26 research outputs found
High cellular monocyte activation in people living with human immunodeficiency virus on combination antiretroviral therapy and lifestyle-matched controls is associated with greater inflammation in cerebrospinal fluid
Background. Increased monocyte activation and intestinal damage have been shown to be predictive for the increased morbidity and mortality observed in treated people living with human immunodeficiency virus (PLHIV). Methods. A cross-sectional analysis of cellular and soluble markers of monocyte activation, coagulation, intestinal damage, and inflammation in plasma and cerebrospinal fluid (CSF) of PLHIV with suppressed plasma viremia on combination antiretroviral therapy and age and demographically comparable HIV-negative individuals participating in the Comorbidity in Relation to AIDS (COBRA) cohort and, where appropriate, age-matched blood bank donors (BBD). Results. People living with HIV, HIV-negative individuals, and BBD had comparable percentages of classical, intermediate, and nonclassical monocytes. Expression of CD163, CD32, CD64, HLA-DR, CD38, CD40, CD86, CD91, CD11c, and CX3CR1 on monocytes did not differ between PLHIV and HIV-negative individuals, but it differed significantly from BBD. Principal component analysis revealed that 57.5% of PLHIV and 62.5% of HIV-negative individuals had a high monocyte activation profile compared with 2.9% of BBD. Cellular monocyte activation in the COBRA cohort was strongly associated with soluble markers of monocyte activation and inflammation in the CSF. Conclusions. People living with HIV and HIV-negative COBRA participants had high levels of cellular monocyte activation compared with age-matched BBD. High monocyte activation was predictive for inflammation in the CSF
Validation of a Novel Multivariate Method of Defining HIV-Associated Cognitive Impairment
Background. The optimum method of defining cognitive impairment in virally suppressed people living with HIV is unknown. We evaluated the relationships between cognitive impairment, including using a novel multivariate method (NMM), patientreported outcome measures (PROMs), and neuroimaging markers of brain structure across 3 cohorts.Methods. Differences in the prevalence of cognitive impairment, PROMs, and neuroimaging data from the COBRA, CHARTER, and POPPY cohorts (total n = 908) were determined between HIV-positive participants with and without cognitive impairment defined using the HIV-associated neurocognitive disorders (HAND), global deficit score (GDS), and NMM criteria.Results. The prevalence of cognitive impairment varied by up to 27% between methods used to define impairment (eg, 48% for HAND vs 21% for NMM in the CHARTER study). Associations between objective cognitive impairment and subjective cognitive complaints generally were weak. Physical and mental health summary scores (SF-36) were lowest for NMM-defined impairment (P<.05). There were no differences in brain volumes or cortical thickness between participants with and without cognitive impairment defined using the HAND and GDS measures. In contrast, those identified with cognitive impairment by the NMM had reduced mean cortical thickness in both hemispheres (P<.05), as well as smaller brain volumes (P<.01). The associations with measures of white matter microstructure and brain-predicted age generally were weaker.Conclusion. Different methods of defining cognitive impairment identify different people with varying symptomatology and measures of brain injury. Overall, NMM-defined impairment was associated with most neuroimaging abnormalities and poorer selfreported health status. This may be due to the statistical advantage of using a multivariate approach
Cognitive function and drivers of cognitive impairment in a European and a Korean cohort of people living with HIV
Although cognitive impairments are still prevalent in the current antiretroviral therapy era, limited investigations have compared the prevalence of cognitive disorder in people living with HIV (PLWH) and its determinants in different regions and ethnicities. We compared cognitive performance across six domains using comparable batteries in 134 PLWH aged ≥45 years from the COBRA study (Netherlands, UK), and 194 PLWH aged ≥18 years from the NeuroAIDS Project (South Korea). Cognitive scores were standardized and averaged to obtain domain and global T-scores. Associations with global T-scores were evaluated using multivariable regression and the ability of individual tests to detect cognitive impairment (global T-score ≤45) was assessed using the area-under-the-receiver-operating-characteristic curve (AUROC). The median (interquartile range) age of participants was 56 (51, 62) years in COBRA (88% white ethnicity, 93% male) and 45 (37, 52) years in NeuroAIDS (100% Korean ethnicity, 94% male). The rate of cognitive impairment was 18.8% and 18.0%, respectively (p = 0.86). In COBRA, Black-African ethnicity was the factor most strongly associated with cognitive function (11.1 [7.7, 14.5] lower scores vs. white ethnicity, p < 0.01), whereas in NeuroAIDS, age (0.6 [0.1, 1.3] per 10-year, p<0.01) and education (0.7 [0.5, 0.9] per year, p<0.01) were significantly associated with cognitive function with anemia showing only a weak association (−1.2 [−2.6, 0.3], p=0.12). Cognitive domains most associated with cognitive impairment were attention (AUROC = 0.86) and executive function (AUROC = 0.87) in COBRA and processing speed (AUROC = 0.80), motor function (AUROC = 0.78) and language (AUROC = 0.78) in NeuroAIDS. Two cohorts of PLWH from different geographical regions report similar rates of cognitive impairment but different risk factors and cognitive profiles of impairment
Do people living with HIV experience greater age advancement than their HIV-negative counterparts?
