Publications by authors named "Cristian Achim"

"Despite ART, we detected occasional microglia containing cell-associated HIV RNA and HIV DNA integrated into open regions of the host's genome (∼0.005%)" should be corrected to: "Despite ART, we detected occasional microglia containing cell-associated HIV RNA and HIV DNA integrated into open regions of the host's genome (∼0.5%).

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The presence of HIV in sequestered reservoirs is a central impediment to a functional cure, allowing HIV to persist despite life-long antiretroviral therapy (ART), and driving a variety of comorbid conditions. Our understanding of the latent HIV reservoir in the central nervous system is incomplete, because of difficulties in accessing human central nervous system tissues. Microglia contribute to HIV reservoirs, but the molecular phenotype of HIV-infected microglia is poorly understood.

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Reverse transcriptase inhibitors (RTIs) are currently broadly prescribed for the treatment of HIV infection but are also thought to prevent Alzheimer's disease (AD) progression by protecting against amyloidosis. Our study evaluates the hypothesis that reverse transcriptase inhibitors protect against Alzheimer-type brain amyloidogenesis in the context of HIV infection. We compiled a case series of participants from a prospective study of the neurological consequences of HIV infection at the HIV Neurobehavioral Research Program (HNRP) who had serial neuropsychological and neurological assessments and were on RTIs.

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Human immunodeficiency virus (HIV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cause significant neurologic disease. Central nervous system (CNS) involvement of HIV has been extensively studied, with well-documented invasion of HIV into the brain in the initial stage of infection, while the acute effects of SARS-CoV-2 in the brain are unclear. Neuropathologic features of active HIV infection in the brain are well characterized whereas neuropathologic findings in acute COVID-19 are largely non-specific.

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Background: Elevated serum pro-inflammatory molecules have been reported in early psychosis. What is not known is whether peripheral inflammatory biomarkers are associated with CNS biomarkers. In the brain, release of pro-inflammatory molecules by microglial hyperactivity may lead to neuronal apoptosis seen in neurodegenerative disorders and account for loss of brain tissue observed in psychotic disorders.

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Reverse transcriptase inhibitors (RTIs) are currently broadly prescribed for the treatment of HIV infection but are also thought to prevent Alzheimer's Disease (AD) progression by protecting against amyloidosis. Our study evaluates the hypothesis that reverse transcriptase inhibitors protect against Alzheimer-type brain amyloidogenesis in the context of HIV infection. We compiled a case series of participants from a prospective study of the neurological consequences of HIV infection at the HIV Neurobehavioral Research Program (HNRP) who had serial neuropsychological and neurological assessments and were on RTIs.

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The aim of the study was to evaluate the incidence of brain opportunistic pathologies and survival in patients living with HIV from a Romanian tertiary center. A 15-year prospective observational study of brain opportunistic infections diagnosed in HIV-infected patients was performed at Victor Babes Hospital, Bucharest, between January 2006 and December 2021. Characteristics and survival were compared related to modes of HIV acquisition and type of opportunistic infection.

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Introduction: An unusual cluster of myoclonic epilepsy was observed in a Romanian pediatric HIV cohort concurrent with measles outbreaks. We describe this particular form of subacute measles encephalitis (SME) in a group of HIV-infected children and adolescents with severe immunosuppression.

Methods: This is a single-center study, starting in 1997 and covering 4 measles outbreaks in Romania.

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Background: Following spinal cord injury (SCI), disease processes spread gradually along the spinal cord forming a spatial gradient with most pronounced changes located at the lesion site. However, the dynamics of this gradient in SCI patients is not established.

Objective: This study tracks the spatiotemporal dynamics of remote anterograde and retrograde spinal tract degeneration in the upper cervical cord following SCI over two years utilizing quantitative MRI.

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Although antiretroviral therapy (ART) has increased the quality of life and lifespan in people living with HIV (PWH), millions continue to suffer from the neurobehavioral effects of the virus. Additionally, the abuse of illicit drugs (methamphetamine in particular) is significantly higher in PWH compared to the general population, which may further impact their neurological functions. The HIV regulatory protein, Tat, has been implicated in the neurobehavioral impacts of HIV and is purported to inhibit dopamine transporter (DAT) function in a way similar to methamphetamine.

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Human immunodeficiency virus (HIV) continues to infect millions worldwide, negatively impacting neurobehavioral function. Further understanding of the combined effects of HIV and methamphetamine use is crucial, as methamphetamine use is prevalent in people with HIV. The HIV-associated protein Tat may contribute to cognitive dysfunction, modeled preclinically in mice using doxycycline (DOX)-inducible Tat expression (iTat).

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Given the co-occurrence of memory impairment in HIV-associated neurocognitive disorders (HAND) and amnestic mild cognitive impairment/Alzheimer's disease (aMCI/AD), biomarkers are needed that can disentangle these conditions among people with HIV (PWH). We assessed whether cerebrospinal fluid (CSF) markers of AD could help in this effort by determining their relationship to learning and memory deficits versus cognitive deficits more characteristic of HAND than aMCI/AD (processing speed and complex visual/motor coordination) among 31 older PWH. CSF amyloid-β phosphorylated-tau, amyloid-β/amyloid-β and phosphorylated-tau/amyloid-β ratio related to learning/memory performance but not HAND-related deficits, suggesting that these biomarkers may have utility in disentangling aMCI/AD from HAND.

