Citations

Abstract In HIV-infected patients, concurrent infections with bacteria and viruses are known to induce HIV replication as assessed by increases in plasma HIV RNA levels. In the present study, we determined the cell surface receptor and molecular mechanisms of enterobacterial LPS-induced HIV transcription. Human dermal microvessel endothelial cells (HMEC) were transfected with an HIV-long terminal repeat (LTR)-luciferase construct and subsequently stimulated with purified bacterial LPS. Our studies demonstrate that human Toll-like receptor 4 (TLR4) mediates LPS-induced NF-κB and HIV-LTR activation in HMEC through IL-1 signaling molecules, namely myeloid differentiation protein, IL-1R-associated kinase, TNFR-associated factor, and NF-κB-inducing kinase. Cotransfection of HMEC with HIV-LTR-luciferase and TLR4 cDNA from LPS-hyporesponsive C3H/HeJ mice abrogates LPS-induced HIV transcription as does the use of dominant-negative mutants of the IL-1 signaling molecules. Transfection of HMEC with an HIV-LTR-mutant that lacks the NF-κB binding site or pretreatment of cells with chemical inhibitors of the NF-κB pathway also blocked LPS-induced HIV-LTR transactivation. These data support the conclusion that TLR4 mediates enterobacterial LPS-induced HIV transcription via IL-1 signaling molecules and NF-κB activation plays an important role in HIV-LTR transactivation.

AbstractMotivationDiseases that progress slowly are often studied by observing cohorts at different stages of disease for short periods of time. The Alzheimer's Disease Neuroimaging Initiative (ADNI) follows elders with various degrees of cognitive impairment, from normal to impaired. The study includes a rich panel of novel cognitive tests, biomarkers, and brain images collected every 6 months for as long as 6 years. The relative timing of the observations with respect to disease pathology is unknown. We propose a general semiparametric model and iterative estimation procedure to estimate simultaneously the pathological timing and long‐term growth curves. The resulting estimates of long‐term progression are fine‐tuned using cognitive trajectories derived from the long‐term “Personnes Agées Quid” study.ResultsWe demonstrate with simulations that the method can recover long‐term disease trends from short‐term observations. The method also estimates temporal ordering of individuals with respect to disease pathology, providing subject‐specific prognostic estimates of the time until onset of symptoms. When the method is applied to ADNI data, the estimated growth curves are in general agreement with prevailing theories of the Alzheimer's disease cascade. Other data sets with common outcome measures can be combined using the proposed algorithm.AvailabilitySoftware to fit the model and reproduce results with the statistical software R is available as the grace package. ADNI data can be downloaded from the Laboratory of NeuroImaging.

Purpose The ACOSOG (American College of Surgeons Oncology Group) Z9001 (Alliance) study, a randomized, placebo-controlled trial, demonstrated that 1 year of adjuvant imatinib prolonged recurrence-free survival (RFS) after resection of primary GI stromal tumor (GIST). We sought to determine the pathologic and molecular factors associated with patient outcome. Patients and Methods There were 328 patients assigned to the placebo arm and 317 to the imatinib arm. Median patient follow-up was 74 months. There were 645 tumor specimens available for mitotic rate or mutation analysis. Results RFS remained superior in the imatinib arm (hazard ratio, 0.6; 95% CI, 0.43 to 0.75; Cox model–adjusted P < .001). On multivariable analysis of patients in the placebo arm, large tumor size, small bowel location, and high mitotic rate were associated with lower RFS, whereas tumor genotype was not significantly associated with RFS. Multivariable analysis of patients in the imatinib arm yielded similar findings. When comparing the two arms, imatinib therapy was associated with higher RFS in patients with a KIT exon 11 deletion of any type, but not a KIT exon 11 insertion or point mutation, KIT exon 9 mutation, PDGFRA mutation, or wild-type tumor, although some of these patient groups were small. Adjuvant imatinib did not seem to alter overall survival. Conclusion Our findings show that tumor size, location, and mitotic rate, but not tumor genotype, are associated with the natural history of GIST. Patients with KIT exon 11 deletions assigned to 1 year of adjuvant imatinib had a longer RFS.

