The possibility of gene flow between two varieties of transgenic rice with bar gene (Y0003 and 99-t) (male) and barnyard grass(Echinochloa crusgalli var. mitis ) (female) was studied by means of reproductive biology. ...The possibility of gene flow between two varieties of transgenic rice with bar gene (Y0003 and 99-t) (male) and barnyard grass(Echinochloa crusgalli var. mitis ) (female) was studied by means of reproductive biology. The germination and growth of rice pollen grains on barnyard grass stigmas at 30 min, and 1-4 h after crossing by hand were observed with an optical microscope. The results were compared with the germination and growth of barnyard grass pollen grains at the corresponding time after self-pollination. The results showed that germination and growth of the pollen grains of the two varieties were similar on barnyard grass stigmas, but differed significantly from self-pollination of barnyard grass. Pollen grains germinated and pollen tubes penetrated stigmas normally, and the number of pollen grains being condensing or releasing their inclusions or having released them increased with the time after self-pollination. Pollen grains of transgenic rice on the stigmas of barnyard grass couldn't germinate or grow normally after crossing, neither could they penetrate the stigmas of barnyard grass. Therefore, it could be concluded that the sexual incompatibility between transgenic rice with bar gene and barnyard grass is due to the rice pollen being unable to penetrate the stigma of barnyard grass. Further proof of incompatibility lies in the fact that the emasculated barnyard grass pollinated with the rice pollen grains could not seed.展开更多
BACKGROUND Streptococcus mitis(S.mitis)is an opportunistic pathogen that can lead to severe ocular infections.In previous reports,penetrating keratoplasty(PK)was usually adopted for the treatment of persistent corneal...BACKGROUND Streptococcus mitis(S.mitis)is an opportunistic pathogen that can lead to severe ocular infections.In previous reports,penetrating keratoplasty(PK)was usually adopted for the treatment of persistent corneal ulcers.This report describes an unusual case of nonhealing descemetocele caused by S.mitis treated by antibiotics plus amniotic membrane transplantation(AMT).CASE SUMMARY A 63-year-old woman presented with a right persistent corneal ulcer that she had suffered from for the past 9 mo.The culture of a corneal scraping yielded S.mitis.The right eye descemetocele decreased in diameter from 3 to 0.8 mm after the continuous administration of topical vancomycin and ceftriaxone for 2 wk.Due to the slow healing,AMT was performed.Her corneal erosion healed and gradually became clear.Her visual acuity recovered from initially counting fingers to 100/200 at the last follow-up,67 mo after AMT.CONCLUSION Antibiotics plus AMT may be an effective alternative treatment other than PK to promote epithelializationand to reduce inflammation in the corneas complicated by S. mitis keratitis.展开更多
Streptococcus mitis is a component of the normal oropharynx, skin, gastrointestinal system, and genital tract florae. It is generally considered as a relatively benign bacterium. We present a case of spontaneous Strep...Streptococcus mitis is a component of the normal oropharynx, skin, gastrointestinal system, and genital tract florae. It is generally considered as a relatively benign bacterium. We present a case of spontaneous Streptococcus mitis meningitis in a patient with liver cirrhosis and no known risk factors for invasive infectious diseases.展开更多
Objective: To evaluate twenty Traditional Chinese Medicines (TCM) against four oral bacteria. Methods: Twenty TCM were tested for sensitivity against Streptococcus mitis, Streptococcus sanguis, Streptococcus mutans an...Objective: To evaluate twenty Traditional Chinese Medicines (TCM) against four oral bacteria. Methods: Twenty TCM were tested for sensitivity against Streptococcus mitis, Streptococcus sanguis, Streptococcus mutans and Porphyromonas gingivalis. Aliquots of suspension of each bacterial species were inoculated on a horse blood agar (HBA) plate, 6 mm diameter paper disks was soaked in different drug suspensions were placed concentrically on a HBA plate. Disks soaked in 0.2% w/v chlorhexidine were used as positive controls. These HBA plates were incubated for 48 hours anaerobically and the