Objectives: Despite successful antiretroviral therapy, people living with HIV (PLWH)
may show signs of premature/accentuated aging. We compared established biomarkers
of aging in PLWH, appropriately chosen HIV-negative individuals, and blood donors,
and explored factors associated with biological age advancement.
Design: Cross-sectional analysis of 134 PLWH on suppressive antiretroviral therapy, 79
lifestyle-comparable HIV-negative controls aged 45 years or older from the Co-mor-
Bidity in Relation to AIDS (COBRA) cohort, and 35 age-matched blood donors.
Methods: Biological age was estimated using a validated algorithm based on 10
biomarkers. Associations between ‘age advancement’ (biological minus chronological
age) and HIV status/parameters, lifestyle, cytomegalovirus (CMV), hepatitis
B (HBV) and hepatitis C virus (HCV) infections were investigated using linear regression.
Results: The average (95% CI) age advancement was greater in both HIV-positive [13.2
(11.6–14.9) years] and HIV-negative [5.5 (3.8–7.2) years] COBRA participants compared
with blood donors [7.0 (4.1 to 9.9) years, both P’s<0.001)], but also in HIV-positive
compared with HIV-negative participants (P<0.001). Chronic HBV, higher anti-CMV
IgG titer and CD8þ T-cell count were each associated with increased age advancement,
independently of HIV-status/group. Among HIV-positive participants, age
advancement was increased by 3.5 (0.1–6.8) years among those with nadir CD4þ
T-cell count less than 200 cells/ml and by 0.1 (0.06–0.2) years for each additional
month of exposure to saquinavir
Validation of a novel multivariate method of defining HIV-associated cognitive impairment
Background. The optimum method of defining cognitive impairment in virally suppressed people living with HIV is unknown.
We evaluated the relationships between cognitive impairment, including using a novel multivariate method (NMM), patient–
reported outcome measures (PROMs), and neuroimaging markers of brain structure across 3 cohorts.
Methods. Differences in the prevalence of cognitive impairment, PROMs, and neuroimaging data from the COBRA, CHARTER,
and POPPY cohorts (total n = 908) were determined between HIV-positive participants with and without cognitive impairment defined using the HIV-associated neurocognitive disorders (HAND), global deficit score (GDS), and NMM criteria.
Results. The prevalence of cognitive impairment varied by up to 27% between methods used to define impairment (eg, 48% for HAND
vs 21% for NMM in the CHARTER study). Associations between objective cognitive impairment and subjective cognitive complaints generally were weak. Physical and mental health summary scores (SF-36) were lowest for NMM-defined impairment (P < .05).
There were no differences in brain volumes or cortical thickness between participants with and without cognitive impairment defined using the HAND and GDS measures. In contrast, those identified with cognitive impairment by the NMM had reduced mean
cortical thickness in both hemispheres (P < .05), as well as smaller brain volumes (P < .01). The associations with measures of white
matter microstructure and brain-predicted age generally were weaker.
Conclusion. Different methods of defining cognitive impairment identify different people with varying symptomatology and
measures of brain injury. Overall, NMM-defined impairment was associated with most neuroimaging abnormalities and poorer selfreported health status. This may be due to the statistical advantage of using a multivariate approac
Versuche zur Bestimmung des Pyridins mit Kieselwolframsäure, insbesondere bei Gegenwart von Nikotin
A nitrogen-base catalyzed generation of organotin(II) hydride from an organotin trihydride under reductive dihydrogen elimination
CPS thanks the Fonds der chemischen Industrie and the Studienstiftung des deutschen Volkes for PhD research scholarshipsSince their first description over a decade ago, organotin(II) hydrides have been an iconic class of compounds in molecular main group chemistry. Among other approaches they have been accessed from the hydrogenation of distannynes. We herein report their accessibility from the other direction by dehydrogenation of organotin trihydride. On reacting pyridine and amine bases with the bulky substituted organotin trihydride Ar*SnH3 (Ar* = 2,6-trip2(C6H3)–, trip = 2,4,6-triisopropylphenyl) hydrogen evolution was observed. In case of catalytic amounts of base the dehydro-coupling product diorganodistannane Ar*H2SnSnH2Ar* was obtained quantitatively whilst for excessive amounts (>4 eq.) the monomeric base adduct to known Ar*SnH was obtained almost exclusively. The base adducts were found to be remarkably thermally robust. They readily react with polar fulvenic CC-bonds in hydro-stannylenylation reactions. The resulting half-sandwich complex Ar*SnCp* was structurally characterized. Moreover, on application of less nucleophilic amine bases, the uncoordinated, in solution dimeric [Ar*SnH]2 is formed. NMR spectroscopic studies on the kinetics of the DMAP-catalysed reductive elimination of dihydrogen were performed. The activation energy was approximated to be 13.7 kcal mol−1. Solvent dependencies and a kinetic isotope effect KIE of kH/kD = 1.65 in benzene and 2.04 in THF were found and along with DFT calculations support a polar mechanism for this dehydrogenation.Publisher PDFPeer reviewe