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11.
A third human CALC (pseudo)gene on chromosome 11 总被引:2,自引:0,他引:2
J W H?ppener P H Steenbergh J Zandberg G J Adema A H Geurts van Kessel C J Lips H S Jansz 《FEBS letters》1988,233(1):57-63
A genomic locus in man (CALC-III) containing nucleotide sequences highly homologous to both exon 2 and exon 3 of the CALC-I and -II genes, is described in this paper. The CALC-I gene produces calcitonin (CT) (encoded by exon 4) or calcitonin gene-related peptide (CGRP) (encoded by exon 5) in a tissue-specific fashion. The CALC-II gene produces a second human CGRP, but probably not a second CT. The CALC-III gene does not seem to encode a CT- or CGRP-related polypeptide hormone and is probably a pseudogene. Like the other two CALC genes, the CALC-III gene is located on human chromosome 11. 相似文献
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Sander A Huisman Wendy Bijman-Lagcher Jan NM IJzermans Ron Smits Ron WF de Bruin 《Cell cycle (Georgetown, Tex.)》2015,14(14):2333-2339
Irinotecan is a widely used topoisomerase-I-inhibitor with a very narrow therapeutic window because of its severe toxicity. In the current study we have examined the effects of fasting prior to irinotecan treatment on toxicity and anti-tumor activity. FabplCre;Apc15lox/+ mice, which spontaneously develop intestinal tumors, of 27 weeks of age were randomized into 3-day fasted and ad libitum fed groups, followed by treatment with a flat-fixed high dose of irinotecan or vehicle. Side-effects were recorded until 11 days after the start of the experiment. Tumor size, and markers for cell-cycle activity, proliferation, angiogenesis, and senescence were measured. Fasted mice were protected against the side-effects of irinotecan treatment. Ad libitum fed mice developed visible signs of discomfort including weight loss, lower activity, ruffled coat, hunched-back posture, diarrhea, and leukopenia. Irinotecan reduced tumor size in fasted and ad libitum fed groups similarly compared to untreated controls (2.4 ± 0.67 mm and 2.4 ± 0.82 mm versus 3.0 ± 1.05 mm and 2.8 ± 1.08 mm respectively, P < 0.001). Immunohistochemical analysis showed reduced proliferation, a reduced number of vascular endothelial cells, and increased levels of senescence in tumors of both irinotecan treated groups. In conclusion, 3 days of fasting protects against the toxic side-effects of irinotecan in a clinically relevant mouse model of spontaneously developing colorectal cancer without affecting its anti-tumor activity. These results support fasting as a powerful way to improve treatment of colorectal carcinoma patients. 相似文献
14.
Nucleotide variation in the triosephosphate isomerase (Tpi) locus of Drosophila melanogaster and Drosophila simulans 总被引:3,自引:0,他引:3
Hasson E; Wang IN; Zeng LW; Kreitman M; Eanes WF 《Molecular biology and evolution》1998,15(6):756-769
DNA sequence variation in a 1.1-kb region including the coding portion of
the Tpi locus was examined in 25 homozygous third-chromosome lines of
Drosophila melanogaster, nine lines of Drosophila simulans, and one line of
Drosophila yakuba. Our data show that the widespread allozyme polymorphism
observed in cosmopolitan D. melanogaster is due to a glutamic acid
substitution occurring in a phylogenetically conserved lysine that has been
identified as part of the "hinged-lid" active site of the enzyme. This
observation suggests that the replacement polymorphism may have important
functional consequences. One replacement polymorphism was also observed in
D. simulans, although its functional relevance is more difficult to assess,
since it affects a site that is not strongly conserved. This amino acid
change in D. simulans is associated with a single lineage possessing seven
unique silent substitutions, which may be indicative of balancing selection
or population subdivision. The absence of fixed amino acid differences
between D. melanogaster and D. simulans and only a single difference with
D. yakuba suggests that triose phosphate isomerase is under strong
functional constraint. Silent variation is slightly higher for D.
melanogaster than for D. simulans. Finally, we outline the general lack of
evidence for old balanced polymorphisms at allozyme loci in D.
melanogaster.
相似文献
15.
