SIRT1-mediated downregulation of p27(Kip1) is essential for overcoming contact inhibition of Kaposi's sarcoma-associated herpesvirus transformed cells

Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic virus associated with Kaposi's sarcoma (KS), a malignancy commonly found in AIDS patients. Despite intensive studies in the last two decades, the mechanism of KSHV-induced cellular transformation and tumorigenesis remains unclear. In this study, we found that the expression of SIRT1, a metabolic sensor, was upregulated in a variety of KSHV-infected cells. In a model of KSHV-induced cellular transformation, SIRT1 knockdown with shRNAs or knockout by CRISPR/Cas9 gene editing dramatically suppressed cell proliferation and colony formation in soft agar of KSHV-transformed cells by inducing cell cycle arrest and contact inhibition. SIRT1 knockdown or knockout induced the expression of cyclin-dependent kinase inhibitor 1B (p27(Kip1)). Consequently, p27 knockdown rescued the inhibitory effect of SIRT1 knockdown or knockout on cell proliferation and colony formation. Furthermore, treatment of KSHV-transformed cells with a SIRT1 inhibitor, nicotinamide (NAM), had the same effect as SIRT1 knockdown and knockout. NAM significantly inhibited cell proliferation in culture and colony formation in soft agar, and induced cell cycle arrest. Significantly, NAM inhibited the progression of tumors and extended the survival of mice in a KSHV-induced tumor model. Collectively, these results demonstrate that SIRT1 suppression of p27 is required for KSHV-induced tumorigenesis and identify a potential therapeutic target for KS.

Delayed-Onset Continuous Bruxism with Olivary Hypertrophy After Top of the Basilar Syndrome

Delayed-onset continuous bruxism due to brain stem infarction has not yet been reported. A 49-year old man presented with quadriplegia and ophthalmoplegia. Brain MRI showed acute infarction in the bilateral midbrain, right thalamus and the superior cerebellum. One month later, the patient developed bruxism which persisted during sleep. A palatal myoclonus was not observed. Follow up MRI taken 4 months later showed bilateral olivary hypertrophy. We suggest that the patient's bruxism may be related to the olivary hypertrophy. The bruxism generator may be located in the pontine-reticular-formation (PRF). Bilateral large midbrain lesions interrupting the cortical inhibition may have produced bilateral olivary hypertrophy, which could stimulate the PRF, producing continuous bruxism

Lupus Myocarditis Presenting as Acute Congestive Heart Failure: A Case Report

A young woman who had a delivery history 3 months previously presented with dyspnea and orthopnea. Initial findings of physical examination, chest radiography, and echocardiogram showed typical congestive heart failure with severe left ventricular (LV) dysfunction. At first, we considered peripartum cardiomyopathy because she had given birth to a baby 3 months previously. However, even though we massively tried conventional drug therapy for 10 days, the patient still remained with refractory heart failure. We performed additional laboratory studies such as complement level and autoantibodies, of which the results supported systemic lupus erythematosus. We could make the diagnosis of acute lupus myocarditis and treated her with corticosteroid. The symptoms were dramatically disappeared and LV function also improved

RSNA International Trends: A Global Perspective on the COVID-19 Pandemic and Radiology in Late 2020

The COVID-19 pandemic has challenged and changed our healthcare systems around the world. There has been a heterogeneity of disease burden, healthcare resources, and non-imaging testing availability, both geographically and over time. In parallel, there has been a continued increase in understanding of how the disease affects patients, effectiveness of therapeutic options, and factors that modulate transmission risk. Here we detail experiences from radiology experts in representative countries from around the world, to share insights gained from local experience. These insights provide a guidepost to help address management challenges as cases continue to rise in many parts of the world and suggest modifications in workflow that are likely to continue after this pandemic subsides

The Effect of Thermal Treatment on the Resistance of 7075 Aluminum Alloy in Aggressive Alkaline Solution

Aluminum has attractive properties in which when properly engineered can be used in wider areas of applications. Due to its reactive abilities and strong affinity for oxygen, aluminum can resist rough environments and overall durable to various chemical agents. This work highlighted the behaviour of 7075 aluminum alloy in an aggressive alkaline environment. Two tempers of T6 and T73 were produced through solution heat treatment procedure; the T6 temper was subjected to solution heat treatment at 470°C for 60 min, quenched for 60 sec and followed by precipitation heat treatment or artificial ageing at 138°C for 960 min whereas the T73 was subjected to solution heat treatment at 470°C for 60 min quenched for 60 sec and followed by two precipitation heat treatment processes at 113°C for 480 min and 182°C for 720 min respectively.  The as received and the tempered materials are immersed in an aggressive alkaline medium consisting sodium chloride and hydrogen peroxide. The samples obtained were characterized by assessing weight loss and subjected to surface morphology analysis using scanning electron microscope. The morphology of the heat treated samples shows the type of localized form of corrosion present is pitting form of corrosion, and the weight analysis shows significant weight loss when the samples are exposed to the aggressive alkaline environment. The weight loss for the as received sample was observed to be more than the T73 and the T6 samples

Polymer Acceptors with Flexible Spacers Afford Efficient and Mechanically Robust All-Polymer Solar Cells

