Description: Objective To study temporal trends of mortality in HIV-infected adults who attended an HIV clinic in Kampala, Uganda, between 2002 and 2012. Design Descriptive retrospective study. Methods Two doctors independently reviewed the clinic database that contained information derived from the clinic files and assigned one or more causes of death to each patient 〉18 years of age with a known date of death. Four cause-of-death categories were defined: ‘communicable conditions and AIDS-defining malignancies’, ‘chronic non-communicable conditions’, ‘other non-communicable conditions’ and ‘unknown’. Trends in cause-of-death categories over time were evaluated using multinomial logistic regression with year of death as an independent continuous variable. Results 1028 deaths were included; 38% of these individuals were on antiretroviral therapy (ART). The estimated mortality rate dropped from 21.86 deaths/100 person years of follow-up (PYFU) in 2002 to 1.75/100 PYFU in 2012. There was a significant change in causes of death over time (p〈0.01). Between 2002 and 2012, the proportion of deaths due to ‘communicable conditions and AIDS-defining malignancies’ decreased from 84% (95% CI 74% to 90%) to 64% (95% CI 53% to 74%) and the proportion of deaths due to ‘chronic non-communicable conditions’, ‘other non-communicable conditions’ and a combination of ‘communicable and non-communicable conditions’ increased. Tuberculosis (TB) was the main cause of death (34%). Death from TB decreased over time, from 43% (95% CI 32% to 53%) in 2002 to a steady proportion of approximately 25% from 2006 onwards (p〈0.01). Conclusions Mortality rate decreased over time. The proportion of deaths from communicable conditions and AIDS-defining malignancies decreased and from non-communicable diseases, both chronic and non-chronic, increased. Nevertheless, communicable conditions and AIDS-defining malignancies continued to cause the majority of deaths, with TB as the main cause. Ongoing monitoring of cause of death is warranted and strategies to decrease mortality from TB and other common opportunistic infections are essential.

Description: In vitro genotoxicity assessment routinely employs an exogenous metabolic activation mixture to simulate mammalian metabolism. Activation mixtures commonly contain post-mitochondrial liver supernatant (i.e. S9) from chemically induced Sprague Dawley rats. Although Organization for Economic Cooperation and Development (OECD) test guidelines permit the use of other S9 preparations, assessments rarely employ human-derived S9. The objective of this study is to review and evaluate the use of human-derived S9 for in vitro genetic toxicity assessment. All available published genotoxicity assessments employing human S9 were compiled for analysis. To facilitate comparative analyses, additional matched Ames data using induced rat liver S9 were obtained for certain highly cited chemicals. Historical human and induced rat S9 quality control reports from Moltox were obtained and mined for enzyme activity and mutagenic potency data. Additional in vitro micronucleus data were experimentally generated using human and induced rat S9. The metabolic activity of induced rat S9 was found to be higher than human S9, and linked to high mutagenic potency results. This study revealed that human S9 often yields significantly lower Salmonella mutagenic potency values, especially for polycyclic aromatic hydrocarbons, aflatoxin B1 and heterocyclic amines (~3- to 350-fold). Conversely, assessment with human S9 activation yields higher potency for aromatic amines (~2- to 50-fold). Outliers with extremely high mutagenic potency results were observed in the human S9 data. Similar trends were observed in experimentally generated mammalian micronucleus cell assays, however human S9 elicited potent cytotoxicity L5178Y, CHO and TK6 cell lines. Due to the potential for reduced sensitivity and the absence of a link between enzyme activity levels and mutagenic potency, human liver S9 is not recommended for use alone in in vitro genotoxicity screening assays; however, human S9 may be extremely useful in follow-up tests, especially in the case of chemicals with species-specific metabolic differences, such as aromatic amines.