Mode of delivery alters dental pulp nociception and pain-induced changes in cognitive performance in adults male rats.

This study examined the effects of delivery mode on the response to inflammatory pulpal pain and pain-induced changes in cognitive performance in adult rats. Experiments were done on rats born by vaginal or caesarean section (C-section) delivery. Dental pulp was irritated by intradental capsaicin (100 µg) application and then nociceptive scores were recorded for 40 min. Spatial and passive avoidance learning and memory were assessed using the Morris water maze (MWM) and shuttle box tools, respectively. Additionally, in vivo recording of field excitatory postsynaptic potential (fEPSP) in the CA1 of the hippocampus was used to verify synaptic plasticity. Capsaicin produced more significant nociceptive behavior in vaginally delivered rats compared to C-section rats (P < 0.01). C-section-delivered rats show better performance in both MWM and shuttle box tests. Likewise, C-section rats had greater fEPSP slopes compared to the vaginally delivered group (P < 0.05). Capsaicin impairs cognitive performance in rats born by each delivery route. However, capsaicin effects were more significant in rats delivered vaginally than by C-section. Overall, C-section-delivered rats show lower sensitivity to capsaicin-evoked pulpal nociception and better cognitive performance than vaginally delivered rats. These effects are in part mediated by reduced neuroinflammation and enhanced neuronal synaptic plasticity following C-section delivery.

Fingertip reconstruction by palmar bipedicular island flap in long fingers (modified neurovascular Tranquilli-Leali flap): A dual-center study.

When bone is exposed, fingertip defects may require a flap procedure. Many types are available, with little consensus about which one is best. But each one has its own disadvantages: esthetic (claw nail deformity), neurological (sensory disorders) or functional (stiffness). The purpose of this study was to evaluate a palmar bipedicular island flap (our modification of the Tranquilli-Leali flap) for fingertip reconstruction. We retrospectively analyzed the prospective data of 42 patients with a mean follow up of 16.4 months (6-30 months) operated in two hospital facilities. Thirty-three patients were men. Mean age was 39.5 years (12-83 years) and 24 (57.1%) were smokers. In 23 cases (54.8%), the trauma was work-related. A crush mechanism was identified in 29 patients (69%). According to Allen's classification of fingertip injuries, there were 26 cases of stage II, 14 cases of stage III and 2 cases of stage IV. All procedures were performed on an emergency basis, within 24 hours of the trauma. No claw nail deformity was observed. The mean discrimination in the Weber test was 3.8mm (2-6mm). The mean Total Active Motion (TAM) was 268.3° (255-275°). The patient satisfaction was graded at 8.7 on a 10-point scale. Results were considered as excellent in 15 cases and good in 23 cases. The modified palmar bipedicular island flap makes the old Tranquilli-Leali flap - which has a poor reputation in the hand surgeon community-simpler and safer to use. This flap restores proper balance between skin, bone and nail in Allen stage II and III fingertip amputations.

Pulp-to-palm distance is associated with inferior short-term outcome after combined plating for distal radius fractures.

Distal radius fractures (DRF) are the most common fracture in adults. A tool is needed to identify patients who may need extra attention from the physical therapist during the rehabilitation process. The purpose of the study was to examine if pulp-to-palm distance (PTP) 4 weeks postoperatively is associated with wrist function 3 months postoperatively in patients undergoing combined plating for a complex DRF. This prospective study involved 53 patients. PTP was assessed by a physical therapist at the second visit, 4 weeks postoperatively. The 3-month follow-up visit consisted of evaluating the following outcomes: PRWE (Patient-Rated Wrist Evaluation), QuickDASH (Disabilities of the Arm, Shoulder and Hand), VAS pain scores, hand grip strength and wrist range of motion. All patients received the same amount of hand therapy. Patients with zero PTP at 4 weeks postoperative had a significantly better range of motion in wrist extension, flexion, radial deviation, ulnar deviation, hand grip strength and QuickDASH scores compared to patients with a PTP>0cm. VAS pain scores did not differ between the two groups. Patients with zero PTP at 4 weeks postoperative were more likely to have a better wrist function at 3 months postoperative compared to patients with measurable PTP. Based on this study's findings, measuring the PTP distance at 4 weeks postoperative could be useful for identifying patients in need of support during the rehabilitation process after DRF surgery. This could potentially improve the allocation of hand rehabilitation resources; screening patients postoperatively could help to begin relevant interventions.

Treatment of defects in the tip and palmar surface of the fingers.

