Fluorescence Anisotropy of Cellular NADH as a Tool to Study Different Metabolic Properties of Human Melanocytes and Melanoma Cells

In this study, we wanted to see if fluorescence anisotropy could be used to detect changes in metabolism in cells with significant light scattering and absorption properties. Fluorescence anisotropy measurements of nicotinamide adenine dinucleotide (NADH) were performed with human melanocytes and melanoma cell lines. To demonstrate the feasibility of using fluorescence anisotropy for detecting metabolic changes, the electron transport chain was blocked using rotenone, inducing an accumulation of intracellular NADH. Total fluorescence increased in all cells as a result of rotenone treatment. Fluorescence anisotropy decreased in the rotenone-treated cells relative to the controls, suggesting an increased ratio of free to protein-bound NADH in the treated cells. In general, the fluorescence anisotropy of the melanocytes was significantly higher than that of the melanoma cell lines. Reflectance spectroscopy showed that the differences in fluorescence anisotropy between the cell types were not due to differences in scattering and absorption properties. Intrinsic cellular NADH fluorescence was experimentally extracted by ratioing polarized fluorescence to polarized reflectance. NADH binding, measured as the ratio of fluorescence intensity at 430 and 465 nm, showed more protein-bound NADH in the melanocytes than in the melanoma cells, consistent with the fluorescence anisotropy measurements.     

Political correctness and academic principles: a reply to Simpson

The author discusses Christopher Simpson's (1996) article, 'Elisabeth Noelle-Neumann's 'Spiral of Silence' and the Historical Context of Communication Theory.' He questions the relevance of biographical data for the evaluation of scientific theories and methods, and analyzes the rhetorical structure of Simpson's arguments. He concludes that Simpson's claims about the influence of Noelle's biography on her scholarly work are not grounded in evidence.     

Outcome of rheumatoid arthritis and psoriasis following autologous stem cell transplantation for hematologic malignancy

Based on successful results in animal models, it has been proposed that high-dose myeloablative therapy followed by autologous bone marrow or stem cell transplantation (ABMT/ASCT) may cure autoimmune disease. The coexistence of autoimmune disease and hematologic malignancy provides an opportunity to examine the response of autoimmune disease to ABMT or ASCT. We describe 4 patients with autoimmune disease (3 with psoriasis and 1 with rheumatoid arthritis) and hematologic malignancy. In each patient, the autoimmune disease remitted posttransplantation, but, in 4 patients with long-term followup, it recurred at 8-24 months. The earliest relapse occurred in a patient treated with interferon-alpha. Our experience suggests that a single autograft with unpurged stem cells is unlikely to cure autoimmune disease, but that other strategies building on this approach are worthy of investigation.     

Multicarrier modulation for narrowband PCS

Investigation of multicarrier modulation has demonstrated the feasibility of using this modulation format to deliver relatively high channel bit rates (24 kbps) to a low cost, pager-like personal communications service (PCS) terminal that enjoys long battery life (e.g., one month on a few pen-light cells). This is to be compared to the 1200 bps carried by typical current paging systems or the 6250 bps attained by the new ERMES paging system. While more complex modulation formats, such as PSK and QAM, might achieve higher bit rates in less (power, size, cost) constrained environments, amplitude keying of the component subcarriers allows simple noncoherent energy detection that is found to be robust in this short message delivery application     

An alternative method for the quantitation of neuronal damage after experimental middle cerebral artery occlusion in rats: analysis of behavioral deficit

We tested the hypothesis that increasing durations of focal ischemia that have been shown to result in enlargement of cortical infarct will be associated with progression of behavioral dysfunction that can be measured by a battery of tests sufficiently sensitive and reproducible to detect a positive effect of pharmacotherapy. Untreated or N-methyl-D-aspartate receptor antagonist (CNS-1102)-treated spontaneously hypertensive rats underwent 45, 60, 90, or 120 min of tandem middle cerebral and common carotid artery occlusion followed by reperfusion. We then evaluated the extent of damage and its recovery for up to 21 days using nine behavioral tests aimed at analyzing strength, coordination, and bilateral asymmetry. Also using a graded bioassay that employs a curve-fitting computer program (ALLFIT) to correlate duration of ischemia with degree of behavioral dysfunction, we calculated the average of maximal behavioral dysfunction and duration of ischemia required to produce half-maximal behavioral dysfunction and compared these values in untreated controls with analogous values obtained from animals treated with CNS-1102. Three behavioral tests, forearm flex, tape (somatosensory neutralization), and foot-fault placing, were each separately and combined able to distinguish between the degrees of damage produced by increasing durations of ischemia. The behavioral abnormalities assessed using the tape test were reversible within a week, whereas those using forearm flex or foot-fault tests persisted for at least 21 days. CNS-1102 significantly reduced behavioral dysfunction measured by all three tests. This analysis of behavioral dysfunction represents a useful experimental model to grade efficacy of therapies aimed at protecting the brain from damage produced by acute stroke and might also be used to assess recovery from preexisting ischemic damage.     

