96 research outputs found
The role of growth in long term investment returns
Stocks with a high valuation compared to fundamental values imply a high growth rate, yet these stocks have typically under-performed in subsequent years supporting Lakonishok, Shleifer and Vishney's (1994) contrarian investment strategies. The precise definition of growth and subtle differences of measuring growth are explored in assessing the role of growth in long-term investment decisions and stock valuation. Results from a later period and with additional tests than employed by LSV indicate that growth is a primary valuation factor, and valuation measures such as E/P and B/M, are imperfect proxies for expected growth. Growth appears mean reverting, but investors do not seem able to discern changes in growth rates and this miss-specification of expected growth may help explain the superiority of value versus growth strategies. In addition, investors' naïve extrapolations of past growth provide explanatory power in future holding period returns
Stampidine prevents mortality in an experimental mouse model of viral hemorrhagic fever caused by lassa virus
BACKGROUND: The potential use of microorganisms as agents of biological warfare (BW) is a growing concern. Lassa virus, a member of the Arenavirus class of Hemorrhagic fever (HF) viruses has emerged as a worldwide concern among public health officials. The purpose of the present study was to further elucidate the antiviral activity spectrum of stampidine, a novel nucleoside analog with potent anti-viral activity against the immunodeficiency viruses HIV-1, HIV-2, and FIV, by examining its effects on survival of mice challenged with Lassa virus. METHODS: We examined the therapeutic effect of Stampidine in CBA mice inoculated with intracerebral injections of the Josiah strain of Lassa virus. Mice were treated either with vehicle or nontoxic doses of stampidine administered intraperitoneally 24 hours prior to, 1 hour prior to, and 24 hours, 48 hours, 72 hours, and 96 hours after virus inoculation. RESULTS: The probability of survival following the Lassa challenge was significantly improved for stampidine treated mice (Kaplan Meier, Chi-squared = 11.7, df = 2, Log-Rank p-value = 0.003). CONCLUSION: Therefore, stampidine shows clinical potential as a new agent for treatment of viral hemorrhagic fevers caused by Lassa virus
Molecular Ecology and Natural History of Simian Foamy Virus Infection in Wild-Living Chimpanzees
Identifying microbial pathogens with zoonotic potential in wild-living primates can be important to human health, as evidenced by human immunodeficiency viruses types 1 and 2 (HIV-1 and HIV-2) and Ebola virus. Simian foamy viruses (SFVs) are ancient retroviruses that infect Old and New World monkeys and apes. Although not known to cause disease, these viruses are of public health interest because they have the potential to infect humans and thus provide a more general indication of zoonotic exposure risks. Surprisingly, no information exists concerning the prevalence, geographic distribution, and genetic diversity of SFVs in wild-living monkeys and apes. Here, we report the first comprehensive survey of SFVcpz infection in free-ranging chimpanzees (Pan troglodytes) using newly developed, fecal-based assays. Chimpanzee fecal samples (n = 724) were collected at 25 field sites throughout equatorial Africa and tested for SFVcpz-specific antibodies (n = 706) or viral nucleic acids (n = 392). SFVcpz infection was documented at all field sites, with prevalence rates ranging from 44% to 100%. In two habituated communities, adult chimpanzees had significantly higher SFVcpz infection rates than infants and juveniles, indicating predominantly horizontal rather than vertical transmission routes. Some chimpanzees were co-infected with simian immunodeficiency virus (SIVcpz); however, there was no evidence that SFVcpz and SIVcpz were epidemiologically linked. SFVcpz nucleic acids were recovered from 177 fecal samples, all of which contained SFVcpz RNA and not DNA. Phylogenetic analysis of partial gag (616 bp), pol-RT (717 bp), and pol-IN (425 bp) sequences identified a diverse group of viruses, which could be subdivided into four distinct SFVcpz lineages according to their chimpanzee subspecies of origin. Within these lineages, there was evidence of frequent superinfection and viral recombination. One chimpanzee was infected by a foamy virus from a Cercopithecus monkey species, indicating cross-species transmission of SFVs in the wild. These data indicate that SFVcpz (i) is widely distributed among all chimpanzee subspecies; (ii) is shed in fecal samples as viral RNA; (iii) is transmitted predominantly by horizontal routes; (iv) is prone to superinfection and recombination; (v) has co-evolved with its natural host; and (vi) represents a sensitive marker of population structure that may be useful for chimpanzee taxonomy and conservation strategies
Critical Loss of the Balance between Th17 and T Regulatory Cell Populations in Pathogenic SIV Infection
Chronic immune activation and progression to AIDS are observed after SIV infection in macaques but not in natural host primate species. To better understand this dichotomy, we compared acute pathogenic SIV infection in pigtailed macaques (PTs) to non-pathogenic infection in African green monkeys (AGMs). SIVagm-infected PTs, but not SIVagm-infected AGMs, rapidly developed systemic immune activation, marked and selective depletion of IL-17-secreting (Th17) cells, and loss of the balance between Th17 and T regulatory (Treg) cells in blood, lymphoid organs, and mucosal tissue. The loss of Th17 cells was found to be predictive of systemic and sustained T cell activation. Collectively, these data indicate that loss of the Th17 to Treg balance is related to SIV disease progression
Managing hyperemesis gravidarum: a multimodal challenge