Defects on the palmar surface of the fingers are an important part of hand emergencies, especially fingertip wounds. Luckily, many coverage methods are available. We will review the anatomy of this area and the thought process for treating these defects. We will also propose an algorithm that can be used to select the best technique based on the type of injury present.

Effect of zoledronate, a third-generation bisphosphonate, on proliferation and apoptosis of human dental pulp stem cells.

Clinical use of zoledronate is accompanied by osteonecrosis of the jaw but the pathogenesis is not well understood. We assumed that zoledronate may have cytotoxicity against stem cells of the oral cavity and in this way helps to initiate or promote osteonecrosis. Dental pulp stem cells (DPSCs) and gingival fibroblasts (GFs) were isolated from volunteers who were undergoing a third molar extraction. The proliferation of DPSCs and GFs was evaluated using the thiazolyl blue tetrazolium bromide assay. The effect of zoledronate on apoptosis was determined by propidium iodide staining and Western blotting analysis. Incubation with zoledronate for 72 h and 7 days significantly decreased proliferation of DPSCs and GFs at concentrations of more than 0.4 µmol/L (p < 0.001). The IC50 of zoledronate was lower for DPSCs than for GFs (0.92 versus 3.5 µmol/L for 7 days of treatment). After 72 h of treatment with zoledronate, the percentage of apoptotic DPSCs significantly increased, which was accompanied by an increased level of pro-apoptotic proteins caspase-3 and Bax and decreased the level of the anti-apoptotic protein Bcl-2. In conclusion, zoledronate has anti-proliferative and pro-apoptotic effects in DPSCs. These effects may be involved in promoting zoledronate-induced osteonecrosis and suggest an unfavorable impact of this drug on regenerative potentials of the body stem cells.

17ß-Estradiol induces odontoblastic differentiation via activation of the c-Src/MAPK pathway in human dental pulp cells.

The present study is aimed at investigating the effects of the exogenous estrogen 17ß-estradiol (E2) on odontoblastic differentiation in human dental pulp cells (HDPCs) immotalized with hTERT gene and their molecular mechanism. Proliferation was detected by BrdU assay, and odontoblast differentiation induction was evaluated by the expression of dentin sialophosphoprotein (DSPP), dentin sialoprotein (DSP) and dentin matrix protein1 (DMP1), and alkaline phosphatase (ALP) activity and mineralization. Estrogen receptor-α (ER-α), c-Src, and mitogen-activated protein kinases (MAPKs) were examined and their inhibitors were used to determine the roles on odontogenic induction. E2 significantly promoted the HDPC proliferation, which was mediated by extracellular signal-related kinase 1/2. E2 upregulated DSPP, DSP, and DMP1 as the odontogenic differentiation markers and enhanced ALP activity and mineralization. E2 increased phosphorylation of ER-α and fulvestrant, an ER downregulator, significantly downregulated DSPP, DMP1, and DSP induced by E2. Moreover, E2 treatment activated c-Src and MAPKs upon odontogenic induction, whereas chemical inhibition of c-Src and MAPKs decreased expression of DSPP, DMP1, and DSP and mineralization augmented by E2. Moreover, fulvestrant reduced E2-induced phosphorylation of c-Src and MAPK and inhibition of c-Src by PP2 attenuated activation of MAPKs during E2-induced odontoblastic differentiation. Taken together, these results indicated that E2 stimulates odontoblastic differentiation of HDPCs via coordinated regulation of ER-α, c-Src, and MAPK signaling pathways, which may play a key role in the regeneration of dentin.

Optimization of treatment with recombinant FGF-2 for proliferation and differentiation of human dental stem cells, mesenchymal stem cells, and osteoblasts.

Basic fibroblast growth factor (bFGF or FGF-2) is widely used to modulate the proliferation and differentiation of certain cell types. An expression and purification system for recombinant human FGF-2 in Escherichia coli was established for the purpose of securing a continuous supply of this protein. The purified recombinant FGF-2 significantly increased the population of human embryonic stem cells. The optimal concentrations of FGF-2 for cell proliferative induction in various adult stem cells including human dental pulp stem cells, full term human periodontal ligament stem cells, human gingival fibroblasts, mesenchymal stem cells, and osteogenic oseosarcoma were established in a dose-dependent manner. When cells were treated with recombinant FGF-2 for 6 days before osteogenic induction, the mRNA expression of the bone markers was upregulated in cells originated from human dental pulp tissue, indicating that pretreatment with FGF-2 during culture increase stem cell/progenitor population and osteogenic potential.