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31.
Joseph W. Mayo William M. Wallace Leroy W. Matthews Don M. Carlson 《Archives of biochemistry and biophysics》1976,175(2):507-513
Submandibular secretions collected from children with cystic fibrosis (CF) showed increased protein concentration (milligrams/milliliter) and increased amylase specific activity (units/milligram of protein) relative to normal secretions. These differences between normal (N) and CF secretions were as follows: protein, 1.25 ± 0.51 (N), 1.75 ± 0.35 (CF) (P < 0.02); and amylase, 58 ± 18 (N), 80 ± 19 (CF) (P < 0.001). To determine the basis for elevated protein in CF saliva, several major proteins resolved by polyacrylamide disc gel electrophoresis were quantitated by densitometry. These included four phosphoproteins (PP), serum albumin, an acid phosphatase-containing fraction, amylase, and an unidentified protein referred to as PI-7.1. Together, these proteins comprise greater than 75% of the total protein in the secretion. Differences in individual protein concentrations (milligrams/milliliter) resolved from normal and CF secretions, respectively, were as follows: PP2, 0.02 ± 0.01, 0.03 ± 0.02 (NS, not significant); PP3, 0.06 ± 0.04, 0.05 ± 0.03 (NS); acid phosphatase fraction, 0.06 ± 0.04, 0.12 ± 0.07 (P < 0.05); amylase, 0.09 ± 0.04, 0.27 ± 0.16 (P < 0.01); and pI-7.1, 0.04 ± 0.02, 0.13 ± 0.08 (P < 0.02). Amylase, the most significant contributor to the elevated protein, comprised 26% of the total protein of normal secretions and 38% of the total protein of CF secretions. Thus, our results do not support the concept of a generalized increase in all organic components in CF submandibular secretions but, rather, increases in specific proteins, namely amylase, component pI-7.1, and an acid phosphatase-containing fraction. 相似文献
32.
We examined spleen cells from newborn to 1-month-old rabbits for easily detectable surface immunoglobulin, complement receptors, and for in vitro proliferative responsiveness to anti-immunoglobulin antisera and several mitogens. From birth through the first month of life about 15% of the cells from rabbit spleens had easily detectable surface immunoglobulin while about 45% had C3 receptors. In adults as many as 77% of the spleen cells had easily detectable surface Ig but the proportion with C3 receptors remained about 45%. The proliferative response to anti-allotype antisera was present at birth, and was at adult levels by 1 month of age. The proliferative response to pokeweed mitogen was low when cells were obtained during the first week of life but was comparable in magnitude to the response of adult cells by 2 weeks of age. In vitro responsiveness to concanavalin A was present at low levels at birth and increased sharply during the first week. We did not observe significant stimulation of spleen cells from neonatal to 4-week-old rabbits by lipopolysaccharide from Salmonella typhosa. Our data suggest that lymphocyte surface markers and functional responses appear asynchronously in spleen cells of developing rabbits. 相似文献
33.
B. S. Chertow G. A. Williams Georgiann R. Baker R. D. Surbaugh G. K. Hargis 《Experimental cell research》1975,93(2):388-394
To determine the role of subcellular organelles in hormone secretion, we studied the interaction of low calcium concentration (low Ca), retinol (vitamin A, vit A), vinblastine (VB), and cytochalasin B (CB) in parathyroid hormone (PTH) secretion. Bovine parathyroid tissue pieces were incubated in media containing the above agents. Vit A stimulated PTH release to a mean of 170% of control. This effect of vit A was diminished when tissues were simultaneously stimulated with low Ca and, furthermore, absent when tissues were pre-incubated in low Ca.VB had no effect on low Ca-stimulated secretion, but did inhibit vit A-induced secretion in the presence of low Ca.CB stimulated PTH secretion to a mean of 150% of control during the second and third hours of incubation. CB had at least an additive effect with low Ca in stimulating PTH secretion, with a more prompt and greater response than seen in normal calcium. VB did not inhibit the acute effect of CB on secretion in normal calcium media, but did inhibit CB-induced secretion during the third hour of incubation.None of the agents stimulated the release of lysosomal cathepsin D, and vit A and CB did not stimulate the release of LDH.Our results suggest that; (1) vit A and low Ca stimulate PTH secretion through a common pathway involving the cell membrane; (2) CB stimulates PTH secretion through a separate effect on the cell membrane or submembrane microfilaments, which normally retards secretion of PTH; and (3) microtubular proteins may facilitate basal secretion of PTH, but are not involved in low Ca-stimulated secretion of PTH. 相似文献
34.
