Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 412
Filter
1.
Lancet ; 2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38857611

ABSTRACT

BACKGROUND: Anti-inflammatory therapy with long-term colchicine prevented vascular recurrence in coronary disease. Unlike coronary disease, which is typically caused by atherosclerosis, ischaemic stroke is caused by diverse mechanisms including atherosclerosis and small vessel disease or is frequently due to an unknown cause. We aimed to investigate the hypothesis that long-term colchicine would reduce recurrent events after ischaemic stroke. METHODS: We did a randomised, parallel-group, open-label, blinded endpoint assessed trial comparing long-term colchicine (0·5 mg orally per day) plus guideline-based usual care with usual care only. Hospital-based patients with non-severe, non-cardioembolic ischaemic stroke or high-risk transient ischaemic attack were eligible. The primary endpoint was a composite of first fatal or non-fatal recurrent ischaemic stroke, myocardial infarction, cardiac arrest, or hospitalisation (defined as an admission to an inpatient unit or a visit to an emergency department that resulted in at least a 24 h stay [or a change in calendar date if the hospital admission or discharge times were not available]) for unstable angina. The p value for significance was 0·048 to adjust for two prespecified interim analyses conducted by the data monitoring committee, for which the steering committee and trial investigators remained blinded. The trial was registered at ClinicalTrials.gov (NCT02898610) and is completed. FINDINGS: 3154 patients were randomly assigned between Dec 19, 2016, and Nov 21, 2022, with the last follow-up on Jan 31, 2024. The trial finished before the anticipated number of outcomes was accrued (367 outcomes planned) due to budget constraints attributable to the COVID-19 pandemic. Ten patients withdrew consent for analysis of their data, leaving 3144 patients in the intention-to-treat analysis: 1569 (colchicine and usual care) and 1575 (usual care alone). A primary endpoint occurred in 338 patients, 153 (9·8%) of 1569 patients allocated to colchicine and usual care and 185 (11·7%) of 1575 patients allocated to usual care alone (incidence rates 3·32 vs 3·92 per 100 person-years, hazard ratio 0·84; 95% CI 0·68-1·05, p=0·12). Although no between-group difference in C-reactive protein (CRP) was observed at baseline, patients treated with colchicine had lower CRP at 28 days and at 1, 2, and 3 years (p<0·05 for all timepoints). The rates of serious adverse events were similar in both groups. INTERPRETATION: Although no statistically significant benefit was observed on the primary intention-to-treat analysis, the findings provide new evidence supporting the rationale for anti-inflammatory therapy in further randomised trials. FUNDING: Health Research Board Ireland, Deutsche Forschungsgemeinschaft (German Research Foundation), and Fonds Wetenschappelijk Onderzoek Vlaanderen (Research Foundation Flanders), Belgium.

2.
Reproduction ; 167(5)2024 May 01.
Article in English | MEDLINE | ID: mdl-38513348

ABSTRACT

In brief: Dairy cattle experience a period of infertility postpartum that is caused in part by the development of IGF1/insulin resistance. This study suggests that an adipokine, FNDC3A, reduces IGF1-dependent glycolysis and may contribute to postpartum infertility. Abstract: Dairy cows go through a period of subfertility after parturition, triggered in part by a disruption of energy homeostasis. The mobilization of body fat alters the secretion of adipokines, which have been shown to impact ovarian function. Fibronectin type III domain-containing 3A (FNDC3A) is a recently discovered adipokine-myokine, and FNDC3A mRNA abundance in subcutaneous adipose tissue is increased postpartum in cattle. In this study, we hypothesized that FNDC3A may compromise granulosa cell function in cattle and investigated this using a well-established in vitro cell culture model. Here, we demonstrate the presence of FNDC3A protein associated with extracellular vesicles in follicular fluid and in plasma, suggesting an endocrine role for this adipokine. FNDC3A protein and mRNA was also detected in the bovine ovary (cortex, granulosa and theca cells, cumulus, oocyte and corpus luteum). Abundance of FNDC3A mRNA in granulosa cells from small follicles was increased by in vitro treatment with the adipokines leptin and TNF but not by visfatin, resistin, adiponectin, chemerin or IGF1. Addition of recombinant FNDC3A at physiological doses (10 ng/mL) to granulosa cells decreased IGF1-dependent progesterone but not estradiol secretion and IGF1-dependent lactate secretion and abundance of GLUT3 and GLUT4 mRNA. This concentration of FNDC3A increased cell viability, abundance of mRNA encoding a putative receptor FOLR1, and increased phosphorylation of Akt. Collectively, these data suggest that FNDC3A may regulate folliculogenesis in cattle by modulating IGF1-dependent granulosa cell steroidogenesis and glucose metabolism.


