[Effects of Bt toxin Cry1Ac on biochemical responses of Eisenia fetida in an artificial soil]

Bt toxin Cry1Ac could be introduced into soil by pollen, root exudates, and plant residues. To investigate its toxic effects, the Bt toxin was added into an earthworm-cultured artificial soil, and the survival, growth rate, sperm count, protein content, and activities of acetylcholinesterase (AchE), catalase (CAT), glutathione S-transferase (GST) and cellulase in Eisenia fetida were determined. The results suggested that Bt toxin Cry1Ac had little effects on the biomass and physiological characteristics of E. fetida, with no acute and subchronic toxicity, and was safe for earthworm at field dose level.

[The study on improvement of survival for lung cancer surgically intervened in PUMC Hospital]

BACKGROUND

Lung cancer is still the most common cause of cancer death. Although it is reported that the 5-year survival rate for lung cancer has been greatly increased, surgical results are controversial. The aim of this study is to investigate and evaluate the improvement of survival of lung cancer surgically intervened in PUMC hospital during the last 15 years.

METHODS

From January 1989 to December 2003, 1574 cases of lung cancer underwent surgical treatment and obtained follow-up. The results were retrospectively a- nalysed . All cases in this series were divided into two groups according to time, group A (1999-2003) and group B (1989-1998), and the differences of survival rate between group A and group B were compared.

RESULTS

The morbidity and mortality of group A decreased significantly when compared to group B (11.2% vs 19.2%, 1.06% vs 1.93%, respectively, P < 0.01). However, the 3- and 5-year survival rates had been obviously raised from 42.35% to 56.07%, and from 28.46% to 38.99%, respectively (P < 0.05 ). A significant improvement in survival was observed in patients with stageI, stage II and stage IIIA, but not in stage IIIB and stage IV. Also, the patients with lobectomy had better results but those with exploratory thoracotomy, limited resection, pneumonectomy and sleeve resection did not show better results.

CONCLUSIONS

Lobectomy associated with systematic dissection of mediastinal lymph nodes has become the standard mode for the resectable lung cancer. Combination of complete resection and lymph nodes dissection, with postoperative adjuvant chemotherapy based on platinum/3rd generation medicine, have preliminarily been justified and proved an important approach for effective improvement of long-term survival of lung cancer.

Perinerin, a novel antimicrobial peptide purified from the clamworm Perinereis aibuhitensis grube and its partial characterization

A novel antimicrobial peptide was isolated and partially characterized from the homogenate of an Asian marine clamworm, Perinereis aibuhitensis Grube. This novel peptide, named Perinerin, was purified to homogeneity by heparin-affinity column and reverse-phase HPLC, and biologically tested with a MTS-PMS colorimetric assay. Perinerin consists of 51 amino acid residues and structurally appears to be highly basic and hydrophobic. It shows marked activity in vitro against both Gram-negative and Gram-positive bacteria and fungi, which indicates a bactericidal effect as well. Perinerin appears to be constitutively present and its sequence is novel among all other known antimicrobial peptides. These results suggest that Perinerin has the potential to serve as a convenient "evaluation marker" for studying alterations in the biochemistry of the host, particularly with respect to environmental changes. In addition, the MTS-PMS colorimetric assay examination of antimicrobial activity appears to be superior to existing methods and may offer more general application in the search for new antibiotic molecules.

Effect of cotton cultivar on development and reproduction of Aphis gossypii (Homoptera: Aphididae) and its predator Propylaea japonica (Coleoptera: Coccinellidae)