Up to 90% of pregnant women experience nausea and vomiting. When prolonged or severe, this is known as hyperemesis gravidarum (HG), which can, in individual cases, be life threatening. In this article the aetiology, diagnosis and treatment strategies will be presented based on a selective literature review. Treatment strategies range from outpatient dietary advice and antiemetic drugs to hospitalization and intravenous (IV) fluid replacement in persistent or severe cases. Alternative methods, such as acupuncture, are not yet evidence based but sometimes have a therapeutic effect
Defining the critical hurdles in cancer immunotherapy
Scientific discoveries that provide strong evidence of antitumor effects in preclinical models often encounter significant delays before being tested in patients with cancer. While some of these delays have a scientific basis, others do not. We need to do better. Innovative strategies need to move into early stage clinical trials as quickly as it is safe, and if successful, these therapies should efficiently obtain regulatory approval and widespread clinical application. In late 2009 and 2010 the Society for Immunotherapy of Cancer (SITC), convened an "Immunotherapy Summit" with representatives from immunotherapy organizations representing Europe, Japan, China and North America to discuss collaborations to improve development and delivery of cancer immunotherapy. One of the concepts raised by SITC and defined as critical by all parties was the need to identify hurdles that impede effective translation of cancer immunotherapy. With consensus on these hurdles, international working groups could be developed to make recommendations vetted by the participating organizations. These recommendations could then be considered by regulatory bodies, governmental and private funding agencies, pharmaceutical companies and academic institutions to facilitate changes necessary to accelerate clinical translation of novel immune-based cancer therapies. The critical hurdles identified by representatives of the collaborating organizations, now organized as the World Immunotherapy Council, are presented and discussed in this report. Some of the identified hurdles impede all investigators; others hinder investigators only in certain regions or institutions or are more relevant to specific types of immunotherapy or first-in-humans studies. Each of these hurdles can significantly delay clinical translation of promising advances in immunotherapy yet if overcome, have the potential to improve outcomes of patients with cancer
Coma hipopotasémico: a propósito de un caso
Introduction: coma is the extreme degradation of consciousness. A syndrome characterized by a loss of vegetative functions, as an expression of acute and severe brain dysfunction.Presentation of the case: a 65-year-old male patient who two years ago commenced showing signs of loss of consciousness for two days In inter-crisis periods the studies did not confirm positive results. He was brought to the emergency room in a state of hyporeflexic coma. All parameters were normal except for a very discrete metabolic alkalosis and severe hypokalemia with 1,3 millimoles of potassium. General measures and complementary examinations were performed. Potassium values were replenished. As the potassium values standardized, a process of consciousness recovery was initiated. It was interpreted as a hypokalemic coma.Conclusions: hypopotassemia is a common imbalance, with repercussions in the different systems; this imbalance can result in alterations of the cardiovascular dynamics, progressive muscle weakness and coma. Therefore, in case of symptoms similar to hypokalemia, it is required to work on its diagnosis and treatment.Introducción: El coma es la máxima degradación del estado de conciencia. Síndrome caracterizado por una pérdida de las funciones de la vida de relación y conservación de las de la vida vegetativa, como expresión de una disfunción cerebral aguda y grave.Presentación del caso: paciente masculino de 65 años de edad que hace dos años comenzó con cuadros de pérdida de conciencia por espacio de dos días. En períodos intercrisis los estudios no arrojaron resultados positivos. Es traído a servicio de urgencia en estado de coma hiporrefléctico. Se tomaron medidas generales y se realizaron complementarios. Todo en parámetros de normalidad excepto por una muy discreta alcalosis metabólica y una hipocaliemia severa con 1,3 mili moles de potasio. Se reponen valores de potasio. En la medida que los valores de potasio se recuperaban se iniciaba un proceso de recuperación de la conciencia. Se interpreta como un coma hipopotasémico.Conclusiones: la hipopotasemia es un desbalance común, con repercusiones en los diferentes sistemas, que puede causar desde alteraciones de la dinámica cardiovascular, debilidad muscular progresiva y coma. De ahí que ante sintomatologías similares a una hipopotasemia se deba trabajar en su diagnóstico y tratamiento.
Robot-Assisted Paravertebral Schwannoma Resection
Robot-assisted thoracic surgery is at the forefront of minimally invasive approaches for resection of various intrathoracic benign and malignant tumors. The robotic approach is particularly suitable for solitary paravertebral schwannomas along the thoracic spine, lacking an intraspinal component, that are typically treated with complete resection and carry an excellent prognosis. Here, robotic platforms have established themselves as safe, reliable, and reproducible tools in expanding the surgeon’s reach in complex tumor resections and enable junior surgeons to overcome the learning curve quicker without compromising oncologic principles or patient safety. This chapter appraises the existing literature and provides an in-depth review of the technical aspects of robot-assisted paravertebral schwannoma resection
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