Generation and characterization of highly purified canine Schwann cells from spinal nerve dorsal roots as potential new candidates for transplantation strategies

Schwann cells are promising candidates for transplantation strategies in the central nervous system by promoting axonal regeneration. The dog represents a translational model for human spinal cord injury (SCI) for studies with new repair strategies after intervertebral disk herniation (IVDH). To overcome the necessity for an additional surgical procedure, for the first time a protocol for the isolation and purification of canine Schwann cells from spinal nerve biopsies during standard hemilaminectomy in IVDH‐affected paraplegic dogs for potential transplantation has been developed. Purity was assessed by flow cytometry. The results were compared with biopsies from dogs without SCI. Within 26 ± 4 days, 90.2 ± 8.8% p75 neurotrophin receptor (p75^NTR)‐positive cells were achieved in IVDH dogs. The total cell count in acute/subacute and chronic IVDH (acute/subacute: 6.82 ± 6.36 × 10⁶; chronic: 2.29 ± 2.00 × 10⁶) differed significantly (p = 0.0120) at the potential time point of transplantation. No differences in culture period and purity were detected between dogs with and without IVDH. Despite the small sample size and the altered environment, the isolation of Schwann cells was successful. Negative influences on isolation and purification due to potential pathological changes at the biopsy site of IVDH‐diseased dogs were ruled out by comparison of Schwann cell pellets from diseased and control dogs. Finally, the functionality of Schwann cells from dogs with IVDH was outlined in co‐culture experiments with canine dorsal root ganglion neurons. In conclusion, nerve root biopsies provide a sufficient number of highly purified and functional Schwann cells within a useful time period for novel therapeutic strategies in dogs with SCI.     

Osteoinductive 3D scaffolds prepared by blend centrifugal spinning for long-term delivery of osteogenic supplements

Bone regeneration is a long-term process requiring proper scaffolding and drug delivery systems. The current study delivers a three-dimensional (3D) scaffold prepared by blend centrifugal spinning loaded with the osteogenic supplements (OS) β-glycerol phosphate, ascorbate-2-phosphate and dexamethasone. The OS were successfully encapsulated into a fibrous scaffold and showed sustained release for 30 days. Furthermore, biological testing showed the osteoinductive properties of the scaffolds on a model of human mesenchymal stem cells and stimulatory effect on a model of osteoblasts. The osteoinductive properties were further proved in vivo in critical size defects of rabbits. The amount of bone trabecules was bigger compared to control fibers without OS. The results indicate that due to its long-term drug releasing properties, single step fabrication process and 3D structure, the system shows ideal properties for use as a cell-free bone implant in tissue-engineering.

Bone regeneration is a long-term process requiring proper scaffolding and drug delivery systems.     

Effect of blood passage through the pulmonary circulation on fibrinolytic parameters

The lung vasculature bed has a unique fibrinolytic potential, which has not yet been completely elucidated. We investigated the effect of blood passage through the pulmonary circulation on the values of fibrinolytic parameters in plasma. Forty-seven patients (16 women, 31 men, mean age 54 years, range 21–67 years) who had undergone elective cardiac catheterization were included in the study. The blood samples were taken simultaneously from the right atrium and the left ventricle. The following fibrinolytic parameters were measured: tissue-type plasminogen (t-PA) antigen and activity, plasminogen activator inhibitor-1 (PAI-1) antigen and activity, and euglobulin clot lysis time (ECLT). No difference was found between the samples obtained from the right atrium and the left ventricle with respect to t-PA antigen: 8.1 (6.7–11.3) vs 8.4 (5.9–11.0)ng/ml; t-PA activity: 92 (5–680) vs 62 (32–696)IU/ml; PAI-1 antigen: 8.4 (5.5–14.3) vs 8.7 (6.2–13.1)ng/ml; and ECLT: 5.5 (4.1–9.1) vs 5.6 (4.1–8.5) 1000/min. In contrast, PAI activity decreased significantly: 7.9 (5.8–10.3) vs 7.4 (6.0–10.4)IU/ml, P 0.01. Patients with and without pulmonary hypertension did not differ in any of measured parameters, either in the right atrium or in the left ventricle. These results show that under basal conditions fibrinolytic activity which is not attributed to t-PA is elevated in lung vasculature. Further, basal fibrinolytic activity in the lungs is not influenced by pulmonary hypertension.     

A new two‐dimensional sonographic approach to the assessment of the fetal hard and soft palates

Facial clefts are among the most common congenital defects. Ultrasound (US) imaging of secondary fetal palate, especially the detection of isolated defects, remains challenging. Currently described two‐dimensional (2D) and three‐dimensional methods are technically demanding and impractical for application during routine fetal anatomy evaluation. As an adjunct method, magnetic resonance imaging can provide additional information but has its limitations. We present a novel 2D US approach using axial and sagittal planes to evaluate the fetal palate and demonstrate the main differences between an intact palate, isolated cleft palate, and a cleft lip with cleft palate.     

Multisite rTMS for the Treatment of Chronic Tinnitus: Stimulation of the Cortical Tinnitus Network—A Pilot Study

Low-frequency repetitive transcranial magnetic stimulation (rTMS) of the auditory cortex has been shown to significantly reduce tinnitus severity in some patients. There is growing evidence that a neural network of both auditory and non-auditory cortical areas is involved in the pathophysiology of chronic subjective tinnitus. Targeting several core regions of this network by rTMS might constitute a promising strategy to enhance treatment effects. This study intends to test the effects of a multisite rTMS protocol on tinnitus severity. 45 patients with chronic tinnitus were treated with multisite stimulation (left dorsolateral prefrontal, 2,000 stimuli, 20 Hz; left temporoparietal, 1,000 stimuli, 1 Hz; right temporoparietal, 1,000 stimuli, 1 Hz). Results were compared with a historical control group consisting of 29 patients who received left temporal stimulation (2,000 stimuli, 1 Hz). Both groups were treated on ten consecutive working days. Tinnitus severity was assessed at three time points: at baseline, after the last treatment session (day 12) and after a follow-up period of 90 days. A change of tinnitus severity over time was tested using repeated measures ANOVA with the between-subjects factor treatment group. Both groups improved similarly from baseline to day 12. However, there was a difference on day 90: the multisite stimulation group showed an overall improvement whereas patients receiving temporal stimulation returned to their baseline level of tinnitus severity. These pilot data suggest that multisite rTMS is superior to temporal rTMS and represents a promising strategy for enhancing treatment effects of rTMS in tinnitus. Future studies should explore this new protocol with respect to clinical and neurobiological effects in more detail.