Ivan J. Sosa

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Each year in the Unites States there are over 10,000 new cases of para- and quadriplegia, and more than 100,000 cases of limited, but permanent, neurological losses. Many of these losses result from blunt trauma and ischemia to the spinal cord which leads to neuron death. Although blunt trauma directly kills neurons due to the physical trauma, over the(More)
OBJECTIVE To determine whether adult human dorsal root ganglion neurons can be isolated and maintained in long-term tissue culture, where they would extend processes. METHODS Dorsal root ganglia were removed from adult human organ donors within 2 hours of clamping the aorta. They were then treated with enzymes for one hour, triturated to dissociate the(More)
BACKGROUND AND IMPORTANCE The standard clinical technique for repairing peripheral nerve gaps is the use of autologous sensory nerve grafts. The present study tested whether a collagen tube filled with autologous platelet-rich fibrin could induce sensory and motor recovery across a 12-cm nerve gap repaired 3.25 years post trauma, and reduce or eliminate(More)
OBJECTIVE To determine the frequency of pediatric brain tumors treated at the University Pediatric Hospital of Puerto Rico over a 6-year period and examine the demographic data and tumor histology of patients in different age groups. METHODS A retrospective study was undertaken at the University Pediatric Hospital. We included patients with brain tumors(More)
Pressure ulcers, also called decubitus ulcers, are a common challenge of humanity and are exceptionally difficult to heal. They are wounds that are initiated by relatively short periods of pressure on the skin that blocks blood circulation causing the skin and underlying tissues to die, leading to an open wound. Pressure release can prevent further tissue(More)
Thoracic Outlet Syndrome (TOS) describes a variety of symptoms caused by the compression of the neurovascular structures in the cervicoaxillary region as they leave the thorax toward the upper limbs. Causes of TOS are vascular and neurogenic, with neurogenic symptoms being the most common presentation (95% of patients). Symptoms related to neurogenic TOS(More)
No clinical techniques induce restoration of neurological losses following spinal cord trauma. Peripheral nerve damage also leads to permanent neurological deficits, but neurological recovery can be relatively good, especially if the ends of a transected nerve are anastomosed soon after the injury. The time until recovery generally depends on the distance(More)
Dorsal root ganglion (DRG) neurons are composed of physiologically distinct subpopulations, each responding to a different sensory stimulus. One can morphologically discriminate between two broad populations of adult rat and frog DRG neurons by their appearance under the light microscope. These groups are called large clear and small dark. However,(More)
Ischemia of intact dorsal root ganglia (DRG) in situ leads to massive neuron death due to ischemia-triggered secondary events, such as massive release of excitatory amino acids from the neurons, their excessive accumulation and activation of neuron NMDA and other receptors, acidification, and loss of calcium homeostasis. The present experiments tested(More)