Subject(s)
Granulosa Cells , Infertility , Animals , Cattle , Female , Adipokines/metabolism , Granulosa Cells/metabolism , Infertility/metabolism , Lactates/metabolism , Progesterone/metabolism , RNA, Messenger/metabolism , Folate Receptor 1/metabolism , Fibronectins/metabolism , Exosomes/genetics , Exosomes/metabolism
3.
Cytotherapy ; 26(4): 383-392, 2024 04.
Article in English | MEDLINE | ID: mdl-38349312

ABSTRACT

BACKGROUND AIMS: The appearance of genetically variant populations in human pluripotent stem cell (hPSC) cultures represents a concern for research and clinical applications. Genetic variations may alter hPSC differentiation potential or cause phenotype variation in differentiated cells. Further, variants may have properties such as proliferative rate, or response to the culture environment, that differ from wild-type cells. As such, understanding the behavior of these variants in culture, and any potential operational impact on manufacturing processes, will be necessary to control quality of putative hPSC-based products that include a proportion of variant threshold in their quality specification. METHODS: Here we show a computational model that mathematically describes the growth dynamics between commonly occurring genetically variant hPSCs and their counterpart wild-type cells in culture. RESULTS: We show that our model is capable of representing the growth behaviors of both wild-type and variant hPSCs in individual and co-culture systems. CONCLUSIONS: This representation allows us to identify three critical process parameters that drive critical quality attributes when genetically variant cells are present within the system: total culture density, proportion of variant cells within the culture system and variant cell overgrowth. Lastly, we used our model to predict how the variability of these parameters affects the prevalence of both populations in culture.


Subject(s)
Cell Culture Techniques , Pluripotent Stem Cells , Humans , Cell Differentiation/genetics , Coculture Techniques
4.
Gastrointest Endosc ; 2024 May 15.
Article in English | MEDLINE | ID: mdl-38759761

ABSTRACT

BACKGROUND AND AIMS: Glucagon-like peptide-1 receptor agonists (GLP-1RA) are increasingly utilized in diabetes and obesity management. GLP-1RAs delay gastric emptying; however, their impact on visibility during esophagogastroduodenoscopy (EGD) remains uncertain. METHODS: A 1:1 matched case-control study was conducted. Individuals undergoing EGD on GLP-1RAs were matched to non-users based on demographics and diabetes status. A validated scale (POLPREP) was used to determine gastric mucosal visibility scores. RESULTS: A total of 84 pairs (n=168) were included. GLP-1RA users showed significantly lower visibility scores, with a 2.54 times higher likelihood of lower scores compared to non-users. Additionally, GLP-1RA users had a higher incidence of retained gastric contents (13.1% vs. 4.8%, aOR:4.62, p=0.025) and aborted procedures due to this issue. No anesthesia-related adverse events were observed. CONCLUSIONS: GLP-1RA use at the time of endoscopy exhibited higher odds of lower gastric mucosal visibility scores, retained contents and aborted procedures. Further research is warranted.

5.
J Biomech Eng ; 146(7)2024 07 01.
Article in English | MEDLINE | ID: mdl-38323667

ABSTRACT

Healthy articular cartilage is a remarkable bearing material optimized for near-frictionless joint articulation. Because its limited self-repair capacity renders it susceptible to osteoarthritis (OA), approaches to reinforce or rebuild degenerative cartilage are of significant interest. While exogenous collagen crosslinking (CXL) treatments improve cartilage's mechanical properties and increase its resistance to enzymatic degradation, their effects on cartilage lubrication remain less clear. Here, we examined how the collagen crosslinking agents genipin (GP) and glutaraldehyde (GTA) impact cartilage lubrication using the convergent stationary contact area (cSCA) configuration. Unlike classical configurations, the cSCA sustains biofidelic kinetic friction coefficients (µk) via superposition of interstitial and hydrodynamic pressurization (i.e., tribological rehydration). As expected, glutaraldehyde- and genipin-mediated CXL increased cartilage's tensile and compressive moduli. Although net tribological rehydration was retained after CXL, GP or GTA treatment drastically elevated µk. Both healthy and "OA-like" cartilage (generated via enzymatic digestion) sustained remarkably low µk in saline- (≤0.02) and synovial fluid-lubricated contacts (≤0.006). After CXL, µk increased up to 30-fold, reaching values associated with marked chondrocyte death in vitro. These results demonstrate that mechanical properties (i.e., stiffness) are necessary, but not sufficient, metrics of cartilage function. Furthermore, the marked impairment in lubrication suggests that CXL-mediated stiffening is ill-suited to cartilage preservation or joint resurfacing.


