FGF signalling through RAS/MAPK and PI3K pathways regulates cell movement and gene expression in the chicken primitive streak without affecting E-cadherin expression

Background  

FGF signalling regulates numerous aspects of early embryo development. During gastrulation in amniotes, epiblast cells undergo an epithelial to mesenchymal transition (EMT) in the primitive streak to form the mesoderm and endoderm. In mice lacking FGFR1, epiblast cells in the primitive streak fail to downregulate E-cadherin and undergo EMT, and cell migration is inhibited. This study investigated how FGF signalling regulates cell movement and gene expression in the primitive streak of chicken embryos.     

Nutrient-induced signal transduction through the protein kinase A pathway and its role in the control of metabolism, stress resistance, and growth in yeast

Yeast cells growing in the presence of glucose or a related rapidly-fermented sugar differ strongly in a variety of physiological properties compared to cells growing in the absence of glucose. Part of these differences appear to be caused by the protein kinase A (PKA) and related signal transduction pathways. Addition of glucose to cells previously deprived of glucose triggers cAMP accumulation, which is apparently mediated by the Gpr1-Gpa2 G-protein coupled receptor system. However, the resulting effect on PKA-controlled properties is only transient when there is no complete growth medium present. When an essential nutrient is lacking, the cells arrest in the stationary phase G0. At the same time they acquire all characteristics of cells with low PKA activity, even if there is ample glucose present. When the essential nutrient is added again, a similar PKA-dependent protein phosphorylation cascade is triggered as observed after addition of glucose to glucose-deprived cells, but which is not cAMP-mediated. Because the pathway involved requires a fermentable carbon source and a complete growth medium, at least for its sustained activation, it has been called “fermentable growth medium (FGM)-induced pathway.”     

Gastric cancers of Western European and African patients show different patterns of genomic instability

Background

Infection with H. pylori is important in the etiology of gastric cancer. Gastric cancer is infrequent in Africa, despite high frequencies of H. pylori infection, referred to as the African enigma. Variation in environmental and host factors influencing gastric cancer risk between different populations have been reported but little is known about the biological differences between gastric cancers from different geographic locations. We aim to study genomic instability patterns of gastric cancers obtained from patients from United Kingdom (UK) and South Africa (SA), in an attempt to support the African enigma hypothesis at the biological level.

Methods

DNA was isolated from 67 gastric adenocarcinomas, 33 UK patients, 9 Caucasian SA patients and 25 native SA patients. Microsatellite instability and chromosomal instability were analyzed by PCR and microarray comparative genomic hybridization, respectively. Data was analyzed by supervised univariate and multivariate analyses as well as unsupervised hierarchical cluster analysis.

Results

Tumors from Caucasian and native SA patients showed significantly more microsatellite instable tumors (p < 0.05). For the microsatellite stable tumors, geographical origin of the patients correlated with cluster membership, derived from unsupervised hierarchical cluster analysis (p = 0.001). Several chromosomal alterations showed significantly different frequencies in tumors from UK patients and native SA patients, but not between UK and Caucasian SA patients and between native and Caucasian SA patients.

Conclusions

Gastric cancers from SA and UK patients show differences in genetic instability patterns, indicating possible different biological mechanisms in patients from different geographical origin. This is of future clinical relevance for stratification of gastric cancer therapy.

     

Tritaenia Maegdefrau et Rudolf, Mesozoic 'Sciadopitys-like' leaves in mass accumulations

The Late Jurassic to Early Cretaceous genus Tritaenia Maegdefrau et Rudolf 1969 is problematic because of: (1) missing authentic material of its type species, T. linkii (Roemer 1839) Maegdefrau et Rudolf; and (2) Watson and Harrison's (1998) synonymization of T. linkii with Pseudotorellia heterophylla Watson. This paper: (1) rectifies the status of T. linkii on the basis of newly recovered specimens carrying the original author's authentication; and (2) gives the basis for rejecting Watson and Harrison's claim that T. linkii and T. crassa (Seward) Bose et Manum 1991 represent linear leaves of the heterophyllous taxon Pseudotorellia heterophylla. The three species of Tritaenia known to date (T. crassa, T. linkii, T. scotica) are reviewed, and the genus is compared with other Mesozoic so-called 'Sciadopitys-like' hypostomatic leaves with a median stomatal zone, many of which occur in mass accumulations such as T. linkii. Deciduousness is indicated for T. linkii and T. crassa by their occurrence in mass accumulations and the possession of well-developed abscission scars. Known mass accumulations of fossil foliage are reviewed and their implications for palaeoenvironmental interpretations discussed.     

