The present study evaluated bone marrow aspirate (BMA) and low‐level laser therapy (LLLT) on bone healing. It was created critical‐size defects (CSD) of 5 mm diameter in rat calvaria of 64 rats. ...Animals were randomly divided into four groups: Control (blood clot), BMA (coagulated BMA), LLLT (laser irradiation and blood clot), and BMA/LLLT (laser irradiation and coagulated BMA). Euthanasia was performed at 15 or 30 days postoperative. Immunohistochemical reactions were performed to identify vascular endothelial growth factor (VEGF), proliferating cell nuclear antigen (PCNA), runt‐related transcription factor‐2 (Runx2), bone morphogenetic protein‐2 (BMP‐2), osteocalcin (OCN), and osteopontin (OPN). The markers were quantified, and data were statistically analyzed. Groups BMA/LLLT and LLLT presented significantly higher VEGF expression than group control. Group BMA/LLLT presented a significantly higher expression of PCNA than all experimental groups. Groups BMA and BMA/LLLT presented significantly higher expression of BMP‐2 than all experimental groups. Groups LLLT and BMA/LLLT presented significantly higher expression of OPN than groups control and BMA. Groups LLLT, BMA, and BMA/LLLT presented a significantly higher expression of OCN than group control. It can be concluded that the association of BMA and LLLT enhanced bone healing by improving expression of VEGF, PCNA, Runx2, BMP‐2, OPN, and OCN.
Background and Objective
Antimicrobial therapy can suppress periodontal pathogens and increase the effectiveness of conventional mechanical treatment. The aim of this study was to assess bone loss ...and the immune inflammatory response of rats under the influence of two photosensitizing agents (MB and TBO) at two different concentrations in antimicrobial photodynamic therapy (aPDT), used as an adjuvant therapy in the treatment of periodontitis.
Material and Methods
Periodontitis was induced in the mandibular first molars of 162 rats. The animals were divided into nine groups: G1 – scaling and root planing (SRP); G2 – SRP plus 100 μg/mL of methylene blue (MB); G3 – SRP plus 10 mg/mL of MB; G4 – SRP plus 100 μg/mL of toluidine blue (TBO); G5 – SRP plus 10 mg/mL of TBO; G6 – SRP plus 100 μg/mL of MB and laser; G7 – SRP plus 10 mg/mL of MB and laser; G8 – SRP plus 100 μg/mL of TBO and laser; and G9 – SRP plus 10 mg/mL of TBO and laser. Six animals from each group were euthanized 7, 15, or 30 d after treatment. Bone loss (BL) in the furcation region was evaluated using histomorphometric and immunohistochemical analyses to detect the receptor activator of nuclear factor‐Κappa B ligand (RANKL), osteoprotegerin (OPG) and tartrate‐resistant acid phosphatase (TRAP).
Results
There was significantly less BL in animals treated with aPDT using low concentrations of MB and TBO at 7, 15 and 30 d. Immunohistochemical analysis revealed decreased RANKL and increased OPG in the aPDT groups and decreased TRAP‐positive cells in G6 and G8.
Conclusions
aPDT, using low concentrations of MB and TBO, was the most effective adjuvant therapy to SRP, acting indirectly as a downregulator of the molecular mechanisms that control bone resorption in periodontitis.
Aim
The lateral pelvic lymph nodes are one of the major sites and sources of local recurrence (LR) after surgery for rectal cancer. Salvage lateral pelvic lymph node dissection (LPLD) is potentially ...curative, but the value of laparoscopic surgery in such cases is unknown. Our aim was to report the technical details of laparoscopic salvage LPLD for LR at these nodes after rectal cancer surgery.
Method
The study was based on nine patients who underwent laparoscopic salvage LPLD for LR at the lateral pelvic lymph nodes after surgery for rectal cancer. The safety and feasibility of this procedure were determined.
Results
The median operation time was 381 min and the median estimated blood loss was 130 ml. There were no conversions. Adjacent structures removed en bloc were the pelvic plexus in four patients, the internal iliac artery in seven patients and the seminal vesicle in one patient. The median number of metastatic lymph nodes was 1 (range 1–11).
Conclusion
Our novel technique of laparoscopic salvage LPLD for LR at the lateral pelvic lymph nodes is safe and feasible.
Aim: This study histologically analysed the effect of autogenous platelet‐rich plasma (PRP), prepared according to a new semiautomatic system, on healing of autogenous bone (AB) grafts placed in ...surgically created critical‐size defects (CSD) in rabbit calvaria.
Material and Methods: Sixty rabbits were divided into three groups: C, AB and AB/PRP. A CSD was created in the calvarium of each animal. In Group C (control), the defect was filled by blood clot only. In Group AB (autogenous bone graft), the defect was filled with particulate autogenous bone. In Group AB/PRP (autogenous bone graft with platelet‐rich plasma), it was filled with particulate autogenous bone combined with PRP. All groups were divided into subgroups (n=10) and euthanized at 4 or 12 weeks post‐operatively. Histometric and histologic analyses were performed. Data were statistically analysed (anova, t‐test, p<0.05).
