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排序方式: 共有2034条查询结果,搜索用时 18 毫秒
91.
92.
Bong-Gyoon Han Ming Dong Haichuan Liu Lauren Camp Jil Geller Mary Singer Terry C. Hazen Megan Choi H. Ewa Witkowska David A. Ball Dieter Typke Kenneth H. Downing Maxim Shatsky Steven E. Brenner John-Marc Chandonia Mark D. Biggin Robert M. Glaeser 《Proceedings of the National Academy of Sciences of the United States of America》2009,106(39):16580-16585
An unbiased survey has been made of the stable, most abundant multi-protein complexes in Desulfovibrio vulgaris Hildenborough (DvH) that are larger than Mr ≈ 400 k. The quaternary structures for 8 of the 16 complexes purified during this work were determined by single-particle reconstruction of negatively stained specimens, a success rate ≈10 times greater than that of previous “proteomic” screens. In addition, the subunit compositions and stoichiometries of the remaining complexes were determined by biochemical methods. Our data show that the structures of only two of these large complexes, out of the 13 in this set that have recognizable functions, can be modeled with confidence based on the structures of known homologs. These results indicate that there is significantly greater variability in the way that homologous prokaryotic macromolecular complexes are assembled than has generally been appreciated. As a consequence, we suggest that relying solely on previously determined quaternary structures for homologous proteins may not be sufficient to properly understand their role in another cell of interest. 相似文献
93.
94.
A Psyrri P Kountourakis Z Yu C Papadimitriou S Markakis R L Camp T Economopoulos M A Dimopoulos 《Annals of oncology》2007,18(4):709-715
BACKGROUND: p53 protein is regarded as a valuable prognostic marker in cancer with a potential use as a molecular target. Here, we sought to determine the prognostic value of p53 in ovarian cancer using a novel method of compartmentalized in situ protein analysis. PATIENTS AND METHODS: A tissue array composed of 141 advanced stage ovarian cancers uniformly treated was constructed. For evaluation of p53 protein expression, we used an immunofluorescence-based method of automated in situ quantitative measurement of protein analysis (AQUA). RESULTS: High nuclear p53 expression levels were associated with better outcome for overall survival (OS) (P = 0.0023) and disease-free survival (P = 0.0338) at 5-years. High cytoplasmic p53 expression levels were associated with better outcome for OS (P = 0.0002). In multivariable analysis, high nuclear and high cytoplasmic p53 level with International Federation of Gynecology and Obstetrics (FIGO) stage were the most significant predictor variables for OS and high nuclear p53 level with FIGO stage were the significant predictor variables for disease-free survival. CONCLUSIONS: Assessment of the prognostic value of p53 protein levels using conventional immunohistochemistry is limited by the nonquantitative nature of the method. AQUA provides precise estimation of p53 protein levels and was able to elucidate the association of p53 protein levels and ovarian cancer prognosis. 相似文献
95.
96.
Bacterial translocation in the newborn rabbit: effect of age on frequency of translocation 总被引:1,自引:0,他引:1
J. M. Van Camp V. Tomaselli R. Drongowski A. G. Coran 《Pediatric surgery international》1995,10(2-3):134-137
Sepsis is a significant cause of morbidity and mortality in neonates, and in a significant number of cases no predisposing factors can be identified. We hypothesize that bacterial translocation (BT) may be the etiology of neonatal sepsis when no source is identified. Mesenteric lymph nodes (MLN), spleen (SPL), and liver (LIV) were harvested from 36 rabbit pups ranging in age from 4 to 24 days and divided into three groups based on their age: group I, 4–6 days; group II, 13–15 days; and group III, 22–24 days. Tissues from each organ were homogenized and placed in both aerobic and anaerobic environments. After 48 h the number of colony-forming units/g tissue was identified. The total percentage of positive growth was significantly higher in group I for MLN (33%) and LIV (23%) when compared to groups II and III (<4% for both groups). Gram-negative growth (as selected by MacConkey [MC] media) was significantly higher in all tissue specimens from group I (MLN + 35%, SPL = 20%, LIV = 25%) compared to groups II and III (0% growth in all MC plates, P <0.01). These data support the hypothesis that spontaneous BT occurs with significant frequency in the neonate. 相似文献
97.
