Cognitive and behavior deficits in sickle cell mice are associated with profound neuropathologic changes in hippocampus and cerebellum.

Strokes are perhaps the most serious complications of sickle cell disease (SCD) and by the fifth decade occur in approximately 25% of patients. While most patients do not develop strokes, mounting evidence indicates that even without brain abnormalities on imaging studies, SCD patients can present profound neurocognitive dysfunction. We sought to evaluate the neurocognitive behavior profile of humanized SCD mice (Townes, BERK) and to identify hematologic and neuropathologic abnormalities associated with the behavioral alterations observed in these mice. Heterozygous and homozygous Townes mice displayed severe cognitive deficits shown by significant delays in spatial learning compared to controls. Homozygous Townes also had increased depression- and anxiety-like behaviors as well as reduced performance on voluntary wheel running compared to controls. Behavior deficits observed in Townes were also seen in BERKs. Interestingly, most deficits in homozygotes were observed in older mice and were associated with worsening anemia. Further, neuropathologic abnormalities including the presence of large bands of dark/pyknotic (shrunken) neurons in CA1 and CA3 fields of hippocampus and evidence of neuronal dropout in cerebellum were present in homozygotes but not control Townes. These observations suggest that cognitive and behavioral deficits in SCD mice mirror those described in SCD patients and that aging, anemia, and profound neuropathologic changes in hippocampus and cerebellum are possible biologic correlates of those deficits. These findings support using SCD mice for studies of cognitive deficits in SCD and point to vulnerable brain areas with susceptibility to neuronal injury in SCD and to mechanisms that potentially underlie those deficits.

Influence of 2 cryopreservation methods to induce CCL-13 from dental pulp cells.

INTRODUCTION: Cryopreservation preserves periodontal ligament cells but has a lower success rate with dental pulp cells (DPCs) because it causes inflammation. There are 2 well-known cryopreservation methods that reduce inflammation, slow freezing and rapid freezing, but the effects of the 2 methods on inflammation are not well-established. The purpose of this study was to compare the effects of the 2 different cryopreservation methods on CCL-13 induction from DPCs by using microarrays, real-time polymerase chain reaction (PCR), Western blotting, enzyme-linked immunosorbent assay, and confocal laser scanning microscopy (CLSM). METHODS: In this study, the concentration of cryoprotectant was fixed, and the methods compared differed with respect to freezing speed. Initially we screened the DPCs of cryopreserved teeth with expression microarrays, and CCL-13 was identified as a differentially expressed gene involved in generalized inflammation. We then compared the expression of CCL-13 after exposing teeth to the 2 cryopreservation methods by using real-time PCR, Western blot, enzyme-linked immunosorbent assay, and CLSM. RESULTS: Expression of CCL-13 was up-regulated significantly only in the rapid freezing group, except in measurements made by real-time PCR. CLSM analysis also confirmed this up-regulation visually. CONCLUSIONS: Rapid freezing increased the expression of CCL-13 in DPCs compared with slow freezing. Understanding the inflammatory effect of cryopreservation should help to establish an optimal cryoprofile to minimize inflammation of DPCs and reduce the need for endodontic treatment.

Long-term follow-ups of revascularized immature necrotic teeth: three case reports.

Revascularization of immature necrotic teeth is a reliable treatment alternative to conventional apexogenesis or apexification. In case 1, a 12-year-old boy had his necrotic, immature mandibular left second premolar treated with a revascularization technique. At a24-month follow-up, periapical radiolucency had disappeared and thickening of the root wall was observed. In cases 2 and 3, a10-year-old boy had his necrotic, immature, bilateral mandibular second premolars treated with the same modality. At 48-month(in case 2) and 42-month (in case 3) follow-ups, loss of periapical radiolucencies and increases in the root wall thickness were also observed.