Blood flow diverts extracellular vesicles from endothelial degradative compartments to promote angiogenesis

Extracellular vesicles released by tumors (tEVs) disseminate via circulatory networks and promote microenvironmental changes in distant organs favoring metastatic seeding. Despite their abundance in the bloodstream, how hemodynamics affect the function of circulating tEVs remains unsolved. We demonstrated that efficient uptake of tEVs occurs in venous endothelial cells that are subjected to hemodynamics. Low flow regimes observed in veins partially reroute internalized tEVs toward non-acidic and non-degradative Rab14-positive endosomes, at the expense of lysosomes, suggesting that endothelial mechanosensing diverts tEVs from degradation. Subsequently, tEVs promote the expression of pro-angiogenic transcription factors in low flow-stimulated endothelial cells and favor vessel sprouting in zebrafish. Altogether, we demonstrate that low flow regimes potentiate the pro-tumoral function of circulating tEVs by promoting their uptake and rerouting their trafficking. We propose that tEVs contribute to pre-metastatic niche formation by exploiting endothelial mechanosensing in specific vascular regions with permissive hemodynamics.

Exploitation Techniques for Data-oriented Attacks with Existing and Potential Defense Approaches

Data-oriented attacks manipulate non-control data to alter a program’s benign behavior without violating its control-flow integrity. It has been shown that such attacks can cause significant damage even in the presence of control-flow defense mechanisms. However, these threats have not been adequately addressed. In this survey article, we first map data-oriented exploits, including Data-Oriented Programming (DOP) and Block-Oriented Programming (BOP) attacks, to their assumptions/requirements and attack capabilities. Then, we compare known defenses against these attacks, in terms of approach, detection capabilities, overhead, and compatibility. It is generally believed that control flows may not be useful for data-oriented security. However, data-oriented attacks (especially DOP attacks) may generate side effects on control-flow behaviors in multiple dimensions (i.e., incompatible branch behaviors and frequency anomalies). We also characterize control-flow anomalies caused by data-oriented attacks. In the end, we discuss challenges for building deployable data-oriented defenses and open research questions.

Tumor extracellular vesicles drive metastasis (it's a long way from home)

Among a plethora of functions, extracellular vesicles released by primary tumors spread in the organism and reach distant organs where they can induce the formation of a premetastatic niche. This constitutes a favorable microenvironment for circulating tumor cells which facilitates their seeding and colonization. In this review, we describe the journey of extracellular vesicles (EVs) from the primary tumor to the future metastatic organ, with a focus on the mechanisms used by EVs to target organs with a specific tropism (i.e., organotropism). We then highlight important tumor EV cargos in the context of premetastatic niche formation and summarize their known effects on extracellular matrix remodeling, angiogenesis, vessel permeabilization, resident cell activation, recruitment of foreign cells, and ultimately the formation of a pro-inflammatory and immuno-tolerant microenvironment. Finally, we discuss current experimental limitations and remaining opened questions in light of metastatic diagnosis and potential therapies targeting PMN formation.

Impairing flow-mediated endothelial remodeling reduces extravasation of tumor cells

Tumor progression and metastatic dissemination are driven by cell-intrinsic and biomechanical cues that favor the growth of life-threatening secondary tumors. We recently identified pro-metastatic vascular regions with blood flow profiles that are permissive for the arrest of circulating tumor cells. We have further established that such flow profiles also control endothelial remodeling, which favors extravasation of arrested CTCs. Yet, how shear forces control endothelial remodeling is unknown. In the present work, we aimed at dissecting the cellular and molecular mechanisms driving blood flow-dependent endothelial remodeling. Transcriptomic analysis of endothelial cells revealed that blood flow enhanced VEGFR signaling, among others. Using a combination of in vitro microfluidics and intravital imaging in zebrafish embryos, we now demonstrate that the early flow-driven endothelial response can be prevented upon specific inhibition of VEGFR tyrosine kinase and subsequent signaling. Inhibitory targeting of VEGFRs reduced endothelial remodeling and subsequent metastatic extravasation. These results confirm the importance of VEGFR-dependent endothelial remodeling as a driving force of CTC extravasation and metastatic dissemination. Furthermore, the present work suggests that therapies targeting endothelial remodeling might be a relevant clinical strategy in order to impede metastatic progression.

Ral GTPases promote breast cancer metastasis by controlling biogenesis and organ targeting of exosomes

Cancer extracellular vesicles (EVs) shuttle at distance and fertilize pre-metastatic niches facilitating subsequent seeding by tumor cells. However, the link between EV secretion mechanisms and their capacity to form pre-metastatic niches remains obscure. Using mouse models, we show that GTPases of the Ral family control, through the phospholipase D1, multi-vesicular bodies homeostasis and tune the biogenesis and secretion of pro-metastatic EVs. Importantly, EVs from RalA or RalB depleted cells have limited organotropic capacities in vivoand are less efficient in promoting metastasis. RalA and RalB reduce the EV levels of the adhesion molecule MCAM/CD146, which favors EV-mediated metastasis by allowing EVs targeting to the lungs. Finally, RalA, RalB, and MCAM/CD146, are factors of poor prognosis in breast cancer patients. Altogether, our study identifies RalGTPases as central molecules linking the mechanisms of EVs secretion and cargo loading to their capacity to disseminate and induce pre-metastatic niches in a CD146-dependent manner.

