Dendritic cells in the arterial wall express C1q: potential significance in atherogenesis.

OBJECTIVE: Dendritic cells (DCs) accumulate in atherosclerotic lesions but their characteristics and their role in atherogenesis are poorly understood. C1q, an element of the first component of complement, is expressed by interdigitating dendritic cells and follicular dendritic cells in the spleen. It has been suggested that C1q is involved in capturing immune complexes in the lymphoid tissue. Immune complexes are also detected in atherosclerotic lesions. The present study investigated whether C1q is expressed by DCs in the arterial wall. Because DCs accumulating within atherosclerotic lesions might originate from monocytes that infiltrate the intima from very early stages of atherosclerosis, C1q expression was also examined in monocyte-derived DCs in vitro. METHODS: Specimens of the aorta, carotid, mammary, popliteal and tibial arteries were obtained during operation. Expression of C1q in the arterial wall was studied by immunohistochemistry. The nature of cells expressing C1q was studied in sections double stained with antibodies to C1q and cell type specific markers including CD1a and S-100 (for identification of DCs), CD68 (macrophages), CD3 (T-cells), von Willebrand factor (endothelial cells), and smooth muscle alpha-actin (smooth muscle cells). In vitro, DCs were differentiated from human peripheral blood monocytes using GM-CSF and IL-4. Peripheral blood monocytes were differentiated to macrophages using M-CSF. The expression of C1q in monocytes and in vitro monocyte-derived DCs and macrophages was determined by RT-PCR, Western blotting, immunofluorescence microscopy and flow cytometry. RESULTS: In all the arterial specimens studied, DCs expressing C1q were detected. C1q was also found in macrophages, macrophage foam cells and in neovascular endothelial cells in atherosclerotic lesions, but no C1q expression was detected in T-cells and smooth muscle cells. In vitro analysis demonstrated that monocyte-derived DCs and macrophages express C1q but no C1q was detected in monocytes. CONCLUSION: C1q is expressed by DCs residing in the arterial wall as well as by monocyte-derived DCs in vitro. Expression of C1q occurs during differentiation of monocytes to DCs and macrophages and might be important in binding and trapping immune complexes in atherosclerotic lesions.

Thermodynamics energy for both supervised and unsupervised learning neural nets at a constant temperature.

Unified Lyaponov function is given for the first time to prove the learning methodologies convergence of artificial neural network (ANN), both supervised and unsupervised, from the viewpoint of the minimization of the Helmholtz free energy at the constant temperature. Early in 1982, Hopfield has proven the supervised learning by the energy minimization principle. Recently in 1996, Bell & Sejnowski has algorithmically demonstrated Independent Component Analyses (ICA) generalizing the Principal Component Analyses (PCA) that the continuing reduction of early vision redundancy happens towards the "sparse edge maps" by maximization of the ANN output entropy. We explore the combination of both as Lyaponov function of which the proven convergence gives both learning methodologies. The unification is possible because of the thermodynamics Helmholtz free energy at a constant temperature. The blind de-mixing condition for more than two objects using two sensor measurement. We design two smart cameras with short term working memory to do better image de-mixing of more than two objects. We consider channel communication application that we can efficiently mix four images using matrices [AO] and [Al] to send through two channels.

Chaotic neuron models and their VLSI circuit implementations.

The design of a chaotic neuron model is proposed and implemented in a CMOS very large scale integration (VLSI) chip. The transfer function of the neuron is defined as a piecewise linear (PWL) N-shaped function. In this paper, the new concept of the baseline function is introduced. It is the mapping of the neuron state to the neuron output. It is used to control the chaotic behavior of collective neurons. The chaotic behavior is analyzed and verified by Lyapunov exponents. An analog CMOS chip was designed to implement the theory and it was fabricated through the MOSIS program. The measurement diagnoses of the chip is demonstrated.

Molecular computing for edge-enhanced laser imaging.

In order to illustrate the self-assembly capability, we consider a laser imaging experiment on a wet film that is made of bacteriorhodopsin (BR) molecules suspended in a diffusion-limited viscous medium. BR wet film is similar to a wet photograph film but having a finer resolution and adaptive pixel locations due to laser-induced thermal diffusion. The synergism between thermal diffusion of BR molecules (induced externally by a write-laser) and molecular photochromism (generated internally by a read-laser) is exploited naturally for edge-enhanced image applications.

Wavelet transform as a bank of the matched filters.

The wavelet transform is a powerful tool for the analysis of short transient signals. We detail the advantages of the wavelet transform over the Fourier transform and the windowed Fourier transform and consider the wavelet as a bank of the VanderLugt matched filters. This methodology is particularly useful in those cases in which the shape of the mother wavelet is approximately known a priori. A two-dimensional optical correlator with a bank of the wavelet filters is implemented to yield the time-frequency joint representation of the wavelet transform of one-dimensional signals.

Optical database/knowledgebase machines.

In this paper we discuss various aspects of databases and knowledgebases and indicate how optics can play an important role in the solution of many of the previously unsolved problems in this field.

Optical expert systems.

A general approach to using spatial light modulators in expert systems and in related AI methods is discussed. The information capacity of such system can far exceed the capacity of the spatial light modulator itself.

Optical implementation of associative memory with controlled nonlinearity in the correlation domain.

A mathematical model for incorporating controllable nonlinearity in the correlation domain of a conventional associative memory is described. Such a mechanism provides the flexibility of rapidly and arbitrarily changing the strengths of the stored states in an associative memory. Such a feature corresponds to shifting of attention in psychological terms. This attentive associative memory can be implemented optically. Results obtained with computer simulation and a design for a compact optical implementation are discussed.

Acousto-optic processors for real-time generation of time-frequency representations.

Acousto-optic processors for calculating different two-dimensional (2-D) time-frequency representations for one dimensional temporal signals in real time are described. The various 2-D representations discussed in the literature, such as the Wigner distribution and the ambiguity function, are shown to be obtainable through minor variations in an acousto-optic processor consisting of two Bragg cells in a parallel configuration. Also obtained and discussed are two new time-frequency representations that, for amplitude-modulated signals, correspond to mean-frequency-selective correlation and Doppler-frequency-selective convolution. Experimental results are presented to highlight the special features of the different time-frequency representation.

Multiplexed coherent optical processor for calculating generalized moments.

A coherent optical processor capable of calculating generalized moments of a two-dimensional pattern is described. A spatial-frequency multiplexing scheme is used to provide for parallel computation of multiple moments. The use of a computer-generated holographic mask permits complete flexibility in choosing moment-generating functions; e.g., the functions could be complex or have a predetermined weighting function. Experimentally, calculation of five geometric moments (corresponding to x, y, xy, x(2), and y(2)) is demonstrated for simple objects. The special features of the proposed coherent optical processor and its space-bandwidth requirements are also discussed.

Optical implementation of integral transforms with Bessel function kernels.

Integral transforms involving Bessel function kernels are useful in analyzing effects of circularly symmetric optical systems on arbitrary inputs. Methods for performing the integral transforms optically are divided into two categories. The first category involves input data available in Cartesian (x, y) format and uses the close connection between the desired integral transform and the two-dimensional Fourier transform in Cartesian coordinates. The second category involves input data in polar (r, theta) format and uses methods such as change of variables to perform the integral transform as a correlation integral. Experimental results obtained with optical implementation for these two categories are presented.