Direct DNA delivery procedures (include biolistics method) often resulted in multiple copies of the transgenes in transformants and certain copies of them were rearranged. Integration of multiple copies of the introduced genes was the main reason of gene silencing which meant inhibition or loss of foreign gene expression in filial generations of transformants. In the present work, we compared the influences of maize Ubi-1 promoter and other promoters on copy number of transgenes in maize transgenic plants. Immature embryos from Zea mays L. plants of sib-pollinated of A188 x H99 genotype were used as initial materials. Type- I embryonic calluses derived from preculture of immature embryos were treated on N6 medium containing 0.6 mol/L sucrose for 3 approximately 5 hours and transformed via particle bombardment with PDS1000/He delivery system (Bio-Rad). Bombarded calluses were treated with hyperosmotic N6 medium for 16 approximately 20 hours continuously. Then the cultures were transferred onto normal N6 medium and incubated at 26 degrees C in dark for two weeks and subsequently selected on N6 medium supplemented with 2 or 5 mg/L phosphinothricin (PPT) but without casamino acid for another two weeks. The calluses after selective culture were transferred onto hormone-free MS medium containing 2 or 5 mg/L PPT but without casamino acid, and incubated at 24 degrees C under 16 h illumination for plant regeneration. Regenerated plantlets over 2 cm in height were transferred to Magenta box containing 1/2 hormone-free MS medium. Plantlets over 8 cm in height were transplanted to soil. After growing for one week in greenhouse, the plants were sprayed with 250 mg/L PPT solution. Fertile transgenic maize plants were regenerated and confirmed by Southern blotting and histochemical localization of beta-glucuronidase (GUS) activity. Relations between promoter and copy number of transgenes in transformants were analyzed. Maize transgenic plants possessing an intact copy and another incomplete copy of beta-glucuronidase gene (gus) were obtained in case gus gene under the control of maize Ubi-1 promoter (pUbi:GUS). Simultaneously the co-transformed phosphinothricin acetyltransferase gene (bar) controlled by CaMV 35S promoter in another plasmid (p35S:BAR) also existed with only one copy. When pDB1 and (pUbi:in2) were cobombarded, the regenerated transgenic maize plant exhibited with only one copy of in2 gene too. It suggested that the copy number of transgenes in maize transformants was low if the transgenes controlled by maize Ubi-1 promoter. The possible reason might be that the foreign genes were integrated site-specifically via homologous recombination between Ubi-1 promoter and its endogenous sequences in maize genome, and two cotransformed plasmids had reconstructed as one intact molecule before integrating into maize chromosome. On the contrary, if p35S:BAR was cobom-barded with plasmid pAct:In1 containing rice Act-1 promoter (without maize Ubi-1 promoter), the transgenic maize plants had 4 approximately 8 copies of bar gene. These results reflected that utilization of self gene promoter could reduce the copy number of the transgenes in transgenic plants of certain species itself and avoid the occurrence of gene silencing. T2 seeds have been harvested.
Gene Dosage ; Plant Proteins ; genetics ; Plants, Genetically Modified ; genetics ; Promoter Regions, Genetic ; Ubiquitin C ; genetics ; Zea mays ; genetics

OBJECTIVETo explore clinical and chest X-ray features of SARS in children to facilitate correct diagnosis.

METHODSClinical manifestations and chest X-ray findings in five children suffering from SARS admitted for treatment in the hospital between February and May, 2003 in Shenzhen area were analyzed. The diagnosis was confirmed by epidemiological, clinical, laboratory and radiological examinations. Among the 5 cases, 1 was a boy and the others were girls at the age of 4 to 13 years.

RESULTSOf the 5 SARS children, 3 presented a history of close contact with SARS patients. Fever was the initiative symptom, 4 had a body temperature of over 38 degrees C with the highest being 40 degrees C; fever sustained from 4 to 7 days with an average of 5.6 days. All the 5 cases developed nonproductive cough; on auscultation, both moist and dry rales could be heard in 3 out of the 5 cases. Mean total white count of peripheral blood was (2.96 - 6.9) x 10(9)/L, and was < 5.0 x 10(9)/L in 4 cases. SARS associated coronavirus specific RNA fragment was found positive by RT-PCR in 1 case; 1 case was positive for both IgM and IgG antibodies to the virus; 1 case was positive for only IgM antibody and another 2 cases were positive for only IgG antibody. IgG and IgM antibodies to Mycoplasma pneumoniae and Chlamydia pneumoniae as well as blood culture for bacteria were all negative. Findings on chest X-ray examination: 4 cases showed presence of patchy or macular opacities with cord-like shadows in unilateral lung plates while 1 case each showed ground-glass-like opacity and migratory changes; 1 case showed interstitial changes in the lungs in the form of irregular reticular lattice and cord-like shadows. Two cases received CT scanning and macular-patchy or spotty shadows were seen all over the lung. The shortest time for absorption of foci in the lungs was 7 days while the longest was 33 days with a mean of 15 +/- 6 days. None of the cases had any signs of fibrosis in the lungs. All the 5 cases were completely cured and discharged 7 to 40 days (mean 18 +/- 11 days) after admission.

CONCLUSIONCompared with adult cases with SARS, children with SARS had milder symptoms and signs. Presence of unilateral patchy shadow in lungs represented the main chest X-ray findings.

Adolescent ; Antibodies, Viral ; analysis ; Child ; Child, Preschool ; Female ; Humans ; Immunoglobulin G ; analysis ; Immunoglobulin M ; analysis ; Male ; Radiography, Thoracic ; Reverse Transcriptase Polymerase Chain Reaction ; SARS Virus ; genetics ; immunology ; Severe Acute Respiratory Syndrome ; diagnostic imaging ; pathology ; virology

Objective To observe the changes of inflammatory factors after the hepatic cystic echinococcosis surgery and explore the intervention effect of ulinastatin on postoperative inflammatory factors. Methods Sixty patients with hepatic cystic echinococcosis were selected and randomly divided into a control group and ulinastatin intervention group according to whether or not use ulinastatin. The peripheral venous blood was extracted in all the patients and the levels of IL-6, IL-8, IL-9, and IL-10 were detected by the ELISA method on the day before operation, 1 day, 3 days, 5 days and 7 days after operation, respectively. The data was statistical analyzed to detect the relationships between/among the inflammatory factors mentioned above and ulina-statin and time. Results The variation of the levels of IL-6, IL-8, IL-9, and IL-10 were changed by the intervention of ulina-statin at different time. The differences of the levels of IL-6, IL-8, IL-9, and IL-10 between the ulinastatin intervention group and the control group were not significant on the day before operation, 1 day and 3 days after operation (t = -1.15 to 1.82, all P > 0.05), but the levels of IL-6, IL-8, IL-9, and IL-10 of the ulinastatin intervention group were significantly lower than those of the control group and there were statistically significant differences 5 days and 7 days after the operation (t = 3.22 and 23.51, both P<0.05) . Conclusion Ulinastatin has a good effect in inhibiting the inflammatory factors and can protect and repair the postoperative hepatic injury as well in patients with hepatic cystic echinococcosis.