Preclinical evaluation of platinum-loaded hydroxyapatite nanoparticles in an embryonic zebrafish xenograft model

Hydroxyapatite (HA) nanoparticles are commonly used as building blocks in the design of bone-substituting biomaterials. Recently, these nanoparticles have been considered for the treatment of metastasis disease, since their pH-dependent dissolution behavior allows for precise tuning of release kinetics of loaded cargo. Herein we show that the capacity of drug-loaded nanoparticles stabilized with citrate ions reduce cancer cell survival in an embryonic zebrafish xenograft model. In particular, in vitro studies demonstrate that PtPP-loaded HA nanoparticles exhibit anti-proliferative activity against breast cancer cells at reduced pH. In vivo studies using an embryonic zebrafish xenograft model reveal that PtPP co-delivered with human breast cancer cells strongly reduce cancer cell survival. Similarly, co-injection of breast cancer cells with citrate-functionalized and PtPP-loaded HA nanoparticles into zebrafish significantly reduces survival of cancer cells due to release of chemotherapeutically active kiteplatin species. These results demonstrate the preclinical efficacy of drug-loaded nanoparticles against human breast cancer cells in a xenogenic embryonic in vivo model.

Neurogenesis in the inner ear: the zebrafish statoacoustic ganglion provides new neurons from a Neurod/Nestin-positive progenitor pool well into adulthood

The vertebrate inner ear employs sensory hair cells and neurons to mediate hearing and balance. In mammals, damaged hair cells and neurons are not regenerated. In contrast, hair cells in the inner ear of zebrafish are produced throughout life and regenerate after trauma. However, it is unknown whether new sensory neurons are also formed in the adult zebrafish statoacoustic ganglion (SAG), the sensory ganglion connecting the inner ear to the brain. Using transgenic lines and marker analysis, we identify distinct cell populations and anatomical landmarks in the juvenile and adult SAG. In particular, we analyze a Neurod/Nestin-positive progenitor pool that produces large amounts of new neurons at juvenile stages, which transitions to a quiescent state in the adult SAG. Moreover, BrdU pulse chase experiments reveal the existence of a proliferative but otherwise marker-negative cell population that replenishes the Neurod/Nestin-positive progenitor pool at adult stages. Taken together, our study represents the first comprehensive characterization of the adult zebrafish SAG showing that zebrafish, in sharp contrast to mammals, display continued neurogenesis in the SAG well beyond embryonic and larval stages.

Bowenoid papulosis unveiling a rare cause of immunosuppression

Bowenoid papulosis (BP) is a premalignant condition usually caused by oncogenic types of human papillomavirus (HPV) presenting clinically as warty genital papules. Adult T-cell leukaemia-lymphoma (ATLL) is a peripheral T-cell leukaemia-lymphoma caused by the retrovirus, human T-cell lymphotropic virus 1 (HTLV-1). We report a case of BP initially mistaken as genital warts; on detailed evaluation the patient had features of chronic immunosuppression. The presence of leukaemic cells in the peripheral blood, bone marrow and skin along with a positive HTLV-1 serology confirmed the diagnosis of ATLL.

Private Set Intersection for Unequal Set Sizes with Mobile Applications

Private set intersection (PSI) is a cryptographic technique that is applicable to many privacy-sensitive scenarios. For decades, researchers have been focusing on improving its efficiency in both communication and computation. However, most of the existing solutions are inefficient for an unequal number of inputs, which is common in conventional client-server settings. In this paper, we analyze and optimize the efficiency of existing PSI protocols to support precomputation so that they can efficiently deal with such input sets. We transform four existing PSI protocols into the precomputation form such that in the setup phase the communication is linear only in the size of the larger input set, while in the online phase the communication is linear in the size of the smaller input set. We implement all four protocols and run experiments between two PCs and between a PC and a smartphone and give a systematic comparison of their performance. Our experiments show that a protocol based on securely evaluating a garbled AES circuit achieves the fastest setup time by several orders of magnitudes, and the fastest online time in the PC setting where AES-NI acceleration is available. In the mobile setting, the fastest online time is achieved by a protocol based on the Diffie-Hellman assumption.

Cutaneous problems in elderly diabetics: A population-based comparative cross-sectional survey

BACKGROUND

There are few population-based studies on prevalence of cutaneous problems in diabetes mellitus.

AIMS

To identify skin problems associated with diabetes mellitus among elderly persons in a village in Kerala.

METHODS

In this population-based cross-sectional survey, we compared the prevalence of skin problems among 287 elderly diabetics (aged 65 years or more) with 275 randomly selected elderly persons without diabetes mellitus.