Object The aim of this study was to determine the prospective hemorrhage rate in a group of retrospectively identified patients in whom symptoms had an unclear relationship to an intracerebral cavernous malformation (ICM) or the malformation itself was an incidental finding. Methods Patients with incidentally discovered ICMs diagnosed between 1989 and 1999 were identified from a previously published cohort. Those with ICMs having an unclear relationship with existing symptoms were also eligible for analysis. Updated clinical and radiographic data pertaining to symptomatic intracerebral hemorrhage related to the ICM or new seizures were obtained through medical chart review and mail survey. In select patients, phone calls were made and death certificates were obtained when possible. The prospective hemorrhage rate was calculated as the number of prospective hemorrhages divided by the number of patient-years of follow-up. Results There were 1311 patient-years of follow-up among the 107 patients (49.5% male; mean age at diagnosis 52 years) eligible for this study. Forty-four patients died in the follow-up period, and the cause of death could be determined in 34 (77%). Two patients had a prospective hemorrhage, which was definitively related to the ICM in only one. Thus, the definitive prospective bleed rate was 0.08% per patient-year. No new seizures developed in any of the patients during the follow-up period. Conclusions The risk of prospective hemorrhage in patients presenting asymptomatically with ICM is very low. This information can be useful in managing such patients and may be most applicable to those with a single ICM.

BACKGROUNDSince 2002, priority Model for End‐stage Liver Disease (MELD) exception status has been given to patients with hepatocellular carcinoma (HCC) who meet the Milan criteria. Since then, the number of liver transplantations performed in patients with HCC has increased, but to the authors' knowledge, few studies to date have examined the effect of MELD exception recommendations on therapy use and survival rates in a nationwide sample. The current study examines therapy use and long‐term survival rates among patients with HCC tumors meeting the Milan criteria in the post‐MELD exception era.METHODSThe current study is a retrospective cohort study of 2179 patients with localized HCC meeting the Milan criteria who were registered between 2004 and 2007 in the Surveillance, Epidemiology, and End Results database.RESULTSA total of 43% of patients did not receive any specific therapy. Overall, the 5‐year relative survival rate for patients receiving only supportive care was dismal at 24% (95% confidence interval [95% CI], 21%‐27%), whereas that for patients undergoing liver transplantation was 77% (95% CI, 71%‐82%). Long‐term survival was found to be dependent on age, race/ethnicity, and type of therapy received. A multivariate Cox proportional hazards model adjusted for age, race/ethnicity, and type of therapy received demonstrated that, compared with white patients, black patients had significantly poorer survival outcomes (hazards ratio, 1.23; 95% CI, 1.03‐1.47 [P = .02]), whereas Asian/Pacific Islander patients had significantly better survival rates when compared with white patients (HR, 0.66; 95% CI, 0.57‐0.77 [P < .001]).CONCLUSIONSDespite having localized disease that met transplantation criteria, nearly 50% of the large nationwide cohort of patients with HCC in the current study received only supportive care and had dismal 5‐year relative survival rates, especially among black patients. Cancer 2014;120:1725–1732. © 2014 American Cancer Society.

Background— Cardiac dysfunction in failing hearts of human patients and animal models is associated with both microtubule densification and transverse-tubule (T-tubule) remodeling. Our objective was to investigate whether microtubule densification contributes to T-tubule remodeling and excitation–contraction coupling dysfunction in heart disease. Methods and Results— In a mouse model of pressure overload–induced cardiomyopathy by transaortic banding, colchicine, a microtubule depolymerizer, significantly ameliorated T-tubule remodeling and cardiac dysfunction. In cultured cardiomyocytes, microtubule depolymerization with nocodazole or colchicine profoundly attenuated T-tubule impairment, whereas microtubule polymerization/stabilization with taxol accelerated T-tubule remodeling. In situ immunofluorescence of heart tissue sections demonstrated significant disorganization of junctophilin-2 (JP2), a protein that bridges the T-tubule and sarcoplasmic reticulum membranes, in transaortic banded hearts as well as in human failing hearts, whereas colchicine injection significantly preserved the distribution of JP2 in transaortic banded hearts. In isolated mouse cardiomyocytes, prolonged culture or treatment with taxol resulted in pronounced redistribution of JP2 from T-tubules to the peripheral plasma membrane, without changing total JP2 expression. Nocodazole treatment antagonized JP2 redistribution. Moreover, overexpression of a dominant-negative mutant of kinesin 1, a microtubule motor protein responsible for anterograde trafficking of proteins, protected against JP2 redistribution and T-tubule remodeling in culture. Finally, nocodazole treatment improved Ca 2+ handling in cultured myocytes by increasing the amplitude of Ca 2+ transients and reducing the frequency of Ca 2+ sparks. Conclusion— Our data identify a mechanistic link between microtubule densification and T-tubule remodeling and reveal microtubule-mediated JP2 redistribution as a novel mechanism for T-tubule disruption, loss of excitation–contraction coupling, and heart failure.