Serum levels of creatinine, cystatin C, or b trace protein allow estimation of GFR, but whether these markers contribute additional prognostic information beyond that reflected in GFR is unknown. Here, we analyzed data from the Modification of Diet in Renal Disease study, which provided baseline levels of these markers for 816 participants with a median follow-up of 16.6 years. We examined associations between the reciprocals of these filtration markers and 125 I iothalamate GFR, expressed per SD, with kidney failure and mortality. In univariate analysis, lower GFR and higher levels of each filtration marker associated with a higher risk for all outcomes. After adjustment for GFR in a Cox proportional hazards model, higher creatinine associated with a higher risk for kidney failure but a lower risk for all-cause mortality. Higher cystatin C and b trace protein associated with a higher risk for both kidney failure and all-cause mortality. In models including either cystatin C or b trace protein, the association of GFR with all-cause mortality was no longer significant after the addition of the filtration marker, suggesting the possibility of multicollinearity. In summary, after adjustment for GFR, levels of creatinine, cystatin C, and b trace protein, each remained directly associated with kidney failure but differed with respect to their associations with mortality. These differences may be a result of non-GFR-related associations of filtration markers, residual confounding by GFR, or collinearity between the filtration markers and GFR. b trace protein and cystatin C seem to provide more consistent prognostic information than creatinine.

No abstract

A series of N-hydroxy-3-phenyl-2-propenamides were prepared as novel inhibitors of human histone deacetylase (HDAC). These compounds were potent enzyme inhibitors, having IC(50)s < 400 nM in a partially purified enzyme assay. However, potency in cell growth inhibition assays ranged over 2 orders of magnitude in two human carcinoma cell lines. Selected compounds having cellular IC(50) < 750 nM were tested for maximum tolerated dose (MTD) and for efficacy in the HCT116 human colon tumor xenograft assay. Four compounds having an MTD > or = 100 mg/kg were selected for dose-response studies in the HCT116 xenograft model. One compound, 9 (NVP-LAQ824), had significant dose-related activity in the HCT116 colon and A549 lung tumor models, high MTD, and low gross toxicity. On the basis, in part, of these properties, 9 has entered human clinical trials in 2002.

“Shock and kill” therapeutic strategies toward HIV eradication are based on the transcriptional activation of latent HIV with a latency-reversing agent (LRA) and the consequent killing of the reactivated cell by either the cytopathic effect of HIV or an arm of the immune system. We have recently found several benzotriazole and benzotriazine analogues that have the ability to reactivate latent HIV by inhibiting signal transducer and activator of transcription 5 (STAT5) SUMOylation and promoting STAT5 binding to the HIV long terminal repeat and increasing its transcriptional activity. To understand the essential structural groups required for biological activity of these molecules, we performed a systematic analysis of >40 analogues. First, we characterized the essential motifs within these molecules that are required for their biological activity. Second, we identified three benzotriazine analogues with similar activity. We demonstrated that these three compounds are able to increase STAT5 phosphorylation and transcriptional activity. All active analogues reactivate latent HIV in a primary cell model of latency and enhance the ability of interleukin-15 to reactivate latent HIV in cells isolated from aviremic participants. Third, this family of compounds also promote immune effector functions in vitro in the absence of toxicity or global immune activation. Finally, initial studies in mice suggest lack of acute toxicity in vivo. A better understanding of the biological activity of these compounds will help in the design of improved LRAs that work via inhibition of STAT5 SUMOylation.

