Human CD8+ EMRA T cells display a senescence‐associated secretory phenotype regulated by p38 MAPK

Cellular senescence is accompanied by a senescence‐associated secretory phenotype (SASP). We show here that primary human senescent CD8⁺ T cells also display a SASP comprising chemokines, cytokines and extracellular matrix remodelling proteases that are unique to this subset and contribute to age‐associated inflammation. We found the CD8⁺ CD45RA⁺CD27^? EMRA subset to be the most heterogeneous, with a population aligning with the naïve T cells and another with a closer association to the effector memory subset. However, despite the differing processes that give rise to these senescent CD8⁺ T cells once generated, they both adopt a unique secretory profile with no commonality to any other subset, aligning more closely with senescence than quiescence. Furthermore, we also show that the SASP observed in senescent CD8⁺ T cells is governed by p38 MAPK signalling.     

Chromosomal distribution of the hamster intracisternal A-particle (IAP) retrotransposons

The retrotransposon-like elements of the intracisternal A-particle (IAP) sequences occur in about 900 copies per haploid hamster cell genome. By applying the fluorescent in situ hybridization (FISH) technique and four different, cloned segments of the IAP element as hybridization probes, these elements were found to be distributed in specific patterns over many of the 44 hamster chromosomes. The hybridization patterns were very similar regardless of whether all four probes or only the IAPI probe carrying the long terminal repeat (LTR) region were used. The IAP elements were found most abundantly, though not exclusively, on the short arms of at least 12 of the autosomes. Of the sex chromosomes, the shorter Y chromosome was stained on both arms, and the X chromosome on one arm by the IAP probes. Primary Syrian hamster cells, the established Syrian hamster cell line BHK21, and the adenovirus type 12 (Ad12)-transformed BHK21 cell line T637 yielded very similar results. In Chinese hamster ovary (CHO) or 3T3 mouse cells, signals could not be elicited by FISH using the Syrian hamster IAP probes. On Southern blots, the DNAs from these cell lines hybridized very weakly, if at all, to the IAP sequences. Thus, IAP sequences were retroposed after Syrian hamster and mouse or Syrian and Chinese hamsters had diverged in evolution.     

High speed sCMOS‐based oblique plane microscopy applied to the study of calcium dynamics in cardiac myocytes

Oblique plane microscopy (OPM) is a form of light sheet microscopy that uses a single high numerical aperture microscope objective for both fluorescence excitation and collection. In this paper, measurements of the relative collection efficiency of OPM are presented. An OPM system incorporating two sCMOS cameras is then introduced that enables single isolated cardiac myocytes to be studied continuously for 22 seconds in two dimensions at 667 frames per second with 960 × 200 pixels and for 30 seconds with 960 × 200 × 20 voxels at 25 volumes per second. In both cases OPM is able to record in two spectral channels, enabling intracellular calcium to be studied via the probe Fluo‐4 AM simultaneously with the sarcolemma and transverse tubule network via the membrane dye Cellmask Orange. The OPM system was then applied to determine the spatial origin of spontaneous calcium waves for the first time and to measure the cell transverse tubule structure at their point of origin. Further results are presented to demonstrate that the OPM system can also be used to study calcium spark parameters depending on their relationship to the transverse tubule structure.

     

Performance of selected indicators in evaluating the consequences of dredged material relocation and marine aggregate extraction

Eleven indicators were applied to macrofaunal species abundance data obtained from four dredged material relocation sites and four aggregate extraction sites in UK waters. Indicators were subsequently scored on a scale of 0 (very poor) to 5 (excellent) according to their performance in relation to six criteria governing their utility. Number of species (S) and number of individuals (N) generally scored highest in terms of understandability, sensitivity and linkage to the human activity whilst biotic indices were assigned relatively low scores, particularly in relation to aggregate extraction activities, according to the same criteria. As the immediate consequences of dredged material relocation and aggregate extraction activities are largely physical in nature the relative insensitivity of these indices may be explained by their dependence on species responses principally to organic enrichment. Indicators that incorporated measures of relatedness of species (i.e. average taxonomic distinctness, taxonomic breadth and average phylogenetic diversity) were assigned relatively low scores due to inconsistency in identifying spatial trends, and relative insensitivity. However, such indices may have the potential advantage of illuminating the causes as well as simply the existence of change and merit further examination. The adopted approach to quantifying indicator utility is critically examined and recommendations are made for future refinements.     

When Math Hurts: Math Anxiety Predicts Pain Network Activation in Anticipation of Doing Math

Math can be difficult, and for those with high levels of mathematics-anxiety (HMAs), math is associated with tension, apprehension, and fear. But what underlies the feelings of dread effected by math anxiety? Are HMAs’ feelings about math merely psychological epiphenomena, or is their anxiety grounded in simulation of a concrete, visceral sensation – such as pain – about which they have every right to feel anxious? We show that, when anticipating an upcoming math-task, the higher one’s math anxiety, the more one increases activity in regions associated with visceral threat detection, and often the experience of pain itself (bilateral dorso-posterior insula). Interestingly, this relation was not seen during math performance, suggesting that it is not that math itself hurts; rather, the anticipation of math is painful. Our data suggest that pain network activation underlies the intuition that simply anticipating a dreaded event can feel painful. These results may also provide a potential neural mechanism to explain why HMAs tend to avoid math and math-related situations, which in turn can bias HMAs away from taking math classes or even entire math-related career paths.     

A rapid screening method for hepatocyte nuclear factor 1 alpha frameshift mutations; prevalence in maturity-onset diabetes of the young and late-onset non-insulin dependent diabetes

Non-insulin dependent diabetes (NIDDM) is a polygenic heterogeneous disorder of glucose homeostasis. Maturity-onset diabetes of the young (MODY) is a monogenic subtype of NIDDM characterised by early-onset (< 25 years) and autosomal dominant inheritance. Mutations in the hepatocyte nuclear factor 1 alpha (HNF-1α) gene have recently been shown to cause MODY. The incidence of mutations in this gene in MODY and late-onset NIDDM is not known. We have developed a rapid specific polymerase chain reaction test for HNF-1α mutations; this test involves the use of fluorescently labelled forward primers and modified reverse primers to detect length polymorphisms resulting from frameshift mutations. With this method, we have screened 102 MODY probands, viz. 60 defined according to strict diagnostic criteria (autosomal dominant inheritance and at least one member diagnosed age < 25 years) and 95 late-onset NIDDM probands (diagnosed 35–70 years with ≥ 1 affected relative), for the presence of 9 known HNF-1α frameshift mutations, including 6 that occur at two sites for recurring mutation (residues 291/292 and 379). Mutations were detected in 11 of the strictly defined MODY probands and one mutation was also found in a single subject with early-onset NIDDM but no family history of the disease. The HNF-1α frameshift mutations were not detected in any late-onset NIDDM subjects, suggesting these mutations do not have a major role in the pathogenesis of NIDDM. Our results indicate that the prevalence of the nine frameshift mutations in strictly defined UK MODY is 18%, with the P291fsinsC mutation alone having a frequency of 13%. Received: 13 May 1997 / Accepted: 13 August 1997