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21.
M. Wolfsperger H. Wilfing K. Matiasek M. Teschler-Nicola 《International Journal of Anthropology》1993,8(1):27-33
Hair samples of 46 prehistoric mummies from five different pre-Inca sites in Peru were analyzed for Ca, Sr, Ni, Mn, and Ba
by DCP/AES. The five sites displayed differing burial customs: whereas the dead of Cahuachi (n=13), Huayuri (n=2) and Brujo
(n=5) had been interred unwrapped in simple stone pits, the mummies of Las Trancas (n=17) and Pacatnamu (n=9) had been granted
protection by fabrics and wooden coffins. At the sites with no protection, the hair samples contained extremely high concentrations
of Ca and Sr which by far exceeded the usual physiological ranges. This can probably be explained by contamination from the
surrounding soil. In contrast, the protected depositions of Las Trancas and Pacatnamu exhibited Ca and Sr concentrations within
the present range of variation. This may indicate that favourable conditions had prevented contamination in these cases. For
Mn the same trend can be observed, both Cahuachi and Huayuri samples showed markedly increased values. For Ni and Ba on the
other hand no correlation with the type of interment was found. In the two non-contaminated series, the mean values of Mn,
Ba, and Ni were considerably higher in Las Trancas than in Pacatnamu. As Mn, Ni, and Ba tend to occur in higher concentrations
in vegetable than in animal food items, these differences may indicate a differential availability of animal protein at the
two locations 相似文献
22.
The behaviour of summer and autumn winged forms of the black bean aphid, Aphis fabae Scopoli (Homoptera: Aphididae), was compared on two plants utilized at different stages of the insect’s life cycle. Adult autumn migrants (gynoparae) are monophagous, colonizing spindle (Euonymus europaeus), whereas polyphagous summer winged aphids (alate virginoparae) are associated with a variety of herbaceous plants, including broad bean (Vicia faba). When aphids from a single clone were given access to a spindle leaf and a bean seedling in choice tests, many virginoparae settled and larviposited on both plant species over 24 h. By contrast, gynoparae showed a clear preference for spindle, with 93.5% of settled adults and 98.3% of larvae on this plant species. Close‐up video monitoring showed that gynoparae discriminated beans from spindle within a 5‐min period, whereas virginoparae behaved similarly on both plant species. For gynoparae, the major behavioural difference on the two plants appeared after a brief (epidermal) stylet penetration, with many insects taking flight within a few seconds of stylet withdrawal from bean. Factors detected during stylet insertion by gynoparae must therefore inhibit take‐off on spindle. Electrical recording experiments showed that aphids often punctured a cell membrane during brief probes on both plant species, and intracellular stylet activities always included a waveform associated with ingestion. When gynoparae puncture spindle cells their behaviour is probably modified by intracellular metabolites detected via gustation of ingested epidermal cell sap. These cues may inhibit the take‐off reflex which otherwise follows probing. 相似文献
23.
Anwesha Dutta Premalatha Shetty Smitha Bhat Yeshaswini Ramachandra Shrinidhi Hegde 《Journal of biomolecular techniques》2012,23(4):128-135
A solvent system that extracts a maximum number of metabolites belonging to diverse chemical classes from complex biofluids, such as plasma, may offer useful inputs to understand the metabolic and physiological state of an individual. The present study compared seven solvent systems for extraction of metabolites from plasma. The extracts were analyzed by mass spectrometry (MS) and MS/MS (MS2) using a quadrupole time-of-flight liquid chromatography/MS system in positive and negative modes of ionization. Metabolites with molecular mass below 400 were identified using Human Metabolome Database MS2 and MS search interfaces. The acetone/isopropanol (2:1) system yielded promising results in positive ionization mode, as the maximum number of MS and MS2 features was detected in the extract. It was found to be superior in extraction of various classes of metabolites, especially organic acids, nucleosides and nucleoside derivatives, and heterocyclic molecules. Glycerophosphocholines in the mass range of 400–700 were found to be efficiently extracted by the methanol/chloroform/water (8:1:1) system. In negative mode as well, the maximum number of MS2 features was detected in methanol/chloroform/water and acetone/isopropanol extracts. The fingerprints of molecular features obtained in the negative and positive modes differed from each other to a significant extent. 相似文献
24.
