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131.
Reconstruction of Mammalian Cells from Nuclear and Cytoplasmic Components Separated by Treatment with Cytochalasin B 总被引:5,自引:10,他引:5 下载免费PDF全文
George Veomett D. M. Prescott Jerry Shay K. R. Porter 《Proceedings of the National Academy of Sciences of the United States of America》1974,71(5):1999-2002
Mouse L929 cells were separated into enucleated cytoplasmic components (cytoplasts) and nucleated subcellular fractions (karyoplasts) in the presence of cytochalasin B. Karyoplasts from cells containing tritiated nuclei were fused, using inactivated Sendai virus, to cytoplasts from cells containing large (1.0-mum diameter) latex spheres in the cytoplasm. Mononucleated cells containing radioactive nuclei and large latex spheres in the cytoplasm were observed among the products of the fusion reaction. Some of these cells were in mitotic configurations. The results indicate that cells capable of undergoing mitosis can be reconstructed from the products of cellular enucleation in the presence of cytochalasin B. 相似文献
132.
Comparison of dobutamine stress echocardiography with and without real-time perfusion imaging for detection of coronary artery disease 总被引:2,自引:0,他引:2
Xie F Tsutsui JM McGrain AC Demaria A Cotter B Becher H Lebleu C Labovitz A Picard MH O'Leary EL Porter TR 《The American journal of cardiology》2005,96(4):506-511
In a pilot study of 27 patients, those who presented with chest pain underwent 2 dobutamine stress echocardiographic studies, 1 with high mechanical index harmonic imaging to analyze wall motion without contrast and 1 with real-time low mechanical index perfusion imaging with intravenous Optison to assess myocardial perfusion and wall motion. All patients then underwent quantitative coronary angiography. Two independent reviewers demonstrated an improvement in sensitivity when analyzing myocardial perfusion. In the 21 patients who had significant coronary stenoses, 14 had abnormal myocardial perfusion detected at peak stress and 7 had abnormal wall motion detected by standard dobutamine stress echocardiography. There was decreased specificity with perfusion imaging by 1 reviewer. The addition of real-time perfusion imaging after intravenous contrast during dobutamine stress echocardiography has the potential to improve detection of coronary artery disease. 相似文献
133.
Maxence Meyer MD Lidia Calabrese MD Anita Meyer MD Florentin Constancias PhD Louise F. Porter MD PhD Marion Muller Manon Leitner Amandine Leitner Antonin Michaud Georges Kaltenbach MD PhD Elise Schmitt MD PhD Patrick Karcher MD Erik Sauleau MD PhD Saïd Chayer PhD HDR Floriane Zeyons MD Marianne Riou MD Soraya El Ghannudi Abdo MD Frédéric Blanc MD PhD Samira Fafi-Kremer PharmD PhD Aurélie Velay PharmD PhD Thomas Vogel MD PhD 《Journal of the American Geriatrics Society》2021,69(5):1167-1170
134.
Durrant JR Klug DR Kwa SL van Grondelle R Porter G Dekker JP 《Proceedings of the National Academy of Sciences of the United States of America》1995,92(11):4798-4802
We consider a model of the photosystem II (PS II) reaction center in which its spectral properties result from weak (approximately 100 cm-1) excitonic interactions between the majority of reaction center chlorins. Such a model is consistent with a structure similar to that of the reaction center of purple bacteria but with a reduced coupling of the chlorophyll special pair. We find that this model is consistent with many experimental studies of PS II. The similarity in magnitude of the exciton coupling and energetic disorder in PS II results in the exciton states being structurally highly heterogeneous. This model suggests that P680, the primary electron donor of PS II, should not be considered a dimer but a multimer of several weakly coupled pigments, including the pheophytin electron acceptor. We thus conclude that even if the reaction center of PS II is structurally similar to that of purple bacteria, its spectroscopy and primary photochemistry may be very different. 相似文献
135.
