Symptomatic RF occurred in 6.8% of adult spinal deformity cases and in 15.8% of PSO patients. The rate of RF was lower with cobalt chromium than with titanium alloy or stainless steel. Early failure was most common after PSO and favored the PSO site, suggesting that RF may be caused by stress at the PSO site. Postoperative sagittal malalignment may increase the risk of RF.
The goal of the present study was to develop a porcine spinal cord injury (SCI) model, and to describe the neurological outcome and characterize the corresponding quantitative and qualitative histological changes at 4-9 months after injury. Adult Gottingen-Minnesota minipigs were anesthetized and placed in a spine immobilization frame. The exposed T12 spinal segment was compressed in a dorso-ventral direction using a 5-mmdiameter circular bar with a progressively increasing peak force (1.5, 2.0, or 2.5 kg) at a velocity of 3 cm/sec. During recovery, motor and sensory function were periodically monitored. After survival, the animals were perfusion fixed and the extent of local SCI was analyzed by (1) post-mortem MRI analysis of dissected spinal cords, (2) qualitative and quantitative analysis of axonal survival at the epicenter of injury, and (3) defining the presence of local inflammatory changes, astrocytosis, and schwannosis. Following 2.5-kg spinal cord compression the animals demonstrated a near complete loss of motor and sensory function with no recovery over the next 4-9 months. Those that underwent spinal cord compression with 2 kg force developed an incomplete injury with progressive partial neurological recovery characterized by a restricted ability to stand and walk. Animals injured with a spinal compression force of 1.5 kg showed near normal ambulation 10 days after injury. In fully paralyzed animals (2.5 kg), MRI analysis demonstrated a loss of spinal white matter integrity and extensive septal cavitations. A significant correlation between the magnitude of loss of small and medium-sized myelinated axons in the ventral funiculus and neurological deficits was identified. These data, demonstrating stable neurological deficits in severely injured animals, similarities of spinal pathology to humans, and relatively good post-injury tolerance of this strain of minipigs to spinal trauma, suggest that this model can successfully be used to study therapeutic interventions targeting both acute and chronic stages of SCI.
The use of 2 surgeons at an experienced spine deformity center decreases the operative time and estimated blood loss, and may be a key factor in witnessed decreased major complication prevalence. This approach also may decrease the rate of premature case termination and return to operating room in 30 days.
In contrast to sagittal craniosynostosis, the role of endoscopic, minimally invasive approaches in the treatment of metopic craniosynostosis with resulting trigonocephaly is not as well defined. We reviewed the senior authors' (H.M. and S.C.) clinical experience in the treatment of children with metopic craniosynostosis using a variety of endoscopic and open techniques. Thirty-three patients were treated at a single institution during a 5-year period with between 3 and 8 years of follow-up. Sixteen patients underwent 3 variations of endoscopic approaches, and 17 patients had open fronto-orbital advancement. Clinical parameters of the 2 groups were examined including age at surgery, blood loss, operative time, transfusion volume, hospital stay, complications, use of postoperative cranial banding, and the need for reoperation for persistent deformity. The various endoscopic and open techniques used by the authors in the treatment of metopic craniosynostosis are discussed in detail, including rational for individual technique selection and preliminary impressions regarding clinical outcome.
In previous studies, we have demonstrated that spinal grafting of human or rat fetal spinal neural precursors leads to amelioration of spasticity and improvement in ambulatory function in rats with spinal ischemic injury. In the current study, we characterize the survival and maturation of three different human embryonic stem (ES) cell line-derived neural precursors (hNPCs) once grafted into ischemia-injured lumbar spinal cord in rats or in naive immunosuppressed minipigs. Proliferating HUES-2, HUES-7, or HUES-9 colonies were induced to form embryoid bodies. During the nestin-positive stage, the rosettes were removed and CD184+ population of ES-hNPCs FAC-sorted and expanded. Male Sprague-Dawley rats with spinal ischemic injury or naive immunosuppressed Gottingen-Minnesota minipigs received 10 bilateral injections of ES-NPCs into the L2-L5 gray matter. After cell grafting, animals survived for 2 weeks to 4.5 months, and the presence of grafted cells was confirmed after staining spinal cord sections with a combination of human-specific (hNUMA, HO14, hNSE, hSYN) or nonspecific (DCX, MAP2, CHAT, GFAP, APC) antibodies. In the majority of grafted animals, hNUMA-positive grafted cells were identified. At 2-4 weeks after grafting, double-labeled hNUMA/ DCX-immunoreactive neurons were seen with extensive DCX + processes. At survival intervals of 4-8 weeks, hNSE + neurons and expression of hSYN was identified. Some hSYN-positive terminals formed putative synapses with the host neurons. Quantitative analysis of hNUMA + cells at 2 months after grafting showed comparable cell survival for all three cell lines. In the presence of low-level immunosuppression, no grafted cell survival was seen at 4.5 months after grafting. Spinal grafting of proliferating pluripotent HUES-7 cells led to consistent teratoma formation at 2-6 weeks after cell transplantation. These data show that ES-derived, FACsorted NPCs can represent an effective source of human NPCs to be used in CNS cell replacement therapies.
The development of T cells is thought to be independent of B cells. However, defects in cell-mediated immunity in individuals with B-cell deficiency suggest the contrary. To test whether B cells affect T-lymphocyte development, we constructed mice with a monoclonal T-cell compartment (MT) and monoclonal B-and T-cell compartments (MBTs). In these mice, the T cells expressed a DO 11.10 transgenic (DO-T) cell receptor restricted to major histocompatibility complex (MHC)
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