Does cognition improve following LVAD implantation?

BACKGROUND: Studies of cognition after LVAD surgery have produced mixed results. To explore whether cognition would improve, decline, or remain stable after LVAD surgery, we examined cognition before and 1- and 3-months after LVAD surgery. Patients with post-surgical stroke were excluded. METHODS: 28 subjects (mean age = 54.31 ± 12 years) comprised an observational case series from the DuraHeart LVAS device® trial. Cognitive testing was performed at baseline, 1-month, and 3-month post-surgery, and included tests of attention, memory, language, visualmotor speed (TMT) and visualconstruction. RESULTS: No difference in cognition was found between baseline and 1-month exams (means z score improvement = 0.06, p = 0.43) but cognition improved significantly between baseline and 3-month exams (mean z score improvement = 0.34, p < 0.00001). Examination of individual test scores found, after correction for multiple comparisons, only the TMT variable was significantly different at the 3-month exam. CONCLUSIONS: We found significantly improved cognition 3 months after LVAD surgery in a subset of patients without post-surgical stroke. The reasons for the lack of cognitive improvement at the 1-month post-surgical assessment may include ongoing medical and physiological disruptions in the immediate post-operative period. Further research into the sources of delayed improvement is warranted. Cognitive assessments performed immediately after surgery should be interpreted with caution because the results may not reflect longer term cognitive outcomes. LVAD patients may require additional support to successfully manage their health in the weeks immediately following surgery but assistance needs may decrease over time.

CCL2 is a potent regulator of prostate cancer cell migration and proliferation.

Tumor cells in the bone interact with the microenvironment to promote tumor cell survival and proliferation, resulting in a lethal phenotype for patients with advanced prostate cancer. Monocyte chemoattractant protein 1 (CCL2) is a member of the CC chemokine family and is known to promote monocyte chemotaxis to sites of inflammation. Here we have shown that human bone marrow endothelial (HBME) cells secrete significantly higher levels of CCL2 compared to human aortic endothelial cells and human dermal microvascular endothelial cells. Furthermore, we demonstrate that CCL2 is a potent chemoattractant of prostate cancer epithelial cells, and that stimulation of PC-3 and VCaP cells resulted in a dose-dependent activation of PI3 kinase/Akt signaling pathway. Activation of the PI3 kinase/Akt pathway was found to be vital to the proliferative effects of CCL2 stimulation of both PC-3 and VCaP cells. Additionally, CCL2 stimulated the phosphorylation of p70-S6 kinase (a downstream target of Akt) and induced actin rearrangement, resulting in a dynamic morphologic change indicative of microspike formation. These data suggest that bone marrow endothelial cells are a major source of CCL2, and that an elevated secretion of CCL2 recruits prostate cancer epithelial cells to the bone microenvironment and regulates their proliferation rate.

Androgen-independent prostate cancer is a heterogeneous group of diseases: lessons from a rapid autopsy program.

Understanding the biology of prostate cancer metastasis has been limited by the lack of tissue for study. We studied the clinical data, distribution of prostate cancer involvement, morphology, immunophenotypes, and gene expression from 30 rapid autopsies of men who died of hormone-refractory prostate cancer. A tissue microarray was constructed and quantitatively evaluated for expression of prostate-specific antigen, androgen receptor, chromogranin, synaptophysin, MIB-1, and alpha-methylacylCoA-racemase markers. Hierarchical clustering of 16 rapid autopsy tumor samples was performed to evaluate the cDNA expression pattern associated with the morphology. Comparisons were made between patients as well as within the same patient. Metastatic hormone-refractory prostate cancer has a heterogeneous morphology, immunophenotype, and genotype, demonstrating that "metastatic disease" is a group of diseases even within the same patient. An appreciation of this heterogeneity is critical to evaluating diagnostic and prognostic biomarkers as well as to designing therapeutic targets for advanced disease.

Humoral immune response to alpha-methylacyl-CoA racemase and prostate cancer.

BACKGROUND: Although prostate-specific antigen (PSA) is a prototypic biomarker for prostate cancer, it has poor specificity. Expression of alpha-methylacyl-CoA racemase (AMACR), which is involved in the conversion of R-stereoisomers of branched-chain fatty acids to S-stereoisomers, has been shown to be specifically increased in prostate cancer epithelia. However, attempts to detect AMACR in circulation have not been successful. Hence, we determined whether an immune response to AMACR could be used as a serum biomarker for prostate cancer. METHODS: Sera from patients with biopsy-proven prostate cancer and from control subjects were screened for a humoral immune response to selected tumor antigens, including AMACR, by using protein microarrays (46 patients, 28 control subjects). Humoral immune response to AMACR was then validated using high-throughput immunoblot analysis (151 patients, 259 control subjects) and enzyme-linked immunosorbent assay (ELISA) (54 patients, 55 control subjects). Receiver operating characteristic curves were used to determine the sensitivity and specificity of the immune response to AMACR to detect prostate cancer. RESULTS: Immunoreactivity against AMACR was statistically significantly higher in sera from patients with prostate cancer than in control subjects by all three techniques (P(protein microarray) =.009, P(immunoblot)<.001, P(ELISA) =.011). High-throughput immunoblot analysis revealed that, in subjects with intermediate PSA levels (4-10 ng/mL), the immune response against AMACR was more sensitive and specific than was PSA in distinguishing sera from prostate cancer patients relative to control subjects (sensitivity and specificity of 77.8% and 80.6% versus 45.6% and 50%, respectively; area under the curve of 0.789 versus 0.492; P<.001). CONCLUSION: Assays to detect a humoral immune response against AMACR may have the potential to supplement PSA screening in identifying patients with clinically significant prostate cancer, especially those with intermediate PSA levels.

Elevated alpha-methylacyl-CoA racemase enzymatic activity in prostate cancer.

Alpha-methylacyl-CoA racemase (AMACR) is a peroxisomal and mitochondrial enzyme involved in the beta-oxidation of branched fatty acids, shown to be elevated in prostate cancer by several recent studies. Sequence variants of AMACR have been linked to prostate cancer risk. Although mRNA transcript, protein, and sequence variants of AMACR have been studied in the context of prostate cancer, AMACR enzymatic activity has not been addressed. Here we present evidence that AMACR activity is consistently elevated in prostate cancer tissue specimens. This activity can be immunodepleted from prostate cancer tissue extracts. Furthermore, mock needle biopsy cores containing foci of prostate cancer exhibited increased AMACR enzymatic activity, correlating with both protein levels and histopathology. Taken together, our studies suggest that AMACR activity is increased in prostate cancer relative to benign epithelia and suggests that monitoring AMACR activity levels in prostate needle biopsies may have clinical applications.