diameters of growth inhibition of three different areas were measured using a calibrated computer software and the mean diameter obtained for each bacteria. Broth microdilution assay was used to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The experiment was repeated on three separate occasions. Results: The TCMs that consistently against Porphyromonas gingivalis, included Folium artemisiae argyi, Fructus crataegi, Rhizoma dryopteris crassirhizomae, Flos magnoliae, Rhizoma polygoni cuspidati, Radix scrophulariae ningpoensis, Galla chinensis, Radix scutellariae baicalensis and Rhizoma coptidis;against Streptococcus mutans included Fructus crataegi, Galla chinensis and Rhizoma copitidis;against Streptococcus mitis and Streptococcus sanguis included Galla chinensis and Rhizoma copitidis. Conclusion: Rhizoma copitidis and Galla chinensis had inhibitory effects on Streptococcus mitis, Streptococcus sanguis, Streptococcus mutans and Porphyromonas gingivalis in vitro.展开更多
While most mammals show birth hour peaks at times of the 24-h cycle when they are less active,there are exceptions to this general pattern.Such exceptions have been little explored,but may clarify evolutionary reasons...While most mammals show birth hour peaks at times of the 24-h cycle when they are less active,there are exceptions to this general pattern.Such exceptions have been little explored,but may clarify evolutionary reasons for the diel timing of births.We investigated intraspecific variation in birth hour in wild blue monkeys Cercopithecus mitis stuhlmanni,a diurnal primate,to identify factors that differentiated daytime versus nighttime births.Behavioral and life history data from 14 groups over 14 years revealed that 4%of 484 births occurred during the day.Probability of daytime birth varied with mother’s age,peaking at 15.7 years.Births whose annual timing deviated most from the population’s peak birth months were 5 times more likely to occur during daytime than those that deviated less.There was no evidence that mother’s rank or infant sex influenced birth hour,and mixed evidence that daytime births were more probable in larger groups.Survivorship did not differ significantly for infants born during the day versus night.Prime-aged mothers may be able to handle the consequences of an unusual birth hour more successfully than mothers with less experience or those weakened by age.Daytime birth may be more advantageous in the off-season because nights are colder at that time of year.These findings are consistent with hypotheses relating birth hour to the risk of losing social protection in group-living animals,but are not consistent with those emphasizing risk of conspecific harassment.Patterns of within-species variation can help in evaluating evolutionary hypotheses for non-random birth hour.展开更多
基金the Ministry ofScience and Technology,P.R.ChinaEvaluation of Safety of Transgenic Crops(E200102).
文摘The possibility of gene flow between two varieties of transgenic rice with bar gene (Y0003 and 99-t) (male) and barnyard grass(Echinochloa crusgalli var. mitis ) (female) was studied by means of reproductive biology. The germination and growth of rice pollen grains on barnyard grass stigmas at 30 min, and 1-4 h after crossing by hand were observed with an optical microscope. The results were compared with the germination and growth of barnyard grass pollen grains at the corresponding time after self-pollination. The results showed that germination and growth of the pollen grains of the two varieties were similar on barnyard grass stigmas, but differed significantly from self-pollination of barnyard grass. Pollen grains germinated and pollen tubes penetrated stigmas normally, and the number of pollen grains being condensing or releasing their inclusions or having released them increased with the time after self-pollination. Pollen grains of transgenic rice on the stigmas of barnyard grass couldn't germinate or grow normally after crossing, neither could they penetrate the stigmas of barnyard grass. Therefore, it could be concluded that the sexual incompatibility between transgenic rice with bar gene and barnyard grass is due to the rice pollen being unable to penetrate the stigma of barnyard grass. Further proof of incompatibility lies in the fact that the emasculated barnyard grass pollinated with the rice pollen grains could not seed.
