In Vivo Production, Development and Storage of Oscheius myriophila (Nematoda: Rhabditida) in Galleria mellonella (Lepidoptera: Pyralidae).

Entomopathogenic nematodes have been used in biological control for some time and are an alternative for the control of insect pests, but during their implementation, situations have arisen that can be improved. These vary with each species and include their production and storage. Oscheius myriophila, an entomopathogenic nematode (EPN), was monitored for its performance when produced in vivo, as well as its development using Galleria mellonella larvae, using the MC5-2014 strain isolated from soil samples in the municipality of Tepalcingo, Morelos, México. For a study with native strains of EPNs, a wide range of tests must be conducted because the required conditions can be very specific. In vivo production was quantified at initial infective juvenile (IJ) inocula of 50, 100 and 500, and we obtained the same production for the three inocula. The life cycle of the EPNs lasted 12 days, and two generations were observed in which adults were found at days 5 and 9. Both evaluations were performed at a temperature of 27 °C in G. mellonella larvae. In addition, the temperatures of 8, 12, 20 and 24 °C were evaluated for their storage, and we observed that the EPNs can be kept for at least 6 months, maintaining a survival rate of 58.67% and a good infective capacity at a temperature of 12 °C, remaining above 60%.

Identification and Venom Characterization of Two Scorpions from the State of Chihuahua Mexico: Chihuahuanus coahuliae and Chihuahuanus crassimannus.

Chihuahua is the largest state in Mexico. The ecosystem of this region is composed of large area of bushes, forests, and grasslands, which allows for a specific diversity of fauna; among them are interesting species of non-lethal scorpions. Most of the Chihuahuan scorpions have been previously morphologically and molecularly described; however, this manuscript could be the first to describe the composition of those venoms. This work aimed at the collection of two scorpion species from the region of Jiménez (Southwest of the State of Chihuahua), which belong to the species Chihuahuanus cohauilae and Chihuahuanus crassimanus; the two species were taxonomically and molecularly identified using a 16S DNA marker. Reverse-phase high-performance liquid chromatography (RP-HPLC) of C. coahuilae and C. crassimanus venoms allowed the identification of three fractions lethal to mice. Additionally, three fractions of each scorpion displayed an effect on house crickets. In the end, three new fractions from the venom of C. coahuilae were positive for antimicrobial activity, although none from C. crassimanus venom displayed growth inhibition. Despite being a preliminary study, the venom biochemical analysis of these two uncharacterized scorpion species opens the opportunity to find new molecules with potential applications in the biomedical and biotechnological fields.

Liposomes Bearing Non-Bilayer Phospholipid Arrangements Induce Specific IgG Anti-Lipid Antibodies by Activating NK1.1+, CD4+ T Cells in Mice.

Liposomes are artificial models of cellular membranes that are used as delivery systems for genes, drugs and protein antigens. We have previously used them to study the antigenic properties of their phospholipids. Here, we used them to induce the production of IgG anti-non-bilayer phospholipid arrangements (NPAs) antibodies in mice; these antibodies cause cell lysis and trigger a lupus-like disease in mice. We studied the mechanisms that lead to the production of these antibodies, and provide evidence that NK1.1+, CD4+ T cells respond to NPA-bearing liposomes and deliver the help required for specific B cell activation and antibody class-switching to IgG. We found increased numbers of IL-4-producing NK1.1+, CD4+ T cells in the secondary lymphoid organs of mice administered with NPAs, and these cells also expressed CD40L, which is required for B cell activation. Additionally, we isolated and purified NK1.1+, CD4+ T cells from spleens and determined that they over-expressed 40 genes, which are key players in inflammatory processes and B cell stimulation and have TRAF6 and UNC39B1 as key nodes in their network. These results show that liposomes are membrane models that can be used to analyze the immunogenicity of lipids.

Effect of B-NIPOx in Experimental Trypanosoma cruzi Infection in Mice.

