Why Do Cascade Sizes Follow a Power-Law?

We introduce random directed acyclic graph and use it to model the information diffusion network. Subsequently, we analyze the cascade generation model (CGM) introduced by Leskovec et al. [19]. Until now only empirical studies of this model were done. In this paper, we present the first theoretical proof that the sizes of cascades generated by the CGM follow the power-law distribution, which is consistent with multiple empirical analysis of the large social networks. We compared the assumptions of our model with the Twitter social network and tested the goodness of approximation.Comment: 8 pages, 7 figures, accepted to WWW 201

Starbursts versus Truncated Star Formation in Nearby Clusters of Galaxies

We present long-slit spectroscopy, B and R bandpass imaging, and 21 cm observations of a sample of early-type galaxies in nearby clusters which are known to be either in a star-forming phase or to have had star formation which recently terminated. From the long-slit spectra, obtained with the Blanco 4-m telescope, we find that emission lines in the star-forming cluster galaxies are significantly more centrally concentrated than in a sample of field galaxies. The broadband imaging reveals that two currently star-forming early-type galaxies in the Pegasus I cluster have blue nuclei, again indicating that recent star formation has been concentrated. In contrast, the two galaxies for which star formation has already ended show no central color gradient. The Pegasus I galaxy with the most evident signs of ongoing star formation (NGC7648), exhibits signatures of a tidal encounter. Neutral hydrogen observations of that galaxy with the Arecibo radiotelescope reveal the presence of ~4 x 10^8 solar masses of HI. Arecibo observations of other current or recent star-forming early-type galaxies in Pegasus I indicate smaller amounts of gas in one of them, and only upper limits in others.Comment: to be published in Astronomical Journa

Radial Color Gradients in K+A Galaxies in Distant Clusters of Galaxies

Galaxies in rich clusters with z $\gtrsim$ 0.3 are observed to have a higher fraction of photometrically blue galaxies than their nearby counterparts. This raises the important question of what environmental effects can cause the termination of star formation between z $\approx$ 0.3 and the present. The star formation may be truncated due to ram-pressure stripping, or the gas in the disk may be depleted by an episode of star formation caused by some external perturbation. To help resolve this issue, surface photometry was carried out for a total of 70 early-type galaxies in the cluster Cl1358+62, at z $\sim$ 0.33, using two-color images from the Hubble Archive. The galaxies were divided into two categories based on spectroscopic criteria: 24 are type K+A (e.g., strong Balmer lines, with no visible emission lines), while the remaining 46 are in the control sample with normal spectra. Radial color profiles were produced to see if the K+A galaxies show bluer nuclei in relation to their surrounding disks. Specifically, a linear gradient was fit to the radial color profile of each galaxy. We find that the K+A galaxies on average tend to have slightly bluer gradients towards the center than the normals. A Kolmogorov-Smirnov two-sample test has been applied to the two sets of color gradients. The result of the test indicates that there is only a $\sim$2% probability that the K+A and normal samples are drawn from the same parent distribution. There is a possible complication from a trend in the apparent magnitude vs. color gradient relation, but overall our results favor the centralized star formation scenario as an important process in the evolution of galaxies in dense clusters.Comment: 16 pages, 12 figures, accepted for publication in A

Does doxorubicin survive thermal ablation? Results of an ex vivo bench top study

PURPOSE:We aimed to test the hypothesis that doxorubicin (DOX) survives thermal ablative heating in an ex vivo model of combined transarterial chemoembolization (TACE) and thermal ablation.METHODS:Fresh porcine psoas major muscle (3 samples, 15×10×3 cm) was submerged in aqueous DOX solution (60 µg/mL, 0.1 M) for 24 hours to passively saturate tissue. DOX-infused tissue was then dried and treated with microwave ablation (MWA) using a 2.45 GHz antenna at 65 W for 2, 5, and 10 minutes. Ablations were repeated in triplicate (9 total). Tissue was then sampled at both ablated and unablated control sites, and DOX concentration was quantified via ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS), with samples analyzed in triplicate. Tissue DOX levels in ablation and control groups were compared using one-way ANOVA.RESULTS:Homogeneous DOX uptake into porcine tissue was evident in all three samples. Mean DOX concentration in unablated tissue was 8.0±2.2 µg/mL. MWA was technically successful in all 9 procedures (100%), with tissue heating to 95–100°C. Mean tissue DOX concentration showed progressive reduction with increasing ablation time, measuring 6.7±1.3, 4.9±0.9, and 4.8±1.3 µg/mL in MWA-treated tissue after 2, 5, and 10 minutes, respectively. Differences in tissue DOX levels between unablated tissue and MWA groups were statistically significant (P < 0.001).CONCLUSION:Contrary to the initial hypothesis, tissue DOX concentration progressively decreased after MWA of longer ablation times. These results suggest that TACE followed by ablation may result in lower intratumoral DOX than would otherwise be anticipated for TACE alone