98.
R H Margolis K J Van Camp R H Wilson W L Creten 《Audiology : official organ of the International Society of Audiology》1985,24(1):44-53
Susceptance and conductance tympanograms were recorded from 10 normal subjects with probe frequencies ranging from 220 to 910 Hz. Tympanometric shapes progressed through an orderly sequence of patterns, becoming more complex with increasing probe frequency. When the direction of ear-canal air pressure change was from negative to positive values, more complicated tympanometric shapes occurred for all subjects, compared to the positive to negative direction. The results are discussed in relation to the Vanhuyse et al. [Scand. Audiol. 4:45-50, 1975] model of tympanometric shapes. In general, the model is a good first approximation to the distribution of tympanometric patterns from normal ears. 相似文献
99.
Systemic therapy alone for metastatic melanoma is relatively ineffective, and surgical resection of metastases to a solitary
site remains the best single treatment to improve survival. While cytoreductive surgery plus chemotherapy play a significant
role in the management of advanced ovarian cancer, the precise role of surgery as an adjunct to systemic therapy for melanoma
metastatic to multiple sites is not well defined. We report a patient with ocular melanoma metastatic to liver and pancreas
treated by cytoreductive surgery consisting of mesohepatic resection, distal pancreatectomy, and portal node dissection, followed
by biochemotherapy with dacarbazine and interferon alpha. The concept of cytoreductive surgery is reviewed, with particular
attention to its use in the management of metastatic melanoma. The patient's postoperative course was unremarkable and she
remains alive and asymptomatic with no detectable disease at 20 months' follow-up. Cytoreductive surgery as a part of an aggressive
multidisciplinary approach may play a role in the treatment of cutaneous and ocular melanoma metastatic to multiple visceral
sites. Data from well-designed, innovative clinical trials of cytoreductive surgery and biochemotherapy are required to determine
the effectiveness of this multidisciplinary approach.
Received: March 1, 2002 / Accepted: May 12, 2002
Offprint requests to: A.W. Hemming 相似文献
100.
McConathy J Martarello L Malveaux EJ Camp VM Simpson NE Simpson CP Bowers GD Olson JJ Goodman MM 《Journal of medicinal chemistry》2002,45(11):2240-2249
Novel radiopharmaceuticals, including amino acids, that target neoplasms through their altered metabolic states have shown promising results in preclinical and clinical studies. Two fluorinated analogues of alpha-aminoisobutyric acid, 2-amino-3-fluoro-2-methylpropanoic acid (FAMP) and 3-fluoro-2-methyl-2-(methylamino)propanoic acid (N-MeFAMP), have been radiolabeled with fluorine-18, characterized in amino acid uptake assays, and evaluated in vivo in normal rats and a rodent tumor model. The key steps in the syntheses of both radiotracers involved the preparation of cyclic sulfamidate precursors. Radiosyntheses of both [18F]FAMP and [18F]N-MeFAMP via no-carrier-added nucleophilic substitution provided high yields (>78% decay-corrected) in high radiochemical purity (>99%). Amino acid transport assays using 9L gliosarcoma cells demonstrated that both compounds are substrates for the A type amino acid transport system, with [18F]N-MeFAMP showing higher specificity than [18F]FAMP for A type transport. Tissue distribution studies in normal Fischer rats and Fischer rats implanted intracranially with 9L gliosarcoma tumor cells were also performed. At 60 min postinjection, the tumor vs normal brain ratio of radioactivity was 36:1 in animals receiving [18F]FAMP and 104:1 in animals receiving [18F]N-MeFAMP. On the basis of these studies, both [18F]FAMP and [18F]N-MeFAMP are promising imaging agents for the detection of intracranial neoplasms via positron emission tomography. 相似文献