Chagas disease is caused by Trypanosoma cruzi and represents a major public health problem, which is endemic in Latin America and emerging in the rest of the world. The two drugs that are currently available for its treatment, Benznidazole and Nifurtimox, are partially effective in the chronic phase of the disease. In this study, we designed and synthesized the benzyl ester of N-isopropyl oxamic acid (B-NIPOx), which is a non-polar molecule that crosses cell membranes. B-NIPOx is cleaved inside the parasite by carboxylesterases, releasing benzyl alcohol (a molecule with antimicrobial activity), and NIPOx, which is an inhibitor of α-hydroxy acid dehydrogenase isozyme II (HADH-II), a key enzyme in T. cruzi metabolism. We evaluated B-NIPOx cytotoxicity, its toxicity in mice, and its inhibitory activity on purified HADH-II and on T. cruzi homogenates. We then evaluated the trypanocidal activity of B-NIPOx in vitro and in vivo and its effect in the intestine of T. cruzi-infected mice. We found that B-NIPOx had higher trypanocidal activity on epimastigotes and trypomastigotes than Benznidazole and Nifurtimox, that it was more effective to reduce blood parasitemia and amastigote nests in infected mice, and that, in contrast to the reference drugs, it prevented the development of Chagasic enteropathy.

Oscheius myriophila (Nematoda: Rhabditida) isolated in sugar cane soils in Mexico with potential to be used as entomopathogenic nematode.

A survey of entomopathogenic nematodes was conducted in sugar cane crops in a total of 14 soils, and positive results were obtained for strain MC5-2014 in the municipality of Tepalcingo, Morelos, in soil with a sandy loam texture and a pH of 6.4. Species determination was performed via morphological and morphometric techniques by searching for a tubular stoma with a swollen cylindrical pharyngeal body and a metacorpus in the basal part. The range of body length (L) was 750 to 1200 µm in females and 720 to 910 µm in males, while the corresponding maximum widths (W) of the body were 30 to 60 µm and 20 to 30 µm, respectively. Males exhibited bursa with a 1 + 1 + 3 + 3 distribution of papillae, and females exhibited a vulva located at the mid-body. For molecular identification, the ITS region of ribosomal DNA was used. Virulence tests (LC50) were conducted with Galleria mellonella, and a value of 4.732 was obtained for infective juveniles (IJs). Taking taxonomic and molecular characteristics into account, the isolate was determined to be Oscheius myriophila. The isolation of this strain represents the first geographic report of O. myriophila in Mexico, and it should be noted that the cultivation of sugar cane occurs with constant application of insecticides, herbicides, fungicides, and fertilizers as well as harvesting activities such as burning of the crop for harvest. The O. myriophila isolate has the potential to be used in the future as a method of biological control in our country.A survey of entomopathogenic nematodes was conducted in sugar cane crops in a total of 14 soils, and positive results were obtained for strain MC5-2014 in the municipality of Tepalcingo, Morelos, in soil with a sandy loam texture and a pH of 6.4. Species determination was performed via morphological and morphometric techniques by searching for a tubular stoma with a swollen cylindrical pharyngeal body and a metacorpus in the basal part. The range of body length (L) was 750 to 1200 µm in females and 720 to 910 µm in males, while the corresponding maximum widths (W) of the body were 30 to 60 µm and 20 to 30 µm, respectively. Males exhibited bursa with a 1 + 1 + 3 + 3 distribution of papillae, and females exhibited a vulva located at the mid-body. For molecular identification, the ITS region of ribosomal DNA was used. Virulence tests (LC50) were conducted with Galleria mellonella, and a value of 4.732 was obtained for infective juveniles (IJs). Taking taxonomic and molecular characteristics into account, the isolate was determined to be Oscheius myriophila. The isolation of this strain represents the first geographic report of O. myriophila in Mexico, and it should be noted that the cultivation of sugar cane occurs with constant application of insecticides, herbicides, fungicides, and fertilizers as well as harvesting activities such as burning of the crop for harvest. The O. myriophila isolate has the potential to be used in the future as a method of biological control in our country.

Biophysical characterization of the insertion of two potent antimicrobial peptides-Pin2 and its variant Pin2[GVG] in biological model membranes.

The aim of this study was to investigate the factors that govern the activity and selectivity of two potent antimicrobial peptides (AMPs) using lipid membrane models of bacterial, erythrocyte and fungal cells. These models were used in calcein liposome leakage experiments to explore peptide efficiency. The AMPs (Pin2 and its variant Pin2[GVG]) showed highest affinity towards the bacterial models in the nanomolar range, followed by the erythrocyte and fungal systems. The presence of sterols modulated the variant's selectivity, while the wild type was unaffected. Liposome leakage experiments with Fluorescein Isothiocyanate-dextran (FITC)-dextran conjugates indicated that pore size depended on peptide concentration. Dynamic Light Scattering revealed peptide aggregation in aqueous solution, and that aggregate size was related to activity. The interacting peptides did not alter liposome size, suggesting pore forming activity rather than detergent activity. Atomic Force Microscopy showed differential membrane absorption, being greater in the bacterial model compared to the mammalian model, and pore-like defects were observed. Electrophysiological assays with the Tip-Dip Patch Clamp method provided evidence of changes in the electrical resistance of the membrane. Membrane potential experiments showed that liposomes were also depolarized in the presence of the peptides. Both peptides increased the Laurdan Generalized Polarization of the bacterial model indicating increased viscosity, on the contrary, no effect was observed with the erythrocyte and the fungal models. Peptide membrane insertion and pore formation was corroborated with Langmuir Pressure-Area isotherms and Brewster Angle Microscopy. Finally, molecular dynamics simulations were used to get an insight into the molecular mechanism of action.

