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931.
John A Giles Elizabeth Hudson Julie Crow Denis Williams Patrick Walker 《BMJ (Clinical research ed.)》1988,296(6629):1099-1102
Two hundred asymptomatic women in a general practice were screened both cytologically and colposcopically for evidence of cervical intraepithelial neoplasia. The prevalence detected by cytology alone was 5%, but the prevalence detected by cytology and colposcopy together was 11%. None of the larger lesions of cervical intraepithelial neoplasia (affecting more than two quadrants of the cervix) was associated with negative cytology. The false negative cytology rate for smaller lesions was 58%.The clinical importance of the smaller lesions that were not accurately detected by cytology screening is unknown. As these lesions affected 6% of the screened population further studies of their clinical course are urgently required. Local destructive treatment in such cases may represent considerable overtreatment. If these lesions prove to be clinically important, however, the results of this study predict an increasing epidemic of preinvasive and invasive disease of the cervix. 相似文献
932.
Forages used by moose, Alces alces , in the aspen-dominated boreal forest were studied to determine seasonal changes in digestibility (nylon bag technique) and chemical composition. Digestibility of all forage classes increased to 70% during spring and summer with the presence of new growth and declined to a low of 30% with plant maturation and dormancy. Mean protein contents during these periods were >20% and <7%, respectively. Nutritional quality of herbaceous forages peaked earlier and higher than that of woody plants in spring but quality declined earlier and reached slightly lower levels in late winter. Cell wall composition of grasses, sedge, and foliage varied seasonally and was correlated with forage digestibility. In multiple linear regression models, hemicellulose, cellulose, and lignin content of browse, grass, and sedge provided significant predictions of digestibility. 相似文献
933.
934.
P McIntyre J F Mercer M G Peterson P Hudson N Hoogenraad 《European journal of biochemistry》1984,143(1):183-187
A cDNA clone corresponding to the mature form of ornithine transcarbamylase (OTCase) was selected from a rat liver cDNA library constructed in bacteriophage lambda gt10. OTCase clones were selected using a synthetic DNA probe of 15 bases corresponding to the 3' end of the OTCase mRNA [Horwich, A. L., Kraus, J.P., Williams, K., Kalousek, F., K?nigsberg, W. & Rosenberg, L.E. (1983) Proc. Natl Acad. Sci. USA, 80, 4258-4262]. Putative OTCase clones were subcloned into the expression vector, pUC9, and the identity of inserts confirmed by colony immunoassay and by electrophoretic transfer of cloned proteins from sodium dodecyl sulphate/polyacrylamide gels to nitrocellulose filters followed by probing with monospecific anti-OTCase antibodies and 125I-labelled protein A. A clone corresponding to the full-length mature form of rat liver OTCase (plus 15 amino acids from Escherichia coli beta-galactosidase) was obtained and the identity of the clone was confirmed by comparison of the 5' sequence with a limited N-terminal amino acid sequence [Lusty, C., Jilka, R. L. & Nietsch, E. H. (1979) J. Biol. Chem. 254, 10030-10036]. A sequence discrepancy between the published sequence (Lusty et al.) and the sequence predicted from the cDNA structure is noted. 相似文献
935.
Melissa E. Heard Roberta Besio MaryAnn Weis Jyoti Rai David M. Hudson Milena Dimori Sarah M. Zimmerman Jeffrey A. Kamykowski William R. Hogue Frances L. Swain Marie S. Burdine Samuel G. Mackintosh Alan J. Tackett Larry J. Suva David R. Eyre Roy Morello 《PLoS genetics》2016,12(4)
Collagen is a major component of the extracellular matrix and its integrity is essential for connective tissue and organ function. The importance of proteins involved in intracellular collagen post-translational modification, folding and transport was recently highlighted from studies on recessive forms of osteogenesis imperfecta (OI). Here we describe the critical role of SC65 (Synaptonemal Complex 65, P3H4), a leprecan-family member, as part of an endoplasmic reticulum (ER) complex with prolyl 3-hydroxylase 3. This complex affects the activity of lysyl-hydroxylase 1 potentially through interactions with the enzyme and/or cyclophilin B. Loss of Sc65 in the mouse results in instability of this complex, altered collagen lysine hydroxylation and cross-linking leading to connective tissue defects that include low bone mass and skin fragility. This is the first indication of a prolyl-hydroxylase complex in the ER controlling lysyl-hydroxylase activity during collagen synthesis. 相似文献
936.
