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901.
F. P. Conte G. L. Peterson R. D. Ewing 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1973,82(3):277-289
Summary Naupliar brine shrimp (Artemia salina) have been used to study the salt-dependent regulation of protein synthesis. Measurement of thein vivo rates of protein synthesis was found to be very complex and dependent upon the leucine concentration of the external medium, rate of leucine entry and time of equilibration between various internal pools of leucine. Techniques were developed which permitted the measurement of rates of incorporation ofl4C-L-leucine into naupliar protein at various salinities under conditions that provided the organisms with a constant internal specific activity. It was found that salinities over 0.25 M NaC1 caused decreased rates of protein biosynthesis. A comparison of the rate of protein synthesis in the presence of chloramphenicol, cycloheximide and puromycin indicated that qualitative as well as quantitative changes in synthesis of proteins was directed by the external salinity. A feed-back mechanism based on the partitioning of available energy (ATP) between ion transport and protein synthesis is hypothesized.This work was supported by AEC grant RLO 2227-T13-1. The authors wish to express their gratitude to Prof. Robert R. Beoker and Robert L. Howard, Department of Biochemistry and Biophysics, for the technical assistance and use of the automatic amino acid analyzer in collecting data presented in Table 1 and Table 2. 相似文献
902.
Luigi Rosa Antimo Cutone Maria Stefania Lepanto Mellani Jinnett Scotti Maria Pia Conte Rosalba Paesano Piera Valenti 《Biometals》2018,31(3):301-312
Human and bovine lactoferrin (hLf and bLf) are multifunctional iron-binding glycoprotein constitutively synthesized and secreted by glandular epithelial cells and by neutrophils following induction. HLf and bLf possess very high similarity of sequence. Therefore, most of the in vitro and in vivo studies are carried out with commercial bLf (cbLf), available in large quantities and recognized by Food and Drug Administration (FDA, USA) as a safe substance. Physico-chemical heterogeneity of different cbLf preparations influences their effectiveness. CbLf iron-saturation affects thermal stability and resistance to proteolysis. Moreover, other metal ions such as Al(III), Cu(II), Mg(II), Mn(II), Zn(II) are chelated by cbLf, even if at lower affinity than Fe(III). Ca(II) is also sequestered by the carboxylate groups of sialic acid present on glycan chains of cbLf thus provoking the release of LPS, contributing to bactericidal activity. Similarly to more than 50% of eukaryotic proteins, cbLf possesses five N-glycosylation sites, also contributing to the resistance to proteolysis and, putatively, to the protection of intestinal mucosa from pathogens. CbLfs possess several functions as anti-microbial, anti-biofilm, anti-adhesive, anti-invasive and anti-inflammatory activities. They are also relevant modulators of iron and inflammatory homeostasis. However, the efficacy of cbLfs in exerting several functions can be erratic mainly depending from integrity, degree of iron and other metal ions saturation, N-glycosylation sites and chains, desialylated forms, Ca(II) sequestration, presence of contaminants and finally the ability to enter inside nucleus. 相似文献
903.
904.
Arianna Mancuso Ruth Yam Fiorella Prada Marco Stagioni Stefano Goffredo Aldo Shemesh 《Geobiology》2023,21(1):119-132
Stable isotopes in mollusc shells, together with variable growth rates and other geochemical properties, can register different environmental clues, including seawater temperature, salinity and primary productivity. However, the strict biological control over the construction of biominerals exerted by many calcifying organisms can constrain the use of these organisms for paleoenvironmental reconstructions. Biologically controlled calcification is responsible for the so called vital effects that cause a departure from isotopic equilibrium during shell formation, resulting in lower shell oxygen and carbon compared to the equilibrium value. We investigated shell oxygen and carbon isotopic composition of the bivalve Chamelea gallina in six sites along with a latitudinal gradient on the Adriatic Sea (NE Mediterranean Sea). Seawater δ18O and δ13CDIC varied from North to South, reflecting variations in seawater temperature, salinity, and chlorophyll concentration among sites. Shell δ18O and δ13C differed among sites and exhibited a wide range of values along with the ~400 km latitudinal gradient, away from isotopic equilibrium for both isotopes. These results hampered the utilization of this bivalve as a proxy for environmental reconstructions, in spite of C. gallina showing promise as a warm temperature proxy. Rigorous calibration studies with a precise insight of environment and shell growth are crucial prior to considering this bivalve as a reliable paleoclimatic archive. 相似文献
905.
Doroti Pirulli Daniela Puzzer Laura Ferri Sergio Crovella A. Amoroso Cristina Ferrettini Martino Marangella Gina Mazzola Fiorella Florian 《Human genetics》1999,104(6):523-525
Systematic screening using the SSCP technique followed by sequencing of bands with abnormal mobility derived from the AGXT exons of 15 unrelated Italian patients with primary hyperoxaluria type 1 (PH1) allowed us to characterize both the mutant
alleles in each individual. Eight new mutations were identified: C155del, C156ins, G244T, C252T, GAG408ins, G468A, G588A and
G1098del. This study demonstrates both the effectiveness of the screening strategy chosen to identify all the mutant alleles
and the high degree of allelic heterogeneity in PH1.
Received: 5 January 1999 / Accepted: 12 April 1999 相似文献
906.
Prevalence,characteristics, and survival of children with esophageal atresia: A 32‐year population‐based study including 1,417,724 consecutive newborns 下载免费PDF全文