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51.
The distribution of cucurbitacins in seeds and growing plants of Iberis umbellata L. has been investigated. The testas of 'Giant Pink', 'Purple', 'Crimson' and 'Iceberg' (Dutch) strains of Iberis umbellata contain Cucurbitacin B with traces of D and E. Seeds of 'Iceberg' (Danish) strain were exceptional in containing cucurbitacins E and I but no B, and this strain was also distinguished by larger redder seeds and by testas which were not readily separable into two layers. Cucurbitacins are rare in other crucifers but they are present in I. gibraltarica L., I. sempervirens L. and Lepidium sativum L. 相似文献
52.
Meade Dale; Chess Catherine; Welbourne Tomas C. 《American journal of physiology. Cell physiology》1998,274(6):C1616
The glutamate (Glu) transporter may modulate cellular glutamine(Gln) metabolism by regulating both the rates of hydrolysis andsubsequent conversion of Glu to -ketoglutarate andNH+4. By delivering Glu, a competitiveinhibitor of Gln for the phosphate-dependent glutaminase (PDG) as wellas an acid-load activator of glutamate dehydrogenase (GDH) flux, thetransporter may effectively substitute extracellularly generated Glufrom the -glutamyltransferase for that derived intracellularly fromGln. We tested this hypothesis in two closely related porcine kidneycell lines, LLC-PK1 and LLC-PK1-F+,the latter selected to grow in the absence of glucose, relying on Glnas their sole energy source. Both cell lines exhibited PDG suppressionas the result of Glu uptake while disrupting the extracellularL-Glu uptake, withD-aspartate-acceleratedintracellular Glu formation coupled primarily to the ammoniagenicpathway (GDH). Conversely, enhancing the extracellular Glu formationwith p-aminohippurate and Glu uptakesuppressed intracellular Gln hydrolysis whileNH+4 formation from Glu increased. Thus theseresults are consistent with the transporter's dual role in modulatingboth PDG and GDH flux. Interestingly, PDG flux was actually higher inthe Gln-adapted LLC-PK1-F+cell line because of a two- to threefold enhancement in Gln uptake despite greater Glu uptake than in the parentalLLC-PK1 cells, revealing theimportance of both Glu and Gln transport in the modulation of PDG flux.Nevertheless, when studied at physiological Gln concentration, PDG fluxfalls under tight Glu transporter control as Gln uptake decreases,suggesting that cellular Gln metabolism may indeed be under Glutransporter control in vivo. 相似文献
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55.
Fatima Amanat Shirin Strohmeier Philip S. Meade Nicholas Dambrauskas Barbara Mühlemann Derek J. Smith Vladimir Vigdorovich D. Noah Sather Lynda Coughlan Florian Krammer 《PLoS biology》2021,19(12)
Vaccines against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) have been highly efficient in protecting against Coronavirus Disease 2019 (COVID-19). However, the emergence of viral variants that are more transmissible and, in some cases, escape from neutralizing antibody responses has raised concerns. Here, we evaluated recombinant protein spike antigens derived from wild-type SARS-CoV-2 and from variants B.1.1.7, B.1.351, and P.1 for their immunogenicity and protective effect in vivo against challenge with wild-type SARS-CoV-2 in the mouse model. All proteins induced high neutralizing antibodies against the respective viruses but also induced high cross-neutralizing antibody responses. The decline in neutralizing titers between variants was moderate, with B.1.1.7-vaccinated animals having a maximum fold reduction of 4.8 against B.1.351 virus. P.1 induced the most cross-reactive antibody responses but was also the least immunogenic in terms of homologous neutralization titers. However, all antigens protected from challenge with wild-type SARS-CoV-2 in a mouse model.This study explores the immune response induced by wild type and variant SARS-CoV-2 spike proteins, and the protection that these immune responses provide against challenge with wild type virus in the mouse model. 相似文献
56.
Kevin R. Calci Gloria K. Meade Robert C. Tezloff David H. Kingsley 《Applied microbiology》2005,71(1):339-343
Previous results demonstrated that hepatitis A virus (HAV) could be inactivated by high hydrostatic pressure (HHP) (D. H. Kingsley, D. Hoover, E. Papafragkou, and G. P. Richards, J. Food Prot. 65:1605-1609, 2002); however, direct evaluation of HAV inactivation within contaminated oysters was not performed. In this study, we report confirmation that HAV within contaminated shellfish is inactivated by HHP. Shellfish were initially contaminated with HAV by using a flowthrough system. PFU reductions of >1, >2, and >3 log10 were observed for 1-min treatments at 350, 375, and 400 megapascals, respectively, within a temperature range of 8.7 to 10.3°C. Bioconcentration of nearly 6 log10 PFU of HAV per oyster was achieved under simulated natural conditions. These results suggest that HHP treatment of raw shellfish will be a viable strategy for the reduction of infectious HAV. 相似文献
57.