The effects of three cotton cultivars with low ('ZMZ13'), medium ('HZ401'), and high ('M9101') gossypol contents on the development, reproduction, and survival of Aphis gossypii Glover and its predator Propylaea japonica (Thunberg) were investigated. Developmental duration and immature survivorship did not vary between aphids on the three cultivars, whereas A. gossypii feeding on M9101 (high gossypol cultivar) displayed significantly shorter adult longevity and lower fecundity than aphids fed on 'ZMS13' and 'HZ401'. Free fatty acid content in cotton aphids reared on 'M9101' was greater than in those reared on 'HZ401' and 'ZMS13'. No significant differences in survival and lifetime fecundity of P. japonica were observed between P. japonica fed cotton aphids reared on the three different cultivars. P. japonica fed aphids from 'M9101' showed a significantly shorter developmental period and greater adult weight than those fed aphids from the other two cultivars. The decreased larval developmental duration and increased adult weight of P. japonica fed cotton aphids reared on the high gossypol-containing cultivar might have been caused by the high fatty acid content of the prey aphids. Our results indicate that high gossypol in host cotton had an antibiotic effect on A. gossypii and showed a positive effect on growth and development of P. japonica at the third trophic level. This suggests compatibility between one form of host plant resistance and biological control by predators. The allelochemical contents should be taken into account in integrated pest management for their effects on both herbivores and entomophagous insects.

[Effect of nitrogen fertilization and square loss on cotton aphid population, cotton leafhopper population and cotton yield]

The study on the effects of nitrogen fertilization (0-450 kg x hm(-2)) and square loss (0-12 x plant(-1)) on cotton aphid population, cotton leafhopper population and cotton yield showed that there were no significant differences in cotton aphid population, cotton leafhopper population, and numbers of effective bolls between transgenic Bt cotton and non-transgenic cotton. Cotton aphid populations on the two cottons were significantly influenced by nitrogen fertilization and by the interaction of nitrogen fertilization and square loss, while leafhopper populations were not significantly influenced by them. Nitrogen fertilization at squaring and flowering stage was one of important factors affecting cotton yield. There was a positive correlation between the application rate of nitrogen fertilizer and cotton yield, but a negative correlation between the number of lost square per plant and the yield of the two cottons.

Diapause induction and clock mechanism in the cabbage beetle, Colaphellus bowringi (Coleoptera: Chrysomelidae)

Photoperiodic control of diapause induction was investigated in the short-day species, Colaphellus bowringi, which enters summer and winter diapause as adult in the soil. Photoperiodic responses at 25 and 28 degrees C revealed a critical night length between 10 and 12 h; night lengths > or =12 h prevented diapause, whereas night lengths <12 h induced summer diapause in different degree. Experiments using non-24-h light-dark cycles showed that the duration of scotophase played an essential role in the determination of diapause. Night-interruption experiments with T=24 h showed that diapause was effectively induced by a 2-h light pulse in most scotophases; whereas day-interruption experiments by a 2-h dark break had a little effect on the incidence of diapause. The experiments of alternating short-night cycles (LD 16:8) and long-night cycles (LD 12:12) during the sensitive larval period showed that the information of short nights as well as long nights could be accumulated. Nanda-Hamner experiments showed three declining peaks of diapause at 24 h circadian intervals. Bünsow experiments showed two very weak peaks for diapause induction, one being 8 h after lights-off, and another 8 h before lights-on, but it did not show peaks of diapause at a 24 h interval. These results suggest that the circadian oscillatory system constitutes a part of the photoperiodic clock of this beetle but plays a limited role in its photoperiodic time measurement.

[Effects of huTNF-α and hIL-2 gene transfection on the expression of MDR1 and LRP genes in lung cancer cell lines]

BACKGROUND

To study the effects of huTNF-α and hIL-2 gene transfection on the expression of MDR1 and LRP genes in lung cancer cell lines.

METHODS

huTNF-α and hIL-2 gene plasmids were constructed and transfected into A549, GLC-82, H446 and H460 cells with lipofectinmin. Positive clones were screened out by G418. The expressions of MDR1 and LRP genes were detected at mRNA level by reverse transcription polymerase chain reaction (RT-PCR) in the non transfected cells and the cloned cells.

RESULTS

MDR1 gene was positive in A549, GLC-82, H446 and H460 cell lines, LRP gene was positive in A549, GLC-82 and H460 cell lines; The transfected cell lines expressed both huTNF-α and hIL-2 gene, and the A549, H446 and H460 cell lines transfected with hIL-2 gene had no MDR1 expression at mRNA level compared with the non transfected ones.

