Mannitol facilitates neurotrophic factor up-regulation and behavioural recovery in neonatal hypoxic-ischaemic rats with human umbilical cord blood grafts

We recently demonstrated that blood–brain barrier permeabilization using mannitol enhances the therapeutic efficacy of systemically administered human umbilical cord blood (HUCB) by facilitating the entry of neurotrophic factors from the periphery into the adult stroke brain. Here, we examined whether the same blood–brain barrier manipulation approach increases the therapeutic effects of intravenously delivered HUCB in a neonatal hypoxic-ischaemic (HI) injury model. Seven-day-old Sprague–Dawley rats were subjected to unilateral HI injury and then at day 7 after the insult, animals intravenously received vehicle alone, mannitol alone, HUCB cells (15k mononuclear fraction) alone or a combination of mannitol and HUCB cells. Behavioural tests at post-transplantation days 7 and 14 showed that HI animals that received HUCB cells alone or when combined with mannitol were significantly less impaired in motor asymmetry and motor coordination compared with those that received vehicle alone or mannitol alone. Brain tissues from a separate animal cohort from the four treatment conditions were processed for enzyme-linked immunosorbent assay at day 3 post-transplantation, and revealed elevated levels of GDNF, NGF and BDNF in those that received HUCB cells alone or when combined with mannitol compared with those that received vehicle or mannitol alone, with the combined HUCB cells and mannitol exhibiting the most robust neurotropic factor up-regulation. Histological assays revealed only sporadic detection of HUCB cells, suggesting that the trophic factor–mediated mechanism, rather than cell replacement per se, principally contributed to the behavioural improvement. These findings extend the utility of blood–brain barrier permeabilization in facilitating cell therapy for treating neonatal HI injury.

Autoantibodies to glucose‐6‐phosphate isomerase are elevated in the synovial fluid of rheumatoid arthritis patients

OBJECTIVE

This study investigated whether anti-glucose-6-phosphate isomerase (GPI) antibody in the synovial fluid is specifically related to human rheumatoid arthritis (RA).

METHODS

Synovial fluid was collected from patients with RA, osteoarthritis (OA), gout, Behcet's disease, or ankylosing spondylitis. GPI-binding activity was measured in the synovial fluid using a surface plasmon resonance (SPR) biosensor.

RESULTS

The mean level of anti-GPI signal in the synovial fluid of RA patients was significantly elevated compared with that of OA patients (2.84 +/- 1.41 AU versus 1.19 +/- 0.42 AU, respectively; p < 0.0001). Anti-GPI signals in the synovial fluids of patients with non-rheumatoid arthritis, such as gout, Behcet's disease, or ankylosing spondylitis were significantly lower than in the synovial fluid of RA patients (p < 0.005), and were similar to those of OA patients.

CONCLUSION

Our study indicates that anti-GPI antibody in the synovial fluid is specifically related to RA, and suggests that GPI and its autoantibody might be important in the pathogenesis of human RA.

Formulation of a cosurfactant-free O/W microemulsion using nonionic surfactant mixtures

A cosurfactant-free O/W microemulsion composed of oil, a mixture of hydrophilic and hydrophobic surfactants, and water has been developed using food-grade components as a nutrient delivery system. We started our investigation to monitor the phase behavior of this system based on a hydrophilic surfactant (Tween 80). From a phase diagram, the weight ratio of 5.4:33.8:60.8 = oil:surfactant:water was selected as a combination ratio for the O/W microemulsion system. We also investigated the combination effect of different hydrophobic surfactants to Tween 80 on microemulsion formation. Use of hydrophobic surfactants with Tween 80 produced smaller droplets than Tween 80 alone. Rheological studies showed that all microemulsions followed shear-thinning behavior. The turbidity of microemulsions did not change after accelerated stability tests, indicating that this microemulsion system was stable under the given harsh conditions. When docosahexaenoic acid (DHA) oil was applied to this microemulsion system, the particle size and the turbidity were not significantly changed. Dilution with a different aqueous medium, either water or acidic fluid, did not significantly change the microemulsion turbidity. DHA oil incorporated in microemulsion showed higher oxidation stability than free DHA oil.

Formulation of a cosurfactant-free O/W microemulsion using nonionic surfactant mixtures

A cosurfactant-free O/W microemulsion composed of oil, a mixture of hydrophilic and hydrophobic surfactants, and water has been developed using food-grade components as a nutrient delivery system. We started our investigation to monitor the phase behavior of this system based on a hydrophilic surfactant (Tween 80). From a phase diagram, the weight ratio of 5.4:33.8:60.8 = oil:surfactant:water was selected as a combination ratio for the O/W microemulsion system. We also investigated the combination effect of different hydrophobic surfactants to Tween 80 on microemulsion formation. Use of hydrophobic surfactants with Tween 80 produced smaller droplets than Tween 80 alone. Rheological studies showed that all microemulsions followed shear-thinning behavior. The turbidity of microemulsions did not change after accelerated stability tests, indicating that this microemulsion system was stable under the given harsh conditions. When docosahexaenoic acid (DHA) oil was applied to this microemulsion system, the particle size and the turbidity were not significantly changed. Dilution with a different aqueous medium, either water or acidic fluid, did not significantly change the microemulsion turbidity. DHA oil incorporated in microemulsion showed higher oxidation stability than free DHA oil.