Objective To establish the ELISA kit of monoclonal antibodies to Clostridium difficile toxin A.Methods A sandwich ELISA was used.Flat-bottomed 96 well polystyrene microtitre plates were coated with 100 ?l of purified rabbit monospecific antitoxin(8 ?g/ml, capturing antibody) in carbonate buffer(pH9.6) and incubated overnight at 4℃, the plates were washed once in PBS containing 0.05% Tween-20, pH7.4 (PBST). After 200 ?l of 10% BSA in PBS-T was added to the wells and incubated at 37℃ for 2h, washed 5 times in PBS-T with 3 min incubation at room temperature between each wash, 100 ?l of C. difficile toxin A or test samples in PBS-T were added to each well and incubated for 1h at 37℃, washed 5 times. Then 100 ?l of 1:1000 diluted monoclonal antibodies IgG-Horseradish peroxidase conjugate(detecting antibody) was added for 1h at 37℃, wells were washed five times with PBS-T, and 0.1ml of tetramethylbenzidines substrate was added to each well. After 15 min at 37℃ in dark, the reactions were stopped by the addition of 1 drop of 2M sulfuric acid and the A450 was measured.Results The tested specimens included culture filtrates of 2 strains of toxigenic C. difficile, 2 non-toxigenic strains of C. difficile, 26 strains of E. coli, 2 strains of S. dysenteriae, 1 strains of Bifidobacterium, 5 strains of V. cholera, 2 strain of S. typhi, 7 strains of C. botulinum, 1 strain of toxigenic C. sordllii, and 1 strain of C. butyricum. The ELISA demonstrated high specificity and good sensitivity, it detected amounts of toxin A as low as 0.1ng/ml.Conclusion An ELISA kits with high specificity and good sensitivity for the rapid detection of C. difficile toxin A was presented. It will be a beneficial tool to clinical detection of Clostridium difficile toxin A.

Objective To explore the impact of amlodipine ,enalapril ,telmisartan and metoprolol on the blood pressure variability (BPV) in the patients with essential hypertension(EH) .Methods 120 patients with EH were divided into the amlodipine ,enala-pril ,telmisartan and metoprolol groups with 30 cases in each group .The ambulatory blood pressure monitoring (ABPM ) was adopt-ed and BPV before treatment and after 8-week treatment was observed .Results The anti-hypertensive effect of amlodipine and telmisartan was more obvious ,and the anti-hypertensive effect of metoprolol on the diastolic blood pressure was significant ,but the anti-hypertensive effect of enalapril was unobvious .Amlodipine and telmisartan lowered BPV at most time .Amlodipine mainly re-duced the daytime diastolic BPV ,while telmisartan reduced the night BPV significantly ;metoprolol and enalapril increased the day-time systolic BPV and decreased the nighttime BPV in 24 h BPV .Conclusion Amlodipine ,enalapril ,telmisartan and metoprolol can reduce the blood pressure in the patients with EH ,but their influences on BPV have difference .The impact of different anti-hyper-tensive drugs on BPV is inconsistent with the anti-hypertensive effect .

Taenia pisiformis is one of the most important parasites of canines and rabbits. T. pisiformis cysticercus (the larval stage) causes severe damage to rabbit breeding, which results in huge economic losses. In this study, the genetic variation of T. pisiformis was determined in Sichuan Province, China. Fragments of the mitochondrial cytochrome b (cytb) (922 bp) gene were amplified in 53 isolates from 8 regions of T. pisiformis. Overall, 12 haplotypes were found in these 53 cytb sequences. Molecular genetic variations showed 98.4% genetic variation derived from intra-region. F(ST) and Nm values suggested that 53 isolates were not genetically differentiated and had low levels of genetic diversity. Neutrality indices of the cytb sequences showed the evolution of T. pisiformis followed a neutral mode. Phylogenetic analysis revealed no correlation between phylogeny and geographic distribution. These findings indicate that 53 isolates of T. pisiformis keep a low genetic variation, which provide useful knowledge for monitoring changes in parasite populations for future control strategies.
Animals ; China ; Cytochromes b/*genetics ; *Genetic Variation ; Helminth Proteins/*genetics ; Humans ; Mitochondria/*genetics ; Molecular Sequence Data ; Phylogeny ; Rabbits ; Taenia/classification/genetics/*isolation & purification ; Taeniasis/*parasitology

Dirofilaria immitis (heartworm) infections affect domestic dogs, cats, and various wild mammals with increasing incidence in temperate and tropical areas. More sensitive antibody detection methodologies are required to diagnose asymptomatic dirofilariasis with low worm burdens. Applying current transcriptomic technologies would be useful to discover potential diagnostic markers for D. immitis infection. A filarial homologue of the mammalian translationally controlled tumor protein (TCTP) was initially identified by screening the assembled transcriptome of D. immitis (DiTCTP). A BLAST analysis suggested that the DiTCTP gene shared the highest similarity with TCTP from Loa loa at protein level (97%). A histidine-tagged recombinant DiTCTP protein (rDiTCTP) of 40 kDa expressed in Escherichia coli BL21 (DE3) showed immunoreactivity with serum from a dog experimentally infected with heartworms. Localization studies illustrated the ubiquitous presence of rDiTCTP protein in the lateral hypodermal chords, dorsal hypodermal chord, muscle, intestine, and uterus in female adult worms. Further studies on D. immitis-derived TCTP are warranted to assess whether this filarial protein could be used for a diagnostic purpose.
Animal Structures/chemistry ; Animals ; Antibodies, Helminth/blood ; Antigens, Helminth/chemistry/*genetics/immunology/*isolation & purification ; Cloning, Molecular ; Dirofilaria immitis/chemistry/*genetics/immunology ; Disease Models, Animal ; Dogs ; Escherichia coli/genetics ; Gene Expression ; Molecular Sequence Data ; Molecular Weight ; Recombinant Fusion Proteins/chemistry/genetics/immunology/isolation & purification ; Sequence Analysis, DNA ; Tumor Markers, Biological/chemistry/*genetics/immunology/*isolation & purification

L-2-aminobutyric acid (L-ABA) is an important chemical raw material and chiral pharmaceutical intermediate. The aim of this study was to develop an efficient method for L-ABA production from L-threonine using a trienzyme cascade route with Threonine deaminase (TD) from Escherichia. coli, Leucine dehydrogenase (LDH) from Bacillus thuringiensis and Formate dehydrogenase (FDH) from Candida boidinii. In order to simplify the production process, the activity ratio of TD, LDH and FDH was 1:1:0.2 after combining different activity ratios in the system in vitro. The above ratio was achieved in the recombinant strain E. coli 3FT+L. Moreover, the transformation conditions were optimized. Finally, we achieved L-ABA production of 68.5 g/L with a conversion rate of 99.0% for 12 h in a 30-L bioreactor by whole-cell catalyst. The environmentally safe and efficient process route represents a promising strategy for large-scale L-ABA production in the future.
Aminobutyrates ; chemical synthesis ; Bacillus thuringiensis ; enzymology ; Candida ; enzymology ; Escherichia coli ; enzymology ; Formate Dehydrogenases ; metabolism ; Leucine Dehydrogenase ; metabolism ; Threonine ; metabolism ; Threonine Dehydratase ; metabolism