137 research outputs found

    Intramitochondrial adenylyl cyclase controls the turnover of nuclear-encoded subunits and activity of mammalian complex I of the respiratory chain

    Get PDF
    In mammalian cells the nuclear-encoded subunits of complex I are imported into mitochondria, where they are assembled with mt-DNA encoded subunits in the complex, or exchanged with pre-existing copies in the complex. The present work shows that in fibroblast cultures inhibition by KH7 of cAMP production in the mitochondrial matrix by soluble adenylyl cyclase (sAC) results in decreased amounts of free non-incorporated nuclear-encoded NDUFS4, NDUFV2 and NDUFA9 subunits of the catalytic moiety and inhibition of the activity of complex I. Addition of permeant 8-Br-cAMP prevents this effect of KH7. KH7 inhibits accumulation in isolated rat-liver mitochondria and incorporation in complex I of "in vitro" produced, radiolabeled NDUFS4 and NDUFV2 subunits. 8-Br-cAMP prevents also this effect of KH7. Use of protease inhibitors shows that intramitochondrial cAMP exerts this positive effect on complex I by preventing digestion of nuclear-encoded subunits by mitochondrial protease(s), whose activity is promoted by KH7 and H89, an inhibitor of PKA

    Poly-L-lactic acid beta-tricalcium phosphate screws: a preliminary in vivo biocompatibility study.

    Get PDF
    The aim of this study is to assess the biocompatibility of two types of Poly-L-lactic acid (PLLA) screws (with either hydroxiapatite (HA) or β-tricalcium phosphate (β-TCP)) implanted in the left femur of four sheep euthanized at 42, 50, 57 and 84 days after surgery. Titanium screws were also implanted for comparison purposes. No signs of inflammation were seen in the 240 specimens. A rating of "+/-"for macrophages and "-"for neutrophils was assigned to all specimens. All specimens were assigned a rating which ranged from "+/-" to "+++" for fibroblasts and osteoblasts. The presence of macrophages, neutrophils and fibroblasts/osteoblasts was not statistically different for the four implantation periods. PLLA implants with β-TCP have a biocompatibility comparable to PLLA implants with HA

    Adiposity Predicts Cognitive Decline in Older Persons with Diabetes: A 2-Year Follow-Up

    Get PDF
    BACKGROUND: The mechanisms related to cognitive impairment in older persons with Type 2 diabetes (DM) remains unclear. We tested if adiposity parameters and body fat distribution could predict cognitive decline in older persons with DM vs. normal glucose tolerance (NGT). METHODOLOGY: 693 older persons with no dementia were enrolled: 253 with DM in good metabolic control; 440 with NGT (age range:65-85 years). Longitudinal study comparing DM and NGT individuals according to the association of baseline adiposity parameters (body mass index (BMI), waist-hip-ratio (WHR), waist circumference (WC) and total body fat mass) to cognitive change (Mini Mental State Examination (MMSE), a composite score of executive and attention functioning (CCS) over time. FINDINGS: At baseline, in DM participants, MMSE correlated with WHR (beta = -0.240; p = 0.043), WC (beta = -0.264; p = 0.041) while CCS correlated with WHR (beta = -0.238; p = 0.041), WC (beta = -0.326; p = 0.013) after adjusting for confounders. In NGT subjects, no significant correlations were found among any adiposity parameters and MMSE, while CCS was associated with WHR (beta = -0.194; p = 0.036) and WC (beta = -0.210; p = 0.024). Participants with DM in the 3(rd) tertile of total fat mass showed the greatest decline in cognitive performance compared to those in 1(st) tertile (tests for trend: MMSE(p = 0.007), CCS(p = 0.003)). Logistic regression models showed that 3(rd) vs. 1(st) tertile of total fat mass, WHR, and WC predicted an almost two-fold decline in cognitive function in DM subjects at 2(nd) yr (OR 1.68, 95%IC 1.08-3.52). CONCLUSIONS: Total fat mass and central adiposity predict an increased risk for cognitive decline in older person with DM

    Early versus delayed antiretroviral therapy based on genotypic resistance test: Results from a large retrospective cohort study

    Get PDF
    Rapid start of antiretroviral therapy (ART) pending genotypic resistance test (GRT) has been recently proposed, but the effectiveness of this strategy is still debated. The rate of virological success (VS), defined as HIV-RNA\u2009<\u200950 copies/ml, with and without GRT was compared in drug-na\uefve individuals enrolled in the Italian ARCA cohort who started ART between 2015 and 2018. 521 individuals started ART: 397 without GRT (pre-GRT group) and 124 following GRT (post-GRT group). Overall, 398 (76%) were males and 30 (6%) were diagnosed with AIDS. In the pre-GRT group, baseline CD4+\u2009cell counts were lower (p\u2009<\u20090.001), and viral load was higher (p\u2009<\u20090.001) than in the post-GRT group. The estimated probability of VS in pre-GRT versus post-GRT group was 72.54% (CI95 : 67.78-76.60) versus 66.94% (CI95 : 57.53-74.26) at Week 24 and 92.40% (CI95 : 89.26-94.62) versus 92.92% (CI95 : 86.35-96.33) at Week 48, respectively (p\u2009=\u20090.434). At Week 48, VS was less frequent among individuals with baseline CD4+\u2009cell counts <200 versus >500 (90.33% vs. 97.33%), log viral load <5.00 versus >5.70 log10 cps/ml (97.17% vs 78.16%; p\u2009<\u20090.001), and those treated with protease inhibitors or non-nucleoside reverse transcriptase inhibitors versus those treated with integrase strand transfer inhibitors (p\u2009<\u20090.001). The rate of VS does not seem to be affected by an early ART initiation pending GRT results, but it could be influenced by the composition of the ART regimen, as well as immuno-virological parameters
    corecore