Ouabain-insensitive salt and water movements in duck red cells. I. Kinetics of cation transport under hypertonic conditions 总被引:10,自引:6,他引:4 下载免费PDF全文
Duck red cells in hypertonic media experience rapid osmotic shrinkage followed by gradual reswelling back toward their original volume. This uptake of salt and water is self limiting and demands a specific ionic composition of the external solution. Although ouabain (10(-4)M) alters the pattern of cation accumulation from predominantly potassium to sodium, it does not affect the rate of the reaction, or the total amount of salt or water taken up. To study the response without the complications of active Na-K transport, ouabain was added to most incubations. All water accumulated by the cells can be accounted for by net salt uptake. Specific external cation requirements for reswelling include: sufficient sodium (more than 23 mM), and elevated potassium (more than 7 mM). In the absence of external potassium cells lose potassium without gaining sodium and continue to shrink instead of reswelling. Adding rubidium to the potassium- free solution promotes an even greater loss of cell potassium, yet causes swelling due to a net uptake of sodium and rubidium followed by chloride. The diuretic furosemide (10(-3)M) inhibits net sodium uptake which depends on potassium (or rubidium), as well as inhibits net sodium uptake which depends on sodium. As a result, cell volume is stabilized in the presence of this drug by inhibition of shrinkage, at low, and of swelling at high external potassium. The response has a high apparent energy of activation (15-20 kcal/mol). We propose that net salt and water movements in hypertonic solutions containing ouabain are mediated by direct coupling or cis-interaction, between sodium and potassium so that the uphill movement of one is driven by the downhill movement of the other in the same direction. 相似文献
16.
Efficient estimation of the prevalence of multiple rare traits 总被引:1,自引:0,他引:1
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J. W. M. Höppener P. H. Steenbergh J. Zandberg A. H. M. Geurts van Kessel S. B. Baylin B. D. Nelkin H. S. Jansz C. J. M. Lips 《Human genetics》1985,70(3):259-263
Summary A second human calcitonin/calcitonin gene related peptide (hCT/CGRP) gene has been identified. This second hCT/CGRP gene has been shown to contain sequences highly homologous to exons 3, 5 (CGRP-encoding), and 6 of the first hCT/CGRP gene, but sequences closely related to exon 4 (CT-encoding) could not be demonstrated. Southern blot hybridization analysis of DNA from human-rodent somatic cell hybrids showed that the second hCT/CGRP gene is located in the q12-pter region of chromosome 11. The first hCT/CGRP gene has previously been assigned to the p13–p15 region of chromosome 11. 相似文献
18.
Ana E.Gutierrez-Cabrera Wesley F.Zandberg Edgar Zenteno Mario H.Rodriguez Bertha Espinoza Carl Lowenberger 《Insect Science》2019,26(5):796-808
Trypanosoma cruzi,the causative agent of Chagas disease, interacts with molecules in the midgut of its insect vector to multiply and reach the infective stage. Many studies suggest that the parasite binds to midgut-specific glycans. We identified several glycoproteins expressed in the intestine and perimicrovillar membrane (PMM) of Triatoma (Meccus) pallidipennis under different feeding conditions. In order to assess changes in protein-linked glycans, we performed lectin and immunoblot analyses on glycoprotein extracts from these intestinal tissues using well-characterized lectins, and an antibody, which collectively recognize a wide range of different glycans epitopes. We observed that the amount and composition of proteins and glycoproteins associated with different glycans structures changed over time in the intestines and PMM under different physiological conditions. PMM extracts contained a wide variety of glycoproteins with different sugar residues, including abundant high-mannose and complex sialylated glycans. We propose that these molecules could be involved in the process of parasite-vector interactions. 相似文献
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Evidence of independent gene duplications during the evolution of archaeal and eukaryotic family B DNA polymerases 总被引:1,自引:0,他引:1
Eukaryotes and archaea both possess multiple genes coding for family B DNA
polymerases. In animals and fungi, three family B DNA polymerases, alpha,
delta, and epsilon, are responsible for replication of nuclear DNA. We used
a PCR-based approach to amplify and sequence phylogenetically conserved
regions of these three DNA polymerases from Giardia intestinalis and
Trichomonas vaginalis, representatives of early-diverging eukaryotic
lineages. Phylogenetic analysis of eukaryotic and archaeal paralogs
suggests that the gene duplications that gave rise to the three replicative
paralogs occurred before the divergence of the earliest eukaryotic
lineages, and that all eukaryotes are likely to possess these paralogs. One
eukaryotic paralog, epsilon, consistently branches within archaeal
sequences to the exclusion of other eukaryotic paralogs, suggesting that an
epsilon-like family B DNA polymerase was ancestral to both archaea and
eukaryotes. Because crenarchaeote and euryarchaeote paralogs do not form
monophyletic groups in phylogenetic analysis, it is possible that archaeal
family B paralogs themselves evolved by a series of gene duplications
independent of the gene duplications that gave rise to eukaryotic paralogs.
相似文献