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81.
Kenneth M. Yamada James A. Weston 《Proceedings of the National Academy of Sciences of the United States of America》1974,71(9):3492-3496
A cell surface component has been isolated in partially purified form from cultured chick embryo and chick heart fibroblasts. This glycoprotein is similar to a protein recently reported to be present at the surface of normal cells, and missing after neoplastic transformation. It is a major cell surface glycoprotein that is synthesized by cultured fibroblasts, but is not collagen. It is shown to be markedly trypsin-sensitive, and its recovery from the cell surface is dependent on cell density. It is excluded from Sephadex G-200, but is not rapidly sedimented by ultracentrifugation, and has an apparent molecular weight of 220,000. The isolation of this cell surface glycoprotein may now provide a means of determining its function. 相似文献
82.
Genome sequence determinations and analyses of novel circoviruses from goose and pigeon 总被引:12,自引:0,他引:12
The genomes of novel circoviruses from goose and pigeon, which were isolated using degenerate primer and inverse primer PCR methods, were cloned and sequenced. Comparative nucleotide (nt) sequence analyses showed that the goose circovirus (GCV) and pigeon circovirus (PiCV) possessed genomes which were 1821 and 2037 or 2036 nt, respectively, and which had features in common with the genomes of porcine circoviruses types 1 and 2 (PCV1, PCV2) and psittacine beak and feather disease virus (BFDV), such that they can now be assigned to the genus Circovirus of the family Circoviridae. Common features include the possession of (i) a potential stem-loop/nonanucleotide motif with which the initiation of rolling circle replication of the virus DNA is associated; (ii) two major ORFs, located on the virus (V1 ORF) and complementary (C1 ORF) strands, which encode the replication-associated protein (Rep) and capsid protein, respectively; (iii) high levels of amino acid identity (41.2--58.2%) shared with other circovirus Rep proteins; and (iv) direct/inverted repeat sequences within the putative intergenic region. On the basis of nt and amino acid sequence identities, GCV is substantially less closely related to BFDV than PiCV is to BFDV. 相似文献
83.
Zeynettin Akkus Jason Cai Arunnit Boonrod Atefeh Zeinoddini Alexander D. Weston Kenneth A. Philbrick Bradley J. Erickson 《Journal of the American College of Radiology》2019,16(9):1318-1328
Ultrasound is the most commonly used imaging modality in clinical practice because it is a nonionizing, low-cost, and portable point-of-care imaging tool that provides real-time images. Artificial intelligence (AI)–powered ultrasound is becoming more mature and getting closer to routine clinical applications in recent times because of an increased need for efficient and objective acquisition and evaluation of ultrasound images. Because ultrasound images involve operator-, patient-, and scanner-dependent variations, the adaptation of classical machine learning methods to clinical applications becomes challenging. With their self-learning ability, deep-learning (DL) methods are able to harness exponentially growing graphics processing unit computing power to identify abstract and complex imaging features. This has given rise to tremendous opportunities such as providing robust and generalizable AI models for improving image acquisition, real-time assessment of image quality, objective diagnosis and detection of diseases, and optimizing ultrasound clinical workflow. In this report, the authors review current DL approaches and research directions in rapidly advancing ultrasound technology and present their outlook on future directions and trends for DL techniques to further improve diagnosis, reduce health care cost, and optimize ultrasound clinical workflow. 相似文献
84.
SMJ Mortazavi MA Mosleh-Shirazi AR Tavassoli M Taheri AR Mehdizadeh SAS Namazi A Jamali R Ghalandari S Bonyadi M Haghani M Shafie 《Dose-response》2013,11(2):281-292
The aim of this study was to investigate the effect of pre-irradiation with microwaves on the induction of radioadaptive response. In the 1st phase of the study, 110 male mice were divided into 8 groups. The animals in these groups were exposed/sham-exposed to microwave, low dose rate gamma or both for 5 days. On day six, the animals were exposed to a lethal dose (LD). In the 2nd phase, 30 male rats were divided into 2 groups of 15 animals. The 1st group received microwave exposure. The 2nd group (controls) received the same LD but there was no treatment before the LD. On day 5, all animals were whole-body irradiated with the LD. Statistically significant differences between the survival rate of the mice only exposed to lethal dose of gamma radiation before irradiation with a lethal dose of gamma radiation with those of the animals pre-exposed to either microwave (p=0.02), low dose rate gamma (p=0.001) or both of these physical adapting doses (p=0.003) were observed. Likewise, a statistically significant difference between survival rates of the rats in control and test groups was observed. Altogether, these experiments showed that exposure to microwave radiation may induce a significant survival adaptive response. 相似文献
85.