The biotransformation of pregnenolone-7alpha-3H and of progesterone-7alpha-3H by porcine fetal and maternal adrenal homogenates at 56 and 112 days of pregnancy and of dehydroepiandrosterone-7alpha-3H by fetal adrenal homogenates has been investigated in vitro. Both pregnenolone-7alpha-3H and progesterone-7alpha-3H were metabolized extensively by maternal adrenal preparations, the principal radioactive metabolites isolated being cortisol, corticosterone, 11-deoxycortisol, deoxycorticosterone, 11beta-hydroxyprogesterone and androstenedione. In addition, 17alpha-hydroxyprogesterone, 20alpha-dihydroprogesterone and cortisone were formed from both substrates and 17alpha-hydroxypregnenolone and progesterone were formed from pregnenolone. Although essentially the same radioactive metabolites were isolated after incubation of fetal adrenal glands with pregnenolone-7alpha-3H or progesterone-7alpha-3H, a greater proportion of the radioactivity was associated with corticosteroids at 112 days of pregnancy than at 56 days. 11beta-Hydroxyandrostenedione and androstenedione were isolated and identified together with an unknown polar metabolite, after incubation of fetal adrenal tissue with dehydroepiandrosterone-7alpha-3H. These results are discussed in relation to feto-placental steroid biosynthesis and metabolism and the role of the fetal adrenal in the initiation of parturition in the pig. 相似文献
35.
Peter S. Thuy-Boun Ana Y. Wang Ana Crissien-Martinez Janice H. Xu Sandip Chatterjee Gregory S. Stupp Andrew I. Su Walter J. Coyle Dennis W. Wolan 《Molecular & cellular proteomics : MCP》2022,21(3):100197
The gut microbiota plays an important yet incompletely understood role in the induction and propagation of ulcerative colitis (UC). Organism-level efforts to identify UC-associated microbes have revealed the importance of community structure, but less is known about the molecular effectors of disease. We performed 16S rRNA gene sequencing in parallel with label-free data-dependent LC-MS/MS proteomics to characterize the stool microbiomes of healthy (n = 8) and UC (n = 10) patients. Comparisons of taxonomic composition between techniques revealed major differences in community structure partially attributable to the additional detection of host, fungal, viral, and food peptides by metaproteomics. Differential expression analysis of metaproteomic data identified 176 significantly enriched protein groups between healthy and UC patients. Gene ontology analysis revealed several enriched functions with serine-type endopeptidase activity overrepresented in UC patients. Using a biotinylated fluorophosphonate probe and streptavidin-based enrichment, we show that serine endopeptidases are active in patient fecal samples and that additional putative serine hydrolases are detectable by this approach compared with unenriched profiling. Finally, as metaproteomic databases expand, they are expected to asymptotically approach completeness. Using ComPIL and de novo peptide sequencing, we estimate the size of the probable peptide space unidentified (“dark peptidome”) by our large database approach to establish a rough benchmark for database sufficiency. Despite high variability inherent in patient samples, our analysis yielded a catalog of differentially enriched proteins between healthy and UC fecal proteomes. This catalog provides a clinically relevant jumping-off point for further molecular-level studies aimed at identifying the microbial underpinnings of UC. 相似文献
36.
Kim SH Shin DH Choi IG Schulze-Gahmen U Chen S Kim R 《Journal of structural and functional genomics》2003,4(2-3):129-135
The dramatically increasing number of new protein sequences arising from genomics 4 proteomics requires the need for methods to rapidly and reliably infer the molecular and cellular functions of these proteins. One such approach, structural genomics, aims to delineate the total repertoire of protein folds in nature, thereby providing three-dimensional folding patterns for all proteins and to infer molecular functions of the proteins based on the combined information of structures and sequences. The goal of obtaining protein structures on a genomic scale has motivated the development of high throughput technologies and protocols for macromolecular structure determination that have begun to produce structures at a greater rate than previously possible. These new structures have revealed many unexpected functional inferences and evolutionary relationships that were hidden at the sequence level. Here, we present samples of structures determined at Berkeley Structural Genomics Center and collaborators laboratories to illustrate how structural information provides and complements sequence information to deduce the functional inferences of proteins with unknown molecular functions.Two of the major premises of structural genomics are to discover a complete repertoire of protein folds in nature and to find molecular functions of the proteins whose functions are not predicted from sequence comparison alone. To achieve these objectives on a genomic scale, new methods, protocols, and technologies need to be developed by multi-institutional collaborations worldwide. As part of this effort, the Protein Structure Initiative has been launched in the United States (PSI; www.nigms.nih.gov/funding/psi.html). Although infrastructure building and technology development are still the main focus of structural genomics programs [1–6], a considerable number of protein structures have already been produced, some of them coming directly out of semi-automated structure determination pipelines [6–10]. The Berkeley Structural Genomics Center (BSGC) has focused on the proteins of Mycoplasma or their homologues from other organisms as its structural genomics targets because of the minimal genome size of the Mycoplasmas as well as their relevance to human and animal pathogenicity (http://www.strgen.org). Here we present several protein examples encompassing a spectrum of functional inferences obtainable from their three-dimensional structures in five situations, where the inferences are new and testable, and are not predictable from protein sequence information alone. 相似文献
37.