G R Nakamura R Byrn K Rosenthal J P Porter M R Hobbs L Riddle D J Eastman D Dowbenko T Gregory B M Fendly 《AIDS research and human retroviruses》1992,8(11):1875-1885
Ten monoclonal antibodies prepared against a soluble, recombinant form of gp160, derived from the IIIB isolate of HIV-1, were characterized. Four of the antibodies neutralized HIV-1IIIB infectivity in vitro, three blocked the binding of recombinant gp120 to CD4, three were reactive with gp41, and one preferentially reacted with an epitope on gp120 within the gp160 precursor. All three CD4 blocking antibodies bound to distinct epitopes, with one mapping to the C1 domain, one mapping to the C4 domain, and one reactive with a conformation-dependent, discontinuous epitope. Of these, the antibody reactive with the discontinuous epitope exhibited neutralizing activity against homologous and heterologous strains of HIV-1. The binding of these monoclonal antibodies to a panel of seven recombinant gp120s prepared from diverse isolates of HIV-1 was measured, and monoclonal antibodies with broad cross reactivity were identified. The epitopes recognized by 7 of the 10 monoclonal antibodies studied were localized by their reactivity with synthetic peptides and with fragments of gp120 expressed as fusion proteins in a lambda gt-11 gp160 epitope library. 相似文献
136.
X-linked chronic granulomatous disease: correction of NADPH oxidase defect by retrovirus-mediated expression of gp91-phox 总被引:3,自引:0,他引:3
Chronic granulomatous disease (CGD) is an inherited immunodeficiency resulting from the inability of an individual's phagocytes to produce superoxide anions because of defective NADPH oxidase. The disease may be treated by bone marrow transplantation and as such is a candidate for somatic gene therapy. Two thirds of patients have defects in an X- linked gene (X-CGD) encoding gp91-phox, the large subunit of the membrane cytochrome b-245 component of NADPH oxidase. Epstein-Barr virus-transformed B-cell lines from patients with CGD provide a model system for the disease. We have used retrovirus-mediated expression of gp91-phox to reconstitute functionally NADPH oxidase activity in B-cell lines from three unrelated patients with X-CGD. The protein is glycosylated and membrane associated, and the reconstituted oxidase is appropriately activated via protein kinase C. The kinetics of superoxide production by such reconstituted cells is similar to that of normal B-cell lines. These data show the potential of gene therapy for this disease. 相似文献
137.
Amir A. Kimia Scotty Williams Peter N. Hadar Assaf Landschaft John Porter Richard G. Bachur 《The American journal of emergency medicine》2018,36(6):931-934
Background
Currant jelly stool is a late manifestation of intussusception and is rarely seen in clinical practice. Other forms of GI bleeding have not been thoroughly studied and little is known about their respective diagnostic values.Objective
To assess the predictive value of GI bleeding (positive guaiac test, bloody stool and rectal bleeding in evaluation of intussusception.Methods
We performed a retrospective cross-sectional study cohort of all children, ages 1 month-6 years of age, who had an abdominal ultrasound obtained evaluating for intussusception over 5 year period. We identified intussusception if diagnosed by ultrasound, air-contrast enema or surgery. Univariate and a multivariate logistic regression analysis were performed.Results
During the study period 1258 cases met the study criteria; median age was 1.7 years (IQR 0.8, 2.9) and 37% were females. Overall 176 children had intussusception; 153 (87%) were ileo-colic and 23 were ileo-ileal. Univariate risk ratio and adjusted Odds ratio were 1.3 (95% CI, 0.8, 2.0) and 1.3 (0.7, 2.4) for positive guaiac test, 1.1 (0.6, 2.1) and 0.9 (0.3, 3.0) for bloody stool, and 1.7 (1.02, 2.8) and 1.3 (0.5, 3.1) for rectal bleeding .Conclusion
Blood in stool, whether visible or tested by guaiac test has poor diagnostic performance in the evaluation of intussusception and is not independently predictive of intussusception. If the sole purpose of a rectal exam in these patients is for guaiac testing it should be reconsidered. 相似文献138.
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