Publications by authors named "Mican J"

Cardiovascular diseases, such as myocardial infarction, ischemic stroke, and pulmonary embolism, are the most common causes of disability and death worldwide. Blood clot hydrolysis by thrombolytic enzymes and thrombectomy are key clinical interventions. The most widely used thrombolytic enzyme is alteplase, which has been used in clinical practice since 1986.

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TfCa, a promiscuous carboxylesterase from , was found to hydrolyze polyethylene terephthalate (PET) degradation intermediates such as bis(2-hydroxyethyl) terephthalate (BHET) and mono-(2-hydroxyethyl)-terephthalate (MHET). In this study, we elucidated the structures of TfCa in its apo form, as well as in complex with a PET monomer analogue and with BHET. The structure-function relationship of TfCa was investigated by comparing its hydrolytic activity on various ortho- and para-phthalate esters of different lengths.

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Stroke burden is substantially increasing but current therapeutic drugs are still far from ideal. Here we highlight the vast potential of staphylokinase as an efficient, fibrin-selective, inexpensive, and evolvable thrombolytic agent. The emphasis is escalated by new recent findings.

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Thermophilic polyester hydrolases (PES-H) have recently enabled biocatalytic recycling of the mass-produced synthetic polyester polyethylene terephthalate (PET), which has found widespread use in the packaging and textile industries. The growing demand for efficient PET hydrolases prompted us to solve high-resolution crystal structures of two metagenome-derived enzymes (PES-H1 and PES-H2) and notably also in complex with various PET substrate analogues. Structural analyses and computational modeling using molecular dynamics simulations provided an understanding of how product inhibition and multiple substrate binding modes influence key mechanistic steps of enzymatic PET hydrolysis.

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Cardio- and cerebrovascular diseases are leading causes of death and disability, resulting in one of the highest socio-economic burdens of any disease type. The discovery of bacterial and human plasminogen activators and their use as thrombolytic drugs have revolutionized treatment of these pathologies. Fibrin-specific agents have an advantage over non-specific factors because of lower rates of deleterious side effects.

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Polyethylene terephthalate (PET) is the most widespread synthetic polyester, having been utilized in textile fibers and packaging materials for beverages and food, contributing considerably to the global solid waste stream and environmental plastic pollution. While enzymatic PET recycling and upcycling have recently emerged as viable disposal methods for a circular plastic economy, only a handful of benchmark enzymes have been thoroughly described and subjected to protein engineering for improved properties over the last 16 years. By analyzing the specific material properties of PET and the reaction mechanisms in the context of interfacial biocatalysis, this Perspective identifies several limitations in current enzymatic PET degradation approaches.

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Resistance to anti-HIV drugs has been a problem from the beginning of antiviral drug treatments. The recent expansion of combination antiretroviral therapy worldwide has led to an increase in resistance to antiretrovirals; understanding the mechanisms of resistance is increasingly important. In this study, we analyzed reverse transcriptase (RT) variants based on sequences derived from an individual who had low-level rebound viremia while undergoing therapy with abacavir, azidothymidine (AZT) (zidovudine), and (-)-l-2',3'-dideoxy-3'-thiacytidine (3TC) (lamivudine).

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Despite recent advances in recanalization therapy, mechanical thrombectomy will never be a treatment for every ischemic stroke because access to mechanical thrombectomy is still limited in many countries. Moreover, many ischemic strokes are caused by occlusion of cerebral arteries that cannot be reached by intra-arterial catheters. Reperfusion using thrombolytic agents will therefore remain an important therapy for hyperacute ischemic stroke.

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In the modern drug discovery process, medicinal chemists deal with the complexity of analysis of large ensembles of candidate molecules. Computational tools, such as dimensionality reduction (DR) and classification, are commonly used to efficiently process the multidimensional space of features. These underlying calculations often hinder interpretability of results and prevent experts from assessing the impact of individual molecular features on the resulting representations.

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Introduction: Liberia has no rheumatology providers for the nation's 4.7 million people. We proposed a short course format rheumatology curriculum to educate Liberian providers as an initial step in providing graduate medical education in musculoskeletal health.

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Background: Patients living with human immunodeficiency virus (PLWH) with low CD4 counts are at high risk for immune reconstitution inflammatory syndrome (IRIS) and death at antiretroviral therapy (ART) initiation.

Methods: We investigated the clinical impact of IRIS in PLWH and CD4 counts <100 cells/μL starting ART in an international, prospective study in the United States, Thailand, and Kenya. An independent review committee adjudicated IRIS events.

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Myocardial infarction and ischemic stroke are the most frequent causes of death or disability worldwide. Due to their ability to dissolve blood clots, the thrombolytics are frequently used for their treatment. Improving the effectiveness of thrombolytics for clinical uses is of great interest.

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Corticosteroid use was associated with development of Kaposi's sarcoma or multicentric Castleman disease in 3 patients with mycobacterial immune reconstitution inflammatory syndrome (IRIS) treated with corticosteroids. Monitoring for development of Kaposi's sarcoma and alternative treatment may be beneficial for patients with IRIS, especially in the presence of preexisting co-infection with Kaposi's sarcoma-associated herpesvirus.

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Background: Immune reconstitution inflammatory syndrome (IRIS) represents an unexpected inflammatory response shortly after initiation of antiretroviral therapy (ART) in some human immunodeficiency virus (HIV)-infected patients with underlying neoplasia or opportunistic infections, including tuberculosis. We hypothesized that IRIS is associated with increased glycolysis and that 18F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) could help identify high-risk subjects.