Subject(s)
Cartilage, Articular , Iridoids , Osteoarthritis , Humans , Lubrication , Glutaral , Collagen , Osteoarthritis/drug therapy , Friction , Stress, Mechanical
6.
Emerg Med J ; 41(7): 429-435, 2024 Jun 20.
Article in English | MEDLINE | ID: mdl-38729751

ABSTRACT

BACKGROUND: Mechanical thrombectomy for stroke is highly effective but time-critical. Delays are common because many patients require transfer between local hospitals and regional centres. A two-stage prehospital redirection pathway consisting of a simple ambulance screen followed by regional centre assessment to select patients for direct admission could optimise access. However, implementation might be challenged by the limited number of thrombectomy providers, a lack of prehospital diagnostic tests for selecting patients and whether finite resources can accommodate longer ambulance journeys plus greater central admissions. We undertook a three-phase, multiregional, qualitative study to obtain health professional views on the acceptability and feasibility of a new pathway. METHODS: Online focus groups/semistructured interviews were undertaken designed to capture important contextual influences. We purposively sampled NHS staff in four regions of England. Anonymised interview transcripts underwent deductive thematic analysis guided by the NASSS (Non-adoption, Abandonment and Challenges to Scale-up, Spread and Sustainability, Implementation) Implementation Science framework. RESULTS: Twenty-eight staff participated in 4 focus groups, 2 group interviews and 18 individual interviews across 4 Ambulance Trusts, 5 Hospital Trusts and 3 Integrated Stroke Delivery Networks (ISDNs). Five deductive themes were identified: (1) (suspected) stroke as a condition, (2) the pathway change, (3) the value participants placed on the proposed pathway, (4) the possible impact on NHS organisations/adopter systems and (5) the wider healthcare context. Participants perceived suspected stroke as a complex scenario. Most viewed the proposed new thrombectomy pathway as beneficial but potentially challenging to implement. Organisational concerns included staff shortages, increased workflow and bed capacity. Participants also reported wider socioeconomic issues impacting on their services contributing to concerns around the future implementation. CONCLUSIONS: Positive views from health professionals were expressed about the concept of a proposed pathway while raising key content and implementation challenges and useful 'real-world' issues for consideration.


Subject(s)
Emergency Medical Services , Focus Groups , Qualitative Research , Stroke , Thrombectomy , Humans , Thrombectomy/methods , England , Emergency Medical Services/methods , Stroke/therapy , Stroke/surgery , Attitude of Health Personnel , Interviews as Topic , Male , Health Personnel , Female
7.
J Am Chem Soc ; 145(36): 20121-20131, 2023 Sep 13.
Article in English | MEDLINE | ID: mdl-37656516

ABSTRACT

High-yield syntheses of the lanthanide dinitrogen complexes [(Cp2tttM)2(µ-1,2-N2)] (1M, M = Gd, Tb, Dy; Cpttt = 1,2,4-C5tBu3H2), in which the [N2]2- ligands solely adopt the rare end-on or 1,2-bridging mode, are reported. The bulk of the tert-butyl substituents and the smaller radii of gadolinium, terbium, and dysprosium preclude formation of the side-on dinitrogen bonding mode on steric grounds. Elongation of the nitrogen-nitrogen bond relative to N2 is observed in 1M, and their Raman spectra show a major absorption consistent with N═N double bonds. Computational analysis of 1Gd identifies that the local symmetry of the metallocene units lifts the degeneracy of two 5dπ orbitals, leading to differing overlap with the π* orbitals of [N2]2-, a consequence of which is that the dinitrogen ligand occupies a singlet ground state. Magnetic measurements reveal antiferromagnetic exchange in 1M and single-molecule magnet (SMM) behavior in 1Dy. Ab initio calculations show that the magnetic easy axis in the ground doublets of 1Tb and 1Dy align with the {M-N═N-M} connectivity, in contrast to the usual scenario in dysprosium metallocene SMMs, where the axis passes through the cyclopentadienyl ligands. The [N2]2- ligands in 1M allow these compounds to be regarded as two-electron reducing agents, serving as synthons for divalent gadolinium, terbium, and dysprosium. Proof of principle for this concept is obtained in the reactions of 1M with 2,2'-bipyridyl (bipy) to give [Cp2tttM(κ2-bipy)] (2M, M = Gd, Tb, Dy), in which the lanthanide is ligated by a bipy radical anion, with strong metal-ligand direct exchange coupling.