O. H. Volk 《Plant Ecology》1984,55(1):57-64
Three associations of the Nanocyperion teneriffae Lebrun 1947 (Sporoboletalia festivi Lebrun 1947) are described. They are physiognomically and ecologically similar to associations of the Mediterranean Isoeto-Nanojuncetea Br.-Bl. et Tx. 1943 and Helianthemetalia guttati Br.-Bl. 1940. They are rich in very specialized therophytes and resurrection plants.
Meinem Lehrer H. Walter, Stuttgart gewidmet. 相似文献
38.
39.
The conversion of arachidonic acid to prostaglandins (PG's) and thromboxane B2 (TXB2) was investigated in homogenates from fetal and adult bovine and rabbit lungs. Adult bovine lungs were very active in converting arachidonic acid (100 μg/g tissue) to both PGE2 (10.7 μg/g tissue) and TXB2 (6.2 μ/g tissue). Smaller amounts of PGF2α (0.9 μ/g) and 6-oxoPGF1α were formed. Homogenates from fetal calf lungs during the third trimester of pregnancy were quite active in converting arachidonic acid to PGE2, but formed very little TXB2, PGF2α or 6-oxoPGF1α. Homogenates from rabbit lungs converted arachidonic acid (100 μg/g) mainly to PGE2, both before and after birth. The amount of PGE2 formed increased during gestation to a maximum of about 6 μg/g tissue at 28 days of gestation. It then decreased to a minimum (1.5 μg/g) which was observed 8 days after birth, followed by an increase to about 4 μg/g in older rabbits. 相似文献
40.
Christina M. Giovas Michelle J. LeFebvre Scott M. Fitzpatrick 《Journal of Biogeography》2012,39(3):476-487
Aim This paper investigates the prehistoric introduction of five mammalian taxa to Carriacou (Lesser Antilles) and refines the known anthropogenic ranges for these fauna in the pre‐Columbian West Indies. The importance of such records for understanding the region’s historical biogeography and ecology is considered. Location Carriacou Island, Grenada (12°28′ N, 61°26′ W). Methods Zooarchaeological assemblages from Carriacou’s earliest documented prehistoric sites, Grand Bay and Sabazan, were analysed, and exotic taxa were identified and quantified. The timing of introductions was established based on multiple radiocarbon assays, including three new accelerator mass spectrometry (AMS) direct dates obtained on the bone of exotic taxa. Source species and location(s) are considered and compared with known prehistoric records for the Caribbean to synthesize anthropogenic distributions for the pre‐Columbian period. The contexts of the zooarchaeological remains are evaluated to better understand the nature and purpose of introductions. Results Zooarchaeological investigation on Carriacou reveals the occurrence of multiple mammal introductions from South American between c. ad 700 and ad 1400. This paper presents the first records for guinea pig (Cavia sp.), armadillo (Dasypus sp.), peccary (Tayassu/Pecari sp.), opossum (Didelphis sp.) and agouti (Dasyprocta sp.) from the island. Human‐mediated transport of these taxa is indicated by their absence from the record prior to human settlement of Carriacou. Several translocated species are either rare or entirely unknown for the region, and overall West Indian distributions are temporally and spatially discontinuous. Archaeological contexts indicate that mammalian introductions arose from human subsistence needs, but other social factors may have shaped the dispersal of these fauna. Main conclusions The taxonomic combination and richness of Carriacou’s introduced fauna are unusual within the region. Importantly, the new records significantly improve the known pre‐Columbian geographic range for peccary, guinea pig and armadillo. Integrated with regional records, these data augment our understanding of the Caribbean’s historical biogeography, and have the potential to improve our understanding of human mobility and anthropogenic environmental impacts in the West Indies prior to the arrival of Europeans. 相似文献