The significance of spinal cord compression as the initial manifestation of lymphoma

Sex hormones have profound effects on immune responses and may influence the outcome of autoimmune diseases such as rheumatoid arthritis (RA). We investigated the effect of gonadal steroids on the production of interleukin-1 (IL-1) and IL-6, cytokines believed to be important in the pathogenesis of RA. Peripheral blood mononuclear cells (PBMCs) were isolated from healthy male donors and male patients with RA, and were stimulated with lipopolysaccharide (LPS) in the presence of different concentrations of 17-beta-estradiol, progesterone or testosterone. In studies of cells from normal male donors, 17-beta-estradiol at pharmacological concentrations (> or = 10(-6) M) enhanced IL-1 and IL-6 secretion as well as the production of cell-associated IL-1. Progesterone and testosterone at similar concentrations inhibited IL-1 secretion but had no significant effect on IL-6 secretion or on the production of cell-associated IL-1. In studies of male RA donors, 17-beta-estradiol failed to enhance IL-1 or IL-6 secretion and progesterone failed to inhibit IL-1 secretion. The inhibitory effects of testosterone, however, appeared to be similar to that in normal donors. It is suggested that 17-beta-estradiol may promote IL-1 and IL-6 production and release, while gestation hormone, progesterone, and testosterone may inhibit IL-1 release in vivo. These data may partly explain the gender and age differences in the incidence of RA and the development of the disease in men with low and androgen levels.     

Synthesis of fault-tolerant feedforward neural networks usingminimax optimization

In this paper we examine a technique by which fault tolerance can be embedded into a feedforward network leading to a network tolerant to the loss of a node and its associated weights. The fault tolerance problem for a feedforward network is formulated as a constrained minimax optimization problem. Two different methods are used to solve it. In the first method, the constrained minimax optimization problem is converted to a sequence of unconstrained least-squares optimization problems, whose solutions converge to the solution of the original minimax problem. An efficient gradient-based minimization technique, specially tailored for nonlinear least-squares optimization, is then applied to perform the unconstrained minimization at each step of the sequence. Several modifications are made to the basic algorithm to improve its speed of convergence. In the second method a different approach is used to convert the problem to a single unconstrained minimization problem whose solution very nearly equals that of the original minimax problem. Networks synthesized using these methods, though not always fault tolerant, exhibit an acceptable degree of partial fault tolerance.     

Eclectic domain mixing for effective adaptation in action spaces

Multimedia Tools and Applications - Although videos appear to be very high-dimensional in terms of duration × frame-rate × resolution, temporal smoothness constraints ensure that the...     

Adrenal pheochromocytoma mimicking small cell carcinoma on fine needle aspiration biopsy. A case report

BACKGROUND: Fine needle aspiration biopsy (FNAB) is a sensitive and specific technique in the diagnosis of adrenal tumors. However, in rare cases the cytomorphologic features may mimic small cell neoplasms. CASE: A 54-year-old male presented with a history of hypertension and left flank pain of recent onset. Abdominal computed tomography (CT) showed a 4-cm mass involving the left adrenal gland. Fine needle aspiration biopsy (FNAB) showed groups of small round cells with hyperchromatic nuclei. The findings were highly suspicious for metastatic small cell carcinoma. Subsequently it was learned that the mass had been noted three years earlier on CT studies but had grown from 2.5 to 4 cm. A chest radiograph was unremarkable. The clinical findings were more in keeping with a primary adrenal tumor. Immunohistochemical staining done retrospectively on the cell block showed positive reactivity for chromogranin and neuron-specific enolase. These findings, correlated with the clinical features, were in keeping with a diagnosis of pheochromocytoma. Left adrenalectomy revealed a pheochromocytoma. CONCLUSION: Adrenal pheochromocytoma should be included in the differential diagnosis of small round cell neoplasms seen on FNAB of the adrenal gland. Immunohistochemistry and clinical findings are helpful in reaching the correct diagnosis.     

Feature selection in MLPs and SVMs based on maximum output information

This paper presents feature selection algorithms for multilayer perceptrons (MLPs) and multiclass support vector machines (SVMs), using mutual information between class labels and classifier outputs, as an objective function. This objective function involves inexpensive computation of information measures only on discrete variables; provides immunity to prior class probabilities; and brackets the probability of error of the classifier. The maximum output information (MOI) algorithms employ this function for feature subset selection by greedy elimination and directed search. The output of the MOI algorithms is a feature subset of user-defined size and an associated trained classifier (MLP/SVM). These algorithms compare favorably with a number of other methods in terms of performance on various artificial and real-world data sets.     

Cervical angiofollicular lymph node hyperplasia (lymphoid hamartoma)

A case of the hyaline vascular type of angiofollicular lymph node hyperplasia (lymphoid hamartoma) in the neck of a 25-year-old Hindu male is reported. A brief review of the literature is presented and relevant clinical, pathological and therapeutic aspects of this lesion are discussed.