8.
Reproduction ; 165(5): 533-542, 2023 05 01.
Article in English | MEDLINE | ID: mdl-36795655

ABSTRACT

In brief: Fertility in the dairy cow is low during the post-partum period of negative energy balance and high plasma irisin concentrations. This study shows irisin modulates granulosa cell glucose metabolism and impairs steroidogenesis. Abstract: Fibronectin type III domain-containing 5 (FNDC5) is a transmembrane protein discovered in 2012 that is cleaved to release the adipokine-myokine, irisin. Originally described as an exercise hormone that browns white adipose tissue and increases glucose metabolism, irisin secretion also increases during periods of rapid adipose mobilization, such as the post-partum period in dairy cattle when ovarian activity is suppressed. The effect of irisin on follicle function is unclear and may be species-dependent. In this study, we hypothesized that irisin may compromise granulosa cell function in cattle using a well-established in vitro cell culture model. We detected FNDC5 mRNA and both FNDC5 and cleaved irisin proteins in follicle tissue and in follicular fluid. The abundance of FNDC5 mRNA was increased by the treatment of cells with the adipokine visfatin but not by other adipokines tested. The addition of recombinant irisin to granulosa cells decreased basal and insulin-like growth factor 1- and follicle-stimulating hormone-dependent estradiol and progesterone secretion and increased cell proliferation but had no effect on viability. Irisin decreased GLUT1, GLUT3, and GLUT4 mRNA levels in granulosa cells and increased lactate release in the culture medium. The mechanism of action is in part through MAPK3/1 but not Akt, MAPK14, or PRKAA. We conclude that irisin may regulate bovine folliculogenesis by modulating granulosa cell steroidogenesis and glucose metabolism.


Subject(s)
Fibronectins , Granulosa Cells , Female , Cattle , Animals , Fibronectins/metabolism , Granulosa Cells/metabolism , RNA, Messenger/metabolism , Adipokines/metabolism , Glucose/metabolism
9.
Inorg Chem ; 62(25): 9924-9933, 2023 Jun 26.
Article in English | MEDLINE | ID: mdl-37314885

ABSTRACT

The structure and magnetic properties of the bimetallic borohydride-bridged dysprosocenium compound [{(η5-Cpttt)(η5-CpMe4t)Dy}2(µ:κ2:κ2-BH4)]+[B(C6F5)4]- ([3Dy][B(C6F5)4]) are reported along with the solution-phase dynamics of the isostructural yttrium and lutetium analogues (Cpttt is 1,2,4-tri(tert-butyl)cyclopentadienyl, CpMe4t is tetramethyl(tert-butyl)cyclopentadienyl). The synthesis of [3M][B(C6F5)4] was accomplished in the 2:1 stoichiometric reactions of [(η5-Cpttt)(η5-CpMe4t)Dy(BH4)] (2M) with [CPh3][B(C6F5)4], with the metallocenes 2M obtained from reactions of the half-sandwich complexes [(η5-Cpttt)M(BH4)2(THF)] (1M) (M = Y, Dy, Lu) with NaCpMe4t. Crystallographic studies show significant lengthening of the M···B distance on moving through the series 1M, 2M, and 3M, with essentially linear {M···B···M} bridges in 3M. Multinuclear NMR spectroscopy indicates restricted rotation of the Cpttt ligands in 3Y and 3Lu in solution. The single-molecule magnet (SMM) properties of [3M][B(C6F5)4] are characterized by Raman and Orbach processes, with an effective barrier of 533(18) cm-1 and relaxation via the second-excited Kramers doublet. Although quantum tunneling of the magnetization (QTM) was not observed for [3M][B(C6F5)4], it was, surprisingly, found in its magnetically dilute version, which has a very similar barrier of Ueff = 499(21) cm-1. Consistent with this observation, slightly wider openings of the magnetic hysteresis loop at 2 K are found for [3M][B(C6F5)4] but not for the diluted analogue. The dynamic magnetic properties of the dysprosium SMMs and the role of exchange interactions in 3Dy are interpreted with the aid of multireference ab initio calculations.

10.
Clin Chem Lab Med ; 61(4): 674-678, 2023 03 28.
Article in English | MEDLINE | ID: mdl-36622196

ABSTRACT

Applying the concept of a value proposition to medical testing is just one of the many ways to identify and monitor the value of tests. A key part of this concept focusses on processes that should take place after a test is introduced into routine local practice, namely test implementation. This process requires identification of the clinical pathway, the stakeholders and the benefits or disbenefits that accrue to those stakeholders. There are various barriers and challenges to test implementation. Implementation requires the process of clinical audit which involves measurement of outcomes external to the laboratory but this is not widely performed in laboratory medicine. A second key challenge is that implementation requires liaison with stakeholders outside of the laboratory including clinicians and other healthcare professional such as finance managers. Many laboratories are remote from clinical care and other stakeholders making such liaison difficult. The implementation process is based on data which again will be primarily on processes outside of the laboratory. However the recent enthusiasm for so-called real world data and new data mining techniques may represent opportunities that will facilitate better test implementation. A final barrier is that a range of new tools not currently in the education curriculum of the laboratory professional is required for implementation such as those of preparing a business case to support the introduction of a test and health economic analysis. The professional bodies in laboratory medicine could assist with education in these areas.


