Disease patterns at arterial branches and their relation to flow

The distribution of lesions around arterial branch points is complex and changes with age. Four distinct patterns - here termed the arrowhead pattern, the lateral pattern, the upstream streak and the volcano - have been reported around the origins of intercostal arteries in the human aorta at different ages. The first two patterns also occur in young and old rabbits, the third in minipigs, and the fourth in apolipoprotein E/LDL receptor knockout mice. It is unclear how all four patterns can depend solely on flow; a particular problem is that the prevalence of lipid deposition remains highly nonuniform for several branch diameters upstream of the ostium. Variations in the prevalence of fatty streaks may originate near the branch and then spread by the migration of activated endothelial cells towards the heart. The pattern of raised lesions may reflect a different aetiology.     

Gene selection and clustering for time-course and dose-response microarray experiments using order-restricted inference

We propose an algorithm for selecting and clustering genes according to their time-course or dose-response profiles using gene expression data. The proposed algorithm is based on the order-restricted inference methodology developed in statistics. We describe the methodology for time-course experiments although it is applicable to any ordered set of treatments. Candidate temporal profiles are defined in terms of inequalities among mean expression levels at the time points. The proposed algorithm selects genes when they meet a bootstrap-based criterion for statistical significance and assigns each selected gene to the best fitting candidate profile. We illustrate the methodology using data from a cDNA microarray experiment in which a breast cancer cell line was stimulated with estrogen for different time intervals. In this example, our method was able to identify several biologically interesting genes that previous analyses failed to reveal.     

Detection of HBD1 peptide in peripheral blood mononuclear cell subpopulations by intracellular flow cytometry

Production of human beta-defensin1 (HBD1) in response to LPS in monocytes, myeloid dendritic cells and plasmacytoid dendritic cells (PDC) was examined. Since PDC make up only 0.1-0.5% of the peripheral blood mononuclear cell population, we developed a method to determine HBD1 peptide levels using four-color flow cytometry, which can examine several cell surface or intracellular markers at once. Coupled with intracellular flow cytometry, we determined that PDC and monocytes only made significant amounts of HBD1 when exposed to >50ng/ml LPS for 2h. This response was limited to monocytes when ultrapure LPS was used, and was inhibited in PDC by chloroquine treatment.     

Favorable effect of VEGF gene transfer on ischemic peripheral neuropathy

Ischemic peripheral neuropathy is a frequent, irreversible complication of lower extremity vascular insufficiency. We investigated whether ischemic peripheral neuropathy could be prevented and/or reversed by gene transfer of an endothelial cell mitogen designed to promote therapeutic angiogenesis. Intramuscular gene transfer of naked DNA encoding vascular endothelial growth factor (VEGF) simultaneously with induction of hindlimb ischemia in rabbits abrogated the substantial decrease in motor and sensory nerve parameters, and nerve function recovered promptly. When gene transfer was administered 10 days after induction of ischemia, nerve function was restored earlier and/or recovered faster than in untreated rabbits. These findings are due in part to enhanced hindlimb perfusion. In addition, however, the demonstration of functional VEGF receptor expression by Schwann cells indicates a direct effect of VEGF on neural integrity as well. These findings thus constitute a new paradigm for the treatment of ischemic peripheral neuropathy.     

Noradrenergic depletion increases inflammatory responses in brain: effects on IkappaB and HSP70 expression

The inflammatory responses in many cell types are reduced by noradrenaline (NA) binding to beta-adrenergic receptors. We previously demonstrated that cortical inflammatory responses to aggregated amyloid beta (Abeta) are increased if NA levels were first depleted by lesioning locus ceruleus (LC) noradrenergic neurons, which replicates the loss of LC occurring in Alzheimer's disease. To examine the molecular basis for increased responses, we used the selective neurotoxin DSP4 to lesion the LC, and then examined levels of putative anti-inflammatory molecules. Inflammatory responses were achieved by injection of aggregated Abeta1-42 peptide and IL-1beta into frontal cortex, which induced neuronal inducible nitric oxide synthase (iNOS) and microglial IL-1beta expression. DSP4-treatment reduced basal levels of nuclear factor kappa B (NF-kappaB) inhibitory IkappaB proteins, and of heat shock protein (HSP)70. Inflammatory responses were prevented by co-injection (ibuprofen or ciglitzaone) or oral administration (pioglitazone) of peroxisome proliferator-activated receptor gamma (PPARgamma) agonists. Treatment with PPARgamma agonists restored IkappaBalpha, IkappaBbeta, and HSP70 levels to values equal or above those observed in control animals, and reduced activation of cortical NF-kappaB. These results suggest that noradrenergic depletion reduces levels of anti-inflammatory molecules which normally limit cortical responses to Abeta, and that PPARgamma agonists can reverse that effect. These findings suggest one mechanism by which PPARgamma agonists could provide benefit in neurological diseases having an inflammatory component.     