Darren Davies Kieran G Meade Shan Herath P David Eckersall Deyarina Gonzalez John O White R Steven Conlan Cliona O'Farrelly I Martin Sheldon 《Reproductive biology and endocrinology : RB&E》2008,6(1):53
Background
The endometrium is commonly infected with bacteria leading to severe disease of the uterus in cattle and humans. The endometrial epithelium is the first line of defence for this mucosal surface against bacteria and Toll-like receptors (TLRs) are a critical component of the innate immune system for detection of pathogen associated molecular patterns (PAMPs). Antimicrobial peptides, acute phase proteins and Mucin-1 (MUC-1) also provide non-specific defences against microbes on mucosal surfaces. The present study examined the expression of innate immune defences in the bovine endometrium and tested the hypothesis that endometrial epithelial cells express functional receptors of the TLR family and the non-specific effector molecules for defence against bacteria. 相似文献58.
59.
Cory T. Miller Kaylin Beck Brooke Meade Xiaoqin Wang 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2009,195(8):783-789
Studies of primate vocal communication systems have generally focused on vocalizations and the information they convey to
conspecifics. But the vocalizations are not the only sources of information. Aspects of each species vocal behaviors are likely
to be communicatively rich as well. During vocal interactions, for example, the latency delay between the calls could communicate
an important message to the signal receiver, such as an interest and willingness to socialize. Here we employed novel, interactive
playback software to address this issue in the antiphonal calling behavior of common marmosets. In these experiments, we parametrically
varied the latency delay of antiphonal call stimuli and measured its effects on subjects’ resultant vocal behavior. Results
showed that marmosets produced successively fewer antiphonal call responses during test conditions with increasing latency
delays. Moreover, although subjects produced significantly more antiphonal than spontaneous calls in conditions with antiphonal
call timing delays up to 9 s, a longer delay resulted in a significant decline in calling. These data suggest that antiphonal
call timing is a salient cue for maintaining antiphonal calling interactions and may be used by marmosets to determine whether
a subsequent call is produced in response to or independently of their own. 相似文献
60.
Kieran G. Meade Fernando Narciandi Sarah Cahalane Carla Reiman Brenda Allan Cliona O’Farrelly 《Immunogenetics》2009,61(2):101-110
Salmonella typhimurium and Campylobacter jejuni pose significant risks to human health and poultry are a major vector for infection. Comparative in vivo infection models were performed to compare the avian host immune response to both bacterial species. Forty-five commercial
broiler chickens were orally challenged with either C. jejuni or S. typhimurium whilst 60 similar control birds were mock challenged in parallel. Birds were sacrificed at 0, 6, 20 and 48 h post-infection
and cloacal swabs, blood and tissue samples taken. Peripheral blood leukocytes were isolated for flow cytometric analyses
and RNA was extracted for gene expression profiling. Colonisation patterns were markedly different between the two bacterial
species, with systemic colonisation of Campylobacter outside the gastrointestinal tract. Salmonella infection induced significant
changes in circulating heterophil and monocyte/macrophage populations, whilst Campylobacter infection had no effect on the
heterophil numbers but caused a significant early increase in circulating monocytes/macrophages. Toll-like receptor 1 (TLR1) gene expression was decreased, and avian β-defensin (AvBD) gene expression (AvBD3, AvBD10 and AvBD12) was significantly increased in response to Salmonella infection (P < 0.05). In contrast, Campylobacter infection induced increased TLR21 gene expression but significantly reduced expression of seven antimicrobial peptide (AMP) genes (AvBD3, AvBD4, AvBD8, AvBD13, AvBD14, CTHL2 and CTHL3; P < 0.05). Considered together, microbiological, cellular and gene expression profiles indicate that the innate immune system
responds differently to Salmonella and to Campylobacter infection. Furthermore, reduction in the expression of AMPs may play
a role in the persistence of high level colonisation of the host by Campylobacter.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献