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1.
A new flavone glucoside macrophylloside has been isolated from the whole plant of Primula macrophylla and its structure was determined by spectroscopic methods as 2′-hydroxy-7-O-β- -glucopyranosyloxyflavone. Sitosterol glucoside was also isolated for the first time from this plant.  相似文献   
2.
We challenge the concept of idiopathic parkinsonism (IP) as inevitably progressive neurodegeneration, proposing a natural history of sequential microbial insults with predisposing host response. Proof-of-principle that infection can contribute to IP was provided by case studies and a placebo-controlled efficacy study of Helicobacter eradication. "Malignant" IP appears converted to "benign", but marked deterioration accompanies failure. Similar benefit on brady/hypokinesia from eradicating "low-density" infection favors autoimmunity. Although a minority of UK probands are urea breath test positive for Helicobacter , the predicted probability of having the parkinsonian label depends on the serum H. pylori antibody profile, with clinically relevant gradients between this "discriminant index" and disease burden and progression. In IP, H. pylori antibodies discriminate for persistently abnormal bowel function, and specific abnormal duodenal enterocyte mitochondrial morphology is described in relation to H. pylori infection. Slow intestinal transit manifests as constipation from the prodrome. Diarrhea may flag secondary small-intestinal bacterial overgrowth. This, coupled with genetically determined intense inflammatory response, might explain evolution from brady/hypokinetic to rigidity-predominant parkinsonism.  相似文献   
3.
The entomopathogenic nematode–bacteria complexes Heterorhabditis bacteriophora/Photorhabdus luminescens and Steinernema carpocapsae/Xenorhabdus nematophila are mass produced for use as biological insecticides. Stability of the bacterial partner in culture is essential for maintaining traits important for both biological control and production. Two geographically distinct strains of each bacterial species were isolated from their nematode partners and serially subcultured on in vitro media to assess trait stability. Subculturing resulted in a shift to secondary cell production in one P. luminescens strain and both X. nematophila strains within ten in vitro culture cycles. However, when cell phenotypic variation was controlled in X. nematophila strains by regular selection for primary variants, no trait change was detected in the primary variant after prolonged subculture. When P. luminescens cell phenotypic variation was controlled by selection for primary variants, changes in the primary variant of both strains were noted including reductions in cell and inclusion body size and inclusion body prevalence. Bacterial ability to cause lethal infections following injection into the hemocoel of Tenebrio molitor larvae declined by more than half in primary variants of one P. luminescens strain. Conversely, yield was enhanced, with the subcultured P. luminescens strains showing 53.5 and 75.8% increases in primary cell density. Field adapted traits of primary variant P. luminescens strains tend to deteriorate during in vitro culture as tradeoffs for gains in yield. In vitro producers of the P. luminescens/H. bacteriophora complex must weigh the need for superior bacterial yield against the need to preserve traits important for biological control.  相似文献   
4.
5.
Cadmium (Cd) accumulation in edible crops is undesirable due to its hazardous influences on human health. The objectives of this study were: i) to evaluate the spatial variability of grain Cd and its relationships with soil properties in 4000 km2 wheat farms; ii) to evaluate the effect of wheat cultivar on the soil properties vs. grain Cd relationships. A number of 255 soil (0–20 cm) and grain samples were taken and Cd concentrations in grain samples and some soil properties were measured. Grain Cd concentrations in 95 percent of the samples exceeded the threshold of 0.2 mg kg?1. Durum wheat had more potential to accumulate Cd in grain (0.76 mg kg?1) than bread (0.69 mg kg?1). There was significant (p < 0.01) correlation between grain Cd and organic carbon (r = 0.66), CEC (r = 0.77) and DTPA-extractable Cd (p < 0.05) (r = 0.57) of the soils. Greater Pearson coefficient values for durum wheat showed that, in the studied calcareous soils, organic carbon, CEC, Cd-DTPA had more effects on durum wheat than bread wheat cultivar. The obtained Kriging map of grain Cd identified three hotspots at the east (durum wheat cultivation), the west (intensive irrigated wheat farms), and south (wheat farms around petrochemical industries) of the region. Agricultural mismanagement due to overusing P-fertilizers increased Cd concentration in the topsoils and grains of wheat farms in the study area.  相似文献   
6.
    
Spermatogonial cells (SCs) are key cells for spermatogenesis. These cells are affected by paracrine signals originated from nearby somatic cells, among them Leydig cells have receptors for osteocalcin, a hormone known for exerting positive roles in the promotion of spermatogenesis. The aim of this study was to evaluate roles for osteocalcin on SCs proliferative and differentiation features after coculture with Leydig cells. SCs and Leydig cells were isolated from neonate NMRI offspring mice and adult NMRI mice, respectively. SCs population were then enriched in a differential attachment technique and assessed for morphological features and identity. Then, SCs were cocultured with Leydig cells and incubated with osteocalcin for 4 weeks. Evaluation of proliferation and differentiation-related factors were surveyed using immunocytochemistry (ICC), Western blot, and quantitative real-time polymerase chain reaction (PCR). Finally, the rate of testosterone release to the culture media was measured at the end of 4th week. Morphological and flow cytometry results showed that the SCs were the population of cells able to form colonies and to express ID4, α6-, and β1-integrin markers, respectively. Leydig cells were also able to express Gprc6α as a specific marker for the cells. Incubation of SCs/Leydig coculture with osteocalcin has resulted in an increase in the rate of expressions for differentiation-related markers. Levels of testosterone in the culture media of SCs/Leydig was positively influenced by osteocalcin. It could be concluded that osteocalcin acts as a positive inducer of SCs in coculture with Leydig cells probably through stimulation of testosterone release from Leydig cells and associated signaling.  相似文献   
7.