Efficacy of Hydromer-Coated and Antibiotic- Impregnated Shunt Systems in Reducing Early Shunt Infections in the Pediatric Population.

OBJECTIVE: Shunt infection is the most common complication following a Cerebrospinal fluid (CSF) diversion procedure with devastating consequences. This study analyzes the efficacy of different shunt systems in reducing early shunt infections in the pediatric population. METHODS: Retrospective case study analysis of 177 pediatric patients with hydrocephalus de novo shunted using hydromer-coated (HC) shunt systems, antibiotic-impregnated (AI) shunt systems and standard non impregnated shunt systems was performed and compared for the incidence of shunt infection in the early postoperative period. RESULTS: Group A consisted of standard shunt systems with 63 patients, Group B were HC shunt systems with 67 patients and group C consisted of 47 patients with antibiotic-impregnated shunt systems. Mean age in Group A was 1.36 +/- 3.36 years Mean age in Group B was 2.32 +/- 4.69 years. Mean age in Group C: 0.64 +/- 1.70 years. In terms of shunt infections, HC group had 4 shunt infections (6.25%), as compared to the control group, where 7 patients (10.45%) had infections. The AI group had 1 infection (2.13%). When comparing HC systems versus Standard Non-Impregnated There were 3 shunt malfunction in Group A (4.8%), 2 shunt malfunction in group B (3.3%) and 0 shunt malfunction in Group C (0%). CONCLUSION: Hydromer-coated shunt systems and antibiotic-impregnated shunt system represent a superior alternative to standard shunt systems for the reduction of shunt infection in the early post operative period.

Anthelmintic Effect of Bacillus thuringiensis Strains against the Gill Fish Trematode Centrocestus formosanus.

Parasitic agents, such as helminths, are the most important biotic factors affecting aquaculture, and the fluke Centrocestus formosanus is considered to be highly pathogenic in various fish species. There have been efforts to control this parasite with chemical helminthicides, but these efforts have had unsuccessful results. We evaluated the anthelmintic effect of 37 strains of Bacillus thuringiensis against C. formosanus metacercariae in vitro using two concentrations of total protein, and only six strains produced high mortality. The virulence (CL50) on matacercariae of three strains was obtained: the GP308, GP526, and ME1 strains exhibited a LC50 of 146.2 µg/mL, 289.2 µg/mL, and 1721.9 µg/mL, respectively. Additionally, these six B. thuringiensis strains were evaluated against the cercariae of C. formosanus; the LC50 obtained from the GP526 strain with solubilized protein was 83.8 µg/mL, and it could be considered as an alternative control of the metacercariae and cercariae of this parasite in the productivity systems of ornamental fishes.

Cromatografía de adsorción para purificar el disacárido espaciador del ingrediente farmacéutico activo de la vacuna QuimiHib® / Adsorption chromatography to purify Spacer disaccharide of Active Pharmaceutical Ingredient of QuimiHib® vaccine

En este trabajo se estudiaron las condiciones de la cromatografía de adsorción en Silicagel 60 para la purificación del disacárido espaciador (DSE), componente del ingrediente farmacéutico activo de la vacuna QuimiHib®. Para ello se realizó un desescalado a una escala analítica que representó el 1,8% del proceso industrial. Se logró reproducibilidad en términos de calidad de empaque, pureza y recobrado entre ambas escalas. Se determinó que la capacidad dinámica de carga de la resina Silicagel 60 por el DSE fuera de aproximadamente 125±0,2 mg/mL de resina empacada; 3,4 veces superior al proceso base. El perfil de elución que se obtuvo indicó la posibilidad de colectar una fracción única en el rango 195±2 y 260±2 min. Si se mantiene un correcto empaque de la resina cromatográfica, determinado por un factor de asimetría entre 0,8 y 1,2 se garantiza un recobrado de 58,9±4,5 por ciento y una pureza equivalente a la del patrón de referencia en el análisis por cromatografía de capa delgada. El ajuste de la condición de adsorción incrementa la productividad de la operación en 3,5 veces, indicando que la propuesta es económicamente factible(AU)