文摘BACKGROUND Streptococcus mitis(S.mitis)is an opportunistic pathogen that can lead to severe ocular infections.In previous reports,penetrating keratoplasty(PK)was usually adopted for the treatment of persistent corneal ulcers.This report describes an unusual case of nonhealing descemetocele caused by S.mitis treated by antibiotics plus amniotic membrane transplantation(AMT).CASE SUMMARY A 63-year-old woman presented with a right persistent corneal ulcer that she had suffered from for the past 9 mo.The culture of a corneal scraping yielded S.mitis.The right eye descemetocele decreased in diameter from 3 to 0.8 mm after the continuous administration of topical vancomycin and ceftriaxone for 2 wk.Due to the slow healing,AMT was performed.Her corneal erosion healed and gradually became clear.Her visual acuity recovered from initially counting fingers to 100/200 at the last follow-up,67 mo after AMT.CONCLUSION Antibiotics plus AMT may be an effective alternative treatment other than PK to promote epithelializationand to reduce inflammation in the corneas complicated by S. mitis keratitis.
文摘Streptococcus mitis is a component of the normal oropharynx, skin, gastrointestinal system, and genital tract florae. It is generally considered as a relatively benign bacterium. We present a case of spontaneous Streptococcus mitis meningitis in a patient with liver cirrhosis and no known risk factors for invasive infectious diseases.
基金supported by the University Research Grant No.:10207346.15633.08003.323.01,The University of Hong Kong.
文摘Objective: To evaluate twenty Traditional Chinese Medicines (TCM) against four oral bacteria. Methods: Twenty TCM were tested for sensitivity against Streptococcus mitis, Streptococcus sanguis, Streptococcus mutans and Porphyromonas gingivalis. Aliquots of suspension of each bacterial species were inoculated on a horse blood agar (HBA) plate, 6 mm diameter paper disks was soaked in different drug suspensions were placed concentrically on a HBA plate. Disks soaked in 0.2% w/v chlorhexidine were used as positive controls. These HBA plates were incubated for 48 hours anaerobically and the diameters of growth inhibition of three different areas were measured using a calibrated computer software and the mean diameter obtained for each bacteria. Broth microdilution assay was used to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The experiment was repeated on three separate occasions. Results: The TCMs that consistently against Porphyromonas gingivalis, included Folium artemisiae argyi, Fructus crataegi, Rhizoma dryopteris crassirhizomae, Flos magnoliae, Rhizoma polygoni cuspidati, Radix scrophulariae ningpoensis, Galla chinensis, Radix scutellariae baicalensis and Rhizoma coptidis;against Streptococcus mutans included Fructus crataegi, Galla chinensis and Rhizoma copitidis;against Streptococcus mitis and Streptococcus sanguis included Galla chinensis and Rhizoma copitidis. Conclusion: Rhizoma copitidis and Galla chinensis had inhibitory effects on Streptococcus mitis, Streptococcus sanguis, Streptococcus mutans and Porphyromonas gingivalis in vitro.
基金the U.S.National Science Foundation(SBE 9523623,BCS 9808273,DGE 0333415,BCS 0554747,DGE 0966166,BCS 1028471),Ford,Leakey,Wenner-Gren and H.F.Guggenheim Foundations,American Association for the Advancement of Science-Women's International Scientific Cooperation Project,and Columbia University,all to M.C.
文摘While most mammals show birth hour peaks at times of the 24-h cycle when they are less active,there are exceptions to this general pattern.Such exceptions have been little explored,but may clarify evolutionary reasons for the diel timing of births.We investigated intraspecific variation in birth hour in wild blue monkeys Cercopithecus mitis stuhlmanni,a diurnal primate,to identify factors that differentiated daytime versus nighttime births.Behavioral and life history data from 14 groups over 14 years revealed that 4%of 484 births occurred during the day.Probability of daytime birth varied with mother’s age,peaking at 15.7 years.Births whose annual timing deviated most from the population’s peak birth months were 5 times more likely to occur during daytime than those that deviated less.There was no evidence that mother’s rank or infant sex influenced birth hour,and mixed evidence that daytime births were more probable in larger groups.Survivorship did not differ significantly for infants born during the day versus night.Prime-aged mothers may be able to handle the consequences of an unusual birth hour more successfully than mothers with less experience or those weakened by age.Daytime birth may be more advantageous in the off-season because nights are colder at that time of year.These findings are consistent with hypotheses relating birth hour to the risk of losing social protection in group-living animals,but are not consistent with those emphasizing risk of conspecific harassment.Patterns of within-species variation can help in evaluating evolutionary hypotheses for non-random birth hour.