Primary cell models of human immunodeficiency virus (HIV) latency have become tools to both understand the mechanisms involved in establishment of latency and test preclinical strategies toward HIV-1 cure. These models rely on infection of CD4 T cells from healthy donors. As such, these models provide an opportunity to explore the role of biological sex, age, and HIV status on establishment and reactivation of latent HIV in vitro. We have used an established primary cell model of latency based on the generation of latently infected central memory CD4 T cells with the CXCR4 strain HIV-1 to address whether these variables influence (i) HIV-1 replication, (ii) establishment of latency, and (iii) latency reversal in CD4 T cells. Our results indicate that replication of HIV-1, but not establishment of latency, is influenced by the age of female, but not male, donors. Moreover, the frequency of latently infected cells in this model is directly correlated with levels of productive infection in both male and female donors independent of age. We did not find differences in the ability of five different latency-reversing agents to reactivate latent HIV-1. Finally, we have found that this model can be generated using cells from aviremic participants. In conclusion, we have further characterized the central memory T cell model of latency regarding biological sex and age and demonstrated that this model is suitable for use with cells isolated from aviremic participants, opening the opportunity to use this primary cell model to address cure approaches, including shock and kill, in HIV-infected individuals.

No abstract

Key points Increased large artery stiffness and impaired endothelium‐dependent dilatation occur with advanced age. We sought to determine whether T cells mechanistically contribute to age‐related arterial dysfunction. We found that old mice exhibited greater proinflammatory T cell accumulation around both the aorta and mesenteric arteries. Pharmacologic depletion or genetic deletion of T cells in old mice resulted in ameliorated large artery stiffness and greater endothelium‐dependent dilatation compared with mice with T cells intact. Abstract Ageing of the arteries is characterized by increased large artery stiffness and impaired endothelium‐dependent dilatation. T cells contribute to hypertension in acute rodent models but whether they contribute to chronic age‐related arterial dysfunction is unknown. To determine whether T cells directly mediate age‐related arterial dysfunction, we examined large elastic artery and resistance artery function in young (4–6 months) and old (22–24 months) wild‐type mice treated with anti‐CD3 F(ab’2) fragments to deplete T cells (150 μg, i.p. every 7 days for 28 days) or isotype control fragments. Old mice exhibited greater numbers of T cells in both aorta and mesenteric vasculature when compared with young mice. Old mice treated with anti‐CD3 fragments exhibited depletion of T cells in blood, spleen, aorta and mesenteric vasculature. Old mice also exhibited greater numbers of aortic and mesenteric IFN‐γ and TNF‐α‐producing T cells when compared with young mice. Old control mice exhibited greater large artery stiffness and impaired resistance artery endothelium‐dependent dilatation in comparison with young mice. In old mice, large artery stiffness was ameliorated with anti‐CD3 treatment. Anti‐CD3‐treated old mice also exhibited greater endothelium‐dependent dilatation than age‐matched controls. We also examined arterial function in young and old Rag‐1–/– mice, which lack lymphocytes. Rag‐1–/– mice exhibited blunted increases in large artery stiffness with age compared with wild‐type mice. Old Rag‐1–/– mice also exhibited greater endothelium‐dependent dilatation compared with old wild‐type mice. Collectively, these results demonstrate that T cells play an important role in age‐related arterial dysfunction.

The remarkable generation of scores of increasingly sophisticated mouse models of mammary cancer over the past two decades has provided tremendous insights into molecular derangements that can lead to cancer. The relationships of these models to human breast cancer, however, remain problematic. Recent advances in genomic technologies offer significant opportunities to identify critical changes that occur during cancer evolution and to distinguish in a complex and comprehensive manner the key similarities and differences between mouse models and human cancer. Comparisons between mouse and human tumors are being performed using comparative genomic hybridization, gene expression profiling, and proteomic analyses. The appropriate use of genetically engineered mouse models of mammary cancer in preclinical studies remains an important challenge which may also be aided by genomic technologies. Genomic approaches to cancer are generating huge datasets that represent a complex system of underlying networks of genetic interactions. Mouse models offer a tremendous opportunity to identify such networks and how they relate to human cancer. The challenge of the future remains to decipher these networks in order to identify the genetic nodes of oncogenesis that may be important targets for chemoprevention and therapy. 2 Estrogen receptor alpha-positive and negative mouse mammary tumors through somatic mutations of p53 in mammary carcinogenesis