RESULTS

Numbness, tingling and burning sensation of extremities,"prayer sign", finger pebbling, skin tags, stiff joints and acanthosis nigricans were noted more frequently in diabetics as compared to non-diabetics. Ache in extremities, dermatophytosis, candidiasis, seborrheic keratoses/dermatosis papulosa nigra, xerosis/ichthyosis, idiopathic guttate hypomelanosis, nonspecific itching, and eczema were equally frequent in both groups. Among the diagnostic categories, neurovascular, metabolic and autoimmune findings were associated with diabetes mellitus, whereas bacterial and fungal infections were not.

LIMITATIONS

Initial misclassification errors, no laboratory confirmation of dermatological diagnosis during survey, coexistence of findings related to aging and not analyzing the effects of glycemic level, concurrent diseases and medications.

CONCLUSIONS

Numbness, tingling and burning sensation of extremities, prayer sign, finger pebbling, skin tags, stiff joints and acanthosis nigricans were associated with diabetes mellitus among elderly persons in a village in Kerala.

Severity of Psoriasis Among Adult Males is Associated with Smoking, Not with Alcohol Use

Context:

Lifestyle factors such as tobacco smoking and alcohol use can affect the presentation and course of psoriasis. There is a paucity of data on this subject from India.

Aims:

To find out whether increased severity of psoriasis in adult Indian males is associated with tobacco smoking and alcohol use.

Settings and Design:

Cross-sectional study in the Department of Dermatology of a Tertiary Care Teaching Hospital.

Subjects and Methods:

Male patients above 18 years of age attending a psoriasis clinic between March 2007 and May 2009 were studied. Severity of psoriasis (measured using Psoriasis Area and Severity Index – PASI) among smokers and non-smokers was compared. We also studied the correlation between severity of psoriasis and nicotine dependence (measured using Fagerström Test for Nicotine Dependence) and alcohol use disorders (measured using Alcohol Use Disorders Identification Test–AUDIT).

Statistical Analysis:

Z-test, Odd's ratio, Chi-square test, Spearman's correlation coefficient.

Results:

Of a total of 338 patients, 148 were smokers and 173 used to consume alcohol. Mean PASI score of smokers was more than that of non-smokers (Z-test, z = −2.617, P = 0.009). Those with severe psoriasis were more likely to be smokers (χ² = 5.47, P = 0.02, OR = 1.8, Confidence Interval 1.09-2.962). There was a significant correlation between PASI scores and Fagerström score (Spearman's correlation coefficient = 0.164, P < 0.01). Mean PASI scores of persons who used to consume alcohol and those who did not were comparable.(Z-test, z = −0.458, P = 0.647). There was no association between severity of psoriasis and alcohol consumption.(χ² = 0.255, P = 0.613, Odds Ratio = 1.14, CI 0.696-1.866). There was no correlation between PASI scores and AUDIT scores (Spearman's correlation coefficient = 0.024, P > 0.05).

Conclusions:

Increased severity of psoriasis among adult males is associated with tobacco smoking, but not with alcohol use.

Unilateral generalized hypertrichosis in proteus syndrome

A young lady was found to have hemihypertrophy, scoliosis, subcutaneous swellings, patchy dermal hypoplasia, plantar hyperplasia and macrodactyly. These suggested a diagnosis of Proteus syndrome. She was also having unilateral generalized hypertrichosis. The association of Proteus syndrome and unilateral generalized hypertrichosis has not been reported in the literature.

Nicotine delays arousal during hypoxemia in lambs

A decreased ability to arouse from sleep in response to arterial hypoxemia may lead to severe asphyxia and has been proposed as a mechanism of sudden infant death syndrome. Based on previous observations that nicotine exposure, a major environmental risk factor for sudden infant death syndrome, may impair hypoxic defense in neonates, we hypothesized that a short-term infusion of nicotine could impair hypoxic arousal through interference with oxygen-sensing mechanisms. Seven chronically instrumented unanesthetized lambs were studied at the age of 4.6 +/- 1.3 d during normoxia and acute hypoxia (0.1 fraction of inspired oxygen) for 5 min. Ventilation, transcutaneous Hb oxygen saturation, blood pressure, heart rate, and time to arousal were compared during a control saline infusion and during a 0.5 microg x kg(-1) x min(-1) nicotine infusion. Activity states, i.e. wakefulness and quiet sleep as well as arousal, were defined by EEG, nuchal electromyogram, and electrooculogram. Each lamb acted as its own control. Arousal from quiet sleep occurred significantly later during nicotine infusion compared with control (177 +/- 93 versus 57 +/- 41 s, p < 0.01) and at a lower transcutaneous Hb oxygen saturation (60 +/- 12 versus 79 +/- 12%, p < 0.01) (paired t test). The ventilatory response to hypoxia in wakefulness was similar during both conditions but was significantly attenuated in quiet sleep during nicotine infusion (p < 0.001, 2-way ANOVA repeated-measures design). Blood pressure and heart rate responses were similar during both conditions. These results suggest that a brief nicotine exposure blunts oxygen sensitivity in young lambs, a finding of potential relevance for sudden infant death syndrome.

Acrokeratosis paraneoplastica

A 60-year old man with squamous cell carcinoma of hypopharynx and acrokeratosis paraneoplastica (Bazex syndrome) is reported.