High efficiency and mechanical robustness are both crucial for the practical applications of all-polymer solar cells (all-PSCs) in stretchable and wearable electronics. In this regard, a series of new polymer acceptors (PAs) is reported by incorporating a flexible conjugation-break spacer (FCBS) to achieve highly efficient and mechanically robust all-PSCs. Incorporation of FCBS affords the effective modulation of the crystallinity and pre-aggregation of the PAs, and achieves the optimal blend morphology with polymer donor (PD), increasing both the photovoltaic and mechanical properties of all-PSCs. In particular, an all-PSC based on PYTS-0.3 PA incorporated with 30% FCBS and PBDB-T PD demonstrates a high power conversion efficiency (PCE) of 14.68% and excellent mechanical stretchability with a crack onset strain (COS) of 21.64% and toughness of 3.86\ua0MJ m-3, which is significantly superior to those of devices with the PA without the FCBS (PYTS-0.0, PCE = 13.01%, and toughness = 2.70\ua0MJ m-3). To date, this COS is the highest value reported for PSCs with PCEs of over 8% without any insulating additives. These results reveal that the introduction of FCBS into the conjugated backbone is a highly feasible strategy to simultaneously improve the PCE and stretchability of PSCs

Tumor marker analyses from the phase III, placebo-controlled, FASTACT-2 study of intercalated erlotinib with gemcitabine/platinum in the first-line treatment of advanced non-small-cell lung cancer

AbstractObjectivesThe FASTACT-2 study of intercalated erlotinib with chemotherapy in Asian patients found that EGFR mutations were the main driver behind the significant progression-free survival (PFS) benefit noted in the overall population. Further exploratory biomarker analyses were conducted to provide additional insight.Materials and methodsThis multicenter, randomized, placebo-controlled, double-blind, phase III study investigated intercalated first-line erlotinib or placebo with gemcitabine/platinum, followed by maintenance erlotinib or placebo, for patients with stage IIIB/IV non-small cell lung cancer (NSCLC). Provision of samples for biomarker analysis was encouraged but not mandatory. The following biomarkers were analyzed (in order of priority): EGFR mutation by cobas® test, KRAS mutation by cobas® KRAS test, HER2 by immunohistochemistry (IHC), HER3 by IHC, ERCC1 by IHC, EGFR gene copy number by fluorescence in-situ hybridization (FISH) and EGFR by IHC. All subgroups were assessed for PFS (primary endpoint), overall survival (OS), non-progression rate and objective response rate.ResultsOverall, 256 patients provided samples for analysis. Considerable overlap was noted among biomarkers, except for EGFR and KRAS mutations, which are mutually exclusive. Other than EGFR mutations (p<0.0001), no other biomarkers were significantly predictive of outcomes in a treatment-by-biomarker interaction test, although ERCC1 IHC-positive status was predictive of improved OS for the erlotinib arm versus placebo in EGFR wild-type patients (median 18.4 vs 9.5 months; hazard ratio [HR] HR=0.32, 95% confidence intervals [CI]: 0.14–0.69, p=0.0024).ConclusionActivating EGFR mutations were predictive for improved treatment outcomes with a first-line intercalated regimen of chemotherapy and erlotinib in NSCLC. ERCC1 status may have some predictive value in EGFR wild-type disease, but requires further investigation

Weekly Paclitaxel and Trastuzumab as a First-Line Therapy in Patients with HER2-Overexpressing Metastatic Breast Cancer: Magnitude of HER2/neu Amplification as a Predictive Factor for Efficacy

We evaluated the efficacy and safety of weekly paclitaxel plus trastuzumab as firs-tline chemotherapy in women with HER2-overexpressing metastatic breast cancer (MBC), and we investigated the prognostic factors including magnitude of HER2/neu amplification in this population. We analyzed 54 patients with HER2-overexpressing MBC that were treated with weekly paclitaxel plus trastuzumab as first-line chemotherapy from February 2004 to December 2006. At a median follow-up of 28 months, median time to progression (TTP) was 16.6 months (95% CI, 9.4 to 23.7 months) and median overall survival was 25.6 months (95% CI, 21.8 to 27.3 months). Therapy was generally well tolerated, although three patients (5.5%) experienced reversible, symptomatic heart failure. Of the 27 patients evaluable for the HER2 FISH, patients with a HER2/CEP17 ratio of ≤4.0 had significantly shorter TTP than those with a HER2/CEP17 ratio of >4.0 (10.8 vs. 23.2 months, P=0.034). A HER2/CEP17 ratio of >4.0 was identified as significant predictive factor of TTP by multivariate analysis (P=0.032). The combination of weekly paclitaxel plus trastuzumab as first-line chemotherapy is an effective regimen in patients with HER2-FISH-positive MBC. Furthermore, the magnitude of HER2 amplification is an independent predictive factor of TTP

GSTT2 promoter polymorphisms and colorectal cancer risk

BACKGROUND: Glutathione S-transferases are a group of enzymes that participate in detoxification and defense mechanisms against toxic carcinogens and other compounds. These enzymes play an important role in human carcinogenesis. In the present study, we sought to determine whether GSTT2 promoter single nucleotide polymorphisms (SNPs) are associated with colorectal cancer risk. METHODS: A total of 436 colorectal cancer patients and 568 healthy controls were genotyped for three GSTT2 promoter SNPs (-537G>A, -277T>C and -158G>A), using real-time TaqMan assay and direct sequencing. An electrophoretic mobility shift assay (EMSA) was performed to determine the effects of polymorphisms on protein binding to the GSTT2 promoter. RESULTS: The -537A allele (-537G/A or A/A) was significantly associated with colorectal cancer risk (OR = 1.373, p = 0.025), while the -158A allele (-158G/A or A/A) was involved in protection against colorectal cancer (OR = 0.539, p = 0.032). Haplotype 2 (-537A, -277T, -158G) was significantly associated with colorectal cancer risk (OR = 1.386, p = 0.021), while haplotype 4 (-537G, -277C, -158A) protected against colorectal cancer (OR = 0.539, p = 0.032). EMSA data revealed lower promoter binding activity in the -537A allele than its -537G counterpart. CONCLUSION: Our results collectively suggest that SNPs and haplotypes of the GSTT2 promoter region are associated with colorectal cancer risk in the Korean population