25 research outputs found

    Analytic philosophy for biomedical research: the imperative of applying yesterday's timeless messages to today's impasses

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    The mantra that "the best way to predict the future is to invent it" (attributed to the computer scientist Alan Kay) exemplifies some of the expectations from the technical and innovative sides of biomedical research at present. However, for technical advancements to make real impacts both on patient health and genuine scientific understanding, quite a number of lingering challenges facing the entire spectrum from protein biology all the way to randomized controlled trials should start to be overcome. The proposal in this chapter is that philosophy is essential in this process. By reviewing select examples from the history of science and philosophy, disciplines which were indistinguishable until the mid-nineteenth century, I argue that progress toward the many impasses in biomedicine can be achieved by emphasizing theoretical work (in the true sense of the word 'theory') as a vital foundation for experimental biology. Furthermore, a philosophical biology program that could provide a framework for theoretical investigations is outlined

    Determinants of access to experimental antiretroviral drugs in an Italian cohort of patients with HIV: a multilevel analysis

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    <p>Abstract</p> <p>Background</p> <p>Identification of the determinants of access to investigational drugs is important to promote equity and scientific validity in clinical research. We aimed to analyze factors associated with the use of experimental antiretrovirals in Italy.</p> <p>Methods</p> <p>We studied participants in the Italian Cohort of Antiretroviral-Naive Patients (ICoNA). All patients 18 years or older who had started cART (≥ 3 drugs including at least two NRTI) after their enrolment and during 1997-2007 were included in this analysis. We performed a random effect logistic regression analysis to take into account clustering observations within clinical units. The outcome variable was the use of an experimental antiretroviral, defined as an antiretroviral started before commercial availability, in any episode of therapy initiation/change. Use of an experimental antiretroviral obtained through a clinical trial or an expanded access program (EAP) was also analyzed separately.</p> <p>Results</p> <p>A total of 9,441 episodes of therapy initiation/change were analyzed in 3,752 patients. 392 episodes (360 patients) involved an experimental antiretroviral. In multivariable analysis, factors associated with the overall use of experimental antiretrovirals were: number of experienced drugs (≥ 8 drugs versus "naive": adjusted odds ratio [AOR] = 3.71) or failed antiretrovirals(3-4 drugs and ≥ 5 drugs versus 0-2 drugs: AOR = 1.42 and 2.38 respectively); calendar year (AOR = 0.80 per year) and plasma HIV-RNA copies/ml at therapy change (≥ 4 log versus < 2 log: AOR = 1.55). The probability of taking an experimental antiretroviral through a trial was significantly lower for patients suffering from liver co-morbidity(AOR = 0.65) and for those who experienced 3-4 drugs (vs naive) (AOR = 0.55), while it increased for multi-treated patients(AOR = 2.60). The probability to start an experimental antiretroviral trough an EAP progressively increased with the increasing number of experienced and of failed drugs and also increased for patients with liver co-morbidity (AOR = 1.44; p = 0.053). and for male homosexuals (vs heterosexuals: AOR = 1.67). Variability of the random effect associated to clinical units was statistically significant (p < 0.001) although no association was found with specific characteristics of clinical unit examined.</p> <p>Conclusions</p> <p>Among patients with HIV infection in Italy, access to experimental antiretrovirals seems to be influenced mainly by exhaustion of treatment options and not by socio-demographic factors.</p

    MANAGEMENT OF CONFLICTS BETWEEN URBAN COYOTES AND HUMANS IN SOUTHERN CALIFORNIA

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    An apparent increase in coyote-human conflicts, notably attacks on humans, demonstrates that such incidents are not rare in California. The authors discuss coyote attacks on 53 humans, resulting in 21 instances of human injury, over the last decade. These illustrate repeated, predictable pre-attack coyote behavior patterns. Specific changes in human environments and in human behavior that have contributed to coyote attacks are discussed. Case histories of attacks reveal contributing factors and suggest appropriate corrective and preventive actions. Padded leghold traps have been the most effective and efficient tool in removing problem coyotes and changing the behavior of coyotes to fear humans and the urban environment. Long-term solutions will require changes in human behavior. Humans must come to view large mammalian predators as a potential hazard. Increased public education is needed to improve methods of landscape management, refuse disposal, care of pets, and recognition of the need for predator management

    Predictors of trend in CD4-positive T-cell count and mortality among HIV-1-infected individuals with virological failure to all three antiretroviral-drug classes.

