Removal of Mixed Pesticides from Aqueous Solutions using Organoclays: Evaluation of Equilibrium and Kinetic Model

Removal of mixed pesticides, namely alachlor, metolachlor, chlorpyriphos, fipronil, α-endosulfan, β-endosulfan, p,p′-DDT and two metabolites p,p′-DDE and endosulfan sulphate from aqueous solution by batch adsorption onto three commercial organo-modified montmorillonite clays [modified with octadecylamine (ODA-M), modified with dimethyl- dialkylamine (DMDA-M) and modified with octadecylamine and aminopropyltriethoxysilane (ODAAPS-M)] were investigated. Effect of process variables, mainly contact time and initial concentration of mixed pesticides, on adsorption phenomenon were evaluated. To understand the adsorption kinetic pseudo-first-order and pseudo-second-order models were tested. The pseudo-second-order model provided the best fit for explaining adsorption kinetics, on the basis of high correlation coefficient (r) and normalized percent deviation values. The adsorption equilibrium was explained by the Freundlich isotherm (r = 0.951–0.992). High values (0.17–0.52 mg g^?1) of Freundlich constant (K_f) indicated higher affinity of pesticides towards all three organoclays, as a result of hydrophobic interaction between the adsorbent/adsorbate systems. Pesticides with high octanol–water partition coefficient (K_ow) and low water solubility showed faster adsorption with higher K_f values as compared to the pesticides with low K_ow and high water solubility. The order of organoclays for removal efficiency of mixed pesticide was ODAAPS-M > DMDA-M > ODA-M. These findings may find application to decontaminate or treat mixed pesticide contaminated industrial/agricultural waste waters.     

Experience with the Amplatz retrievable vena caval filter. Work in progress

The Amplatz retrievable vena caval filter was designed in an attempt to decrease complications associated with the placement of Mobin-Uddin or Kimray-Greenfield filters. The design allows percutaneous retrieval, thus expanding application of the filter to situations requiring temporary prophylaxis against pulmonary embolism. Filters have been placed in 16 patients, nine (56%) for prophylactic purposes. All filters were easily inserted percutaneously. Complications occurred in three patients; these included complete thrombosis of the inferior vena cava below the filter, misplacement of one filter into the pericaval retroperitoneal tissue, and development of thrombus cranial to the filter. With the current introduction system, the possibility of filter misplacement has been essentially eliminated. No patient experienced symptoms suggestive of pulmonary embolism after filter insertion. One filter retrieval has been performed, with no complications.     

Effect of medial arch-heel support in inserts on reducing ankle eversion: a biomechanics study

Background  

Excessive pronation (or eversion) at ankle joint in heel-toe running correlated with lower extremity overuse injuries. Orthotics and inserts are often prescribed to limit the pronation range to tackle the problem. Previous studies revealed that the effect is product-specific. This study investigated the effect of medial arch-heel support in inserts on reducing ankle eversion in standing, walking and running.     

Tarlov cyst as a rare cause of S1 radiculopathy: A case report

A 37-year-old female physician presented with a chief complaint of left posterior thigh pain, which began insidiously approximately 4 months before her initial examination. Initially, she had been evaluated by her physician, and magnetic resonance imaging (MRI) was ordered. The MRI scan was reported to be within normal limits, with the exception of minimal disc bulging at L4-5. She had received physical therapy with little benefit and was referred for physiatric assessment. Review of the patient's original MRI scan showed the presence of perineurial (Tarlov) cysts within the sacral canal at the level of S2, with compression of the adjacent nerve root. Subsequent electrodiagnostic testing showed axonal degeneration consistent with an S1 radiculopathy. Tarlov cysts can be a rare cause of lumbosacral radiculopathy and should be considered in the differential diagnosis of radicular leg pain.     

