Effects of hyperbaric oxygen therapy on biochemical and histological parameters of muscle groups in proximity to the distracted rat tibia.

We investigated the effect of hyperbaric oxygen therapy (HBOT) on rat muscles during tibial distraction osteogenesis (DO) at normal and hyperdistraction rates. Animals in groups 1 and 2 were distracted by 0.5 mm/day and those in groups 3 and 4 by 1 mm/day. Groups 2 and 4 received HBOT during distraction. Group 5 served as control. Superoxide dismutase (SOD; U/g protein), malondialdehyde (nmol/g protein), glutathione (mmol/g protein), and protein levels (g/dl) were determined. SOD was significantly higher in group 2 (4.59 ± 0.97) than in controls (2.19 ± 0.7) (P = 0.0001), and lower in group 4 (3.74 ± 1.70) than in group 2 (P=0.011). Malondialdehyde was significantly higher in group 2 (0.72 ± 0.23) than in controls (0.38 ± 0.10) (P=0.005). Total protein levels were better preserved with HBOT in distracted muscles: group 2 (3.24 ± 0.37) vs. group 1 (1.88 ± 0.60), and group 4 (3.45 ± 0.70) vs. group 3 (2.03 ± 0.75) (both P=0.0001). Numbers of fibres were lower in group 1 (4.88 ± 0.59) than in group 2 (6.07 ± 0.86), and in group 3 (5.13 ± 0.36) than in group 4 (6.14 ± 0.74) (both P=0.001). Numbers of nuclei were higher in group 1 (11.29 ± 2.47) than in group 2 (9.03 ± 1.53) (P=0.04), and in group 3 (12.43 ± 3.32) than in group 4 (9.08 ± 1.58) (P=0.001). Fibres and nuclei with HBOT were similar to those of controls. HBOT decreased the inflammatory cell infiltrate for group 1 (19.8 ± 8.54) vs. group 2 (4.2 ± 2.53) and group 3 (36.54 ± 11.29) vs. group 4 (21.5 ± 9.23) (both P=0.001). HBOT improves the adaptation of distracted muscle by increasing fibres and antioxidants while decreasing inflammation.

Cumulative effect of low-level laser therapy and low-intensity pulsed ultrasound on bone repair in rats.

Many studies have assessed the effects of either low-level laser therapy (LLLT) or low-intensity pulsed ultrasound (LIPUS) on bone repair; however, an evaluation of the combination of these modalities (LLLT + LIPUS) has not yet been considered. The aim of this study was to demonstrate the effects of LLLT + LIPUS on bone repair. Male Wistar rats (n = 128; four groups of 32) were used; the animals underwent a partial tibial bone osteotomy. One group had the osteotomized limb treated with LLLT, the second group with LIPUS, and the third group with the combined treatment protocols of the LLLT and LIPUS groups; the fourth group received no further treatment (control). Each group was divided into two subgroups for assessment at two different time-points, 14 and 21 days. After the completion of treatment rats were sacrificed and the tibias submitted to a three-point bending test or to histomorphometric analysis. Histological evaluation showed increased bone trabeculae, increased vascularization, and decreased inflammation in the LLLT + LIPUS group. Mechanical evaluation revealed increased biomechanical properties including maximum force, maximum stress, and stiffness, in the LLLT + LIPUS group. Combined LLLT + LIPUS treatment enhanced bone healing both histologically and mechanically, shortening the length of the treatment period, when compared to treatment with LLLT or LIPUS alone.

Talon cusp: a morphological dental anomaly.

Talon cusp is a rare developmental anomaly that occurs most commonly on the lingual side of the incisors. It may cause various clinical problems, such as occlusal interference, irritation of the tongue, pulpal necrosis, caries and periodontal problems. Genetics is thought to be a major cause for the occurrence of this anomaly. This article reports three cases of talon cusp in three members of the same family. Clinical and radiographic findings of talon cusp in two siblings and the mother are presented. Early diagnosis of talon cusp helps in selecting the correct treatment procedure and avoiding complications.

