Ultra-short echo time cardiovascular magnetic resonance of atherosclerotic carotid plaque.

BACKGROUND: Multi-contrast weighted cardiovascular magnetic resonance (CMR) allows detailed plaque characterisation and assessment of plaque vulnerability. The aim of this preliminary study was to show the potential of Ultra-short Echo Time (UTE) subtraction MR in detecting calcification. METHODS: 14 ex-vivo human carotid arteries were scanned using CMR and CT, prior to histological slide preparation. Two images were acquired using a double-echo 3D UTE pulse, one with a long TE and the second with an ultra-short TE, with the same TR. An UTE subtraction (DeltaUTE) image containing only ultra-short T2 (and T2*) signals was obtained by post-processing subtraction of the 2 UTE images. The DeltaUTE image was compared to the conventional 3D T1-weighted sequence and CT scan of the carotid arteries. RESULTS: In atheromatous carotid arteries, there was a 71% agreement between the high signal intensity areas on DeltaUTE images and CT scan. The same areas were represented as low signal intensity on T1W and areas of void on histology, indicating focal calcification. However, in 15% of all the scans there were some incongruent regions of high intensity on DeltaUTE that did not correspond with a high intensity signal on CT, and histology confirmed the absence of calcification. CONCLUSIONS: We have demonstrated that the UTE sequence has potential to identify calcified plaque. Further work is needed to fully understand the UTE findings

Evaluating the effect of chlorpheniramine on patch test reactions amongst eczema patients sensitised to nickel

Discontinuing antihistamines for patch testing (PT) in allergic contact dermatitis (ACD) is more conventional than evidence based. Data suggests that non-sedating antihistamines do not interfere with PT. Investigating the effects of sedating antihistamines are more relevant as these are recommended for eczema. We aimed to evaluate the effect of chlorpheniramine on PT, to determine the prevalence of nickel sensitization and common sensitizing allergens. An open labeled cohort study was conducted at two dermatology clinics. Patients indicated for PT underwent standard protocol where antihistamines were discontinued. Patients sensitised to nickel were subjected to a second nickel PT while taking chlorpheniramine. Results were evaluated using the North American Contact Dermatitis Research Group (NACDRG) score, a Mexameter measured erythema and pruritus was assessed using a visual analogue score. A total 82 patients were recruited, 28 (34.1%) were sensitised to nickel. The mean age was 40 ± 17.7 years with 22(26.8%) males and 60 (73.2%) females. Indications for PT included suspected ACD (57.3%), hand and feet eczema (34.1%) and severe eczema with suspected superimposed ACD (6.1%). The commonest sensitizing allergens were methyldibromoglutaronitrile (40.2%) nickel sulphate (34.1%), potassium dichromate (29.3%) and formaldehyde (24.4%). A second PT was performed on 23 patients. There was no difference in the NACDRG score with chlorpheniramine or without chlorpheniramine (p=0.968). Pruritus score was reduced by 1.39 ± 2.9, p=0.031 with chlorpheniramine. The degree of erythema was 611.46 ± 21.59 with chlorpheniramine versus 613.87 ± 27.5 without chlorpheniramine, p=0.671. Chlorpheniramine did not affect PT based on clinical and objective scorings. It has the additional benefit of reducing test-induced itch

DLX1 acts as a crucial target of FOXM1 to promote ovarian cancer aggressiveness by enhancing TGF-β/SMAD4 signaling

Recent evidence from a comprehensive genome analysis and functional studies have revealed that FOXM1 is a crucial metastatic regulator that drives cancer progression. However, the regulatory mechanism by which FOXM1 exerts its metastatic functions in cancer cells remains obscure. Here, we report that DLX1 acts as a FOXM1 downstream target, exerting pro-metastatic function in ovarian cancers. Both FOXM1 isoforms (FOXM1B or FOXM1C) could transcriptionally upregulate DLX1 through two conserved binding sites, located at +61 to +69bp downstream (TFBS1) and -675 to -667bp upstream (TFBS2) of the DLX1 promoter, respectively. This regulation was further accentuated by the significant correlation between the nuclear expression of FOXM1 and DLX1 in high-grade serous ovarian cancers. Functionally, the ectopic expression of DLX1 promoted ovarian cancer cell growth, cell migration/invasion and intraperitoneal dissemination of ovarian cancer in mice, whereas small interfering RNA-mediated DLX1 knockdown in FOXM1-overexpressing ovarian cancer cells abrogated these oncogenic capacities. In contrast, depletion of FOXM1 by shRNAi only partially attenuated tumor growth and exerted almost no effect on cell migration/invasion and the intraperitoneal dissemination of DLX1-overexpressing ovarian cancer cells. Furthermore, the mechanistic studies showed that DLX1 positively modulates TGF- signaling by upregulating PAI-1 and JUNB through direct interaction with SMAD4 in the nucleus upon TGF-1 induction. Taken together, these data strongly suggest that DLX1 plays a pivotal role in FOXM1 signaling to promote cancer aggressiveness through intensifying TGF-/SMAD4 signaling in high-grade serous ovarian cancer cells.published_or_final_versio

