Application of capacitively coupled electric field enhances periimplant osteogenesis in the dog mandible

PURPOSE: Expeditious postoperative ingrowth of bone into dental implants is desired for clinically successful fixation of oral implants. The present study was performed to evaluate the effect of applying a capacitively coupled electric field (CCEF) on periimplant osteogenesis in the dog mandible. MATERIALS AND METHODS: Twelve adult male beagles were used in this study. All of the premolars on both sides of the mandible were removed from each dog. A POI (Ti-6Al-4V) 3-piece implant (3.7 mm in diameter and 8.0 mm in length) whose surface had been treated with anodic oxidation was placed into each test site by self-tapping. Daily application of CCEF (8 h/day) was initiated on the day following the surgery and was continued through the day of sacrifice. A CCEF was induced by an external source delivering 10-Vp-p, 60-kHz sine-wave signals through an oral electrode plate. One side of the mandible of each dog was treated with CCEF, while the other side was not. On the control side, an oral electrode plate was attached for 8 hours per day, but CCEF was not applied. The effect of daily application of CCEF on the ingrowth of bone into the implant was examined at 14, 21, or 30 days after implant placement. A fourth control group was not treated with CCEF and was maintained for 90 days to confirm that CCEF treatment enhances bone ingrowth in dental implants. RESULTS: Daily application of CCEF significantly increased the bone-contact ratio at days 14, 21, and 30 after implant placement in comparison with the respective controls. The bone-area ratios of the 14- and 21-day CCEF-treated groups were significantly larger than those of the respective controls and were similar to those of the 90-day control group. CONCLUSION: CCEF treatment increases periimplant osteogenesis in the dog mandible, confirming its usefulness in oral implantology.     

Mechanical stress enhances production of cytokines in human periodontal ligament cells induced by Porphyromonas gingivalis

Objective

We have previously reported that human periodontal ligament (hPDL) cells produced many kinds of cytokines as a result of bacterial stimulation, including stimulation with Porphyromonas gingivalis (P. gingivalis). However, the effects of mechanical stress on cytokine production in hPDL cells stimulated by periodontopathogenic bacteria are not clearly understood. In this study, we investigated the effects of mechanical stress on the production of inflammatory cytokines in hPDL cells induced by stimulation with P. gingivalis.

Methods

The hPDL cells were exposed to various levels of mechanical stress (1, 6, 10 and 50 MPa) and costimulated with mechanical stress and P. gingivalis for 24 h. Cytokine mRNA expressions were determined by RT-PCR. Cytokines in the culture supernatant were assessed by ELISA, and morphologic changes in hPDL cells were observed.

Results

The expressions of interleukin (IL)-6, IL-8 and tumor necrosis factor-α mRNA were observed in hPDL cells after exposure to mechanical stress. Moreover, the production of IL-6 and IL-8 increased significantly after exposure to mechanical stress ranging from 1 to 10 MPa. The amount of IL-8 in the culture supernatants of hPDL cells costimulated with P. gingivalis and mechanical stress was significantly higher than the expected additive amount. The morphology of hPDL cells did not change after exposure to 6 MPa, but these cells were partly detached from the Petri dish after exposure to 50 MPa.

Conclusions

These results suggest that local inflammation of the periodontal ligament may be induced mainly by periodontal bacteria, and mechanical stress may promote local inflammation.     

Pathomorphological description of the shunted portion of a filum terminale arteriovenous fistula

Background contextThe clinical morphology of a filum terminale arteriovenous fistula (f-AVF) is well known; however, pathological details of the fistulized portion are unknown. Herein, we report the pathological findings of the f-AVF.Study designCase report and literature review.PurposeTo present a detailed pathological examination of the fistulized portion of the f-AVF.MethodsA 71-year-old man presented with gradually worsening bilateral foot paresthesias and anal dysesthesia. T2-weighted magnetic resonance imaging showed flow voids surrounding an edematous conus medullaris and cauda equina with spinal stenosis at L3–L4 and L4–L5. Spinal digital subtraction angiography demonstrated an f-AVF fed by the left T9 intercostal artery.ResultsWe performed laminotomies of L3 and L4 to open the dura mater and found a hypertrophic filum terminale. It was resected, leaving a length of 2 cm between the abnormal proximal end and normal distal end. The f-AVF completely disappeared after the surgery. On pathological examination, the filum terminale included two vessels at the proximal end and one at the distal end. At the proximal end, immunostaining showed one vessel that was definitively an artery with both an internal elastic membrane (IEM) and smooth muscle. The other was a vein and lacked an IEM. On the distal side, the collagen fibers gradually increased, the IEM partially disappeared from the arterial wall, and the vein became arterialized with a thin IEM. At the distal end the two vessels joined. Therefore, we speculated that the fistulized portion of the f-AVF was not a fistula point but had some lengths where the artery had characteristics of a vein and there was venous arterialization.ConclusionsThe filum arteriovenous shunting occurred at the portion where there was venous arterialization and the artery had the characteristics of a vein. Therefore, resecting the filum terminale requires more proximal from the normal distal end.     

Clinical characteristics of spontaneous isolated visceral artery dissection

Objective

Spontaneous isolated visceral artery dissection (SIVAD) involving the celiac artery or superior mesenteric artery is rare, but it can be fatal. Given its rare incidence, the clinical characteristics of SIVAD are not fully understood. Therefore, the aim of this study was to investigate the clinical characteristics and prognosis of SIVAD.

The loss of BAP1 protein expression predicts poor prognosis in patients with nonmetastatic clear cell renal cell carcinoma with inferior vena cava tumor thrombosis

Objectives

Renal cell carcinoma (RCC) is characterized by a propensity for extension into the renal vein and inferior vena cava (IVC) and is associated with poor prognosis. BAP1 mutation, which occurs in about 15% of patients with clear cell RCC (ccRCC), also predicts poor prognosis. The aim of this study was to elucidate the association between BAP1 protein expression and clinicopathological outcomes in patients with nonmetastatic ccRCC with an IVC tumor thrombus (IVCTT).