基于7次跨膜受体的药物发现基本方法——细胞检测

随着检测技术进步,含7个跨膜α螺旋结构的受体性质已渐为人们所了解。7次跨膜（7TM）受体不仅具有开关功能,更类似于信息微处理器;特定配体只能参与特定受体介导的部分信号机制,这就为药物发现开拓了一个新领域。为进一步发现7TM受体与配体间的新行为并量化评价药物对这一复杂系统的作用效能,进而指导药物化学研究,药理学检测已成为关注焦点。本文阐述从还原重组体到整体系统测定方法的回归,讨论药物效价与评价其效应的特定检测方法间的联系,强调新的检测方法在药物发现过程中的价值。     

CD3+ leukemic large granular lymphocytes utilize diverse T-cell receptor V beta genes

CD3+ large granular lymphocyte (LGL) leukemia is a disease of unknown etiology characterized by clonal proliferation of T cells that usually express T-cell receptor (TCR) alpha beta heterodimers. The purpose of this study was to identify the variable (V), joining (J), and diversity (D) region TCR beta-chain genes expressed by CD3+ LGL leukemic cells in an attempt to gain insights into the etiology of this disorder. Twelve patients with LGL leukemia were studied, including seven with both LGL leukemia and rheumatoid arthritis (RA). RA is also a disease of unknown etiology that occurs frequently in patients with LGL leukemia. Clonally expanded T cells that express specific TCR V beta genes have been identified in fluid and tissue specimens from the joints of patients with RA. In this study, V beta expression was determined by PCR using a panel of 22 unique V beta primers to amplify cDNA prepared from peripheral blood mononuclear cells (PBMC). A dominant V beta gene product was readily apparent in all patients. To confirm that the dominant V beta gene originated from a clonal expansion, DNA fragments corresponding to the dominant V beta genes were subcloned into plasmids and independently isolated recombinants were sequenced. V-D-J region sequences that occurred repeatedly indicated clonality. The V beta and J beta genes expressed by the leukemic cells showed a pattern of distribution that followed the frequency with which these genes are represented in the peripheral blood. The residues corresponding to the third complementarity-determining region of the TCR beta chain were different in all cases. A specific pattern of VDJ usage was not identified for those patients with both LGL leukemia and RA; however, utilization of V beta-6 by LGL clones (N = 3) was observed only in the setting of RA. These data suggest that leukemic CD3+ LGL cells have been clonally transformed in a random fashion with respect to the TCR beta chain.     

Induction of NK activity in large granular lymphocyte leukemia: activation with anti-CD3 monoclonal antibody and interleukin 2

Large granular lymphocyte (LGL) leukemia is a rare disease characterized by clonal expansion of LGL associated with chronic neutropenia, multiple auto-antibodies, and occasionally polyarthritis. We studied cell surface antigen expression and functional activity of leukemic LGL from ten such patients. Using two-color flow cytometric analysis, we found that leukemic LGL from all ten patients expressed the CD3 and HNK-1 markers, while cells from only four patients expressed IgG Fc receptors (FcR). The LGL leukemic cells had little or no NK activity (defined as MHC-nonrestricted cytotoxicity against K562 target cells); however, NK activity could be induced in leukemic LGL by in vitro treatment with as little as 0.05 microgram/mL of anti-CD3 monoclonal antibody. Cell sorting experiments demonstrated that NK activity was induced in CD3+ leukemic LGL (either CD3+, HNK-1+ or CD3+, FcR+) with anti-CD3 monoclonal antibody but not in normal CD3+, FcR- T cells. Treatment with purified interleukin 2 (IL 2) also caused direct activation of some CD3+ leukemic LGL. Despite induction with anti-CD3 MAb or IL 2, activated leukemic LGL did not proliferate or express high density IL 2 receptors detectable by cell sorter analysis. Treatment with alpha interferon had minimal effect on NK activity of LGL leukemic cells. These results suggest that leukemic LGL may provide a useful model for examining the signals required for LGL maturation and activation.