Results: Group C presented significantly less bone formation compared with Group AB and AB/PRP in both periods of analysis (p<0.001). At 4 weeks, Group AB/PRP showed a statistically greater amount of bone formation than Group AB (64.44 ± 15.0%versus 46.88 ± 14.15%; p=0.0181). At 12 weeks, no statistically significant differences were observed between Groups AB and AB/PRP (75.0 ± 8.11%versus 77.90 ± 8.13%; p>0.05). It is notable that the amount of new bone formation in Group AB/PRP at 4 weeks was similar to that of Group AB at 12 weeks (p>0.05).
Conclusion: Within its limitation, the present study has indicated that (i) AB and AB/PRP significantly improved bone formation and (ii) a beneficial effect of PRP was limited to an initial healing period of 4 weeks.
Mechanism of fatigue failure in ultralong life regime MURAKAMI, Y.; YOKOYAMA, N. N.; NAGATA, J.
Fatigue & fracture of engineering materials & structures,
September 2002, Letnik:
25, Številka:
8-9
Journal Article, Conference Proceeding
Recenzirano
ABSTRACT The fatigue fracture surfaces of specimens of heat treated hard steels which failed in the regime of N = 105 to 5 × 108 cycles, were investigated by optical microscopy and SEM. Specimens ...having a longer fatigue life had a particular morphology beside the inclusion at the fracture origin. The particular morphology looked optically dark and in the previous paper it was named the Optically Dark Area, ODA. The roughness inside ODA is larger than outside ODA. The relative size of the ODA to the size of the inclusion at the fracture origin increases with increase in fatigue life. Thus, the ODA is considered to have a crucial role in the mechanism of ultra long life fatigue failure. Direct evidences of existence of hydrogen at the inclusion at fracture origin are presented. It is presumed that the ODA is made by the cyclic stress coupled with the hydrogen which is trapped by the inclusion at the fracture origin. To verify the influence of hydrogen, specimens containing different levels of hydrogen were prepared by different heat treatments. The results obtained by fatigue tests of these specimens suggest that the hydrogen trapped by inclusions is a crucial factor which causes the ultra long fatigue failure of high strength steels. Aspects of the double S–N curve are also discussed in terms of experimental methods, specimen size and statistical distribution of inclusions sizes.
Immature avulsed teeth are not usually treated with pulp revascularization because of the possibility of complications. However, this therapy has shown success in the treatment of immature teeth with ...periapical lesions. This report describes the case of an immature replanted tooth that was successfully treated by pulp revascularization. An 8‐year‐old boy suffered avulsion on his maxillary left lateral incisor. The tooth showed incomplete root development and was replanted after 30 minutes. After diagnosis, revascularization therapy was performed by irrigating the root canal and applying a calcium hydroxide paste and 2% chlorhexidine gel for 21 days. In the second session, the intracanal dressing was removed and a blood clot was stimulated up to the cervical third of the root canal. Mineral trioxide aggregate was placed as a cervical barrier at the entrance of the root canal and the crown was restored. During the follow‐up period, periapical repair, apical closure and calcification in the apical 4 mm of the root canal was observed. An avulsed immature tooth replanted after a brief extra‐alveolar period and maintained in a viable storage medium may be treated with revascularization.
We investigated the ability of
Garcinia cambogia extract containing (−)-hydroxycitric acid (HCA) to suppress body fat accumulation in developing male Zucker obese (fa/fa) rats. We also examined ...histopathologically the safety of its high doses. Diets containing different levels of HCA (0, 10, 51, 102 and 154
mmol/kg diet) were fed to 6-week-old rats for 92 or 93 days. Each diet group was pair-fed to the 154
mmol HCA/kg diet group. Epididymal fat accumulation and histopathological changes in tissues were observed. The highest dose of HCA-containing
Garcinia cambogia (154
mmol HCA/kg diet) showed significant suppression of epididymal fat accumulation in developing male Zucker obese rats, compared with the other groups. However, the diets containing 102
mmol HCA/kg diet and higher (778 and 1244
mg HCA/kg BW/d, respectively) caused potent testicular atrophy and toxicity, whereas diets containing 51
mmol HCA/kg diet (389
mg HCA/kg BW/d) or less did not. Accordingly, 51
mmol HCA/kg diet (389
mg HCA/kg BW/d) was deemed to be the no observed adverse effect level (NOAEL).
Summary There are several reports suggesting that forward head posture is associated with temporomandibular disorders and restraint of mandibular growth, possibly due to mandibular displacement ...posteriorly. However, there have been few reports in which the condylar position was examined in forward head posture. The purpose of this study was to test the hypothesis that the condyle moves posteriorly in the forward head posture. The condylar position and electromyography from the masseter, temporal and digastric muscles were recorded on 15 healthy male adults at mandibular rest position in the natural head posture and deliberate forward head posture. The condylar position in the deliberate forward head posture was significantly more posterior than that in the natural head posture. The activity of the masseter and digastric muscles in the deliberate forward head posture was slightly increased. These results suggest that the condyle moves posteriorly in subjects with forward head posture.
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