Epstein-Barr virus myelitis and Castleman's disease in a patient with acquired immune deficiency syndrome: a case report

<p>Abstract</p> <p>Introduction</p> <p>Few cases of Epstein-Barr virus myelitis have been described in the literature. Multi-centric Castleman's disease is a lymphoproliferative disorder that is well known for its associations with the human immunodeficiency virus, human herpes virus 8, and Kaposi's sarcoma. The concurrent presentation of these two diseases in a patient at the same time is extremely unusual.</p> <p>Case Presentation</p> <p>We describe the case of a 43-year-old Caucasian man with acquired immune deficiency syndrome who presented with fever, weight loss and diffuse lymphadenopathy, and was diagnosed with multi-centric Castleman's disease. He presented three weeks later with lower extremity weakness and urinary retention, at which time cerebrospinal fluid contained lymphocytic pleocytosis and elevated protein. Magnetic resonance imaging demonstrated abnormal spinal cord signal intensity over several cervical and thoracic segments, suggesting the diagnosis of myelitis. Our patient was ultimately diagnosed with Epstein-Barr virus myelitis, as Epstein-Barr virus DNA was detected by polymerase chain reaction in the cerebrospinal fluid.</p> <p>Conclusion</p> <p>To the best of our knowledge, this is the first case of multi-centric Castleman's disease followed by acute Epstein-Barr virus myelitis in a human immunodeficiency virus-infected patient. Clinicians caring for human immunodeficiency virus-infected patients should be vigilant about monitoring patients with increasing lymphadenopathy, prompting thorough diagnostic investigations when necessary.</p

An unusual presentation of Castleman's Disease:a case report

BACKGROUND: Castleman's disease (CD), a rare condition of uncertain etiology, involves a massive proliferation of lymphoid tissues and typically presents as mediastinal masses. We describe a patient with CD who presented with diffuse adenopathy involving the inguinal, paratracheal, retroperitoneal, axillary, and pelvic regions. CASE PRESENTATION: Case report describing presentation, work-up, management and clinical course of a patient with Castleman's disease in the setting of a county hospital in metropolitan area. Patient was treated with chemotherapeutic agents. CONCLUSIONS: To our knowledge, this represents the first case of CD involving an HIV-positive patient with a negative Human Herpes Virus (HHV-8) viral panel. Because patients with similar clinical histories are at high risk for the development of non-Hodgkin's lymphoma and Kaposi sarcoma, regular medical surveillance is recommended

Preventing Ovarian Cancer through early Excision of Tubes and late Ovarian Removal (PROTECTOR): protocol for a prospective non-randomised multi-center trial.

BACKGROUND: Risk-reducing salpingo-oophorectomy is the 'gold standard' for preventing tubo-ovarian cancer in women at increased risk. However, when performed in pre-menopausal women, it results in premature menopause and associated detrimental health consequences. This, together with acceptance of the central role of the fallopian tube in etiopathogenesis of high-grade serous carcinoma, by far the most common type of tubo-ovarian cancer, has led to risk-reducing early salpingectomy with delayed oophorectomy being proposed as a two-step surgical alternative for pre-menopausal women declining/delaying oophorectomy. PRIMARY OBJECTIVE: To evaluate the impact on sexual function of risk-reducing early salpingectomy, within a two-step, risk-reducing, early salpingectomy with delayed oophorectomy tubo-ovarian cancer prevention strategy in pre-menopausal women at increased risk of tubo-ovarian cancer. STUDY HYPOTHESIS: Risk-reducing early salpingectomy is non-inferior for sexual and endocrine function compared with controls; risk-reducing early salpingectomy is superior for sexual/endocrine function, non-inferior for quality-of-life, and equivalent in satisfaction to the standard risk-reducing salpingo-oophorectomy. TRIAL DESIGN: Multi-center, observational cohort trial with three arms: risk-reducing early salpingectomy with delayed oophorectomy; risk-reducing salpingo-oophorectomy; controls (no surgery). Consenting individuals undergo an ultrasound, serum CA125, and follicle-stimulating hormone measurements and provide information on medical history, family history, quality-of-life, sexual function, cancer worry, psychological well-being, and satisfaction/regret. Follow-up by questionnaire takes place annually for 3 years. Women receiving risk-reducing early salpingectomy can undergo delayed oophorectomy at a later date of their choosing, or definitely by the menopause. MAJOR INCLUSION/EXCLUSION CRITERIA: Inclusion criteria: pre-menopausal; aged >30 years; at increased risk of tubo-ovarian cancer (mutation carriers or on the basis of a strong family history); completed their family (for surgical arms). EXCLUSION CRITERIA: post-menopausal; previous bilateral salpingectomy or bilateral oophorectomy; pregnancy; previous tubal/ovarian/peritoneal malignancy; <12 months after cancer treatment; clinical suspicion of tubal/ovarian cancer at baseline. PRIMARY ENDPOINT: Sexual function measured by validated questionnaires. SAMPLE SIZE: 1000 (333 per arm). ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS: It is estimated recruitment will be completed by 2023 and results published by 2027. TRIAL REGISTRATION NUMBER: ISRCTN registry: 25 173 360 (https://doi.org/10.1186/ISRCTN25173360)

