Two Cases of Cutaneous Diphtheria Associated with Occupational Pig Contact in Germany

In 2010, two independent cases of cutaneous diphtheria caused by toxigenic C. ulcerans were identified in Germany. Both patients had intense occupational contact with pigs. Diagnostic work‐up comprising biochemical differentiation, rpoB sequencing, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF) analysis, real‐time tox PCR and Elek test as well as public health measures including an intensified source tracing involving 83 asymptomatic pigs of an associated pig farm are presented.     

Effects of temperature and concentration of the accelerators ethoxylated alcohols,diethyl suberate and tributyl phosphate on the mobility of [14C]2,4‐dichlorophenoxy butyric acid in plant cuticles

Intrinsic activities of monodisperse ethoxylated dodecanols (MEDs), diethyl suberate (DESU) and tributyl phosphate (TBP) were investigated using Stephanotis floribunda leaf cuticular membranes (CMs) and [¹⁴C]2,4‐dichlorophenoxy butyric acid (2,4‐DB) as a model solute. When sorbed in cuticular membranes, MEDs, DESU and TBP increase solute mobility and are called accelerators for this reason. With MEDs, dose‐effect curves (log mobility vs accelerator concentration) were linear but, with DESU and TBP, curves convex to the x axes were obtained that approached a maximum at 90 and 150 g kg⁻¹, respectively. Accelerators increased the mobility of 2,4‐DB in the CMs by 9‐ to 48‐fold, and effects were larger at lower temperatures (range 15–30 °C). Activation energy for diffusion of 2,4‐DB was 105 kJ mol⁻¹, decreasing with increasing accelerator concentrations to 26 kJ mol⁻¹ with DESU at 90 g kg⁻¹ and 64 kJ mol⁻¹ with TBP at 150 g kg⁻¹. Thus, the intrinsic activity of DESU was much higher than that of TBP, which implies that, for a given effect, less DESU than TBP would be needed. MEDs were also very effective accelerators, lowering activation energies to 36 kJ mol⁻¹. Data are discussed in relation to increasing rates of foliar penetration of active ingredients at low temperatures. © 2001 Society of Chemical Industry     

Photolysis of imidacloprid (NTN 33893) on the leaf surface of tomato plants

The photolytic behaviour of the insecticide imidacloprid on the surface of tomato leaves as a result of exposure to natural sunlight was investigated. Photodegradation in sunlight was rapid and the degradation products (⩾10%) were similar to those found in plant degradation studies.     

Physicochemical and Biological Characterization of Fucoidan from Fucus vesiculosus Purified by Dye Affinity Chromatography

A comparative study concerning the physicochemical, monomeric composition and biological characters among different fucoidan fractions is presented. Common purification techniques for fucoidan usually involve many steps. During these steps, the important structural features might be affected and consequently alter its biological activities. Three purified fractions were derived from Fucus vesiculosus water extract which, afterwards, were purified by a recently-developed dye affinity chromatography protocol. This protocol is based on dye-sulfated polysaccharide interactions. The first two fractions were obtained from crude precipitated fucoidan at different pH values of the adsorption phase: pH 1 and 6. This procedure resulted in fucoidan_1 and 6 fractions. The other, third, fraction: fucoidan_M, however, was obtained from a buffered crude extract at pH 1, eliminating the ethanol precipitation step. All of the three fractions were then further evaluated. Results revealed that fucoidan_M showed the highest sulfur content (S%), 12.11%, with the lowest average molecular weight, 48 kDa. Fucose, galactose, and uronic acid/glucose dimers were detected in all fractions, although, xylose was only detected in fucoidan_1 and 6. In a concentration of 10 µg·mL⁻¹, Fucoidan_6 showed the highest heparin-like anticoagulant activity and could prolong the APTT and TT significantly to 66.03 ± 2.93 and 75.36 ± 1.37 s, respectively. In addition, fucoidan_M demonstrated the highest potency against HSV-1 with an IC₅₀ of 2.41 µg·mL⁻¹. The technique proved to be a candidate for fucoidan purifaction from its crude extract removing the precipitation step from common purification protocols and produced different fucoidan qualities resulted from the different incubation conditions with the immobilized thiazine toluidine blue O dye.     

纳米材料对林木生长发育影响及其在林木生物学上的应用

纳米材料已广泛应用于电子学、化学、医学材料、信息、环境、能源和安全等领域, 但在林业上的应用和研究才刚刚起步。文中主要综述纳米材料对林木生长发育的影响及其在林木生物技术上的应用(主要集中在纳米量子点荧光探针标记以及用纳米材料作为载体介导外源基因进行遗传转化等方面), 以及纳米技术在林木生物制药方面的开发应用, 对其发展前景进行了展望。     

Chlamydial infections in duck farms associated with human cases of psittacosis in France

Five severe cases of psittacosis in individuals associated with duck farms were notified in France between January and March 2006. Diagnostic examination included serology and/or molecular detection by PCR from respiratory samples. As a consequence, we investigated all duck flocks (n=11) that were housed in the three farms where human infections occurred. While serology by complement fixation test was negative for all samples, cloacal and/or tracheal chlamydial excretion was detected by PCR in all three units. Notably, one duck flock was tested strongly positive in 2 of the 3 affected farms, and Chlamydophila (C.) psittaci strains were isolated from cloacal and/or tracheal swab samples from both farms. Human samples and duck isolates exhibited the same PCR-RFLP restriction pattern, which appeared to be an intermediate between genotypes A and B. Analysis of ompA gene sequences and comparison to those of the type strains showed that the isolates could not be strictly assigned to any of the generally accepted genotypes of C. psittaci. Further analysis by MLVA of the PCR-positive human samples revealed two distinct patterns, which were related to previously isolated C. psittaci duck strains.