Molecular docking analysis of SARS-CoV-2 linked RNA dependent RNA polymerase (RdRp) with compounds from Plectranthus amboinicus

It is of interest to document the moelcular docking analysis of SARS-CoV-2 linked RNA dependent RNA polymerase (RdRp) with compounds from Plectranthus amboinicus. Hence, we report the binding features of rutin, Luteolin, Salvianolic acid A, Rosmarinic acid and p-Coumaric acid with the target protein SARS-CoV-2 linked RNA dependent RNA polymerase (RdRp) for further consideration.     

Intimal lining layer macrophages but not synovial sublining macrophages display an IL-10 polarized-like phenotype in chronic synovitis

Introduction

Synovial tissue macrophages play a key role in chronic inflammatory arthritis, but the contribution of different macrophage subsets in this process remains largely unknown. The main in vitro polarized macrophage subsets are classically (M1) and alternatively (M2) activated macrophages, the latter comprising interleukin (IL)-4 and IL-10 polarized cells. Here, we aimed to evaluate the polarization status of synovial macrophages in spondyloarthritis (SpA) and rheumatoid arthritis (RA).

Methods

Expression of polarization markers on synovial macrophages, peripheral blood monocytes, and in vitro polarized monocyte-derived macrophages from SpA versus RA patients was assessed by immunohistochemistry and flow cytometry, respectively. The polarization status of the intimal lining layer and the synovial sublining macrophages was assessed by double immunofluorescence staining.

Results

The expression of the IL-10 polarization marker cluster of differentiation 163 (CD163) was increased in SpA compared with RA intimal lining layer, but no differences were found in other M1 and M2 markers between the diseases. Furthermore, no significant phenotypic differences in monocytes and in vitro polarized monocyte-derived macrophages were seen between SpA, RA, and healthy controls, indicating that the differential CD163 expression does not reflect a preferential M2 polarization in SpA. More detailed analysis of intimal lining layer macrophages revealed a strong co-expression of the IL-10 polarization markers CD163 and cluster of differentiation 32 (CD32) but not any of the other markers in both SpA and RA. In contrast, synovial sublining macrophages had a more heterogeneous phenotype, with a majority of cells co-expressing M1 and M2 markers.

Conclusions

The intimal lining layer but not synovial sublining macrophages display an IL-10 polarized-like phenotype, with increased CD163 expression in SpA versus RA synovitis. These differences in the distribution of the polarized macrophage subset may contribute to the outcome of chronic synovitis.     

长春市儿童医院1998～2001年婴幼儿杯状病毒腹泻流行病学研究

人类杯状病毒(human calicivirus,HuCV)是引起儿童和成人非菌性胃肠炎的主要病原之一.为了掌握HuCV在我国的流行情况,1998年7月至2001年6月,从长春市儿童医院2343例5岁以下腹泻患儿中共收集粪便标本1264份,其中1056份来自2135例住院患儿.对轮状病毒检测为阴性的588份标本,经多价酶免疫试验(EIA)和两组引物反转录-聚合酶链反应(RT-PCR)检测HuCV,202份为阳性,其中住院患儿标本178份,HuCV检出率为16.9%.HuCV腹泻以2岁以下儿童为主(占96%),流行高峰季节为11月至次年3月.选择17株HuCV进行分子鉴定,15株属GⅡ-4群,1株属GⅡ-3群,另1株属GⅠ-2群,表明GⅡ-4群HuCV是我国流行的优势株.根据HuCV住院患儿的监测资料初步估计,HuCV腹泻住院率约为0.5‰～2.4‰.讨论了长春地区HuCV的流行趋势和疾病负担.以上结果为我国HuCV腹泻的预防和控制提供了科学依据.     

Ammonia Assimilation in the Roots of Nitrate- and Ammonia-Grown Hordeum Vulgare (cv Golden Promise)

¹⁵N kinetic labeling studies were performed on seedlings of Hordeum vulgare L. var. Golden Promise growing under steady state conditions. Patterns of label incorporation in the pools of nitrogen compounds of roots fed [¹⁵N]ammonium were compared with computer-simulated labeling curves. The data were found to be quantitatively consistent with a three-compartment model in which ammonium is assimilated solely into the amide-N of glutamine. Labeling data from roots fed [¹⁵N]nitrate were also found to be at least qualitatively consistent with the assimilation of ammonia into glutamine. Methionine sulfoximine almost completely blocked the incorporation of ¹⁵N label into the amino acid pools of barley roots fed [¹⁵N]nitrate. These observations suggest that ammonia assimilation occurs solely via the glutamine synthetase/glutamate synthase pathway in both nitrate- and ammonia-grown barley roots.