    
Seeds of seven dune species were collected from sand dunes of Lakes Erie and Huron and buried to various depths in a natural sand dune habitat along Lake Huron. The seed samples were then retrieved after varying lengths of time and examined for their germinability and dormancy. Results showed that buried seeds remained viable for at least 2.5 years and had the potential to form a persistent seed bank. Seed banks were larger and longer lasting at greater depths of burial than those at shallow burial depths. The results suggested that failure to verify the existence of effective seed banks in previous studies may be due to insufficient number of samples, shallow sample depth, local population variations, and fruiting events. Several species also possessed a temporary, aboveground seed reserve formed by retention of a small proportion of viable seeds on the previous year's inflorescences. In some species, seeds retained aboveground were dormant and thus capable of forming a persistent seed bank when they entered the soil.  相似文献   
8.
Stem cells from human exfoliated deciduous teeth (SHED) are highly proliferative, clonogenic and multipotent stem cells with a neural crest cell origin. Additionally, they can be collected with minimal invasiveness in comparison with other sources of mesenchymal stem cells (MSCs). Therefore, SHED could be a desirable option for potential therapeutic applications. In this study, SHEDs were established from enzyme-disaggregated deciduous dental pulp obtained from 6 to 9 year-old children. The cells had typical fibroblastoid morphology and expressed antigens characteristic of MSCs, STRO1, CD146, CD45, CD90, CD106 and CD166, but not the hematopoietic and endothelial markers, CD34 and CD31, as assessed by FACS analysis. Differentiation assessment revealed a strong osteogenic and adipogenic potential of SHEDs. In order to further evaluate the in vitro differentiation potential of SHED into neural cells, a simple short time growth factor-mediated induction was used. Immunofluorescence staining and flow cytometric analysis revealed that SHED rapidly expressed nestin and b-III tubulin, and later expressed intermediate neural markers. In addition, the intensity and percentages of nestin and b-III tubulin and mature neural markers (PSA-NCAM, NeuN, Tau, TH, or GFAP) increased significantly following treatment. Moreover, RT-PCR and Western blot analyses showed that the neural markers were strongly up-regulated after induction. In conclusion, these results provide evidence that SHED can differentiate into neural cells by the expression of a comprehensive set of genes and proteins that define neural-like cells in vitro. SHED cells might be considered as new candidates for the autologous transplantation of a wide variety of neurological diseases and neurotraumatic injuries.  相似文献   
9.
Summary Glycolipids should have potential effects as antitumor agents. However, very few studies have examined this property of digalactosyl diacylglycerol (DGDG) and sulfoquinovosyl diacylglycerol (SQDG) on colon cancer cells. Cell viability was determined every 24 h with sodium 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2, 4-disulfophenyl)-2H-tetrazolium dye reduction assay up to 72 h. Alkaline phosphatase activity was measured for assessing cell differentiation. Apoptosis was tested with enzyme-linked immunosorbent assay analysis. Growth of Caco-2 cells was inhibited apparently at 48 h after addition of SQDG and at 72 h with DGDG. Alkaline phosphatase activity of Caco-2 cells obviously increased in combination with DGDG or SQDG and sodium butyrate (NaBT) at 72 h, indicating that DGDG and SQDG enhanced cell differentiation induced with NaBT. An increased enrichment factor was found when the cell was treated in combination with DGDG or SQDG and NaBT. These results strongly suggest that DGDG and SQDG should be considered as the leading compounds of potentially useful colon cancer chemotherapy agents when NaBT is combined.  相似文献   
10.
Differentiation process of mesenchymal stem cells (MSCs) into adipocyte is involved in obesity. Multiple factors such as Ca2+ play important roles in different stages of this process. Because of the complicated roles of Ca2+ in adipogenesis, the aim of present investigation was to study the influx and efflux of Ca2+ into and out of the cells during adipogenesis. Adipose-derived MSCs were used to differentiate into adipocytes. MSCs were exposed to 2.5 mM Ca2+ or 1.8 mM Ca2+ plus calcium ionophore, A23187, for 3 days. Lipid staining, triglycerides (TG) content, and glyceraldehyde phosphate dehydrogenase (GAPDH) activity were evaluated to confirm the efficiency of the differentiation. Gene expression of GLUT4, PPARγ2, RAR-α, and calreticulin, as well as the protein levels of GLUT4 and PPARγ2 were determined. Ca2+ and in particular Ca2+ plus A23187 significantly lowered the efficiency of differentiation accompanied by decrease in intracellular TG deposits, GAPDH activity and alleviation of gene, and protein levels of GLUT4 and PPARγ2. While calreticulin and RAR-α were remarkably upregulated in A23187 group. This study showed the inhibitory effects of calcium in adipogenesis. Additionally, it indicated the greater inhibitory effect of calreticulin and RAR-α in controlling adipogenesis by higher levels of calcium.  相似文献   
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