James I. Cohen

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Spinal motor neurons must extend their axons into the periphery through motor exit points (MEPs), but their cell bodies remain within spinal motor columns. It is not known how this partitioning is established in development. We show here that motor neuron somata are confined to the CNS by interactions with a neural crest subpopulation, boundary cap (BC)(More)
In developing neurons, somal migration and initiation of axon outgrowth often occur simultaneously and are regulated in part by similar classes of molecules. When neurons reach their final destinations, however, somal translocation and axon extension are uncoupled. Insights into the mechanisms underlying this process of disengagement came from our study of(More)
Boundary cap (BC) cells are neural crest derivatives that form clusters at the surface of the neural tube, at entry and exit points of peripheral nerve roots. Using various knock-in alleles of the mouse gene Egr2 (also known as Krox20), the expression of which, in trunk regions, is initially restricted to BC cells, we were able to trace BC cell progeny(More)
We have used monolayers of control 3T3 cells and 3T3 cells transfected with a cDNA encoding human N-CAM as a culture substrate for embryonic chick retinal ganglion cells (RGCs). At embryonic day 6 (E6), but not at E11, RGCs extended longer neurites on monolayers of N-CAM-transfected cells. This loss of RGC responsiveness was not associated with substantial(More)
BACKGROUND AND PURPOSE Ultrasmall superparamagnetic iron oxide particles result in shortening of T1 and T2 relaxation time constants and can be used as MR contrast agents. We tested four hypotheses by evaluating MR images of intracranial tumors after infusion of two iron oxide agents in comparison with a gadolinium chelate: 1) Ferumoxtran in contrast to(More)
Little is known of the pathophysiology of invasive pulmonary aspergillosis (IPA), an opportunistic fungal infection usually caused by Aspergillus fumigatus. It has been suggested that the ability of the fungus to degrade elastin may aid its invasion and growth in lung tissue. We have described previously the construction of a strain of A. fumigatus in which(More)
BACKGROUND Monitoring for hypocalcemia after thyroidectomy, using only symptoms and serum calcium levels, can delay the discharge of patients who will remain normocalcemic and can delay the treatment of hypocalcemic patients. STUDY DESIGN We conducted a systematic search for articles describing use of parathyroid hormone (PTH) assay, checked within hours(More)
OBJECTIVE To determine the safety and efficacy of BAY x 1351, a murine monoclonal antibody to recombinant human tumor necrosis factor (TNF)-alpha, in patients with sepsis. DESIGN An international, multicenter, prospective, placebo-controlled trial in patients with sepsis, stratified into shock/nonshock groups. SETTING Forty acute clinical care(More)
The abilities of embryonic and adult rat sensory neurons to regenerate were compared when cultured on cryostat sections of normal and lesioned sciatic nerve tissues. Differences in neurite growth, visualized by GAP-43 immunolabelling, were most pronounced on substrata consisting of longitudinal sections of normal versus predegenerated sciatic nerve. Adult(More)
While salmonellosis is often considered to affect primarily the gastrointestinal tract, infection at other sites may occur, producing characteristic clinical syndromes. We reviewed cases from our institutions and the literature on focal manifestations of salmonella infections. In the past, most extra-intestinal salmonella infections were caused by S.(More)