Suramin induces and enhances apoptosis in a model of hyperoxia-induced oligodendrocyte injury

Recent evidence suggests oxygen as a powerful trigger for cell death in the immature white matter, leading to periventricular leukomalacia (PVL) as a cause of adverse neurological outcome in survivors of preterm birth. This oligodendrocyte (OL) death is associated with oxidative stress, upregulation of apoptotic signaling factors (i.e., Fas, caspase-3) and decreased amounts of neurotrophins. In search of neuroprotective strategies we investigated whether the polysulfonated urea derivative suramin, recently identified as a potent inhibitor of Fas signaling, affords neuroprotection in an in vitro model of hyperoxia-induced injury to immature oligodendrocytes. Immature OLs (OLN-93) were subjected to 80% hyperoxia (48 h) in the presence or absence of suramin (0, 30, 60, 120 microM). Cell death was assessed by flow cytometry (Annexin V, caspase-3 activity assay) and immunohistochemistry for activated caspase-3. Immunoblotting for the death receptor Fas, cleaved caspase-8 and the phosphorylated isoform of the serine-threonin kinase Akt (pAkt) was performed. Suramin lead to OL apoptosis and potentiated hyperoxia-induced injury in a dose-dependent manner. Immunoblotting revealed increased Fas and caspase-8 expression by suramin treatment. This effect was significantly enhanced when suramin was combined with hyperoxia. Furthermore, pAkt levels decreased following suramin exposure, indicating interference with neurotrophin-dependent growth factor signaling. These data indicate that suramin causes apoptotic cell death and aggravates hyperoxia-induced cell death in immature OLs. Its mechanism of action includes an increase of previously described hyperoxia-induced expression of pro-apoptotic factors and deprivation of growth factor dependent signaling components.     

Prevention of acute exacerbation of chronic obstructive pulmonary disease after bronchoscopic lung volume reduction with endobronchial valves

IntroductionBronchoscopic lung volume reduction (BLVR) with endobronchial valves (EBVs) has emerged as an important treatment method for patients with severe chronic obstructive pulmonary disease (COPD). Acute exacerbations of COPD (AECOPD) are a frequent complication following BLVR with EBV. However, there is no consensus on the prevention of AECOPD.ObjectivesOur study aims to compare the outcomes of different prophylactic measures on the occurrence of AECOPD after BLVR with EBV.MethodsWe conducted a multicenter, retrospective study of patients who underwent BLVR with EBV at six different institutions. Emphasis was directed towards the specific practices aimed at preventing AECOPD: antibiotics, steroids, antibiotics plus steroids, or no prophylaxis. Subgroups were compared, and odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were calculated.ResultsA total of 170 patients were reviewed. The rate of AECOPD was 21.2% for the full cohort. Patients who received prophylaxis had a significantly lower rate of AECOPD compared with those who did not (16.7% vs. 46.2%; p = 0.001). The rate was lowest in patients who received antibiotics alone (9.2%). There was no significant difference in the rate of AECOPD between patients who received steroids alone or antibiotics plus steroids, compared with the other subgroups. The OR for AECOPD was 4.3 (95% CI: 1.8–10.4; p = 0.001) for patients not receiving prophylaxis and 3.9 (95% CI: 1.5–10.1; p = 0.004) for prophylaxis other than antibiotics alone.ConclusionsAdministration of antibiotics after BLVR with EBV was associated with a lower rate of AECOPD. This was not observed with the use of steroids or in combination with antibiotics.     

Men’s experience of perpetrating intimate partner violence following disclosure of HIV status by their seropositive female intimate partners: a qualitative study

BackgroundGender-Based (GB) intimate partner violence is a social and public health issue globally. Several risks of violence related to male sexual partners’ perpetration of intimate partner violence (IPV) following the disclosure of their female intimate partners’ HIV + status have been reported. No research has been conducted on male sexual partner’s perspectives of perpetrating IPV following their female intimate partners’ disclosure of human immunodeficiency virus (HIV) seropositive status as a risk factor for the perpetration of IPV in Ghana.ObjectiveThe objective of this study is to explore and describe male sexual partners’ views or perspectives of perpetrating IPV following their female intimate partners’ disclosure of being HIV positive in Ghana.MethodsInterpretive phenomenological approach was used to collect and analyse data from a purposive sample of 18 Male participants whose female intimate relations informed them of being HIV + in Ghana. The sample population was taken from Ghana because such research has been reported elsewhere but none has been done in Ghana. A semi-structured interview guide was used to collect the data. The interview guide covered topics such as background information, participants’ reaction to HIV positive disclosure, lived experiences of participants, and Participants’ understanding of different forms of IPV.ResultsThe findings of this study reveal five main themes that emerged from the interviews which include views on the perpetration of emotional, psychological, and verbal abuse; views on the perpetration of sexual deprivation; views on the perpetration of social isolation; views on the perpetration of financial abuse and views on escalated perpetration of physical abuse.ConclusionFrom the data, HIV positive status disclosure served as a risk factor for different forms of GB IPV against HIV positive women in Ghana, thus making this group more vulnerable and exposed to more GB IPV. Strategies to prevent the perpetration of IPV against women newly diagnosed as HIV positive are needed. We recommend screening all newly diagnosed HIV-positive women for abuse as an additional prevention strategy for IPV associated with disclosure of positive HIV status.

KEY MESSAGES

• HIV positive status disclosure serves as a risk for the perpetration of IPV.
• Men are predisposed to violence upon hearing that their female heterosexual intimate partners are HIV positive.
• HIV infection information is distressful to receive from an intimate partner.