Subject(s)
Curriculum , Laboratories , Humans
11.
J Assist Reprod Genet ; 40(8): 1961-1971, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37204638

ABSTRACT

PURPOSE: To assess the effects of the oocyte on mRNA abundance of FSHR, AMH and major genes of the maturation cascade (AREG, EREG, ADAM17, EGFR, PTGS2, TNFAIP6, PTX3, and HAS2) in bovine cumulus cells. METHODS: (1) Intact cumulus-oocyte complexes, (2) microsurgically oocytectomized cumulus-oolema complexes (OOX), and (3) OOX + denuded oocytes (OOX+DO) were subjected to in vitro maturation (IVM) stimulated with FSH for 22 h or with AREG for 4 and 22 h. After IVM, cumulus cells were separated and relative mRNA abundance was measured by RT-qPCR. RESULTS: After 22 h of FSH-stimulated IVM, oocytectomy increased FSHR mRNA levels (p=0.005) while decreasing those of AMH (p=0.0004). In parallel, oocytectomy increased mRNA abundance of AREG, EREG, ADAM17, PTGS2, TNFAIP6, and PTX3, while decreasing that of HAS2 (p<0.02). All these effects were abrogated in OOX+DO. Oocytectomy also reduced EGFR mRNA levels (p=0.009), which was not reverted in OOX+DO. The stimulatory effect of oocytectomy on AREG mRNA abundance (p=0.01) and its neutralization in OOX+DO was again observed after 4 h of AREG-stimulated IVM. After 22 h of AREG-stimulated IVM, oocytectomy and addition of DOs to OOX caused the same effects on gene expression observed after 22 h of FSH-stimulated IVM, except for ADAM17 (p<0.025). CONCLUSION: These findings suggest that oocyte-secreted factors inhibit FSH signaling and the expression of major genes of the maturation cascade in cumulus cells. These may be important actions of the oocyte favoring its communication with cumulus cells and preventing premature activation of the maturation cascade.


Subject(s)
Cumulus Cells , Epidermal Growth Factor , Female , Animals , Cattle , Cumulus Cells/metabolism , Epidermal Growth Factor/pharmacology , Cyclooxygenase 2/metabolism , Follicle Stimulating Hormone/genetics , Follicle Stimulating Hormone/pharmacology , Follicle Stimulating Hormone/metabolism , Oocytes/metabolism , ErbB Receptors/metabolism , ErbB Receptors/pharmacology , In Vitro Oocyte Maturation Techniques
12.
Int J Mol Sci ; 24(5)2023 Feb 22.
Article in English | MEDLINE | ID: mdl-36901794

ABSTRACT

Vitamin D (VD) is one of the important nutrients required by livestock; however, VD deficiency is reported to be widespread. Earlier studies have suggested a potential role for VD in reproduction. Studies on the correlation between VD and sow reproduction are limited. The aim of the current study was aimed to determine the role of 1,25-dihydroxy vitamin D3 (1α,25(OH)2D3) on porcine ovarian granulosa cells (PGCs) in vitro to provide a theoretical basis for improving the reproductive efficiency of sows. We used chloroquine (autophagy inhibitor) and reactive oxygen species (ROS) scavenger N-acetylcysteine in conjunction with 1α,25(OH)2D3 to explore the effect on PGCs. The results showed that 10 nM of 1α,25(OH)2D3 increased PGC viability and ROS content. In addition, 1α,25(OH)2D3 induces PGC autophagy according to the gene transcription and protein expression levels of LC3, ATG7, BECN1, and SQSTM1 and promotes the generation of autophagosomes. 1α,25(OH)2D3-induced autophagy affects the synthesis of E2 and P4 in PGCs. We investigated the relationship between ROS and autophagy, and the results showed that 1α,25(OH)2D3-induced ROS promoted PGC autophagy. The ROS-BNIP3-PINK1 pathway was involved in PGC autophagy induced by 1α,25(OH)2D3. In conclusion, this study suggests that 1α,25(OH)2D3 promotes PGC autophagy as a protective mechanism against ROS via the BNIP3/PINK1 pathway.


Subject(s)
Calcitriol , Vitamin D , Female , Animals , Swine , Calcitriol/pharmacology , Reactive Oxygen Species/metabolism , Vitamin D/metabolism , Autophagy , Granulosa Cells/metabolism , Protein Kinases
13.
J Cell Physiol ; 237(5): 2528-2538, 2022 05.
Article in English | MEDLINE | ID: mdl-35315069