In this paper we study the conditions of adsorption chromatography on Silica gel 60 for purification of Spacer disaccharide a component of Active Pharmaceutical Ingredient (API) of QuimiHib® vaccine. For that, we made a scale down on an analytical scale that represented at 1.8% of industrial process, indicating reproducibility between two procedures in terms of packing efficiency, purity and recovery. Dynamic binding capacity of the resin Silicagel 60 by the DSE was roughly 125±0.2 mg /mL, 3.4 times the base process. The elution profile obtained, showed the possibility of collecting a unique fraction at range 195±2 and 260±2 minutes, if it is maintained a proper packing of the chromatography resin determined by asymmetry factor from 0.8 to 1.2, which ensures a recovery of 58.9±4.5 percent and high purity analyzed by Thin Layer Chromatography. Adjusting the adsorption conditions increases the productivity of chromatographic operation up to 3.5 fold, indicating that it is feasible in economic terms(AU)

Vagus nerve stimulation for intractable seizures in children: the University of Puerto Rico experience.

OBJECTIVE: Vagus nerve stimulation (VNS) is considered an alternative treatment for patients with medically refractory epilepsy who are not candidates for resective surgery. It consists of intermittent electrical stimulation of the left vagus nerve in the neck. Such stimulation has been demonstrated to be efficacious, safe, and well tolerated, offering these patients another option for seizure control. The aim of this study was to evaluate the experience of VNS at the University of Puerto Rico, and to examine demographic data, types of seizures, and seizure-control outcomes among treated subjects. This study is the first account of VNS in a pediatric population living in the Caribbean area. METHODS: A retrospective analysis of 13 patients treated at the University Pediatric Hospital in San Juan, Puerto Rico, was undertaken. Different types of seizures were identified and managed. RESULTS: The mean age at implantation was 12 years; 77% of patients were female. The most common type of seizure treated was generalized tonic-clonic (24%), followed by complex partial (23%). Sixty-nine percent of patients demonstrated a reduction in monthly seizure frequency. Ninety-three percent of caregivers reported improvements in alertness and communication. CONCLUSION: Vagus nerve stimulation is a safe and effective way to treat medically refractory epilepsy and should be considered as a non-pharmacological treatment for select patients with medically refractory epilepsy.

Pediatric brain tumors in Puerto Rico.

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 that had been newly diagnosed during the period covering from January 2002 to December 2007. All cases were analyzed by age, gender, histologic diagnosis, and affected area. RESULTS: One hundred thirty-six patients were included in the study. Overall, males were more frequently affected than were females. Children in the 1 to 4 years old age group had the highest number of newly diagnosed brain tumors. Regarding anatomic location, supratentorial tumors were more frequent than were infratentorial tumors. The most common single tumor was the pilocytic astrocytoma (WHO grade I), representing 31% of the total pediatric brain tumors. CONCLUSION: Our results provide an objective platform for further epidemiological studies and for the development of local health strategies for the timely diagnosis and treatment of the most common pediatric tumors in Puerto Rico.

Endoscopic third ventriculostomy: a surgeon's experience.

INTRODUCTION: Endoscopic third ventriculostomy (ETV) is considered an alternative treatment for certain types ofhydrocephalus. Depending on patient's age and etiology of hydrocephalus, it carries a success rate of around 90%. However, as in any surgical procedure, inherent risks are present and a risk-benefit analysis must be done prior to selecting patients for this intervention. OBJECTIVE: To evaluate retrospectively the experience of ETV at the University of Puerto Rico and examine the etiological factors, demographic data and symptoms among the Puerto Rico population. This study represents the data of one neurosurgeon and is the first account of endoscopic third ventriculostomy as a mode of treatment in the Caribbean area. METHODS: Retrospective analysis was undertaken of 29 patients treated at the University Pediatric Hospital (UPH) and University District Hospital (UDH) in San Juan was undertaken Different etiologies of hydrocephalus were identified and managed. RESULTS: The most common indication for ETV was aqueductal stenosis (59%) with male predominance (55%). Also, the most common population treated were adults (72%) and the most common symptom presented were headaches (52%) and gait disturbances (43%). CONCLUSIONS: Endoscopic third ventriculostomy is a safe and effective way to treat hydrocephalus and should be considered as first choice of treatment for certain patients with hydrocephalus unless otherwise contraindicated.

