Primary aortoenteric fistula: a rare cause of gastrointestinal bleeding in young adults

Aortoenteric fistula is defined as a communication between the native aorta and any portion of the gastrointestinal tract. Depending on previous aortic grafting it can be classified as primary, without previous grafting, or secondary. Primary aortoenteric fistula is less frequent and usually arises from an abdominal aortic aneurysm. Clinical presentation is usually gastrointestinal bleeding. The main diagnostic procedures are gastroscopy and computed tomography. We report the case of a 46-year-old man who presented to the emergency room with gastrointestinal bleeding and an abdominal pulsatile mass. Although complementary tests and clinical signs suggested a diagnosis of primary aortoenteric fistula, the communication was not observed on gastroscopy and was confirmed by exploratory laparotomy. Despite aggressive surgical treatment, the prognosis of this entity is poor.     

Cell Phone Internet Access,Online Sexual Solicitation,Partner Seeking,and Sexual Risk Behavior Among Adolescents

Archives of Sexual Behavior - Online partner seeking is associated with sexual risk behavior among young adults (specifically men who have sex with men), but this association has yet to be explored...     

Cyberbullying Perpetration and Victimization Among Middle-School Students

Objectives. We examined correlations between gender, race, sexual identity, and technology use, and patterns of cyberbullying experiences and behaviors among middle-school students.Methods. We collected a probability sample of 1285 students alongside the 2012 Youth Risk Behavior Survey in Los Angeles Unified School District middle schools. We used logistic regressions to assess the correlates of being a cyberbully perpetrator, victim, and perpetrator–victim (i.e., bidirectional cyberbullying behavior).Results. In this sample, 6.6% reported being a cyberbully victim, 5.0% reported being a perpetrator, and 4.3% reported being a perpetrator–victim. Cyberbullying behavior frequently occurred on Facebook or via text messaging. Cyberbully perpetrators, victims, and perpetrators–victims all were more likely to report using the Internet for at least 3 hours per day. Sexual-minority students and students who texted at least 50 times per day were more likely to report cyberbullying victimization. Girls were more likely to report being perpetrators–victims.Conclusions. Cyberbullying interventions should account for gender and sexual identity, as well as the possible benefits of educational interventions for intensive Internet users and frequent texters.Cyberbullying is the “willful and repeated harm inflicted [on another] through the use of computers, cell phones, or other electronic devices.”1^(p5) Among 6th- through 10th-grade students nationally, 4% reported being cyberbullying perpetrators, 5% reported being a victim of cyberbullying, and 5% reported being perpetrators–victims (meaning that they have both perpetrated and been victimized by cyberbullying) during the previous 2 months.2 Among middle-school students in the southeastern and northwestern United States, a nonprobability sample of 3767 students by Kowalski and Limber3 found that 11% reported being a victim of cyberbullying, 4% were cyberbullying perpetrators, and 7% were perpetrators–victims during the previous 2 months. Cyberbullying may be more insidious than traditional bullying, because cyberbullying can quickly reach wide audiences (e.g., e-mails sent to an entire school), can be perpetrated anonymously, and is not bound to in-person interactions.4,5 Although cyberbullying has garnered widespread media attention, to our knowledge, no previous study has explored correlates of cyberbullying with a representative probability sample in an urban middle-school sample.Cyberbullying is associated with a host of health and behavioral health consequences. Research has suggested that cyberbullying may have a greater effect on depression and suicidal ideation than traditional offline bullying.6 Both perpetration and victimization are associated with mental health consequences, including lower self-esteem,7 recent depressive symptoms,5,8,9 and suicidal ideation.5,8,10 Cyberbullying perpetrators are more likely to have problems with their behavior, peer relationships, and emotions, and are less likely to be prosocial than their peers who are neither cyberbullying perpetrators nor victims of cyberbullying.11 Specifically, female cyberbullying perpetrators express greater anxiety and depression than their female peers who are not cyberbullying perpetrators.12 Cyberbullying victimization is also strongly associated with substance use, violent behavior, and risky sexual behavior among high-school students.10Cyberbullying disproportionately affects youths who are already vulnerable to mental health and behavioral health disparities, including members of sexual minorities (i.e., gay, lesbian, bisexual), girls, and racial and ethnic minorities. More than half of sexual-minority middle- and high-school students nationally report being a cyberbully victim during the previous year, with almost one fifth reporting often or frequent victimization.13 Female students are significantly more likely to be cyberbully perpetrators–victims than their male peers.9,14 Studies have reported that male students are significantly more likely to be cyberbullying perpetrators2,15 and significantly less likely to be cyberbully victims.2,6,9 Middle-school boys are more likely to cyberbully others because of their race, sexual identity, or both.16 African American students are more likely to be cyberbully perpetrators and Hispanic students are more likely to be cyberbully perpetrators–victims than their White peers.2Cyberbullying may occur across a variety of technology platforms, and the specific qualities of each platform may affect how cyberbullying is perpetrated and experienced. Earlier studies suggested that instant messaging, chat rooms, and message boards were the most common mediums for middle-school students who experienced cyberbullying.3,17 More recently, youths have migrated to social media platforms such as Facebook,18–20 necessitating an examination of cyberbullying across more contemporary and emerging platforms for youth interaction.More frequent use of technology has also been associated with cyberbullying. Students who use the Internet for at least 3 hours per day and those who use instant messaging and Web cams are significantly more likely to have been cyberbully victims at least 7 times during the previous year.17 Frequent Internet users are significantly more likely to be cyberbully perpetrators, victims, and perpetrators–victims.14Research has shown that even though cyberbullying takes place in a virtual space, most cyberbullying perpetrators know their victims and vice versa. Moreover, 73% of victims reported being “pretty sure” or “totally sure” about the identity of their cyberbully, with 51% of cyberbullying perpetrators identified as a classmate, 43% as someone who they only knew online, and 20% as an in-person, nonclassmate relation.17 Cyberbullying perpetrators of middle-school victims were most often a classmate or a stranger; cyberbullying perpetrators most often reported that they cyberbullied classmates, friends, and strangers.3This study expanded previous work with high-school samples2 and nonprobability samples of middle-school students3,17 to explore the role of sexual identity, gender, race, and technology use patterns in a random sample of urban middle-school students in Los Angeles County, California. The study focused on demographic characteristics including sexual identity, patterns of technology use (i.e., frequency of Internet use, texting, parental rules regarding Internet use), and platforms on which middle-school students experience cyberbullying (i.e., Facebook, Twitter, e-mail, text messaging) to inform interventions to disrupt this maladaptive behavior and help protect early adolescents from the consequences of cyberbullying.     

