3,749 research outputs found
Withaferin A activates TRIM16 for its anti-cancer activity in melanoma.
Although selective BRAF inhibitors and novel immunotherapies have improved short-term treatment responses in metastatic melanoma patients, acquired resistance to these therapeutics still represent a major challenge in clinical practice. In this study, we evaluated the efficacy of Withaferin A (WFA), derived from the medicinal plant Withania Somnifera, as a novel therapeutic agent for the treatment of melanoma. WFA showed selective toxicity to melanoma cells compared to non-malignant cells. WFA induced apoptosis, significantly reduced cell proliferation and inhibited migration of melanoma cells. We identified that repression of the tumour suppressor TRIM16 diminished WFA cytotoxicity, suggesting that TRIM16 was in part responsible for the cytotoxic effects of WFA in melanoma cells. Together our data indicates that WFA has potent cytopathic effects on melanoma cells through TRIM16, suggesting a potential therapeutic application of WFA in the disease
How early can myocardial iron overload occur in Beta thalassemia major?
BACKGROUND: Myocardial siderosis is the most common cause of death in patients with beta thalassemia major(TM). This study aimed at investigating the occurrence, prevalence and severity of cardiac iron overload in a young Chinese population with beta TM.
METHODS AND RESULTS: We analyzed T2* cardiac magnetic resonance (CMR), left ventricular ejection fraction (LVEF) and serum ferritin (SF) in 201 beta TM patients. The median age was 9 years old. Patients received an average of 13 units of blood per year. The median SF level was 4536 ng/ml and 165 patients (82.1%) had SF>2500 ng/ml. Myocardial iron overload was detected in 68 patients (33.8%) and severe myocardial iron overload was detected in 26 patients (12.6%). Twenty-two patients ≤10 years old had myocardial iron overload, three of whom were only 6 years old. No myocardial iron overload was detected under the age of 6 years. Median LVEF was 64% (measured by CMR in 175 patients). Five of 6 patients with a LVEF<56% and 8 of 10 patients with cardiac disease had myocardial iron overload.
CONCLUSIONS: The TM patients under follow-up at this regional centre in China patients are younger than other reported cohorts, more poorly-chelated, and have a high burden of iron overload. Myocardial siderosis occurred in patients younger than previously reported, and was strongly associated with impaired LVEF and cardiac disease. For such poorly-chelated TM patients, our data shows that the first assessment of cardiac T2* should be performed as early as 6 years old
Observation of pseudogap behavior in a strongly interacting Fermi gas
Ultracold atomic Fermi gases present an opportunity to study strongly
interacting Fermi systems in a controlled and uncomplicated setting. The
ability to tune attractive interactions has led to the discovery of
superfluidity in these systems with an extremely high transition temperature,
near T/T_F = 0.2. This superfluidity is the electrically neutral analog of
superconductivity; however, superfluidity in atomic Fermi gases occurs in the
limit of strong interactions and defies a conventional BCS description. For
these strong interactions, it is predicted that the onset of pairing and
superfluidity can occur at different temperatures. This gives rise to a
pseudogap region where, for a range of temperatures, the system retains some of
the characteristics of the superfluid phase, such as a BCS-like dispersion and
a partially gapped density of states, but does not exhibit superfluidity. By
making two independent measurements: the direct observation of pair
condensation in momentum space and a measurement of the single-particle
spectral function using an analog to photoemission spectroscopy, we directly
probe the pseudogap phase. Our measurements reveal a BCS-like dispersion with
back-bending near the Fermi wave vector k_F that persists well above the
transition temperature for pair condensation
Clinical and physiological effects of transcranial electrical stimulation position on motor evoked potentials in scoliosis surgery
<p>Abstract</p> <p>Background</p> <p>During intraoperative monitoring for scoliosis surgery, we have previously elicited ipsilateral and contralateral motor evoked potentials (MEP) with cross scalp stimulation. Ipsilateral MEPs, which may have comprised summation of early ipsilaterally conducted components and transcallosally or deep white matter stimulated components, can show larger amplitudes than those derived purely from contralateral motor cortex stimulation. We tested this hypothesis using two stimulating positions. We compared intraoperative MEPs in 14 neurologically normal subjects undergoing scoliosis surgery using total intravenous anesthetic regimens.</p> <p>Methods</p> <p>Trancranial electrical stimulation was applied with both cross scalp (C3C4 or C4C3) or midline (C3Cz or C4Cz) positions. The latter was assumed to be more focal and result in little transcallosal/deep white matter stimulation. A train of 5 square wave stimuli 0.5 ms in duration at up to 200 mA was delivered with 4 ms (250 Hz) interstimulus intervals. Averaged supramaximal MEPs were obtained from the tibialis anterior bilaterally.</p> <p>Results</p> <p>The cross scalp stimulating position resulted in supramaximal MEPs that were of significantly higher amplitude, shorter latency and required lower stimulating intensity to elicit overall (Wilcoxon Signed Rank test, p < 0.05 for all), as compared to the midline stimulating position. However, no significant differences were found for all 3 parameters comparing ipsilaterally and contralaterally recorded MEPs (p > 0.05 for all), seen for both stimulating positions individually.</p> <p>Conclusions</p> <p>Our findings suggest that cross scalp stimulation resulted in MEPs obtained ipsilaterally and contralaterally which may be contributed to by summation of ipsilateral and simultaneous transcallosally or deep white matter conducted stimulation of the opposite motor cortex. Use of this stimulating position is advocated to elicit MEPs under operative circumstances where anesthetic agents may cause suppression of cortical and spinal excitability. Although less focal in nature, cross scalp stimulation would be most suitable for infratentorial or spinal surgery, in contrast to supratentorial neurosurgical procedures.</p