Effect of neurotensin on pancreatic function in man

The effect of neurotensin on submaximally-stimulated hepatobiliary and pancreatic secretion was studied in 6 healthy subjects. An intravenous infusion of neurotensin 1.4 ± 0.3 pmol/kg/min, designed to reproduce plasma neurotensin immunoreactivity levels within the physiological range, produced a significant increase in pancreatic bicarbonate output. Plasma concentrations of pancreatic polypeptide rose by 83 ± 16 pmol/l and were associated with a small reduction in trypsin, but no significant change in bilirubin outputs.     

Proposal for Naming Host Cell-Derived Inserts in Retrovirus Genomes

We propose a system for naming inserted sequences in transforming retroviruses (i.e., onc genes), based on using trivial names derived from a prototype strain of virus.     

Extra-virgin olive oil diet and mild physical activity prevent cartilage degeneration in an osteoarthritis model: an in vivo and in vitro study on lubricin expression

Mediterranean diet includes a relatively high fat consumption mostly from monounsaturated fatty acids mainly provided by olive oil, the principal source of culinary and dressing fat. The beneficial effects of olive oil have been widely studied and could be due to its phytochemicals, which have been shown to possess anti-inflammatory properties. Lubricin is a chondroprotective glycoprotein and it serves as a critical boundary lubricant between opposing cartilage surfaces. A joint injury causes an initial flare of cytokines, which decreases lubricin expression and predisposes to cartilage degeneration such as osteoarthritis. The aim of this study was to evaluate the role of extra-virgin olive oil diet and physical activity on inflammation and expression of lubricin in articular cartilage of rats after injury. In this study we used histomorphometric, histological, immunocytochemical, immunohistochemical, western blot and biochemical analysis for lubricin and interleukin-1 evaluations in the cartilage and in the synovial fluid. We report the beneficial effect of physical activity (treadmill training) and extra-virgin olive oil supplementation, on the articular cartilage. The effects of anterior cruciate ligament transection decrease drastically the expression of lubricin and increase the expression of interleukin-1 in rats, while after physical activity and extra-virgin olive oil supplemented diet, the values return to a normal level compared to the control group. With our results we can confirm the importance of the physical activity in conjunction with extra-virgin olive oil diet in medical therapy to prevent osteoarthritis disease in order to preserve the articular cartilage and then the entire joint.     

Clinical and Biological Relevance of Genomic Heterogeneity in Chronic Lymphocytic Leukemia

Background

Chronic lymphocytic leukemia (CLL) is typically regarded as an indolent B-cell malignancy. However, there is wide variability with regards to need for therapy, time to progressive disease, and treatment response. This clinical variability is due, in part, to biological heterogeneity between individual patients’ leukemias. While much has been learned about this biological variation using genomic approaches, it is unclear whether such efforts have sufficiently evaluated biological and clinical heterogeneity in CLL.

Methods

To study the extent of genomic variability in CLL and the biological and clinical attributes of genomic classification in CLL, we evaluated 893 unique CLL samples from fifteen publicly available gene expression profiling datasets. We used unsupervised approaches to divide the data into subgroups, evaluated the biological pathways and genetic aberrations that were associated with the subgroups, and compared prognostic and clinical outcome data between the subgroups.

Results

Using an unsupervised approach, we determined that approximately 600 CLL samples are needed to define the spectrum of diversity in CLL genomic expression. We identified seven genomically-defined CLL subgroups that have distinct biological properties, are associated with specific chromosomal deletions and amplifications, and have marked differences in molecular prognostic markers and clinical outcomes.

Conclusions

Our results indicate that investigations focusing on small numbers of patient samples likely provide a biased outlook on CLL biology. These findings may have important implications in identifying patients who should be treated with specific targeted therapies, which could have efficacy against CLL cells that rely on specific biological pathways.