中国平脉树螽属五新种记述：直翅目：螽斯科：树螽亚科

本文报道中国平脉树螽属5个新种。每个新种皆有详细的形态描述和形态特征图。所有模式标本存于北京农业大学昆虫标本室。     

Transformation of UV-hypersensitive Chinese hamster ovary cell mutants with UV-irradiated plasmids

Transfection of UV-hypersensitive, DNA repair-deficient Chinese hamster ovary (CHO) cell lines and parental, repair-proficient CHO cells with UV-irradiated pHaprt-1 or pSV2gpt plasmids resulted in different responses by recipient cell lines to UV damage in transfected DNA. Unlike results that have been reported for human cells, UV irradiation of transfecting DNA did not stimulate the genetic transformation of CHO recipient cells. In repair-deficient CHO cells, proportionally fewer transformants were produced with increasing UV damage than in repair-proficient cells in transfections with the UV-irradiated hamster adenine phosphoribosyltransferase (APRT) gene contained in plasmid pHaprt-1. However, transfection of CHO cells with UV-irradiated pSV2gpt resulted in neither decline in transformation frequencies in repair-deficient cell lines relative to repair-proficient cells nor stimulation of genetic transformation by UV damage in the plasmid. Blot hybridization analysis of DNA samples isolated from transformed cells showed no dramatic changes in copy number or arrangement of transfected plasmid DNA with increasing UV dose. We conclude that the responses of recipient cells to UV-damaged transfecting plasmids depend both on the type of recipient cell and the characteristics of the genetic sequence used for transfection.     

The HCH-1 model of enzymatic cellulose hydrolysis

Solka Floc BW200 was enzymatically hydrolyzed in a batch reactor using a commercial cellulase preparation. A total of 50 different hydrolysis conditions were run within a 10-fold range in enzyme concentration and a 30-fold range in cellulose concentration. The data were evaluated in three ways using five different models. Previous literature models were not as successful in correlating the data as the HCH-1 Model derived in this work.     

Incidence of Dumping after Truncal and Selective Vagotomy with Pyloroplasty and Highly Selective Vagotomy without Drainage Procedure

The incidence of dumping after truncal or selective vagotomy with pyloroplasty and highly selective vagotomy without a drainage procedure was assessed both clinically and experimentally. At a gastric follow-up clinic dumping was found to be significantly less frequent in patients who had undergone highly selective vagotomy without a drainage procedure than in patients who had undergone truncal or selective vagotomy with pyloroplasty (P < 0·05 or < 0·001, respectively). Hypertonic glucose given by mouth provoked the onset of dumping in 20% of patients with duodenal ulcer before operation, in 73% after truncal vagotomy and pyloroplasty, in 80% after selective vagotomy and pyloroplasty, and in 47% after highly selective vagotomy. The test meal also produced significantly greater decreases in blood pressure and increases in pulse rate in patients who had undergone vagotomy with pyloroplasty than in patients who had undergone highly selective vagotomy.     

Monitoring the persistence of Laccaria bicolor as an ectomycorrhizal symbiont of nursery-grown Douglas fir by PCR of the rDNA intergenic spacer

The large-scale inoculation of selected beneficial ectomycorrhizal fungi in forest nurseries has generated renewed interest in the ecology of these symbiotic fungi. However, information on the dissemination and persistence of introduced symbionts is scarce due to the limitation of the current identification methods. To identify ectomycorrhizal fungi on single root tips, we investigated the polymorphism of the PCR-amplified ribosomal DNA intergenic spacer (IGS) from a wide range of ectomycorrhizal fungi. To investigate the reliability of this molecular approach in large-scale surveys, the dissemination and persistence on Douglas fir seedlings of the introduced Laccaria bicolor S238N were assessed in a forest nursery in the Massif Central (France). Several hundred ectomycorrhizas and fruiting bodies were sampled from plots where control and L. bicolor inoculated-Douglas fir seedlings were grown for 1.5 years. PCR typing of mycorrhizas indicated that trees inoculated with L. bicolor S238N remained exclusively colonized by that isolate (or sexually derived isolates) for the entire test period. In contrast, control seedlings were infected by indigenous isolates of Laccaria laccata and Thelephora terrestris. The molecular evidence for the persistence of the introduced mycobiont despite the competition from indigenous isolates of the same species provides further illustration of the potential of exotic species for large-scale microbial application.     

Factors influencing alkali-induced heat resistance in Salmonella enteritidis phage type 4

The culture of cells of Salmonella enteritidis PT4 at either 25, 30 or 37°C in media at pH values between 8.0 and 9.75 resulted in significant increases in heat resistance. At 37°C, induction was rapid and was dependent on protein synthesis, being inhibited by chloramphenicol. Thermotolerance was stable when cells were transferred from pH 9.2 to pH 7.0 and cultures only became heat sensitive again following significant multiplication at the lower pH.