Hervé Sauquet Peter H. Weston Cajsa Lisa Anderson Nigel P. Barker David J. Cantrill Austin R. Mast Vincent Savolainen 《Proceedings of the National Academy of Sciences of the United States of America》2009,106(1):221-225
Dating the Tree of Life has now become central to relating patterns of biodiversity to key processes in Earth history such as plate tectonics and climate change. Regions with a Mediterranean climate have long been noted for their exceptional species richness and high endemism. How and when these biota assembled can only be answered with a good understanding of the sequence of divergence times for each of their components. A critical aspect of dating by using molecular sequence divergence is the incorporation of multiple suitable age constraints. Here, we show that only rigorous phylogenetic analysis of fossil taxa can lead to solid calibration and, in turn, stable age estimates, regardless of which of 3 relaxed clock-dating methods is used. We find that Proteaceae, a model plant group for the Mediterranean hotspots of the Southern Hemisphere with a very rich pollen fossil record, diversified under higher rates in the Cape Floristic Region and Southwest Australia than in any other area of their total distribution. Our results highlight key differences between Mediterranean hotspots and indicate that Southwest Australian biota are the most phylogenetically diverse but include numerous lineages with low diversification rates. 相似文献
86.
Weston MW Vijayangar R Overton RM Vesely DL 《International journal of cardiology》2000,74(2-3):145-152
A proposed treatment of end-stage heart disease is partial left ventricular resection (i.e., Batista procedure). To determine if congestive heart failure objectively improves after this procedure, we prospectively evaluated partial left ventriculectomy with objective plasma markers of the severity of congestive heart failure (i.e., three N-terminal atrial natriuretic peptide prohormone radioimmunoassays and atrial natriuretic peptide radioimmunoassay) prior to and during the 12 months after partial left ventriculectomy. The four measured atrial natriuretic peptides improved in 30% of the subjects at 1 month post-surgery. Eighty percent of the subjects, however, had higher circulating atrial natriuretic peptides (P<0.01) at 3, 6, and 12 months than prior to surgery indicating that their congestive heart failure was objectively worse than prior to surgery. Likewise, at 3, 6, and 12 months post-surgery the ejection fractions were not significantly better than prior to surgery. By 6 months the subjects with the highest circulating atrial natriuretic peptides had died (60% of subjects). In conclusion, congestive heart failure improves within 1 month in some patients but then deteriorates at 3, 6, and 12 months after the Batista procedure. There was no survival benefit with 60% of the patients expiring within 6 months after the Batista procedure. 相似文献
87.
In a prospective study of transfused neonates, 32 of 262 infants were viruric at greater than 20 days of life. Of 212 neonates whose early status was known, postnatally acquired infection was proven in 21, two of whom were seronegative at birth and were thought to have transfusion-acquired cytomegalovirus (CMV). Maternal transmission of CMV is important in this population as there was 91% seropositivity for CMV at birth among the 21 babies who acquired CMV compared with 55% positivity among 150 babies who did not shed CMV (P less than 0.01). Significantly increased morbidity (increased length of stay in hospital, increased use of antibiotics, and longer duration of antibiotic administration) was found in babies with acquired CMV compared with matched controls who did not become viruric. Significant morbidity and mortality was not restricted to the two seronegative babies with transfusion-acquired CMV. The cost of providing CMV antibody negative blood for this neonatal unit would be less than the cost of providing the extended hospital care needed by the two babies with transfusion-acquired CMV found during this 3 year study. 相似文献
88.
Strickland Paul T.; Kang Daehee; Bowman Elise D.; Fitzwilliam Ailsa; Downing Tricia E.; Rothman Nathaniel; Groopman John D.; Weston Ainsley 《Carcinogenesis》1994,15(3):483-487
Humans are exposed to polycyclic aromatic hydrocarbons (PAHs)from various occupational, environmental, medicinal and dietarysources. The measurement of specific PAH metabolites, particularly1-hydroxypyrene, in human urine treated with deconjugating enzymes(e.g. ß-glucuronidase) has been extensively used asa means of assessing recent exposure to PAHs. We have examinedpyrene metabolites in human urine prior to enzymatic deconjugationin order to determine the relative proportions of conjugatedand unconjugated pyrene metabolites. The analytical method utilizedimmuno-affinity chromatography, high performance liquid chromatography(HPLC) and the complementary techniques of synchronous fluorescencespectroscopy (SFS) and gas chromatography-mass spectrometry(GC-MS) to measure pyrene-containing metabolites. SFS analysisof immunoaffinity-purified urine samples showed fluorescencespectra characteristic of the pyrene moiety (using wavelengthdifferences of 34 nm, 54 nm and 102 nm). These spectra are producedby several PAHs containing the pyrene moiety. HPLC analysiswith fluorescence detection indicated that the major fluorescentmetabolite in immunoaffinity-purified urine was much more polarthan simple hydroxylated metabolites of pyrene (1-hydroxypyrene)or benzo[a]pyrene (benzofa] pyrene-diols or -tetrols). Followingdigestion with ß-glucuronidase, this metabolite co-chromatographedwith authentic 1-hydroxypyrene and exhibited fluorescence spectracharacteristic of 1-hydroxypyrene, suggesting that the majormetabolite was a glucuronide conjugate of 1-hydroxypyrene. Thiswas subsequently confirmed by GC-MS analysis of trimethylsilylderivatives of the major metabolite; both 1-hydroxypyrene andglucuronic acid were detected independently as derivatized products.Since 1-hydroxypyrene glucuronide is approximately 5-fold morefluorescent than 1-hydroxypyrene, it may provide a more sensitivebiomarker for assessing exposure to pyrene in mixtures of PAHs. 相似文献
89.