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    Background Treatment strategies for patients in whom HIV replication is not suppressed after exposure to several drug classes remain unclear. We aimed to assess the inter-relations between viral load, CD4-cell count, and clinical outcome in patients who had experienced three-class virological failure.Methods We undertook collaborative joint analysis of 13 HIV cohorts from Europe, North America, and Australia, involving patients who had had three-class virological failure (viral load >1000 copies per mL for >4 months). Regression analyses were used to quantify the associations between CD4-cell-count slope, HIV-1 RNA concentration, treatment information, and demographic characteristics. Predictors of death were analysed by Cox\u2019s proportional-hazards models.Findings 2488 patients were included. 2118 (85%) had started antiretroviral therapy with single or dual therapy. During 5015 person-years of follow-up, 276 patients died (mortality rate 5\ub75 per 100 person-years; 3-year mortality risk 15\ub73% (95% CI 13\ub75\u201317\ub73). Risk of death was strongly influenced by the latest CD4-cell count with a relative hazard of 15\ub78 (95% CI 9\ub728\u201327\ub70) for counts below 50 cells per \u3bcL versus above 200 cells per L. The latest viral load did not independently predict death. For any given viral load, patients on treatment had more favourable CD4- cell-count slopes than those off treatment. For patients on treatment and with stable viral load, CD4-cell counts tended to be increasing at times when the current viral load was below 10 000 copies per mL or 1\ub75 log10 copies per mL below off-treatment values.Interpretation In patients for whom viral-load suppression to below the level of detection is not possible, achievement and maintenance of a CD4-cell count above 200 per L becomes the primary aim. Treatment regimens that maintain the viral load below 10 000 copies per mL or at least provide 1\ub75 log10 copies per mL suppression below the off-treatment value do not seem to be associated with appreciable CD4-cell-count decline

    Efficacy, tolerability and risk factors for virological failure of darunavir-based therapy for treatment-experienced HIV-infected patients: the Swiss HIV Cohort Study

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    OBJECTIVES: Darunavir was designed for activity against HIV resistant to other protease inhibitors (PIs). We assessed the efficacy, tolerability and risk factors for virological failure of darunavir for treatment-experienced patients seen in clinical practice. METHODS: We included all patients in the Swiss HIV Cohort Study starting darunavir after recording a viral load above 1000 HIV-1 RNA copies/mL given prior exposure to both PIs and nonnucleoside reverse transcriptase inhibitors. We followed these patients for up to 72 weeks, assessed virological failure using different loss of virological response algorithms and evaluated risk factors for virological failure using a Bayesian method to fit discrete Cox proportional hazard models. RESULTS: Among 130 treatment-experienced patients starting darunavir, the median age was 47 years, the median duration of HIV infection was 16 years, and 82% received mono or dual antiretroviral therapy before starting highly active antiretroviral therapy. During a median patient follow-up period of 45 weeks, 17% of patients stopped taking darunavir after a median exposure of 20 weeks. In patients followed beyond 48 weeks, the rate of virological failure at 48 weeks was at most 20%. Virological failure was more likely where patients had previously failed on both amprenavir and saquinavir and as the number of previously failed PI regimens increased. CONCLUSIONS: As a component of therapy for treatment-experienced patients, darunavir can achieve a similar efficacy and tolerability in clinical practice to that seen in clinical trials. Clinicians should consider whether a patient has failed on both amprenavir and saquinavir and the number of failed PI regimens before prescribing darunavir
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