Chondrogenic differentiation of mesenchymal cells is generally thought to be initiated by the inductive action of specific
growth factors and depends on intimate cell-cell interactions. The aim of our investigation was to characterize the influences
of basic fibroblast growth factor (bFGF) and ferroussulfate (FeSO4) on proliferation and differentiation of human articular chondrocytes (HAC). This is the first report of the effects of FeSO4 on chondrogenesis of HAC. Multiplied chondrocytes of hip and shoulder joints were cultured in chondrocyte growth medium supplemented
with bFGF, FeSO4, or both bFGF + FeSO4 for4weeks. A 20 μl aliquot of a cell suspension containing2 × 107 cells ml−1 was delivered onto each well of 24-well tissue culture plates. Cells cultured with the growth medium only was used as a control.
Alamar blue and alcian blue staining were done to determine the chondrocyte proliferation and differentiation, respectively,
after 4 weeks. The samples exposed to bFGF, FeSO4, and combination of both indicated sufficient cell proliferation similar to the control level. Differentiations of the HAC
exposed to bFGF, FeSO4,and bFGF + FeSO4 were 1.2-, 2.0-, and 2.2-fold of the control, respectively. Therefore, chondrocyte differentiation was significantly enhanced
by the addition of FeSO4 andbFGF + FeSO4. The combined effects of bFGF and FeSO4 were additive, rather than synergistic. These results suggest that treatment with ferrous sulfate alone or in combination
with basic fibroblast growth factor etc, is a powerful tool to promote the differentiation of HAC for the clinical application.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
25.
Résumé L'ultrastructure générale des cellules K endométriales est semblable chez l'Homme, le Rat et le Singe. Mais les granulations des cellules K humaines sont plus variées que dans ces deux dernières espèces et ont certains aspects suggérant une fonction catabolique.Etant donné cet aspect catabolique et l'existence connue d'une activité phosphatasique acide de ces cellules contenant de la relaxine, les auteurs suggèrent que les cellules K pourraient être des cellules sécrétantes en involution et ques les cellules sécrétant activement la relaxine pourraient avoir un aspect morphologique quelque peu différent de celui des cellules K.
Ultrastructure of the normal human endometriumIII. The endometrial granular stroma cells
Summary The general ultrastructure of endometrial granular stroma cells is similar in man, rat, and monkey. But the granulations of human granular stroma cells are more various than in these two last species and have some aspects suggesting a catabolic function.With respect to this catabolic aspect and the previously shown acid-phosphatase activity of these relaxin-containing cells the authors suggest that the granular stroma cells could be involutive secretory cells and that the active relaxin-secretory cells may have some different morphological aspect.相似文献
26.
Eight new iridal-type triterpenoid derivatives, including two noriridals with ether bridge (1–2); two iridals lactone (3–4), four monocyclic iridals (5–8), together with five known iridals (9–14) were identified from the rhizome of Belamcanda chinensis. Their structures were elucidated on the basis of comprehensive spectroscopic methods and electronic circular dichroism (ECD) calculations. Bioassay results showed that belamcanoxide B (1) exhibited moderated cytotoxic activities against HCT-116 and MCF-7 cell lines with IC50 values of 5.58 and 3.35 μM. 相似文献
27.
We propose a model of the human circadian system. The sleep-wake and body temperature rhythms are assumed to be driven by a pair of coupled nonlinear oscillators described by phase variables alone. The novel aspect of the model is that its equations may be solved analytically. Computer simulations are used to test the model against sleep-wake data pooled from 15 studies of subjects living for weeks in unscheduled, time-free environments. On these tests the model performs about as well as the existing models, although its mathematical structure is far simpler.Supported by NIGMS Grant No. 5-R01-GM-30719-03 相似文献
28.