Immune-related gene expression profiling after PD-1 blockade in non–small cell lung carcinoma, head and neck squamous cell carcinoma, and melanoma

Antibody targeting of the immune checkpoint receptor PD1 produces therapeutic activity in a variety of solid tumors, but most patients exhibit partial or complete resistance to treatment for reasons that are unclear. In this study, we evaluated tumor specimens from 65 patients with melanoma, lung nonsquamous, squamous cell lung or head and neck cancers who were treated with the approved PD1-targeting antibodies pembrolizumab or nivolumab. Tumor RNA before anti-PD1 therapy was analyzed on the nCounter system using the PanCancer 730-Immune Panel, and we identified 23 immune-related genes or signatures linked to response and progression-free survival (PFS). In addition, we evaluated intra- and interbiopsy variability of PD1, PD-L1, CD8A, and CD4 mRNAs and their relationship with tumor-infiltrating lymphocytes (TIL) and PD-L1 IHC expression. Among the biomarkers examined, PD1 gene expression along with 12 signatures tracking CD8 and CD4 T-cell activation, natural killer cells, and IFN activation associated significantly with nonprogressive disease and PFS. These associations were independent of sample timing, drug used, or cancer type. TIL correlated moderately (~0.50) with PD1 and CD8A mRNA levels and weakly (~0.35) with CD4 and PD-L1. IHC expression of PD-L1 correlated strongly with PD-L1 (0.90), moderately with CD4 and CD8A, and weakly with PD1. Reproducibility of gene expression in intra- and interbiopsy specimens was very high (total SD <3%). Overall, our results support the hypothesis that identification of a preexisting and stable adaptive immune response as defined by mRNA expression pattern is reproducible and sufficient to predict clinical outcome, regardless of the type of cancer or the PD1 therapeutic antibody administered to patients

Analysis of Tumor Microenvironment Changes after Neoadjuvant Chemotherapy with or without Bevacizumab in Advanced Ovarian Cancer (GEICO-89T/MINOVA Study)

The aim of our study was to elucidate the impact of bevacizumab added to neoadjuvant chemotherapy (NACT) on the tumor immune microenvironment and correlate the changes with the clinical outcome of the patients. IHC and multiplex immunofluorescence for lymphoid and myeloid lineage markers were performed in matched tumor samples from 23 patients with ovarian cancer enrolled in GEICO 1205/NOVA clinical study before NACT and at the time of interval cytoreductive surgery. Our results showed that the addition of bevacizumab to NACT plays a role mainly on lymphoid populations at the stromal compartment, detecting a significant decrease of CD4 + T cells, an increase of CD8 + T cells, and an upregulation in effector/regulatory cell ratio (CD8 + /CD4 + FOXP3 +). None of the changes observed were detected in the intra-epithelial site in any arm (NACT or NACT-bevacizumab). No differences were found in myeloid lineage (macrophage-like). The percentage of Treg populations and effector/regulatory cell ratio in the stroma were the only two variables significantly associated with progression-free survival (PFS). The addition of bevacizumab to NACT did not have an impact on PFS in the GEICO 1205 study. However, at the cellular level, changes in CD4 +, CD8 + lymphocyte populations, and CD8 + /CD4 + FOXP3 ratio have been detected only at the stromal site. On the basis of our results, we hypothesize about the existence of mechanisms of resistance that could prevent the trafficking of T-effector cells into the epithelial component of the tumor as a potential explanation for the lack of efficacy of ICI in the first-line treatment of advanced epithelial ovarian cancer