CONCLUSIONS

MDR1 and LRP genes are expressed in lung cancer cell lines, which indicates the presence of intrinsic drug resistance before any form of therapy. MDR1 gene is not expressed in hIL-2 transfected cell lines, which demonstrates that hIL-2 gene modulates the MDR1 gene expression at mRNA level, and may reverse the multidrug resistance of lung cancer.

[Edge effect on the dynamics of pests and natural enemies in cotton agroecosystems]

Investigation on the population dynamics of pests and natural enemies on the cotton plants in the middle and edge of cotton agroecosystems showed that the population of the 2nd generation of cotton bollworms (Heliocopavar armigia) and seedling aphids (Aphis gossyppi) was respectively 1.94 times and 1.09 times higher, but that of the 3rd generation cotton bollworms and summer aphids population was respectively 62.12% and 97.73% lower in the edge than in the middle of cotton agroecosystem. The population of predacious ladybeetles, predacious bugs, spiders and parasites in the edge of cotton agroecosystem was 73.81%, 35.79%, 52.90% and 39.11% of that in the middle of cotton agroecosystem, respectively. The greater diversity of pest community and the less diversity of natural enemies community were found in the edge than in the middle of cotton agroecosystem. The increase of energy utilization efficiency and gross production in the edge of cotton agroecosystems showed the edge effect of cotton agroecosystems.

[Surgical management of metastatic disease in the conjunctive area between neck and thorax]

OBJECTIVE

To study the surgical management of metastatic disease in the conjunctive area between the neck and thorax and its efficacy.

METHODS

Fourteen cases with metastatic node disease in the area between neck and thorax were collected and analysed. Eleven tumors were from the thyroid cancer, and the other three were from the hypopharyngeal cancer, esophagual cancer and malignant pheochromocytoma, respectively. The clavicle was displaced or resected, and the upper half of the manubrium might also be resected when necessary. The recurrent laryngeal nerve and phrenic nerve were exposed and protected. The metastatic disease was completely removed with the internal jugular and/or the brachiocephalic vein resected or spared, depending on the disease condition.

RESULTS

In 10 cases with metastases from the thyroid, no local recurrence was found within the follow-up period from 2 to 5 years. In contrast, no patient with metastatic disease from hypopharyngeal or esophageal cancer survived more than 11 months. No serious complications were found in this group.

CONCLUSIONS

The surgical treatment of node metastases in the conjunctive area between neck and thorax from the well-developed thyroid cancer has promising effect and is comparatively safe.

Reconfirmation of antimicrobial activity in the coelomic fluid of the earthwormEisenia fetida andrei by colorimetric assay

A novel tetrazolium salt, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphophenyl)-2H-tetrazolium (MTS) was used in the assessment of antimicrobial activity in earthworm in the presence of phenazine methosulphate (PMS) as an electron coupling reagent. This activity was purified from the coelomic fluid of the earthworm (ECF), Eisenia fetida andrei (Oligochaeta, Lumbricidae, annelids) using a series of column chromatography techniques and was tested against three Gram-negative strains of Escherichia coli, Pseudomonas aeruginosa, Aeromonas hydrophila and three Gram-positive strains of Staphylococcus aureus, Bacillus megaterium, Arthrobacter sp., respectively. Only the pigment-free eluate of coelomic fluid of the earthworm (ECFPE) showed activity against B. megaterium amongst three isolated active fractions. The anion (DEAE-52) exchange effluent of the ECFPE was reported to have the strongest activity against P. aeruginosa amongst the three active fractions. The 20% acetonitrile eluate (AE) by Sep-Pak C18 cartridge was also tested and showed fair resistance against E. coli, P. aeruginosa and Arthrobacter sp., respectively.