Determination of the allelic frequencies of an L-myc and a p53 polymorphism in human lung cancer 总被引:5,自引:2,他引:5
Weston Ainsley; Ling-Cawley Helen M.; Caporaso Neil E.; Bowman Elise D.; Hoover Robert N.; Trump Benjamin F.; Harris Curtis C. 《Carcinogenesis》1994,15(4):583-587
The L-myc and p53 genes have been implicated in lung cancer.Both of these genes have restriction fragment length polymorphisms(RFLPs) that could account for differential expression or activityof variant forms. An EcoRI restriction site in the L-myc genewas previously reported to be a predictor of poor prognosisin Japanese lung cancer patients. There are several RFLPs inthe p53 gene. In exon 4 there is a polymorphism that codes foreither an arginine or proline residue at codon 72. We previouslyreported the frequency of DNA-RFLPs at these gene loci revealedby EcoRI and AccII respectively. Here we report results froma study comparing lung cancer cases (n = 31) with chronic obstructivepulmonary disease controls (n = 49). No association was foundbetween these RFLPs and disease status. Previous observationsthat the frequencies of these RFLPs varied by race were confirmed.The p53 arginine allele was found to be more common in Caucasians(0.71) than African Americans (0.50). The EcoRI restrictionsite present allele in L-myc was more frequent in African-Americans(0.71) than Caucasians (0.49). Thus, the allelic frequency forL-myc was similar in African Americans to that reported forJapanese, and the allelic frequency for p53 was similar in Caucasiansto that reported for Japanese. 相似文献
90.
Kang D.H.; Rothman N.; Poirier M.C.; Greenberg A.; Hsu C.H.; Schwartz B.S.; Baser M.E.; Groopman J.D.; Weston A.; Strickland P.T. 《Carcinogenesis》1995,16(5):1079-1085
Biological markers of internal dose and macromolecular dosefrom PAHs provide a potential means of assessing environmentalexposure to PAHs through inhalation, ingestion and percutaneousabsorption. In this study we examined the time course and interindividualvariation of 1-hydroxypyrene-glucuronide (1-OHP-gluc) excretionin urine and PAHDNA adduct formation in peripheral whiteblood cells (WBCs) after charbroiled (CB) beef consumption.As a marker of internal dose, 1-OHP-gluc was measured in humanurine using immunoaffinity chromatography and synchronous fluorescencespectroscopy. PAHDNA adducts were measured in WBCs byenzyme-linked immunosorbent assay (ELISA) in order to assessmacromolecular dose. Ten healthy non smoking males consumedidentical amounts of CB beef on five consecutive days. Multipleblood and urine samples were collected before, during, and afterthe feeding period. The morning after the first day of CB beefconsumption, individual urinary concentrations of 1-OHP-glucincreased 10- to 80-fold (range:2.016.6 pmol/ml urine)aboveprefeed baseline concentreations (0.23±0.11pmol/ml) inthe 10 subjects. 1-OHP-gluc concentration decreased to nearbaseline levels by 2472 h after CB beef consumption ended.In contrast, PAHDNA adducts in WBCs increased markedlyin only four of 10 subjects during or after CB beef consumption.Significant interindividual variation was observed for bothurinary 1-OHP-gluc concentration (P < 0.001 by KruskalWallis)and PAHDNA adduct levels (P < 0.005) during the feedingperiod. The mean urinary 1-OHP-gluc concentration for each subjectduring and immediately after (days 28) the feeding periodwas significantly correlated with their mean PAHDNA adductlevel in WBCs during the same time period (Spearman r = 0.79,P<0.01). Evidence of segregation of the subjects into separateresponse groups based on level of urinary 1-OHP-gluc was observed,suggesting that discrete determaints may regulate the absorption,metabolism and/or excretion of ingested pyrene. 相似文献