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61.
Horowitz AR Gorman K Ross G Denholm I 《Archives of insect biochemistry and physiology》2003,54(4):177-186
The inheritance of resistance to pyriproxyfen, an insect growth regulator (a juvenoid, with ovicidal and larvicidal activities), was studied in the whitefly Bemisia tabaci (Gennadius). Two parental strains, both belonging to Q biotype, were assayed with pyriproxyfen; a susceptible strain (ALM-1) originating from Spain and a pyriproxyfen-resistant one (Pyri-R) from Israel. The resistance ratio between the two parental strains was approximately 7,000-fold. Concentration-mortality lines for F(1) heterozygous females from reciprocal crosses (SS female symbol X R male symbol and RR female symbol X S male symbol ) were derived by statistical modelling and proved intermediate to those of the parents. The pooled degree of dominance from both reciprocal crosses was +0.26, indicating that resistance was incompletely or partially dominant. Mortality curves for F(2) males produced by virgin F(1) heterozygous females displayed a broad plateau at 50% mortality, indicating that resistance to pyriproxyfen in B. tabaci is conferred primarily by a mutant allele at a single locus. The role of arrhenotoky in influencing the mode of inheritance of resistance, and its selection in field populations, is discussed. 相似文献
62.
Recent work with exotic 24-h light:dark:light:dark (LDLD) cycles indicates surprising flexibility in the entrainment patterns of Syrian hamsters. Following exposure to an LDLD cycle, hamsters may adopt a form of rhythm splitting in which markers of subjective night (e.g., activity, melatonin) are expressed in each of the twice daily scotophases. This pattern contrasts markedly with that of conventionally entrained hamsters in which markers of subjective night are expressed once daily in only 1 of the 2 dark periods. The "split" entrainment pattern was examined further here in Syrian and Siberian hamsters and in mice exposed to LDLD 7:5:7:5, a condition that reliably induces split activity rhythms in all 3 species. The phase angle of entrainment and activity duration were generally similar comparing the 2 daily activity bouts in each species. The stability of this split entrainment state was assessed by deletions of photophases on individual days, by exposure to skeleton photoperiods, and by transfer to constant darkness. As in Syrian hamsters, the one-time substitution of darkness for one 7-h photophase did not grossly alter activity patterns of Siberian hamsters but acutely disrupted the split rhythms of mice. Skeleton light pulses of progressively shorter duration did not significantly alter split entrainment patterns of either Syrian or Siberian hamsters. Both species continued to exhibit stable entrainment with activity expressed in alternate scotophases of an LD 1:5 cycle presented 4 times daily. In contrast, the split activity rhythms of mice were not maintained under skeleton pulses. In constant darkness, rhythms of Siberian hamsters remained distinctly split for a minimum of 2 cycles. Split entrainment to these novel LDLD and 4-pulse skeleton lighting regimes demonstrates a marked degree of plasticity common to the circadian systems of several rodent species and identifies novel entrainment patterns that may be reliably elicited with simple environmental manipulations. Inter- and intraspecific differences in the stability of split activity rhythms likely reflect differences in coupling interactions between the component circadian oscillators, which, adopting separate phase relations to these novel LD cycles, yield a split entrainment pattern. 相似文献
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Identification and Characterization of a Constitutively Active STAT5 Mutant That Promotes Cell Proliferation 总被引:26,自引:2,他引:24
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Antonia L. Pritchard Marcus L. Hastie Michelle Neller Jeffrey J. Gorman Chris W. Schmidt Nicholas K. Hayward 《Pigment cell & melanoma research》2015,28(3):281-294
Advancements in high‐resolution HPLC and mass spectrometry have reinvigorated the application of this technology to identify peptides eluted from immunopurified MHC class I molecules. Three melanoma cell lines were assessed using w6/32 isolation, peptide elution and HPLC purification; peptides were identified by mass spectrometry. A total of 13 829 peptides were identified; 83–87% of these were 8–11 mers. Only approximately 15% have been described before. Subcellular locations of the source proteins showed even sampling; mRNA expression and total protein length were predictive of the number of peptides detected from a single protein. HLA‐type binding prediction for 10 078 9/10 mer peptides assigned 88–95% to a patient‐specific HLA subtype, revealing a disparity in strength of predicted binding. HLA‐B*27‐specific isolation successfully identified some peptides not found using w6/32. Sixty peptides were selected for immune screening, based on source protein and predicted HLA binding; no new peptides recognized by antimelanoma T cells were discovered. Additionally, mass spectrometry was unable to identify several epitopes targeted ex vivo by one patient's T cells. 相似文献
69.
van Beers JJ Raijmakers R Alexander LE Stammen-Vogelzangs J Lokate AM Heck AJ Schasfoort RB Pruijn GJ 《Arthritis research & therapy》2010,12(6):R219
Introduction
Rheumatoid arthritis (RA) frequently involves the loss of tolerance to citrullinated antigens, which may play a role in pathogenicity. Citrullinated fibrinogen is commonly found in inflamed synovial tissue and is a frequent target of autoantibodies in RA patients. To obtain insight into the B-cell response to citrullinated fibrinogen in RA, its autoepitopes were systematically mapped using a new methodology. 相似文献70.
Leshnower BG Sakamoto H Hamamoto H Zeeshan A Gorman JH Gorman RC 《American journal of physiology. Heart and circulatory physiology》2007,293(3):H1799-H1804
It is widely accepted that, during acute coronary occlusion, ischemic cell death progresses from the subendocardium to the subepicardium in a wavefront fashion. This concept, which implies that the subendocardium is the most susceptible myocardial region to ischemic injury, was established using a canine model with an extensive system of subepicardial coronary collaterals. In humans, particularly in those with coronary artery disease, there is a wide range in the distribution and functional capacity of the collateral circulation, which may affect the pattern of infarct evolution. Using an ovine model with a limited system of preformed subendocardial coronary collaterals, we characterized the effect of increasing lengths of ischemia on regional blood flow and infarct size in three regions of the ventricular wall: subendocardium, midmyocardium, and subepicardium. Our results demonstrate that the myocardium and microvasculature in these three regions are equally susceptible to injury after 45 min of ischemia. When ischemic time is increased to 1 h, infarct size in the midmyocardium (90 +/- 2%) is greater than in the subendocardium (76 +/- 4%, P = 0.004) and subepicardium (84 +/- 3%, P = 0.13). Microvascular dysfunction as assessed as a percentage of baseline flow is also greater in the midmyocardium (14 +/- 5%) compared with the subendocardium (20 +/- 3%, P = 0.23) and subepicardium (51 +/- 9%, P = 0.007). These findings suggest that, in subjects with a limited system of coronary collateral circulation, the midmyocardium is the most susceptible myocardial region to ischemia and the subendocardium is the most resistant. Myocardial viability during coronary occlusion appears to be primarily determined by the distribution and functional capacity of the collateral circulation. 相似文献