Acetylcholine receptor (AChR) purified from human skeletal muscle affinity-alkylated with bromoacetyl[methyl-3H]choline bromide ([3H]BAC) in mildly reducing conditions to yield a specifically radiolabeled polypeptide, Mr 44,000, the alpha-subunit. The binding of [125I]alpha-bungarotoxin to AChR was completely inhibited by affinity-alkylation, indicating that the human AChR's binding site for alpha-bungarotoxin is closely associated with the alpha-subunit's acetylcholine binding site. Structures in the vicinity of the alpha-bungarotoxin binding sites of AChRs from human muscle and Torpedo electric organ were compared by varying the conditions of alkylation. Under optimal conditions of reduction and alkylation, both human and Torpedo AChR incorporated BAC in equivalence to the number of alpha-bungarotoxin binding sites. However, with limited conditions of reduction but sufficient BAC to alkylate 100% of the alpha-bungarotoxin binding sites of human AChR, only 71% of the Torpedo AChR's binding sites were alkylated. In optimal conditions of reduction but with the minimal concentration of BAC that permitted 100% alkylation of the human AChR's alpha-bungarotoxin sites, only 74% of the Torpedo AChR's binding sites were alkylated. These data suggest that the neurotransmitter binding region of human muscle AChR is structurally dissimilar from that of Torpedo electric organ, having a higher binding affinity for BAC and an adjacent disulfide bond that is more readily accessible to reducing agents. 相似文献
29.
《Cell calcium》2019
Bone morphogenetic protein-2 (BMP-2) promotes the differentiation of non-osteogenic mesenchymal cells to osteogenic cells. In this study, we isolated human adipose-derived stem cells (hASCs) and investigated the effects of recombinant human BMP-2 (rhBMP-2) and extracellular Ca2+ concentration ([Ca2+]out) on the osteogenic differentiation of hASCs. rhBMP-2 promoted calcium deposition in hASCs and stimulated the mRNA expressions of six proteins known to be involved in the osteogenic differentiation of hASCs: Runx2, osterix, alkaline phosphatase, osteonectin, bone sialoprotein and osteocalcin. Elevation of [Ca2+]out enhanced the level of alkaline phosphatase enzyme, increased the mRNA expressions of Runx2 and osteocalcin and induced the expressions of BMP-2 mRNA and protein in hASCs. Elevation of [Ca2+]out transiently increased the intracellular Ca2+ concentration ([Ca2+]in) due to activation of the calcium-sensing receptor (CaSR). The Ca2+-induced expressions of BMP-2 mRNA and protein were inhibited by the calmodulin antagonist, W-7. Furthermore, elevation of [Ca2+]out decreased the cytoplasmic level of phosphorylated nuclear factor of activated T-cell-2 (NFAT-2) and increased the nuclear level of dephosphorylated NFAT2. Taken together, these results suggest that rhBMP-2 promotes the osteogenic differentiation of hASCs. Furthermore, an increase in [Ca2+]out enhances the expression of BMP-2 via activation of the CaSR, elevation of [Ca2+]in and stimulation of Ca2+/calmodulin-dependent NFAT-signaling pathways. 相似文献
30.
Electron-microscopic and immunocytochemical analyses of Weibel-Palade bodies in the human umbilical vein during pregnancy 总被引:3,自引:0,他引:3
Summary The present study was done to elucidate the biological significance of the Weibel-Palade body of human umbilical vein endothelial cells. Quantitative determinations of these endothelial-specific granules throughout pregnancy revealed that their numbers and size per cell profile were maintained at low levels from 12 to 19 weeks of gestation; then both rapidly increased from 33 weeks to full term. This increase coincided with the development of the rough endoplasmic reticulum and an increase in the number of endothelial cell pinocytotic vesicles. Light-microscopic peroxidase anti-peroxidase and electron-microscopic protein A-gold techniques provided evidence that factor VIII-related antigen was localized in the Weibel-Palade bodies. Furthermore, in vitro treatment of incubated umbilical vein tissue with compound 48/80, a histamine releaser, induced degranulation of Weibel-Palade bodies from the endothelium. The present study indicates that Weibel-Palade bodies are storage sites of both histamine and factor VIII-related antigen and have an important role in the obliteration of this vessel. 相似文献