Methods: In this prospective cohort study, 30 HIV-infected patients (CD4+ count <100 cells/µL) underwent FDG-PET/CT scans at baseline and 4-8 weeks after ART initiation.

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Idiopathic CD4 lymphopenia (ICL) is a rare syndrome defined by low CD4 T-cell counts (<300/µL) without evidence of HIV infection or other known cause of immunodeficiency. ICL confers an increased risk of opportunistic infections and has no established treatment. Interleukin-7 (IL-7) is fundamental for thymopoiesis, T-cell homeostasis, and survival of mature T cells, which provides a rationale for its potential use as an immunotherapeutic agent for ICL.

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Objective: Immune restoration disease (IRD) can develop in HIV-infected patients following antiretroviral therapy (ART) initiation as unmasking or paradoxical worsening of opportunistic infections and, rarely, autoimmune phenomena. Although IRD usually occurs in the first months of ART during memory CD4 T-cell recovery, Graves' disease occurs as a distinctive late-onset IRD and its pathogenesis is unclear.

Design: Seven patients who developed Graves' disease following ART initiation from the primary HIV care clinic at the National Institutes of Health were retrospectively identified and each was matched with two HIV-infected controls based on age, sex, and baseline CD4 T-cell count.

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HIV infection is characterized by rapid and error-prone viral replication resulting in genetically diverse virus populations. The rate of accumulation of diversity and the mechanisms involved are under intense study to provide useful information to understand immune evasion and the development of drug resistance. To characterize the development of viral diversity after infection, we carried out an in-depth analysis of single genome sequences of HIV pro-pol to assess diversity and divergence and to estimate replicating population sizes in a group of treatment-naive HIV-infected individuals sampled at single (n = 22) or multiple, longitudinal (n = 11) time points.

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Background/aims: Microalbuminuria is a marker for early kidney disease and cardiovascular risk. The purposes of this study were to determine the prevalence of microalbuminuria in an HIV-infected clinic population, to test the predictive value of a single urine albumin/creatinine ratio (ACR) to identify persistent microalbuminuria and to examine covariates of microalbuminuria.

Methods: We conducted a prospective cohort study of HIV-infected subjects (n = 182) without proteinuria (urine protein/creatinine ratio ≥0.

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Objective: HIV and type 2 diabetes are known risk factors for albuminuria, but no previous reports have characterized albuminuria in HIV-infected patients with diabetes.

Research Design And Methods: We performed a cross-sectional study including 73 HIV-infected adults with type 2 diabetes, 82 HIV-infected non-diabetics, and 61 diabetic control subjects without HIV. Serum creatinine >1.

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IL-7 is essential for T-cell homeostasis. Elevated serum IL-7 levels in lymphopenic states, including HIV infection, are thought to be due to increased production by homeostatic feedback, decreased receptor-mediated clearance, or both. The goal of this study was to understand how immune reconstitution through antiretroviral therapy (ART) in HIV(+) patients affects IL-7 serum levels, expression of the IL-7 receptor (CD127), and T-cell cycling.

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Objective: HIV infection is associated with coagulation abnormalities and significantly increased risk of venous thrombosis. It has been shown that higher plasma levels of coagulation and inflammatory biomarkers predicted mortality in HIV. We investigated the relationship between venous thrombosis and HIV-related characteristics, traditional risk factors of hypercoagulability, and pre-event levels of biomarkers.

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HIV infection occurs in disproportionately high rates among racial and ethnic minorities in the United States, making it imperative that individuals from these groups be included in research studies. However, it is often difficult to recruit HIV-infected Hispanics and African Americans in clinical trials, but a skilled interdisciplinary team that includes researchers with racial and ethnic diversity can help. This article describes a successful approach for building an interdisciplinary team that values the participation of racial and ethnic minorities in clinical trials and has the skills to work with these groups.

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Underrepresentation of HIV-infected Hispanics and African Americans in clinical trials seriously limits our understanding of the benefits and risks of treatment in these populations. This qualitative study examined factors that racial/ethnic minority patients consider when making decisions regarding research participation. A total of 35 HIV-infected Hispanic and African American patients enrolled in clinical research protocols at the National Institutes of Health were recruited to participate in focus groups and in-depth interviews.

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The HIV Resistance Response Database Initiative (RDI), which comprises a small research team in the United Kingdom and collaborating clinical centers in more than 15 countries, has used antiretroviral treatment and response data from thousands of patients around the world to develop computational models that are highly predictive of virologic response. The potential utility of such models as a tool for assisting treatment selection was assessed in two clinical pilot studies: a prospective study in Canada and Italy, which was terminated early because of the availability of new drugs not covered by the system, and a retrospective study in the United States. For these studies, a Web-based user interface was constructed to provide access to the models.

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Immune reconstitution inflammatory syndrome (IRIS) is a considerable problem in the treatment of HIV-infected patients. To identify immunologic correlates of IRIS, we characterized T-cell phenotypic markers and serum cytokine levels in HIV patients with a range of different AIDS-defining illnesses, before and at regular time points after initiation of antiretroviral therapy. Patients developing IRIS episodes displayed higher frequencies of effector memory, PD-1(+), HLA-DR(+), and Ki67(+) CD4(+) T cells than patients without IRIS.

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