Cost analysis of psoriasis treatment modalities in Malaysian public hospitals

Psoriasis imposes a great economic burden as a result of higher expenditures for different interventions, diagnostic procedures, pharmaceuticals and loss of productivity. Less is known about the economic impact of psoriasis treatment in Asean region. The aim of this research was to calculate the costs associated with four psoriasis treatment modalities. A prospective cohort study was conducted in five hospitals involving 91 moderate to severe psoriasis patients. Costs were calculated from the societal perspective using the principle of Step Down and Activity Based Costing (ABC) within a six (6) months follow-up duration. The components of the costs borne by the provider were inpatient cost, cost of medication, laboratory investigation and radiology. Patient’s cost included out of pocket expenses, travelling cost and loss of productivity. Cost per patient per day was RM1,105.24 (inpatient) (US$315.94) and RM298.02 (outpatient) (US$85.19). Medication accounted for almost 90% (RM457,014.00) (US$130 638.45) of the total provider cost. Meanwhile, loss of productivity represented 84$47,862.80) of the total patient’s cost. Biologic treatment exhibited the highest cost which was RM342,377.00 (US$97,869.21), followed by systemic treatment (RM105,607.00) (US$30,187.99), topical treatment (RM38,280.00) (US$10,942.42) and topical phototherapy treatment (RM21,824.00) (US$6,238.44). Understanding the relationship between direct and indirect costs from both perspectives is important to accurately identify and evaluate effective treatment for psoriasis

The clinical profile of right temporal lobe atrophy

Frontotemporal lobar degeneration is currently associated with three syndromic variants. Disorders of speech and language figure prominently in two of the three variants, and are associated with left-sided frontotemporal atrophy. The detailed characterization of these syndromes contrasts with the relative paucity of information relating to frontotemporal lobar degeneration primarily affecting the right cerebral hemisphere. The objective of this study was to identify the clinical profile associated with asymmetrical, predominantly right-sided, temporal lobe atrophy. Twenty patients with predominant right temporal lobe atrophy were identified on the basis of blinded visual assessment of the MRI scans. The severity of right temporal lobe atrophy was quantified using volumetric analysis of the whole temporal lobes, the amygdala and the hippocampus. Profiles of cognitive function, behavioural and personality changes were obtained on each patient. The pattern of atrophy and the clinical features were compared with those observed in a group of patients with semantic dementia and predominant left-sided temporal lobe atrophy. The mean right temporal lobe volume in the right temporal lobe atrophy group was reduced by 37%, with the mean left temporal lobe volume reduced by 19%. There was marked atrophy of the right hippocampus and right amygdala, with mean volumes reduced by 41 and 51%, respectively (left hippocampus and amygdala volumes were reduced by 18 and 33%, respectively). The most prominent cognitive deficits were impairment of episodic memory and getting lost. Prosopagnosia was a symptom in right temporal lobe atrophy patients. These patients also exhibited a variety of behavioural symptoms including social disinhibition, depression and aggressive behaviour. Nearly all behavioural disorders were more prevalent in the right temporal lobe atrophy patient group than the semantic dementia group. Symptoms particular to the right temporal lobe atrophy patient group included hyper-religiosity, visual hallucinations and cross-modal sensory experiences. The combination of clinical features associated with predominant right temporal lobe atrophy differs significantly from those associated with the other syndromes associated with focal degeneration of the frontal and temporal lobes and it is, therefore, proposed that this right temporal variant should be considered a separate syndromic variant of frontotemporal lobar degeneration

Asymmetric localization of DLC1 defines avian trunk neural crest polarity for directional delamination and migration

Following epithelial-mesenchymal transition, acquisition of avian trunk neural crest cell (NCC) polarity is prerequisite for directional delamination and migration, which in turn is essential for peripheral nervous system development. However, how this cell polarization is established and regulated remains unknown. Here we demonstrate that, using the RHOA biosensor in vivo and in vitro, the initiation of NCC polarization is accompanied by highly activated RHOA in the cytoplasm at the cell rear and its fluctuating activity at the front edge. This differential RHOA activity determines polarized NC morphology and motility, and is regulated by the asymmetrically localized RhoGAP Deleted in liver cancer (DLC1) in the cytoplasm at the cell front. Importantly, the association of DLC1 with NEDD9 is crucial for its asymmetric localization and differential RHOA activity. Moreover, NC specifiers, SOX9 and SOX10, regulate NEDD9 and DLC1 expression, respectively. These results present a SOX9/SOX10-NEDD9/DLC1-RHOA regulatory axis to govern NCC migratory polarization.published_or_final_versio

