The History, Theory, and Present Status of Brain Transplantation

Parkinson's disease and anaesthesia

Parkinson's disease (PD), one of the most common disabling neurological diseases, affects about 1% of the population over 60 years of age. It is a degenerative disease of the central nervous system caused by the loss of dopaminergic fibers in basal ganglia of the brain. PD is an important cause of perioperative morbidity and with an increasingly elderly population, it is being encountered with greater frequency in surgical patients. Particular anaesthetic problems in PD include old age, antiparkinsonian drug interaction with anaesthetic drugs and various alterations in the respiratory, cardiovascular, autonomic, and neurological systems. This brief review focuses on the preoperative, intraoperative, and postoperative anesthetic management of PD and gives a brief account of intraoperative exacerbation of PDs and anesthetic management of stereotactic pallidotomy.

Comparison of neural precursor cell fate in second trimester human brain and spinal cord

Neural transplantation holds promise for the treatment of traumatic brain and spinal cord injury by replacing lost cellular elements as well as repairing neural damage. Fetal human stem cells derived from central nervous system (CNS) tissue are potential transplantable sources for all cell types found in the mature human nervous system including neurons, astrocytes and oligodendroglia. Although nearly all areas of the fetal human neuraxis contain undifferentiated neural precursor cells, the phenotypic fate of the daughter cells might vary from one region to another during a specific developmental period. The purpose of this study was to compare the various cell types derived from neural precursors cultured from second trimester fetal human brain and spinal cord. To this end, brains (n = 8) and spinal cords (n = 8) of 15-24 week fetuses were dissociated and grown in culture medium supplemented with epidermal growth factor (EGF), basic fibroblast growth factor (FGF) and leukemia inhibitory factor (LIF). The proliferating precursor cells from both brain and spinal cord grew as spherical masses that were plated on laminin-coated dishes after seven days in culture. During the next 5-7 days, the cells that emerged from these spheres were fixed and processed for immunocytochemistry. Brain derived spheres gave rise to cells expressing antigens specific for neurons (MAP-2ab and neuron specific-intermediate filaments), astrocytes (GFAP) and oligodendrocytes (A007). In contrast, cells that emerged from spinal cord derived spheres were only immunoreactive for GFAP. These data suggest that neuroepithelial precursor cells from different CNS regions, although similar in their responsiveness to proliferative growth factors, might differ in their ability to generate different cell types in the adult CNS.

Intracerebral transplantation of bone marrow with BDNF after MCAo in rat

We tested the hypothesis that a composite graft of fresh bone marrow (BM) along with brain-derived neurotrophic factor (BDNF), transplanted into the ischemic boundary zone (IBZ) of rat brain, facilitates BM cells to survive and differentiate, and improves functional recovery after middle cerebral artery occlusion (MCAo). The fresh BM was harvested from adult rats injected with bromodeoxyuridine (BrdU) as a tracer. Rats (n=37) were subjected to 2h of MCAo, received grafts at 24h and were sacrificed at 7days after MCAo. Test groups consisted of: (1) control - MCAo alone (n=9); (2) injection of phosphate buffered saline (n=4); (3) transplantation of BM (n=8); (4) injection of BDNF (n=7); and (5) transplantation of BM with BDNF (n=9) into the IBZ. Immunohistochemistry was used to identify cells derived from the BM stem cells. Behavioral tests (rotarod motor test; adhesive-removal somatosensory test) were performed before and 7days after MCAo. The data indicate that intracerebral grafting of a combination of BM with BDNF enhances differentiation of BM cells and significantly improves motor recovery of rotarod (P<0.05) and adhesive-removal (P<0.05) tests. We anticipate that BM along with neurotrophic factors may provide a powerful autoplastic therapy for human neurological injury and degenerative disorders.

Porcine embryonic brain cell cytotoxicity mediated by human natural killer cells

Intracerebral transplantation of porcine embryonic dopamine-producing neurons has been suggested as a method to treat patients with Parkinson's disease. Even though the brain is an immunologically privileged site, neuronal xenografts are usually rejected within a few weeks. T cells are important for this process, but the exact cellular events leading to rejection are poorly characterized. Brain cells from ventral mesencephalon of 26-27-day-old pig embryos were used as target cells in flow cytometry-assessed cytotoxicity assays using non- and IL-2-activated CD3- CD16+ CD56+ human natural killer (NK) cells as effector cells. The ability of human NK cells to kill pig embryonic brain cells by antibody-dependent cellular cytotoxicity (ADCC) in the presence of nondepleted and anti-Gal alpha1,3Gal antibody-depleted human blood group AB serum (AB serum) was evaluated using the same assay. Both nondepleted and anti-Gal alpha1,3Gal antibody-depleted AB serum could mediate ADCC of pig embryonic VM cells when human NK cells were used as effector cells. Nonactivated NK cells did not show any direct cytotoxic effect on freshly isolated VM cells, whereas IL-2-activated NK cells killed approximately 50% of the VM cells at an effector-to-target ratio of 50:1 in a 4-h cytotoxicity assay. Activation of VM cells by TNF-alpha did not change their sensitivity to human NK cell cytotoxicity. Human NK cells may thus contribute to a cellular rejection of pig neuronal xenografts by ADCC, or following IL-2 activation, by a direct cytotoxic effect.

Pallidotomy: a survey of current practice in North America

Twenty-eight centers completed a survey about their current practice of pallidotomy. This sample represents a non-exhaustive survey of the current practice of pallidotomy in North America and is not a study of outcomes. 1015 patients underwent 1219 pallidotomies: 811 (80%) unilateral, 72 (7%) staged bilateral, and 132 (13%) simultaneous bilateral. Pallidotomy has long been an accepted procedure and the indications for this surgery, in the opinion of the responding centers, were rated on a scale of 1 (poor) to 4 (excellent) and demonstrated dyskinesia as the best indication (median = 4); on-off fluctuations, dystonia, rigidity, and bradykinesia as good indications (median = 3); and freezing, tremor and gait disturbance as fair indications (median = 2). Most centers used MRI alone (50%) or in combination with CT scan (n = 6) or ventriculopathy (n = 5) to localize the target. The median values of pallidal coordinates were: 2 mm anterior to the midcommissural point 21 mm lateral to the midsagittal plane and 5 mm below the intercommissural line. Microrecording was performed by half of the centers (n = 14) and half of the remaining centers were considering starting it (n = 7). Main criteria used to define the target included the firing pattern of spontaneous neuronal discharges (n = 13) and the response to joint movement (n = 10). Most centers performed motor (n = 26) and visual (n = 23) macrostimulation. Twenty four centers performed test lesions using median values of 55 degrees C temperatures for 30 s. Final lesions consisted of 3 permanent lesions placed 2 mm apart, each lesion created with median values of 75 degrees C temperatures for 1 minute. Median hospital stay was 2 days.