[Effect of nitrogen fertilizer on pest population and cotton production]

Field experiments were conducted from 1999 to 2000 to assess the effect of nitrogen fertilization levels (0.225 and 450 kg.hm-2) on the population dynamics of cotton bollworm (Helicoverpa armigera) and cotton aphid (Aphid gossypii), and on the numbers of cotton buds and bolls in North China. The population densities of cotton bollworm and cotton aphid increased with increasing nitrogen fertilization during 1999 to 2000, but the differences between treatments were not significant (P > 0.05). There were significant differences of cotton bollworm populations and no significant differences of cotton aphid populations between years. Nitrogen fertilization at flower-bud stage decreased the loss of cotton buds and flowers and increased the number of effective bolls and cotton yield, but the decrement and increment did not get to significant level (P < 0.05). No obvious correlations of nitrogen levels with main pest abundance and cotton production were observed.

[Life-table of Helicoverpa armigera in northern China and characters of population development in southern and northern China]

The population dynamics of Helicoverpa armigera in Raoyang County, Hebei Province as an example in Northern China was researched, and its natural life-table was established. The results showed that total mortality of first to fourth generations of cotton bollworm in Northern China were 98.3%, 98.34%, 98.69% and 99.13%, and the population tendency index (I) were 3.97, 1.50, 1.41 and 1.09, respectively. A comparative analysis of the natural life-table of cotton bollworm in Southern China and in Northern China showed that the survival curves were concave curves in the two cotton zones. The curve showed that the mortality of cotton bollworm was higher in its egg stage to the second instar, and lower after the third instar. The key death factor of cotton bollworm was the scouring effect of rain and wind in Southern China, and the predation of its natural enemies in Northern China. The hatch period to the first instar was the key stage in Northern China and Southern China, and in this time, its larva instar was slim, fragile and sensitive to bad circumstances, so its mortality was higher. The second and third generations were the key damage generations in Northern China, while the third and fourth generations were the key damage generations in Southern China. The development and damage characters of each generation in Northern China and in Southern China were discussed.

[Biological control efficiency of ladybirds on arthropod pests in cotton agroecosystems]

Based on the systematical investigation of population dynamics of predacious ladybird in different cotton agroecosystem, the energy flow for predacious ladybirds was analyzed by the way of ecological energetic. The biological control efficiency of ladybirds was compared in different planting-time and inter-crop cotton agroecosystems using available date on the prepapers of ladybird ingestion to pest production. The results showed that the ingestion of predacious ladybirds were 26.45-70 kJ.m-2 yr.-1, accounting for 28.30-47.88% of all predacious natural enemies in different cotton agroecosystems. The biological control efficiency of ladybirds to aphids were 5.07-12.85%, which was decreased in inter-crop cotton agroecosystems and the ecosystems with the delay of planting-time. It is suggested that the ladybirds play the important role of potential biological control in cotton agroecosystems.

[Factors influencing the activity of fibrinolytic enzymes from earthworm, Eeisenia foetida]

OBJECTIVE

To study the factors influencing the activity of fibrinolytic enzymes from earthworm and to obtain the better way to extract fibrinolytic enzymes as well as keep its optimum activity.

METHOD

75% alcohol, 0.9% NaCl and 10% saccharose was used to extract the crude fibrinolytic enzymes from earthworm, the method of urokinase gelose-fibrin plate was used to measure the activity of fibrinolytic enzymes from earthworm. and the method of 3,3'-diaminobezidine tetrahydrochloride colorimetry to was used measure the content of selenium. The method use ts of measuring the content of arsenic was silver diethyldithiocarbamate colorimetry.

RESULT

The fibrinolytin of earthworms reared with cattle soils had higher activity than that reared with garbage. The arsenic in the earthworm's body could improve the activity of earthworm's fibrinolytin. However, the selenium had litter influence on it. Among the three methods of extraction, the 75% alcohol one was the most efficient, the 0.9% NaCl was next, and the 10% saccharose was the lowest. The influence of dialysis on the activity of fibrinolytin was less than that of ultrafiltration, when the earthworm's fibrinolytin enzyme was further sublimated.

CONCLUSION

The activity of the earthworm's fibrinolytin will be increased earthworm is reared with the fitting baits and when appropriate methods, of extraction and purification are used.