Checkpoints are blind to replication restart and recombination intermediates that result in gross chromosomal rearrangements

Replication fork inactivation can be overcome by homologous recombination, but this can cause gross chromosomal rearrangements that subsequently missegregate at mitosis, driving further chromosome instability. It is unclear when the chromosome rearrangements are generated and whether individual replication problems or the resulting recombination intermediates delay the cell cycle. Here we have investigated checkpoint activation during HR-dependent replication restart using a site-specific replication fork-arrest system. Analysis during a single cell cycle shows that HR-dependent replication intermediates arise in S phase, shortly after replication arrest, and are resolved into acentric and dicentric chromosomes in G2. Despite this, cells progress into mitosis without delay. Neither the DNA damage nor the intra-S phase checkpoints are activated in the first cell cycle, demonstrating that these checkpoints are blind to replication and recombination intermediates as well as to rearranged chromosomes. The dicentrics form anaphase bridges that subsequently break, inducing checkpoint activation in the second cell cycle

A comparison of intrauterine haemopoietic cell transplantation and lentiviral gene transfer for the correction of severe β-thalassaemia in a HbbTh3/+ murine model

Major haemoglobinopathies place tremendous strain on global resources. Intrauterine haemopoietic cell (IUHCT) and gene (IUGT) therapies can potentially reduce perinatal morbidities with greater efficacy than postnatal therapy alone. We performed both procedures in the thalassaemic HbbTh3/+ murine model. Intraperitoneal delivery of coisogenic cells at E13-14 produced dose-dependent chimerism. High-dose adult bone marrow (BM) cells maintained 0.2-3.1% chimerism over ~24 weeks and treated heterozygotes demonstrated higher chimerism than wild-type pups (1.6 vs. 0.7%). Fetal liver cells produced higher chimerism compared to adult BM when transplanted at the same doses, maintaining 1.8-2.4% chimerism over ~32 weeks. We boosted transplanted mice postnatally with adult BM cells following busulfan conditioning. Engraftment was maintained at >1% only in recipients which were chimeric prior to boosting. IUHCT-treated non-chimeras and non-IUHCT mice showed micro- or no chimerism. Additional fludarabine treatment produced higher chimerism than busulfan alone. Engraftment was more effective following higher starting chimerism prior to boosting and in heterozygotes. Chimeric heterozygotes expressed 2.2-15.1% donor cells with eventual decline at 24 weeks (vs. <1% in non-chimeras) and demonstrated improved haematological indices and smaller spleens compared to untreated heterozygotes. Intravenous delivery of GLOBE lentiviral-vector expressing HBB (human β-globin) resulted in vector concentration of 0.001-0.6 copies/cell. Most haematological indices were higher in treated than untreated heterozygotes including haemoglobin and mean corpuscular volume, though still lower than in wild-types. Thus both direct IUGT and IUHCT strategies can be used to achieve haematological improvement but require further dose optimisation. IUHCT will be useful combined with postnatal transplantation to further enhance engraftment

Expression of Protease-Activated Receptor 1 and 2 and Anti-Tubulogenic Activity of Protease-Activated Receptor 1 in Human Endothelial Colony-Forming Cells

Endothelial colony-forming cells (ECFCs) are obtained from the culture of human peripheral blood mononuclear cell (hPBMNC) fractions and are characterised by high proliferative and pro-vasculogenic potential, which makes them of great interest for cell therapy. Here, we describe the detection of protease-activated receptor (PAR) 1 and 2 amongst the surface proteins expressed in ECFCs. Both receptors are functionally coupled to extracellular signal-regulated kinase (ERK) 1 and 2, which become activated and phosphorylated in response to selective PAR1- or PAR2-activating peptides. Specific stimulation of PAR1, but not PAR2, significantly inhibits capillary-like tube formation by ECFCs in vitro, suggesting that tubulogenesis is negatively regulated by proteases able to stimulate PAR1 (e.g. thrombin). The activation of ERKs is not involved in the regulation of tubulogenesis in vitro, as suggested by use of the MEK inhibitor PD98059 and by the fact that PAR2 stimulation activates ERKs without affecting capillary tube formation. Both qPCR and immunoblotting showed a significant downregulation of vascular endothelial growth factor 2 (VEGFR2) in response to PAR1 stimulation. Moreover, the addition of VEGF (50–100 ng/ml) but not basic Fibroblast Growth Factor (FGF) (25–100 ng/ml) rescued tube formation by ECFCs treated with PAR1-activating peptide. Therefore, we propose that reduction of VEGF responsiveness resulting from down-regulation of VEGFR2 is underlying the anti-tubulogenic effect of PAR1 activation. Although the role of PAR2 remains elusive, this study sheds new light on the regulation of the vasculogenic activity of ECFCs and suggests a potential link between adult vasculogenesis and the coagulation cascade