937.
938.
Andrew Hudson 《Current biology : CB》2019,29(24):R1305-R1307
939.
J. G. Hudson Angela L. Bowen Pilar Navia Jaime Rios-Dalenz Andrew J. Pollard David Williams Donald Heath 《International journal of biometeorology》1999,43(2):85-90
Recognition of thrombosis as a complication of exposure to high altitude has stimulated interest in rheological changes resulting
from hypobaric hypoxia. Previous studies of platelet counts at high altitude have yielded conflicting results and have not
been studied in conjunction with potential mediating cytokines. We studied the effects of high-altitude exposure on platelet
numbers, thrombopoietin (tpo) and erythropoietin (epo) levels in man. A group of 28 volunteers from the Bolivian Airforce
stationed at Santa Cruz (600 m altitude) were studied 48 h and 1 week after their ascent to La Paz (3600 m). In addition 105
volunteers based at Santa Cruz for at least 1 year were compared with 175 age- and sex-matched residents at El Alto (4200
m). Platelet counts were measured immediately after sampling and serum samples assayed for tpo and epo. In the ascending group,
mean platelet counts were 251×109, 367×109 and 398×109/l at 600 m and following 48 h and 1 week at 3600 m respectively. Mean tpo levels were 132.5, 76 and 92 pg/ml with epo values
of 2.98, 11.6 and 7.9 mIU/ml respectively. In the resident populations mean platelet counts were 271×109/l in the low- and 471×109/l in the high-altitude groups. Mean tpo and epo levels measured 69.3 pg/ml and 4.5 mIU/ml respectively at 600 m and 58.5
pg/ml and 5.1 mIU/ml at 4200 m. In conclusion we have demonstrated a significant and sustained elevation in platelet numbers
within 48 h of ascent to high altitude. Our findings do not support a role for tpo as a mediator of the increased platelet
count. However, these data do not discount epo as a potential candidate.
Received: 28 December 1998 / Revised: 13 May 1999 / Accepted: 26 May 1999 相似文献
940.
Drew M. Titmarsh James E. Hudson Alejandro Hidalgo Andrew G. Elefanty Edouard G. Stanley Ernst J. Wolvetang Justin J. Cooper-White 《PloS one》2012,7(12)
Timed exposure of pluripotent stem cell cultures to exogenous molecules is widely used to drive differentiation towards desired cell lineages. However, screening differentiation conditions in conventional static cultures can become impractical in large parameter spaces, and is intrinsically limited by poor spatiotemporal control of the microenvironment that also makes it impossible to determine whether exogenous factors act directly or through paracrine-dependent mechanisms. We detail here the development of a continuous flow microbioreactor array platform that combines full-factorial multiplexing of input factors with progressive accumulation of paracrine factors through serially-connected culture chambers, and further, the use of this system to explore the combinatorial parameter space of both exogenous and paracrine factors involved in human embryonic stem cell (hESC) differentiation to a MIXL1-GFP+ primitive streak-like population. We show that well known inducers of primitive streak (BMP, Activin and Wnt signals) do not simply act directly on hESC to induce MIXL1 expression, but that this requires accumulation of surplus, endogenous factors; and, that conditioned medium or FGF-2 supplementation is able to offset this. Our approach further reveals the presence of a paracrine, negative feedback loop to the MIXL1-GFP+ population, which can be overcome with GSK-3β inhibitors (BIO or CHIR99021), implicating secreted Wnt inhibitory signals such as DKKs and sFRPs as candidate effectors. Importantly, modulating paracrine effects identified in microbioreactor arrays by supplementing FGF-2 and CHIR in conventional static culture vessels resulted in improved differentiation outcomes. We therefore demonstrate that this microbioreactor array platform uniquely enables the identification and decoding of complex soluble factor signalling hierarchies, and that this not only challenges prevailing strategies for extrinsic control of hESC differentiation, but also is translatable to conventional culture systems. 相似文献