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191.
Elzein E Kalla R Li X Perry T Marquart T Micklatcher M Li Y Wu Y Zeng D Zablocki J 《Bioorganic & medicinal chemistry letters》2007,17(1):161-166
A series of new selective, high affinity A(1)-AdoR agonists is reported. Compound 23 that incorporated a carboxylic acid functionality in the 4-position of the pyrazole ring displayed K(iL) value of 1 nM for the A(1)-AdoR and >5000-fold selectivity over the A(3) and A(2A)-AdoRs. In addition, compound 19 that incorporated a carboxamide functionality in the 4-position of the pyrazole ring displayed subnanomolar affinity for the A(1)-AdoR (K(iL)=0.6 nM) and >600-fold selectivity over the A(3) and A(2A)-AdoRs. 相似文献
192.
POFs: what we don't know can hurt us 总被引:1,自引:0,他引:1
Over a quarter of all eukaryotic genes encode proteins with obscure features that lack currently defined motifs or domains (POFs). Interestingly, most of the differences in gene repertoire among species were recently found to be attributed to POFs. A comparison of the Arabidopsis, rice and poplar genomes reveals that Arabidopsis contains 5069 POFs, of which 2045 have no obvious homologs in rice or poplar and are likely to be involved in species- or phylogenetic-specific functions in Arabidopsis. The study of POFs is an important endeavor that will shed much needed light on the genetic properties that make any given plant species unique. Furthermore, with respect to many species-specific features, such studies show that we seem to be limited in what we can expect to learn from a model plant such as Arabidopsis. 相似文献
193.
James A. Sulikowski William B. Driggers III G. Walter Ingram Jr. Jeff Kneebone Darren E. Ferguson Paul C. W. Tsang 《Environmental Biology of Fishes》2007,80(2-3):285-292
Information regarding sexual maturity and reproductive cycles in skates has largely been based on gross morphological changes
within the reproductive tract. While this information has proved valuable in obtaining life history information, it also necessitates
sacrificing the skates to obtain this data. In contrast, few studies have used circulating steroid hormones to establish when
these batoids become reproductively capable or for the determination of reproductive cyclicity. This study summarizes our
current knowledge of hormonal analyses in determining skate reproductive status and offers information that suggests analysis
of circulating steroid hormone concentrations provide a means to determine size at sexual maturity and asses reproductive
cycles without the need to sacrifice the skate. 相似文献
194.
Arendt J 《Biological reviews of the Cambridge Philosophical Society》2007,82(2):241-256
Body size is important to most aspects of biology and is also one of the most labile traits. Despite its importance we know remarkably little about the proximate (developmental) factors that determine body size under different circumstances. Here, I review what is known about how cell size and number contribute to phenetic and genetic variation in body size in Drosophila melanogaster, several fish, and fruits and leaves of some angiosperms. Variation in resources influences size primarily through changes in cell number while temperature acts through cell size. The difference in cellular mechanism may also explain the differences in growth trajectories resulting from food and temperature manipulations. There is, however, a poorly recognized interaction between food and temperature effects that needs further study. In addition, flies show a sexual dimorphism in temperature effects with the larger sex responding by changes in cell size and the smaller sex showing changes in both cell size and number. Leaf size is more variable than other organs, but there appears to be a consistent difference between how shade-tolerant and shade-intolerant species respond to light level. The former have larger leaves via cell size under shade, the latter via cell number in light conditions. Genetic differences, primarily from comparisons of D. melanogaster, show similar variation. Direct selection on body size alters cell number only, while temperature selection results in increased cell size and decreased cell number. Population comparisons along latitudinal clines show that larger flies have both larger cells and more cells. Use of these proximate patterns can give clues as to how selection acts in the wild. For example, the latitudinal pattern in D. melanogaster is usually assumed to be due to temperature, but the cellular pattern does not match that seen in laboratory selection at different temperatures. 相似文献
195.
The success of molecular research and its applications in both the clinical and basic research arenas is strongly dependent
on the collection, handling, storage, and quality control of fresh human tissue samples. This tissue bank was set up to bank
fresh surgically obtained human tissue using a Clinical Annotated Tissue Database (CATD) in order to capture the associated
patient clinical data and demographics using a one way patient encryption scheme to protect patient identification. In this
study, we determined that high quality of tissue samples is imperative for both genomic and proteomic molecular research.
This paper also contains a brief compilation of the literature involved in the patient ethics, patient informed consent, patient
de-identification, tissue collection, processing, and storage as well as basic molecular research generated from the tissue
bank using good clinical practices. The current applicable rules, regulations, and guidelines for handling human tissues are
briefly discussed. More than 6,610 cancer patients have been consented (97% of those that were contacted by the consenter)
and 16,800 tissue specimens have been banked from these patients in 9 years. All samples collected in the bank were QC’d by
a pathologist. Approximately 1,550 tissue samples have been requested for use in basic, clinical, and/or biomarker cancer
research studies. Each tissue aliquot removed from the bank for a research study were evaluated by a second H&E, if the samples
passed the QC, they were submitted for genomic and proteomic molecular analysis/study. Approximately 75% of samples evaluated
were of high histologic quality and used for research studies. Since 2003, we changed the patient informed consent to allow
the tissue bank to gather more patient clinical follow-up information. Ninety two percent of the patients (1,865 patients)
signed the new informed consent form and agreed to be re-contacted for follow-up information on their disease state. In addition,
eighty five percent of patients (1,584) agreed to be re-contacted to provide a biological fluid sample to be used for biomarker
research. 相似文献
196.
Putra Rocky Waterman Jamie M. Mathesius Ulrike Wojtalewicz Dominika Powell Jeff R. Hartley Susan E. Johnson Scott N. 《Plant and Soil》2022,476(1-2):201-218
Plant and Soil - Root residues are an important factor influencing soil phosphorus (P) availability for crop uptake, but how the residues from different species combinations in sole cropping or... 相似文献
197.
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199.
RNase E is a major intracellular endoribonuclease in many bacteria and participates in most aspects of RNA processing and degradation. RNase E requires a divalent metal ion for its activity. We show that only Mg2+ and Mn2+ will support significant rates of activity in vitro against natural RNAs, with Mn2+ being preferred. Both Mg2+ and Mn2+ also support cleavage of an oligonucleotide substrate with similar kinetic parameters for both ions. Salts of Ni2+ and Zn2+ permitted low levels of activity, while Ca2+, Co3+, Cu2+, and Fe2+ did not. A mutation to one of the residues known to chelate Mg2+, D346C, led to almost complete loss of activity dependent on Mg2+; however, the activity of the mutant enzyme was fully restored by the presence of Mn2+ with kinetic parameters fully equivalent to those of wild-type enzyme. A similar mutation to the other chelating residue, D303C, resulted in nearly full loss of activity regardless of metal ion. The properties of RNase E D346C enabled a test of the ionic requirements of RNase E in vivo. Plasmid shuffling experiments showed that both rneD303C (i.e., the rne gene encoding a D-to-C change at position 303) and rneD346C were inviable whether or not the selection medium was supplied with MnSO4, implying that RNase E relies on Mg2+ exclusively in vivo. 相似文献
200.