Realizing and manipulating space-time inversion symmetric topological semimetal bands with superconducting quantum circuits
published_or_final_versio
NRF2-driven miR-125B1 and miR-29B1 transcriptional regulation controls a novel anti-apoptotic miRNA regulatory network for AML survival
Transcription factor NRF2 is an important regulator of oxidative stress. It is involved in cancer progression, and has abnormal constitutive expression in acute myeloid leukaemia (AML). Posttranscriptional regulation by microRNAs (miRNAs) can affect the malignant phenotype of AML cells. In this study, we identified and characterised NRF2-regulated miRNAs in AML. An miRNA array identified miRNA expression level changes in response to NRF2 knockdown in AML cells. Further analysis of miRNAs concomitantly regulated by knockdown of the NRF2 inhibitor KEAP1 revealed the major candidate NRF2-mediated miRNAs in AML. We identified miR-125B to be upregulated and miR-29B to be downregulated by NRF2 in AML. Subsequent bioinformatic analysis identified putative NRF2 binding sites upstream of the miR-125B1 coding region and downstream of the mir-29B1 coding region. Chromatin immunoprecipitation analyses showed that NRF2 binds to these antioxidant response elements (AREs) located in the 5′ untranslated regions of miR-125B and miR-29B. Finally, primary AML samples transfected with anti-miR-125B antagomiR or miR-29B mimic showed increased cell death responsiveness either alone or co-treated with standard AML chemotherapy. In summary, we find that NRF2 regulation of miR-125B and miR-29B acts to promote leukaemic cell survival, and their manipulation enhances AML responsiveness towards cytotoxic chemotherapeutics
Standard psychological consultations and follow up for women at increased risk of hereditary breast cancer considering prophylactic mastectomy
__Background:__ Women at increased (genetic) risk of breast cancer have to weigh the personal pros and cons of prophylactic mastectomy (PM) as an option to reduce their cancer risk. So far, no routine referral to a psychologist has been investigated for women considering PM.
Aim of this study was to asses:
1) the acceptance of the offer of a standard psychological consultation as part of pre-surgical decision-making in high-risk women,
2) reasons for PM and reasons for postponing it,
3) the need for additional psychological interventions, and factors associated, and
4) the frequency of psychiatric/psychological treatment history.
__Methods:__ During a 30 months period, women at high risk considering PM were offered a psychological consultation. The content of these, and follow-up, consultations were analyzed.
__Results:__ Most women (70 out of 73) accepted the psychological consultation, and 81% proceeded with PM. Main reasons for undergoing PM were to reduce anxiety about cancer, and to reduce the cancer risk. Uncertainty about surgery and the need for further information were the reasons given most frequently for postponing PM. Additional psychological support was given to 31% before and 14% after PM. The uptake of additional support was significantly higher in women with a BRCA1/2 mutation. A history of psychiatric/psychological treatment was present in 36%, mainly consisting of depression and grief after death of a mother.
__Conclusion:__ The uptake-rate of the standard psychological consultation indicates a high level of acceptability of this service for women deciding about PM. Since anxiety is one of the main reasons for considering PM, and depression and grief were present in a third, a standard consultation with a psychologist for high-risk women considering PM may be indicated. This may help them arrive at an informed decision, to detect and manage psychological distress, and to plan psychological support services
Exploiting inflammation for therapeutic gain in pancreatic cancer
Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy associated with <5% 5-year survival, in which standard chemotherapeutics have limited benefit. The disease is associated with significant intra- and peritumoral inflammation and failure of protective immunosurveillance. Indeed, inflammatory signals are implicated in both tumour initiation and tumour progression. The major pathways regulating PDAC-associated inflammation are now being explored. Activation of leukocytes, and upregulation of cytokine and chemokine signalling pathways, both have been shown to modulate PDAC progression. Therefore, targeting inflammatory pathways may be of benefit as part of a multi-target approach to PDAC therapy. This review explores the pathways known to modulate inflammation at different stages of tumour development, drawing conclusions on their potential as therapeutic targets in PDAC
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