Early chronic lead exposure reduces exploratory activity in young C57BL/6J mice

Research has suggested that chronic low‐level lead exposure diminishes neurocognitive function in children. Tests that are sensitive to behavioral effects at lowest levels of lead exposure are needed for the development of animal models. In this study we investigated the effects of chronic low‐level lead exposure on exploratory activity (unbaited nose poke task), exploratory ambulation (open field task) and motor coordination (Rotarod task) in pre‐adolescent mice. C57BL/6J pups were exposed to 0 ppm (controls), 30 ppm (low‐dose) or 230 ppm (high‐dose) lead acetate via dams’ drinking water administered from birth to postnatal day 28, to achieve a range of blood lead levels (BLLs) from not detectable to 14.84 µg dl^–1). At postnatal day 28, mice completed behavioral testing and were killed (n = 61). BLLs were determined by inductively coupled plasma mass spectrometry. The effects of lead exposure on behavior were tested using generalized linear mixed model analyses with BLL, sex and the interaction as fixed effects, and litter as the random effect. BLL predicted decreased exploratory activity and no threshold of effect was apparent. As BLL increased, nose pokes decreased. The C57BL/6J mouse is a useful model for examining effects of early chronic low‐level lead exposure on behavior. In the C57BL/6J mouse, the unbaited nose poke task is sensitive to the effects of early chronic low‐level lead exposure. This is the first animal study to show behavioral effects in pre‐adolescent lead‐exposed mice with BLL below 5 µg dl^–1. Copyright © 2014 John Wiley & Sons, Ltd.     

MT1-MMP collagenolytic activity is regulated through association with tetraspanin CD151 in primary endothelial cells

MT1-MMP plays a key role in endothelial function, as underscored by the angiogenic defects found in MT1-MMP deficient mice. We have studied the molecular interactions that underlie the functional regulation of MT1-MMP. At lateral endothelial cell junctions, MT1-MMP colocalizes with tetraspanin CD151 (Tspan 24) and its associated partner alpha3beta1 integrin. Biochemical and FRET analyses show that MT1-MMP, through its hemopexin domain, associates tightly with CD151, thus forming alpha3beta1 integrin/CD151/MT1-MMP ternary complexes. siRNA knockdown of HUVEC CD151 expression enhanced MT1-MMP-mediated activation of MMP2, and the same activation was seen in ex vivo lung endothelial cells isolated from CD151-deficient mice. However, analysis of collagen degradation in these experimental models revealed a diminished MT1-MMP enzymatic activity in confined areas around the cell periphery. CD151 knockdown affected both MT1-MMP subcellular localization and its inclusion into detergent-resistant membrane domains, and prevented biochemical association of the metalloproteinase with the integrin alpha3beta1. These data provide evidence for a novel regulatory role of tetraspanin microdomains on the collagenolytic activity of MT1-MMP and indicate that CD151 is a key regulator of MT1-MMP in endothelial homeostasis.     

Coinfection of other respiratory pathogens and HIV in COVID‐19 patients: Is there a pattern?

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS‐Cov‐2) has led to the elaboration of multiple studies to increase knowledge and understanding, hence, having the ability to accomplish an adequate and timely diagnosis and give an optimal treatment according to the patient's condition. The clinical manifestations of COVID‐19 pose a series of challenges both in understanding and delimiting the disease secondary to the SARS‐CoV‐2 infection. This is due to the fact that the main axis of this disease is the endothelial compromise and the production of a “cytokine storm,” triggering multiple organ failure and death. Given that a complete understanding of its pathophysiology and clinical behavior has not yet been achieved, we wondered if coinfection with other respiratory viruses modifies its performance and outcomes described so far. A literature search was performed, obtaining 68 articles, of which 25 were analyzed. The analysis showed us that there is a high variety both in the types of associated infections and in the clinical behavior of patients and their outcomes. Therefore, we consider that the search for other infections should be performed exhaustively, especially in those cases that may be susceptible to treatment such as Influenza A, human immunodeficiency virus, or bacterial infections. As well as optimize the analysis of these cases and establish if there are characteristics that allow establishing the possibility of carrying an additional infection to that of SARS‐CoV‐2 and the implications for the management and prognosis of the patient.     

COVID-19 in the Context of Inborn Errors of Immunity: a Case Series of 31 Patients from Mexico

Journal of Clinical Immunology - Patients with inborn errors of immunity (IEI) have a compromised or inappropriate immune response. Although they might be considered a high-risk group for severe...