Soft tissue changes during distraction osteogenesis.

This study aimed to investigate soft tissue changes in distraction osteogenesis depending on various distraction and consolidation periods. Fifteen male rabbits were divided into three groups and evaluated for five parameters. An external custom-made device was placed on the right side of the mandible. The postoperative latent period was 4 days. The groups were distracted for different periods (6 days, 3mm; 11 days, 5.5mm, 16 days, 8mm). For histomorphometric analyses, specimens were retrieved from both study and control sides of the mandible and were examined with light microscopy. The number of muscle fibres and nuclei on the study side increase proportionally with the distraction period. Regeneration in the first group continued in its natural pattern; in the second group, there seemed to be degeneration rather than regeneration; and in the third group there seemed to be a balance between regeneration and degeneration processes. In conclusion, when a massive amount of bone is to be obtained, instead of distracting the bone at once, it is thought to give better results if the total amount of distraction is divided into several time periods.

Comparison of c-Fos immunoreactivity in pancreatic beta cells and cells with neural crest, endoderm and mesoderm origin in rats.

AIMS: Pancreatic beta cells are known to share many similarities with neuronal cells, but their origin remains controversial. It has been hypothesized that pancreatic beta cells are derived from neural crest cells. The aim of this study was to investigate the similarities between pancreatic beta cells and cells with neural crest, endoderm and mesoderm origin with respect to c-Fos immunoreactivity (c-Fos-ir), which has a role in important cellular processes including cellular proliferation, growth, differentiation and apoptosis. METHODS: c-Fos-ir was analyzed by immunohistochemical methods in formaline-fixed, paraffin-embedded sections of rat pancreatic beta cells (BCs), in adrenal medullary chromaffin cells (CCs) that are derived from neural crest, in exocrine pancreatic acinar cells (ACs) that are derived from endoderm, and in adrenal cortex zona reticularis cells (RCs) that are derived from mesoderm. RESULTS: The statistical comparisons revealed no significant differences between BCs and CCs with respect to c-Fos-ir (p>0.05). However, a highly significant difference (p<0.001) with respect to c-Fos-ir both between ACs and RCs, and between these two cell types and each of the two other cell types was noted. CONCLUSIONS: As opposed to findings in cells without neural crest origin, the observed similarity between BCs and CCs with respect to c-Fos-ir, provides additional evidence for the similarity of these cells with cells derived from neural crest.

A morphometric consideration of nasal septal deviations by people with paranasal complaints; a computed tomography study.

The purpose of our study was to examine the localizations and the value of septal deviation by examining the coronal computed tomography of 143 persons with paranasal complaints which 72 of them were female and 71 of them were male, without taking into consideration if a deviation existed or not. The localization of the deviations of the septum nasi was investigated and the relationship between the genders were compared. The septum nasi was examined in the anterior, media, posterior regions for the left and the right directions in each person and was also examined at the superior, media and inferior levels except for the caudal end area. The value and the direction of the deviation was established. A deviation was found in one region in at least 76.2% of the 143 persons (70% female and 81% male). The maximum average deviations were found to be 1.43 +/- 2.1 mm in mediomedia "MM" (the vertically and sagittaly middle region of the septum nasi) region with a percentage of 34.7% towards the right-hand side in the female group, and 1.0 +/- 1.7 mm in the MM region with a percentage of 31.9% also towards the right-hand side in the male group. The maximum deviation in the female group was found to be 7.8 mm in the MM region and 7.9 mm in the AT region in the male group. No statistically significant difference was found for the averages of the deviations (0.298 +/- 0.345 mm in the female group and 0.295 +/- 0.269 mm in the male group) in different regions (p > 0.05). No statistically significant difference was found for the averages of the deviations towards the right-hand and left-hand sides between the male (right 0.302 +/- 0.292 mm; left 0.287 +/- 0.261 mm) and the female (right 0.350 +/- 0.438 mm; left 0.247 +/- 0.235 mm) group (p > 0.05). Separation of the nasal septum into 10 segments will constitute a new basically aspect for an objective, simple and practical consideration and classification.