ABSTRACT

Increasing the efficiency of farm animal reproduction is necessary to reduce the environmental impact of food production systems. One approach is to increase the number of healthy eggs (oocytes) produced per female for fertilization, thus it is important to understand factors that decrease oocyte health. One paracrine factor that decreases ovarian follicle growth is fibroblast growth factor 18 (FGF18) secreted by cells in the theca layer of the ovarian follicle, however the factors that regulate FGF18 secretion are unknown. In this study we hypothesized that FGF18 secretion is controled by intrafollicular factors and is linked to fertility, which we tested by using cell culture and sheep genetic models in vivo. Separation of theca cell populations revealed that FGF18 messenger RNA (mRNA) is located mainly in thecal endothelial rather than endocrine cells, and immunohistochemistry localized FGF18 protein to microvessels in the theca layer in situ. Culture of ovine theca-derived endothelial cells was used to demonstrate stimulation of FGF18 mRNA and protein abundance by bone morphogenetic protein 4 (BMP4), a growth factor derived from theca endocrine cells. Taking advantage of a sheep genetic model, we demonstrate reduced ovarian and peripheral FGF18 concentrations in the hyperprolific Booroola ewe harboring the FecBB mutation in BMPR1B. These data suggest a novel control of fertility by follicular endothelial cells, in which theca endocrine cells secrete BMP4 that stimulates the secretion of FGF18 from thecal endothelial cells, which in turn diffuses into the granulosa cell layer and promotes apoptosis.


Subject(s)
Endothelial Cells , Theca Cells , Animals , Endothelial Cells/metabolism , Female , Fibroblast Growth Factors/genetics , Fibroblast Growth Factors/metabolism , Granulosa Cells/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Sheep , Theca Cells/metabolism
14.
Reproduction ; 164(1): R1-R9, 2022 05 23.
Article in English | MEDLINE | ID: mdl-35521900

ABSTRACT

Dietary stress such as obesity and short-term changes in energy balance can disrupt ovarian function leading to infertility. Adipose tissue secretes hormones (adipokines), such as leptin and adiponectin, that are known to alter ovarian function. Muscles can also secrete endocrine factors, and one such family of myokines, the eleven Fibronectin type III domain-containing (FNDC) proteins, is emerging as important for energy sensing and homeostasis. In this review, we summarize the known roles the FNDC proteins play in energy homeostasis and explore potential impacts on fertility in females. The most well-known member, FNDC5, is the precursor of the 'exercise hormone', irisin, secreted by both muscle and adipose tissue. The receptors for irisin are integrins, and it has recently been shown to alter steroidogenesis in ovarian granulosa cells although the effects appear to be species or context specific, and irisin may improve uterine and placental function in women and rodent models. Another member, FNDC4, is also cleaved to release a bioactive protein that modulates insulin sensitivity in peripheral tissues and whose receptor, ADGRF5, is expressed in the ovary. As obese women and farm animals in negative energy balance (NEB) both have altered insulin sensitivity, secreted FNDC4 may impact ovarian function. We propose a model in which NEB or dietary imbalance alters plasma irisin and secreted FNDC4 concentrations, which then act on the ovary through their cognate receptors to reduce granulosa cell proliferation and follicle health. Research into these molecules will increase our understanding of energy sensing and fertility and may lead to new approaches to alleviate post-partum infertility. In Brief: Hormones secreted by muscle cells (myokines) are involved in the adaptive response to nutritional and metabolic changes. In this review, we discuss how one family of myokines may alter fertility in response to sudden changes in energy balance.


Subject(s)
Infertility , Insulin Resistance , Adipokines/metabolism , Animals , Female , Fibronectin Type III Domain , Fibronectins/metabolism , Humans , Obesity/metabolism , Placenta/metabolism , Pregnancy , Proteins , Reproduction
15.
Reprod Domest Anim ; 57(6): 625-634, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35244300

ABSTRACT

It is well known that approximately 99% of ovarian follicles in mammals suffer from a degenerative process known as atresia, which is a huge waste of genetic resource in female animals. Studies have shown that activin A (ACT-A) is located in ovarian granulosa cells and has different effects in granulosa cell depending on species. Although granulosa cells play a critical role during follicular atresia, the mechanism of action of ACT-A in bovine ovarian granulosa cells (BGC) is poorly understood. In this study, we first determined the apoptosis of BGCs isolated from growth follicles and atretic follicles respectively. Then, BGC isolated from atretic follicles were used as a model to elucidate the role of ACT-A in cattle ovary. The results showed that apoptosis occurred in both growing follicles and atretic follicles, and the percentage of apoptotic cells in atretic follicles was higher than that in growing follicles. The current results indicated that ACT-A can attenuate apoptosis of BGC by maintaining the function of BGC in atretic follicles. Increased ERß induced by ACT-A promoted BGC autophagy but had no effect on apoptosis. In summary, this study suggests that ACT-A attenuates BGC apoptosis in atretic follicles by ERß-mediated autophagy signalling.