Construction of double-copy glucose isomerase gene engineering strain of Streptomyces diastaticus by homologous recombination

The plasmid pUT for homologous recombination was constructed by the insertion of the 1.1-kb thiostrepton resistance ( tsr(R)) gene into the E. coli plasmid pUB1-GI1. Plasmid pUTK was produced through ligating the cleaved plasmid pUT by KpnI. After pUT and pUTK were introduced into Streptomyces diastaticus No.7 strain M1033 (SM33) by protoplast transformation, a series of tsr(R) transformants were obtained, further based on enzyme assays. These results for polymerase chain reaction (PCR), DNA sequencing, restriction enzyme digestion, and recovery of cloned fragments from the transformant chromosome demonstrated the plasmid pUT and pUTK had integrated into the SM33 chromosome in three different patterns of single cross-over by homologous recombination. This directly results in double-copy GI gene in the transformant chromosome, of which one is wild-type GI gene, the other mutant GI ( GIG138P, GI1) gene. Among the strains of the three kinds of recombinant patterns, one transformant was chosen and named K1, T2, and T3, respectively. The further identification of the three recombinant strains by PCR, DNA sequencing, restriction enzyme digestion, and Southern hybridization also proved there is a double-copy GI gene within their chromosome. Enzyme activity assay and thermostability analysis indicated that all three engineering strains expressed not only wild-type enzyme but also mutant GI.

Site-specific integration of the double-mutation glucose isomerase (GIG138PG247D) gene in Streptomyces lividans and its stable expression

A recombinant expression plasmid pYH12, containing the double-mutation glucose isomerase (GIG138PG247D, GI2) coding gene and its natural regulatory sequence, was constructed for site-specific integration in Streptomyces. The resulting plasmid was introduced into Streptomyces lividans TK54 by protoplast transformation and two apramycin-resistance (AmR) transformants, designated GY2 and BY7, respectively, were obtained further based on enzyme assays. These results for polymerase chain reaction (PCR), Dot blot, and recovery of cloned fragments from the transformant chromosome indicated that the GI2 gene was integrated into the S. lividans chromosome by site-specific recombination, and which was further verified by Southern blot. We found that the free form of plasmid pYH12 co-existing with the integrated form was present in S. lividans. SDS-PAGE analysis showed that the GI2 gene was expressed in S. lividans. The intracellular GI2 specific activity was 1.15 U/mg. The stability of integrants demonstrated that the cloned GI2 gene was stably integrated and expressed even in the absence of selective pressure.

Heterologous expression of the single-mutation glucose isomerase (GIG138P) gene in Streptomyces lividans and its genetic instability

A 1.3-kb PstI-BamHI fragment containing the single-mutation glucose isomerase (GIG138P, GI1) gene and its natural promoter was inserted into PstI-BglII linearized Streptomyces vector pIJ702. The ligation mixture was then introduced into Streptomyces lividans TK54 protoplasts; transformants were identified based on their thiostrepton resistance (ThR) and insertional inactivation of the melanin phenotype; and three white colonies, XY-2, 6, and 9, harboring recombinant expression plasmid pYH703, were obtained. Enzyme assay and SDS-PAGE analysis indicated that the GI1 gene was expressed, the intracellular GI1 specific activity was 6 U/mg, and GI1 accounted for 20% of the soluble proteins in S. lividans. Restriction analysis and Southern blot of pYH703 showed the existence of plasmid deletion, presumably owing to the interaction between the mel and GI1 sequences. Continuous liquid cultures of the recombinant strain demonstrated that the GI1 specific activity and GI1 expression in S. lividans decreased, and more obviously under non-selective conditions.