Schwann cell chondroitin sulfate proteoglycan inhibits dorsal root ganglion neuron neurite outgrowth and substrate specificity via a soma and not a growth cone mechanism.

Sensory axons do not regenerate into or within the spinal cord because of the presence of the axon regeneration inhibitor chondroitin sulfate proteoglycan (CSPG) on activated astrocytes. In the peripheral nervous system, CSPG associated with denervated Schwann cells retards axon regeneration, but regeneration occurs because the balance of regenerating, inhibiting, and promoting factors favors regeneration. The present experiments were aimed at determining the mechanism by which Schwann cells inhibit adult human dorsal root ganglia (H-DRG) neuron growth cone elongation and substrate specificity, restricting the growth cones to Schwann cell membranes and inhibiting their growth onto a poly-l-lysine/laminin substrate. Neurites of H-DRG neurons free of soma contact with Schwann cells, or after the Schwann cell membranes' CSPG had been digested, were 11.1-fold longer than those of neurons in soma contact with untreated Schwann cells. Growth cones of DRG neuron somas without Schwann cell CSPG showed no outgrowth inhibition or substrate specificity. These results indicate that the Schwann cell CSPG influences act via contact with neuron somas but not growth cones. These results suggest that eliminating CSPG associated with Schwann cells within DRG in vivo will make the neurons' growth cones insensitive to the regeneration inhibitory influences of CSPG, allowing them to regenerate through the dorsal root entry zone and into and within the spinal cord, where they can establish appropriate and functional synaptic connections.

Elimination of a pressure ulcer with electrical stimulation--a case study.

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 degeneration, and some ulcers heal and disappear by themselves. However, many pressure ulcers never heal and continue to grow in diameter and depth. By one year, such unhealing ulcers are referred to as chronic ulcers. Chronic ulcers frequently jeopardize the life of the patient due to infections that become increasingly deep until they invade bones and the circulatory system. We report on a patient with a chronic pressure ulcer at his coccyx prominence. Fourteen months after the ulcer had appeared, a surface pulse electromagnetic force (PEMF) stimulator was applied over T7-T8, 45 cm cephalic to the ulcer, as part of a nerve stimulation study. Although the ulcer had continued to grow both in diameter and depth for 14 months and showed no signs of healing, within 6 days of applying the PEMF stimulator, the ulcer began to heal and was fully eliminated after 3 months. We concluded that the electrical stimulation induced the healing of the pressure ulcer. The ulcer elimination is quite surprising due to the exceptionally low electric field-force being generated by the stimulator at a distance of 45 cm.

A novel technique leading to complete sensory and motor recovery across a long peripheral nerve gap.

Sensory nerve grafts are the "gold standard" for inducing neurological recovery in peripheral nerves with a gap. However, the effectiveness of sensory nerve grafts is variable, generally not leading to complete sensory and motor recovery, with good recovery limited to gaps shorter than 2 cm, and the extent of recovery decreasing with increasing graft length. An alternative technique using a conduit filled with pure fibrin to bridge a nerve gap leads to only limited neurological recovery. We tested the effectiveness of a novel nerve repair technique in which a 5-cm long radial nerve gap was repaired using two sural nerve graft surrounded by a collage tube filled with pure fibrin. By 1 1/2 years post surgery, the patient recovered complete sensory and motor function. In conclusion, this study suggests that the combination of pure fibrin surrounding sural nerve grafts is responsible for inducing the extensive neurological recovery induced by either pure fibrin or sural grafts alone. This technique is presently being tested in a clinical trial.

Morphological characterization of six subpopulations of adult human DRG neurons at the light microscopic level.

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, additional subpopulations have not been identified by visual observation. Such identification requires application of immunochemistry or biophysical techniques. Although these are useful techniques, they do not allow the rapid discrimination of different neuron subpopulations, which would be useful for pharmacological studies on unique neuron subpopulations. Such experiments would be greatly facilitated if viable DRG neuron subpopulations could be identified based on their morphology at the light microscopic level. Just as for adult frog and rat DRG neurons, when adult human DRG neurons are observed under phase optics, two subpopulations can be seen, small dark and large light. However, under bright-field illumination, six distinct subpopulations can be distinguished based solely on morphological features. Five subpopulations contain rusty-colored cytoplasmic inclusions with different sized granules and differences in the size and density of the granule clusters, while one is granule-free. Analysis of the soma diameter distribution shows each of the six granule-containing and the non-granule-containing (clear) neuron subpopulations has a statistically significant difference in size distribution. We propose that neurons with different morphologies correspond to unique physiological subpopulations of DRG neurons. Experiments are underway using immunochemical techniques to determine whether neurons with the unique morphologies correspond with unique physiological functions.