Subject(s)
Estrogen Receptor beta , Follicular Atresia , Activins , Animals , Apoptosis/genetics , Autophagy , Cattle , Female , Granulosa Cells , Mammals , Ovarian Follicle
16.
BMC Emerg Med ; 22(1): 29, 2022 02 28.
Article in English | MEDLINE | ID: mdl-35227206

ABSTRACT

BACKGROUND: Stroke is a common medical emergency responsible for significant mortality and disability. Early identification improves outcomes by promoting access to time-critical treatments such as thrombectomy for large vessel occlusion (LVO), whilst accurate prognosis could inform many acute management decisions. Surface electroencephalography (EEG) shows promise for stroke identification and outcome prediction, but evaluations have varied in technology, setting, population and purpose. This scoping review aimed to summarise published literature addressing the following questions: 1. Can EEG during acute clinical assessment identify: a) Stroke versus non-stroke mimic conditions. b) Ischaemic versus haemorrhagic stroke. c) Ischaemic stroke due to LVO. 2. Can these states be identified if EEG is applied < 6 h since onset. 3. Does EEG during acute assessment predict clinical recovery following confirmed stroke. METHODS: We performed a systematic search of five bibliographic databases ending 19/10/2020. Two reviewers assessed eligibility of articles describing diagnostic and/or prognostic EEG application < 72 h since suspected or confirmed stroke. RESULTS: From 5892 abstracts, 210 full text articles were screened and 39 retained. Studies were small and heterogeneous. Amongst 21 reports of diagnostic data, consistent associations were reported between stroke, greater delta power, reduced alpha/beta power, corresponding ratios and greater brain asymmetry. When reported, the area under the curve (AUC) was at least good (0.81-1.00). Only one study combined clinical and EEG data (AUC 0.88). There was little data found describing whether EEG could identify ischaemic versus haemorrhagic stroke. Radiological changes suggestive of LVO were also associated with increased slow and decreased fast waves. The only study with angiographic proof of LVO reported AUC 0.86 for detection < 24 h since onset. Amongst 26 reports of prognostic data, increased slow and reduced fast wave EEG changes were associated with future dependency, neurological impairment, mortality and poor cognition, but there was little evidence that EEG enhanced outcome prediction relative to clinical and/or radiological variables. Only one study focussed solely on patients < 6 h since onset for predicting neurological prognosis post-thrombolysis, with more favourable outcomes associated with greater hemispheric symmetry and a greater ratio of fast to slow waves. CONCLUSIONS: Although studies report important associations with EEG biomarkers, further technological development and adequately powered real-world studies are required before recommendations can be made regarding application during acute stroke assessment.


Subject(s)
Brain Ischemia , Hemorrhagic Stroke , Ischemic Stroke , Stroke , Brain Ischemia/diagnosis , Brain Ischemia/therapy , Electroencephalography , Humans , Stroke/diagnosis , Stroke/therapy
17.
BMC Emerg Med ; 22(1): 153, 2022 09 03.
Article in English | MEDLINE | ID: mdl-36057767

ABSTRACT

BACKGROUND: Emergency medical services (EMS) are the first point of contact for most acute stroke patients. EMS call to hospital times have increased in recent years for stroke patients in the UK which is undesirable due to the relationship between time and effectiveness of reperfusion treatment. This review aimed to identify and describe interventions devised to improve the efficiency of acute stroke care which reported an impact on ground-based EMS call to hospital times. METHODS: A systematic review of published literature identified from five databases (Medline, EMBASE, CINAHL, the Cochrane library and the Database of Research in Stroke (DORIS)) from January 2000 to December 2020 with narrative synthesis was conducted. Inclusion criteria were primary studies of ground-based EMS, focused on stroke and aiming to improve EMS times. Papers published before 2000, focussing on mobile stroke units or in languages other than English were excluded. Two reviewers independently screened prospective titles. Cochrane ROB2 and ROBINS-I tools were used to assess for risk of bias. This review was funded by a Stroke Association fellowship. RESULTS: From 3767 initial records, 11 studies were included in the review. Included studies were categorised into three groups: studies targeting EMS dispatch and EMS clinicians (n = 4); studies targeting EMS clinicians only (n = 4); and studies targeting whole system change (n = 3). Suspected stroke patients were the primary population studied and most (n = 10) interventions involved clinician education. Only one study (9%) reported a significant decrease in call to hospital time in one subgroup whereas two studies (18%) reported a significant increase in call to hospital time and all other studies (73%) reported no significant change. CONCLUSIONS: Based on the included studies, interventions intended to improve the efficiency of the acute stroke pathway rarely improved EMS call to hospital times. Included studies were heterogenous and rarely focussed on the review topic which limits the usability of the findings. Further research is needed to explore the trade-off between changes to EMS stroke care and call to hospital times and subsequent impacts on in-hospital care and patient outcomes.