[Determination of phospholipid in Cibotium barometz by supercritical fluid extraction and RP-HPLC]

A supercritical fluid extraction (SFE) method was used to extract phospholipids in Cibotium barometz. After a homogeneous design experiment, SFE conditions were obtained which were pressure at 31.5 MPa, temperature at 46.2 degrees C and a 0.37 L/kg modifier in supercritical fluid. The sample was extracted for 2 hours. A RP-HPLC method was developed for the determination of phosphatidylcholine. RP-HPLC conditions included a RP-HPLC column packed with Waters Symmetry C18(5 microns), a mobile phase composed of methanol-1% phoshporic acid(90:10) and the detection wavelength at 206 nm. The content of phosphatidylcholine was 0.198%(RSD 4.2%), and the method can be a measure of quality control for Cibotium barometz and its preparations.

[Studies on the supercritical-CO2 fluid extraction of complex prescription Danshen-Jiangxiang]

This paper first reported the supercritical-CO2 fluid extraction of complex prescription Danshen-Jiangxiang. With the active constituents and yield of extracts as index, the each other effect of each drug and effect on total complex prescription in extraction were studied. And the effects of pressure and temperature were also studied. The results showed the effects were different in complex prescription extraction and single prescription. Active constituents can be extracted, but a obvious effect exist each other and effects together the yield of extract, extraction rate and content of active constituents of complex prescription extraction, which are concerned in extraction conditions. These study results have important reference on the modernization of traditional Chinese medicines.

Fabricating and imaging carbon-fiber immobilized enzyme ultramicroelectrodes with scanning electrochemical microscopy

The scanning electrochemical microscope (SECM) is used to image the activity of enzymes immobilized on the surfaces of disk-shaped carbon-fiber electrodes. SECM was used to map the concentration of enzymatically produced hydroquinone or hydrogen peroxide at the surface of a 33-microm diameter disk-shaped carbon-fiber electrode modified by an immobilized glucose-oxidase layer. Sub-monolayer coverage of the enzyme at the electrode surface could be detected with micrometer resolution. The SECM was also employed as a surface modification tool to produce microscopic regions of enzyme activity by using a variety of methods. One method is a gold-masking process in which microscopic gold patterns act as mask for producing patterns of chemical modification. The gold masks allow operation in both a positive or negative process for patterning enzyme activity. A second method uses the direct mode of the SECM to produce covalently attached amine groups on the carbon surface. The amine groups are anchors for attachment of glucose oxidase by use of a biotin/avidin process. The effect of non-uniform enzyme activity was investigated by using the SECM tip to temporarily damage an immobilized enzyme surface. SECM imaging can observe the spatial extent and time-course of the enzyme recovery process.

[Studies on the supercritical CO2 fluid extraction and separation of psoralen, isopsoralen and fatty oils from Psoralea corylifolia]

Opimum extraction conditions were studied by supercritical carbon dioxide fluid extraction technology and orthogonal tests. Crystal of psoralen can be achieved directly from the extractives. Magnified experiments were carried out. The chemical constituents of fatty oils were analyzed by GC-MS. The result shows that the optimum conditions are: extraction pressure 27 MPa, extraction temperature 70 degrees C; seperation pressure 9 MPa, seperation temperature 60 degrees C. Six components such as oleic acid, linoleic acid etc. were identified in the fatty oils.

[Supercritical-CO2 fluid extraction of fatty oils from Perilla frutescens seeds and pharmacological study]

Fatty oils from the seeds of Perilla frutescens were extracted by supercritical-CO2 fluid or petroleum ether and its quality was analyzed by GC-MS method. Pharmacological action of lowering blood-lipid for the oils was studied. The results showed that the technology of supercritical-CO2 extraction of the oils of P. frutescens seeds is superior than that of petroleum ether and the oil from SFE-CO2 have the action of lowering blood-lipid with low toxicity.

[Studies on the supercritical-CO2 fluid extraction and quality evaluation of ginger oils]

Essential oils from the dried rhizomes of Zingiber officinale were extracted by supercritical-CO2 fluid(SFE-CO2) and traditional water still distillation (WSD) methods, and the SFE extraction technology and quality (GC-MS, etc.) of the oils were studied. The results showed that the SFE-CO2 contains 49 constituents, such as 6-paradol, etc, the ginger peppery component of them gets to 22.90%.