Kinetics of modification of the mitochondrial succinate-ubiquinone reductase by 5,5''-dithiobis-(2-nitro-benzoic acid)

In the present study, we examined the effect of the thromboxane/prostaglandin endoperoxide analogue U46619 on proliferation and hypertrophy in cultured rat vascular smooth muscle cells and the roles of protein kinase C and transforming growth factor-beta (TGF-beta) in the mediation of the hypertrophic response to U46619. Since an increase in basic fibroblast growth factor (bFGF) was previously shown to mediate the hypertrophic response to U46619, we also assessed the relationship between bFGF and TGF-beta in the expression of U46619 actions. U46619 increased [35S]methionine incorporation into protein and protein content of vascular smooth muscle cells but had no effect on cell number. A role for TGF-beta was supported by the following observations: (1) exogenous human TGF-beta 1 increased protein synthesis; (2) antibody to TGF-beta blocked both TGF-beta- and U46619-induced increases in protein content; (3) U46619 increased active and total TGF-beta bioactivities; and (4) the actions of U46619 on protein content and TGF-beta bioactivity were blocked by the thromboxane/prostaglandin endoperoxide receptor antagonist SQ 29,548. Previous observations had demonstrated a role for bFGF in the expression of U46619 actions on protein synthesis. Results of the present study suggest that TGF-beta and bFGF interact in mediating the protein synthetic response to U46619. First, the concentration of exogenous TGF-beta (10 pmol/L) alone required to produce a protein synthetic response equivalent to that induced by U46619 was much higher than the concentration of endogenous active TGF-beta that accumulated in the media in response to U46619 (0.7 pmol/L). Second, bFGF (20 ng/mL) increased total TGF-beta bioactivity and stimulated protein synthesis. The hyper-trophic response to bFGF was blocked by anti-TGF-beta. The ability of U46619 and bFGF to increase protein synthesis and protein content in vascular smooth muscle cells was associated with TGF-beta-induced suppression of proliferation, as evidenced by the ability of antibody to TGF-beta to enhance U46619- and bFGF-induced increases in [3H]thymidine incorporation into DNA. Results of the present study also supported a role for protein kinase C in the expression of U46619 and bFGF actions. U46619 increased protein kinase C activity in the particulate fraction of vascular smooth muscle cells. Moreover, the protein kinase C inhibitors GF109203X and staurosporine blocked U46619- and bFGF-induced increases in protein synthesis as well as active and total TGF-beta bioactivities. By contrast, the protein kinase C inhibitors did not prevent the increases in protein synthesis induced by exogenous TGF-beta. The results demonstrate that thromboxane/prostaglandin endoperoxide signals increased TGF-beta bioactivity via protein kinase C. Increases in both bFGF and TGF-beta are required for an optimal hypertrophic response to U46619. The hypertrophic response to TGF-beta occurs through a protein kinase C-independent pathway.     

Do We Stand on Common Ground? A Threat Appraisal Model for Terror Alerts Issued by the Department of Homeland Security

The fabric and faces of threat, and the expediency and efficiency in the communication of threat, are examined with a threat appraisal model. This model is empirically tested on an ongoing communication challenge, the issuance of terror alerts by the United States' Department of Homeland Security (DHS), focusing on how threat is appraised by both the conservative and liberal audiences. Findings showed a shared view by the DHS and conservative audiences on the levels and nature of threats; liberal audiences thought otherwise. Though there appeared to be a consensus between the conservative and liberal audiences on the efficacy of threat communication, more internal consistency within DHS is needed to optimise its effectiveness.     

Optimal control and operation of drum granulation processes

Process optimisation and optimal control of batch and continuous drum granulation processes are studied in this paper. The main focus of the current research has been: (i) construction of optimisation and control relevant, population balance models through the incorporation of moisture content, drum rotation rate and bed depth into the coalescence kernels; (ii) investigation of optimal operational conditions using constrained optimisation techniques; (iii) development of optimal control algorithms based on discretized population balance equations; and (iv) comprehensive simulation studies on optimal control of both batch and continuous granulation processes. The objective of steady state optimisation is to minimise the recycle rate with minimum cost for continuous processes. It has been identified that the drum rotation-rate, bed depth (material charge), and moisture content of solids are practical decision (design) parameters for system optimisation. The objective for the optimal control of batch granulation processes is to maximize the mass of product-sized particles with minimum time and binder consumption. The objective for the optimal control of the continuous process is to drive the process from one steady state to another in a minimum time with minimum binder consumption, which is also known as the state-driving problem. It has been known for some time that the binder spray-rate is the most effective control (manipulative) variable. Although other possible manipulative variables, such as feed flow-rate and additional powder flow-rate have been investigated in the complete research project, only the single input problem with the binder spray rate as the manipulative variable is addressed in the paper to demonstrate the methodology. It can be shown from simulation results that the proposed models are suitable for control and optimisation studies, and the optimisation algorithms connected with either steady state or dynamic models are successful for the determination of optimal operational conditions and dynamic trajectories with good convergence properties.