Subject(s)
Emergency Medical Dispatch , Emergency Medical Services , Stroke , Critical Care , Humans , Prospective Studies , Stroke/therapy
18.
BMC Emerg Med ; 22(1): 2, 2022 01 10.
Article in English | MEDLINE | ID: mdl-35012462

ABSTRACT

BACKGROUND: Prehospital stroke trials will inevitably recruit patients with non-stroke conditions, so called stroke mimics. We undertook a pre-specified analysis to determine outcomes in patients with mimics in the second Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial (RIGHT-2). METHODS: RIGHT-2 was a prospective, multicentre, paramedic-delivered, ambulance-based, sham-controlled, participant-and outcome-blinded, randomised-controlled trial of transdermal glyceryl trinitrate (GTN) in adults with ultra-acute presumed stroke in the UK. Final diagnosis (intracerebral haemorrhage, ischaemic stroke, transient ischaemic attack, mimic) was determined by the hospital investigator. This pre-specified subgroup analysis assessed the safety and efficacy of transdermal GTN (5 mg daily for 4 days) versus sham patch among stroke mimic patients. The primary outcome was the 7-level modified Rankin Scale (mRS) at 90 days. RESULTS: Among 1149 participants in RIGHT-2, 297 (26%) had a final diagnosis of mimic (GTN 134, sham 163). The mimic group were younger, mean age 67 (SD: 18) vs 75 (SD: 13) years, had a longer interval from symptom onset to randomisation, median 75 [95% CI: 47,126] vs 70 [95% CI:45,108] minutes, less atrial fibrillation and a lower systolic blood pressure and Face-Arm-Speech-Time tool score than the stroke group. The three most common mimic diagnoses were seizure (17%), migraine or primary headache disorder (17%) and functional disorders (14%). At 90 days, the GTN group had a better mRS score as compared to the sham group (adjusted common odds ratio 0.54; 95% confidence intervals 0.34, 0.85; p = 0.008), a difference that persisted at 365 days. There was no difference in the proportion of patients who died in hospital, were discharged to a residential care facility, or suffered a serious adverse event. CONCLUSIONS: One-quarter of patients suspected by paramedics to have an ultra-acute stroke were subsequently diagnosed with a non-stroke condition. GTN was associated with unexplained improved functional outcome observed at 90 days and one year, a finding that may represent an undetected baseline imbalance, chance, or real efficacy. GTN was not associated with harm. TRIAL REGISTRATION: This trial is registered with International Standard Randomised Controlled Trials Number ISRCTN 26986053 .


Subject(s)
Brain Ischemia , Stroke , Adult , Aged , Ambulances , Hospitals , Humans , Nitroglycerin/therapeutic use , Prospective Studies , Stroke/diagnosis , Stroke/drug therapy , Treatment Outcome
19.
Biophys J ; 120(22): 5074-5089, 2021 11 16.
Article in English | MEDLINE | ID: mdl-34627766

ABSTRACT

Mechanotransduction describes activation of gene expression by changes in the cell's physical microenvironment. Recent experiments show that mechanotransduction can lead to long-term "mechanical memory," in which cells cultured on stiff substrates for sufficient time (priming phase) maintain altered phenotype after switching to soft substrates (dissipation phase) as compared to unprimed controls. The timescale of memory acquisition and retention is orders of magnitude larger than the timescale of mechanosensitive cellular signaling, and memory retention time changes continuously with priming time. We develop a model that captures these features by accounting for positive reinforcement in mechanical signaling. The sensitivity of reinforcement represents the dynamic transcriptional state of the cell composed of protein lifetimes and three-dimensional chromatin organization. Our model provides a single framework connecting microenvironment mechanical history to cellular outcomes ranging from no memory to terminal differentiation. Predicting cellular memory of environmental changes can help engineer cellular dynamics through changes in culture environments.


Subject(s)
Mechanotransduction, Cellular , Reinforcement, Psychology , Gene Expression , Phenotype
20.
Int J Cancer ; 149(3): 494-504, 2021 08 01.
Article in English | MEDLINE | ID: mdl-33521932

ABSTRACT

There is emerging evidence that resident microbiota communities, that is, the microbiota, play a key role in cancer outcomes and anticancer responses. Although this has been relatively well studied in colorectal cancer and melanoma, other cancers, such as breast cancer (BrCa), have been largely overlooked to date. Importantly, many of the environmental factors associated with BrCa incidence and progression are also known to impact the microbiota, for example, diet and antibiotics. Here, we explore BrCa risk factors from large epidemiology studies and microbiota associations, and more recent studies that have directly profiled BrCa patients' gut microbiotas. We also discuss how in vivo studies have begun to unravel the immune mechanisms whereby the microbiota may influence BrCa responses, and finally we examine how diet and specific nutrients are also linked to BrCa outcomes. We also consider future research avenues and important considerations with respect to study design and implementation, and we highlight some of the important unresolved questions, which currently limit our overall understanding of the mechanisms underpinning microbiota-BrCa responses.


Subject(s)
Breast Neoplasms/pathology , Diet , Gastrointestinal Microbiome , Immune System , Nutrients , Breast Neoplasms/etiology , Female , Humans , Risk Factors
SELECTION OF CITATIONS
SEARCH DETAIL