Neuroprotection of adult human neurons against ischemia by hypothermia and alkalinization.

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 whether hypothermia and alkalinization, separately or combined, provide neuroprotection against 1-4 hours of ischemia to the neurons within intact DRG acutely removed from organ donors. DRG under hypothermic (20-15 degrees C) or alkaline (pH 8.0-9.3) conditions yielded more viable neurons than DRG maintained under physiological conditions (37 degrees C/pH 7.4), 4.1-fold vs. 7.8-fold respectively, but, hypothermia and alkalinization combined (20 degrees C/pH 9.3) increased the yield of viable neurons 26-fold compared to DRG maintained under physiological conditions. These results show that combined hypothermia and alkalinization provide adult human DRG neurons significant neuroprotection against ischemia, and ischemia-induced causes of neuron death.

Promoting neurological recovery following a traumatic peripheral nerve injury.

If a peripheral nerve is crushed, or if the nerve is cut and the ends sutured together soon after the lesion (anastomosed), neurological recovery is good. When a length of a peripheral nerve is destroyed, and anastomosis is not possible, the standard surgical repair technique is to graft a length/s of sensory nerve from the patient, into the gap. For gaps <2 cm neurological recovery is moderate, for gaps 2-4 cm recovery is generally poor, and for gaps >4 cm recovery is limited to non-existent. The limited recovery is because sensory nerves act as passive scaffolds for axon regeneration and do not actively promote axon regeneration. However, such grafts remain the "gold standard" for nerve repairs. New techniques are required that induce improved neurological recovery. This paper reviews current clinical and basic research techniques for inducing neurological recovery following traumatic peripheral nerve injuries.

Advances in spinal cord repair techniques.

Daily US accidents result annually in over 20,000 cases of traumatic spinal cord injury associated with complete and permanent paraplegias and quadriplegias frequently associated chronic pain. This amounts to new annual health care a costs of dollar 3.2 billion, and a total annual cost for all such individuals in the US of dollar 96 billion. Tens of thousands of additional people suffer lesser degrees of permanent debilitating lost spinal cord function. To help these people recover neurological functions, and simultaneously reduce the enormous suffering, and the associated medical expenses, requires developing techniques that induce the regeneration of lesioned adult human spinal cord axons. A number of techniques lead to varying degrees of axon regeneration and neurological recovery in the rat, but the recovery is invariably limited. While other approaches show potential, they have not led reliable neurological recovery. Most spinal cord repair techniques cannot be applied clinically because they require materials that are not FDA-approved. However, several FDA-approved materials are available that hold great promise for inducing axon regeneration, especially when used simultaneously. Here we review efforts to induce the regeneration of spinal cord axons, how what is known about promoting regeneration of axons across peripheral nerve gaps may be applied to repairing spinal cord lesions, and finally, how several readily available materials may induce axons to regenerate in the spinal cord and restore neurological function.

Neuroprotection of spinal neurons against blunt trauma and ischemia.

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 subsequent 48 hours an even larger population of neurons dies due to secondary causes. One of leading triggers of this neuron death is ischemia due to the disruption of the blood circulation. Selective, but unavoidable, spinal cord ischemia occurs during thoracoabdominal surgery to repair aortic aneurysms. This ischemia leads to neuron death, functional neurological loss, and paraplegia in up to 33% of the cases. Thus, both blunt trauma and induced ischemia have similar triggers of neuron death. To reduce the neurological losses resulting from ischemia mechanisms must be found to make spinal neurons more tolerant to ischemic insult and other secondary causes of neuron death. In this review we discuss mechanisms being developed, predominantly using animal models, to provide neuroprotection to prevent neurological losses following blunt trauma and during induced spinal cord ischemia. In parallel, our own experiments are looking at neuroprotective techniques using adult human neurons. We believe the optimal neuroprotective approach will involve the perfusion of the ischemic region of the spinal cord with a hypothermia solution containing a combination of pharmacological agents.