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Objective: Determine concentrations of antiretroviral therapy (ART) drugs in the human brain.

Design: Cohort study of persons with HIV who consented to antemortem assessment and postmortem autopsy.

Methods: Eleven persons with HIV who were taking ART at the time of death and had detectable concentrations of at least one ART drug in intracardiac aspirate at autopsy were evaluated.

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Introduction: Research examining the role of inflammation in psychosis has produced inconsistent results. Variables that influence inflammation, including antipsychotic medication, are inconsistently controlled across studies and variation of inflammatory analytes across stages of psychosis may also influence findings. The purpose of this study was to assess for evidence of immuno-inflammatory dysregulation across the stages of early psychosis.

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Background: HIV-associated neurocognitive disorders (HAND) persist despite the widespread implementation of combined antiretroviral therapy (ART). As people with HIV (PWH) age on ART regimens, the risk of age-related comorbidities, such as Alzheimer's disease may increase. However, questions remain as to whether HIV or ART will alter such risks.

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Mounting evidence suggests that antiretroviral therapy (ART) drugs may contribute to the prevalence of HIV-associated neurological dysfunction. The HIV envelope glycoprotein (gp120) is neurotoxic and has been linked to alterations in mitochondrial function and increased inflammatory gene expression, which are common neuropathological findings in HIV+ cases on ART with neurological disorders. Tenofovir disproxil fumarate (TDF) has been shown to affect neurogenesis in brains of mice and mitochondria in neurons.

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HIV-associated neurocognitive disorders (HAND) continue to be reported even in patients with successful antiretroviral treatment. We investigated the prevalence of neurocognitive impairment and possible HIV-associated determinants of cognition in a Romanian cohort of young adults, parenterally infected with HIV during their first years of life. Two hundred fourteen treatment-experienced HIV-positive individuals [median age: 24 years, males: 48%, median duration on combined antiretroviral therapy (cART): 12 years] underwent standard immunologic and virological monitoring and antiretroviral resistance testing using pol gene sequencing in both plasma and, when available, cerebrospinal fluid (CSF) paired samples.

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The neuropathogenesis of HIV associated neurocognitive disorders (HAND) involves disruption of mitochondrial homeostasis and increased neuroinflammation. However, it is unknown if alterations in mitochondrial biogenesis in the brain underlie the neuropathogenesis of HAND. In this study, neuropathological and molecular analyses of mitochondrial biogenesis and inflammatory pathways were performed in brain specimens from a well-characterized cohort of HIV+ cases that were on antiretroviral regimens.

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People over the age of 50 are the fastest growing segment of the HIV-infected population in the USA. Although antiretroviral therapy has remarkable success controlling the systemic HIV infection, HIV-associated neurocognitive disorder (HAND) prevalence has increased or remained the same among this group, and cognitive deficits appear more severe in aged patients with HIV. The mechanisms of HAND in the aged population are not completely understood; a leading hypothesis is that aged individuals with HIV might be at higher risk of developing Alzheimer's disease (AD) or one of the AD-related dementias (ADRD).

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Neuroinflammation is a common pathological correlate of HIV-associated neurocognitive disorders (HAND) in individuals on antiretroviral therapy (ART). Triggering receptor expressed on myeloid cells 2 (TREM2) regulates neuroinflammation, clears extracellular Amyloid (A)-β, surveys for damaged neurons, and orchestrates microglial differentiation. TREM2 has not been studied in HIV+ brain tissues.

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Mild neurocognitive impairments are common in people with human immunodeficiency virus (HIV) infection. HIV-encoded proteins, such as trans-activator of transcription (TAT), contribute to neuropathology and cognitive function in medicated subjects. The combination of TAT and comorbid methamphetamine use may further impair neurocognitive function in HIV-positive individuals by affecting dopaminergic systems in the brain.

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Introduction: Sex differences in cognition of HIV positive (HIV) patients are controversial. We aimed to investigate the relationship between cognition, HIV status, and sex, in a highly homogenous cohort of young Romanians parenterally infected during early childhood.

Methods: In total, 250 HIV participants were compared with age-matched HIV negative (HIV) controls (n = 72) in a cross-sectional study.

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Objective: Higher plasma soluble cluster of differentiation (CD)163 (sCD163), shed by monocytes and macrophages, correlates with neurocognitive impairment in HIV infection. We hypothesized that higher antemortem plasma or cerebrospinal fluid (CSF) sCD163 would be associated with greater postmortem neurodegeneration and/or microgliosis.

Design: Retrospective, postmortem observational study.

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This study aimed to investigate the influence of antiretroviral therapy on methylation markers, in a group of HIV infected, heavily treated patients. Immune and molecular methods were used to investigate potential changes in methylation profile in DNA isolated from peripheral blood mononuclear cells collected from antiretroviral-experienced HIV infected patients and healthy controls. The percentage of 5-methylcytosine was inversely correlated with proviral DNA and active replication while DNMT1 (p = 0.

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Despite extensive investigations, we still do not fully understand the dynamics of the total body HIV reservoir and how sub-reservoirs in various compartments relate to one another. Studies using macaque models are enlightening but eradication strategies will still need to be tested in humans. To take the next steps in understanding and eradicating HIV reservoirs throughout the body, we propose to develop a “peri-mortem translational research model” of HIV-infected individuals (called ‘The Last Gift’), which is similar to existing models in cancer research.

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