme with rejection of linearized byproducts using membrane filtration. The MlrA enzyme was expressed in Escherichia coli (E. coli) and purified via a His-tag with 95% purity. Additionally, composite membranes made of 95% polysulfone and 5% sulfonated polyether ether ketone (SPEEK) were fabricated and used to filter a solution containing cyclic and linearized MC-LR. Tests were also performed to measure the adsorption and desorption of MC-LR on polysulfone/SPEEK membranes. Liquid chromatography-mass spectrometry (LC-MS) was used to characterize the progress of linearization and removal of MC-LR. Results indicate that the MlrA was successful at linearizing MC-LR. Membrane filtration tests showed rejection of 97% of cyclic MC-LR and virtually all linearized MC-LR, with adsorption to the membranes being the main rejection mechanism. Adsorption/desorption tests indicated that methanol could be used to strip residual MC-LR from membranes to regenerate them. This study demonstrates a novel strategy of remediation of microcystin-tainted water, combining linearization of MC-LR to a low-toxicity byproduct along with removal by membrane filtration.     

Electrical burns to the hand from lawn-mowers

Fifteen cases of electrical burns to the hand are described resulting from the use of electric lawn-mowers. These injuries caused significant morbidity and time off work, and one death. Most of the burns appear to have been preventable, and ways of averting these injuries are discussed.     

Pathologic effects of ESWL on canine renal tissue

The introduction of extracorporeal shock wave lithotripsy (ESWL) has provided an avenue for dealing with many urinary stones noninvasively. The margin of safety for the kidney during shock wave administration is largely undefined. A pilot study was performed where six kidneys in five female mongrel dogs were shocked. Group A kidneys were given 1,776, 4,500, 6,000, or 8,000 shocks, respectively, at 18-24 kV. Group B kidneys received 1,600 and 8,000 shocks (18-24 kV). The number of shocks per electrode ranged from 500 to 4,538 and averaged 2,490. The dogs were sacrificed forty-eight to seventy-two hours (Group A) or twenty-eight to thirty-two days (Group B) post-treatment. Modest damage (hematoma and/or interstitial hemorrhage) was noted in all kidneys. Evidence of permanent change (fibrosis) was noted in both Group B kidneys. Complete necrosis of the kidney was not seen after administration of 8,000 shocks. These preliminary data indicate that lithotripsy can, in some circumstances, produce renal damage in the canine model.     

苯丙烯酸类衍生物和类似物的合成及其抗炎和抗癌活性研究(英文)

近年研究表明,炎症和癌症都与花生四烯酸的代谢产物环氧酶和5-脂氧酶密切相关。据此选择对环氧酶或5-脂氧酶具有抑制作用的苯丙烯酸类化合物作为抗炎、抗癌先导化合物,并对其酯类衍生物及其苯乙烯酮类类似物进行初步探讨。本文作者设计并合成上述类型化合物共十九个,其中十五个为未见文献报道的新化合物,并经红外光谱、¹H-核磁共振光谱及元素分析等证实其化学结构。对所合成的化合物进行了抗炎及抗癌药理活性初步筛选。体内抗炎实验表明,所合成的苯丙烯酸类化合物Ⅰ_A,Ⅰ_B,Ⅰ_C人及其酯类衍生物Ⅱ_2A,Ⅱ_2C,Ⅱ_5C和苯乙烯酮类似物Ⅲ_C对巴豆油诱发的小鼠耳廓肿胀均有不同程度和抑制作用。体外抗癌作用初步筛选结果表明,化合物Ⅰ_B,Ⅱ_5A,Ⅱ_5C,及Ⅲ_D对HL-60人癌细胞均有较好的抑制作用。值得注意的是,化合物Ⅰ_B和Ⅱ_5C不仅对体外HL-60人癌细胞具有明显的抑制作用,而且对巴豆油所致小鼠炎症亦有较强的活性。深入的药理实验还在进行中。     

Use of an efficient method for culturing human mammary epithelial cells to study adriamycin sensitivity

Summary Techniques are described for isolating, cryopreserving, and culturing human mammary epithelial cells of both normal and malignant origin. The cells can be grown either in mass culture or as a clonal assay suitable for quantitating drug sensitivity. With this clonal assay plating efficiencies of 6%–41% were routinely obtained. We examined the response to adriamycin of five different primary carcinoma cultures from patients without prior drug therapy. We were able to detect heterogeneity in response to adriamycin among the breast carcinoma cultures as well as heterogeneity among subpopulations within a single carcinoma. The differences in adriamycin sensitivity were unrelated to growth rates in culture.     

A retrospective review of pregnancies on biologics for the treatment of dermatological conditions

Psoriasis often first presents in young adulthood, with the average age of diagnosis in women being 28 years, thus in the prime reproductive years. In addition, approximately 50% of pregnancies worldwide are unplanned. Although biologic therapies have revolutionized the treatment of moderate-to-severe psoriasis, there are no controlled studies of biologics in pregnant women. The increasing use of these agents in women of childbearing age highlights the need to further assess their safety during pregnancy. Postmarketing experience regarding the safety of these drugs is accumulating and being published, with largely reassuring results. We present our real-world experience of 17 pregnancies occurring in women on treatment with biologic agents for dermatological conditions to further add to the body of knowledge.