Effect of gamma rays on the bone repair process in rats with estrogen deficiency

Silva, Mariliani Chicarelli da; Ramos, Flávia Maria de Moraes; Manzi, Flávio Ricardo; Novaes, Pedro Duarte; Bóscolo, Frab Norberto; Almeida, Solange María de

doi:10.1590/s1806-83242007000100013

“…The success of the ovariectomy was evaluated by analyzing the estrous cycle, 2 weeks after the surgical procedure [15], and the atrophy of uterine horns during the euthanasia of the animals [16].…”

Section: Ovariectomymentioning

confidence: 99%

Low-level laser therapy improves bone formation: stereology findings for osteoporosis in rat model

Scalize

¹

,

Sousa

²

,

Regalo

³

et al. 2015

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Low-level laser therapy (LLLT) benefits bone metabolism, but its use needs to be standardized. We evaluated the effects of LLLT on bone defects in calvaria of ovariectomized rats. Stereology was used to calculate tissue repair volume (V tr ), density of trabecular bone volume (Vv t ), total volume of newly formed trabecular bone (Vtot), and the area occupied by collagen fibers (A C ). Fifty-four Wistar rats were submitted to bilateral ovariectomy, and bone defects were created in calvaria after 150 days. The animals were divided into nine groups (n = 6), and 24 h after defects, the treatment started with a 780-nm low-intensity GaAlAs laser: G1, G2, and G3 received 3 sessions of 0, 20, and 30 J/cm(2) respectively; G4, G5, and G6 received 6 sessions of 0, 20, and 30 J/cm(2), respectively; and G7, G8, and G9 received 12 sessions of 0, 20, and 30 J/cm(2), respectively. A normal distribution was found for all of the data. The test used to verify the normality was the Kolmogorov-Smirnov (KS, p > 0.05). The one-way ANOVA followed by Tukey's post hoc test was used for data processing. A difference of p < 0.05 was considered statistically significant. Groups G2 and G1 showed significance for V tr , Vv t , Vtot, and (A C ). Results were significant for (Vv t ) and (Vtot) between G3 and G1. There were no significant results between G5 and G4 as well as between G8 and G7. Groups G6 and G4 results showed statistical difference for V tr , Vv t , Vtot, and (A C ). Groups G9 and G7 showed significance for V tr , Vv t , Vtot, and (A C ). In conclusion, there was new bone formation in the groups that received 20 and 30 J/cm(2) when compared to control groups, but over time, the dose of 30 J/cm(2) showed better stereological parameters when compared to 20 J/cm(2).

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“…Bone irradiation causes undesirable side effects leading to unfavorable bone remodeling and repair (8)(9)(10)(11) and, in the worst case, osteoradionecrosis (16). In the present study, we exposed cortical bone chips to a gamma radiation dose up to 120 Gy and investigated the subsequent effects on the activity of TGF-β target genes.…”

Section: Discussionmentioning

confidence: 98%

“…Adverse effects include pathologic fractures, continuity defects, and abnormalities in osteosynthesis (8)(9)(10)(11). Substantial evidence indicates that irradiation disrupts bone microvasculature (12,13).…”

Section: Introductionmentioning

confidence: 99%

High-dose irradiation of bone chips preserves the <i>in vitro</i> activity of bone-conditioned medium

Sawada

¹

,

Miron

²

,

Leiser

³

et al. 2016

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Extracorporeal irradiation sterilizesresected tumor bone used as autografts in reconstruction surgery. Therapeutic irradiation is a standard technique in head and neck cancer therapy that aims to preserve organ function. Bone irradiation has a complex, mostly inhibitory, effect on remodeling and regeneration, although the underlying mechanisms are still not fully understood. It remains unclear if extracorporeal irradiation affects the paracrine-like activity of the corresponding autografts. We recently reported that bone-conditioned medium from autogenous bone chips contains a number of factors that might affect cell activity. In the present study, we investigated the effects of extracorporeal irradiation of porcine cortical bone chips on the activity of the corresponding bone-conditioned medium. The effects of bone-conditioned medium on the expressions of transforming growth factor-beta (TGF-β) target genes in oral fibroblasts were assessed. Bone-conditioned medium from bone chips exposed to a total radiation dose up to 120 Gy did not affect expressions of TGF-β target genes, including adrenomedullin, BTB/ POZ domain-containing protein 11, proteoglycan 4, NADPH oxidase 4, and interleukin 11, in oral fibroblasts. In conclusion, bone irradiation does not alter the capability of the corresponding bone-conditioned medium to provoke a robust fibroblastic cell response in vitro. (J Oral Sci 58, 325-331, 2016)

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“…Each animal received an intramuscular injection of 0.1 mL/100 g weight of small‐size veterinary pentabiotic (Fort Dodge ® , Campinas, SP, Brazil), followed by 0.2 mL/100 g of Banamine ® injectable analgesic (Schering‐Plough, Cotia, SP, Brazil). The success of the ovariectomy was evaluated by analyzing the estrous cycle 2 weeks after the surgical procedure and the atrophy of uterine horns observed following the euthanasia of the animals …”

Section: Methodsmentioning

confidence: 99%

Low‐level laser therapy enhances the number of osteocytes in calvaria bone defects of ovariectomized rats

Scalize

¹

,

Sousa

²

,

Gonçalves

³

et al. 2019

Anim Models and Exp Med

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Background Osteoporosis can make bone repair difficult. Low‐level laser therapy ( LLLT ) has been shown to be a promising tool for bone neoformation. This study aimed to analyze the effect of LLLT on calvaria bone defects of ovariectomized rats using stereology. Methods Fifty‐four Wistar rats were subjected to bilateral ovariectomy, and bone defects were created in calvaria after 150 days. The animals were divided into nine groups (n = 6 per group), and 24 hours after the bone defects were created they received 3, 6 or 12 sessions of LLLT at 0, 20 or 30 J/cm 2 , using a 780‐nm low‐intensity GaAlAs laser. One‐way ANOVA followed by Tukey's post hoc test was used for data processing. A difference of P < 0.05 was considered statistically significant. The parameters evaluated were osteocyte density ( Nv ost ), total osteocyte number ( Nto ost ), trabecular surface density ( Sv t ), and trabecular surface area ( Sa t ). Results Data obtained showed that Nto ost , Sv t , and Sa t in group G2 rats were significantly different from G1 (0 J/cm 2 ) ( P < 0.05). Compared to group G4, G5 presented higher values for the parameters Sv t and Sa t , and G6 presented significantly higher values for almost all the analyzed parameters ( Nv ost , Nto ost , Sv t , and Sa t ) ( P < 0.05). Compared to group G7, G8 showed a higher value only for the parameter Sa t , and G9 showed significantly higher values for parameters Nv ost , Nto ost , Sv t , and Sa t . Conclusion We conclude that LLLT stimulated bone neoformation and contributed to an increase in the total number of osteocytes, especially with a laser energy density of 30 J/cm 2 given for 6 and 12 sessions.

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Effect of gamma rays on the bone repair process in rats with estrogen deficiency

Cited by 10 publications

References 22 publications

Low-level laser therapy improves bone formation: stereology findings for osteoporosis in rat model

Low-level laser therapy improves bone formation: stereology findings for osteoporosis in rat model

High-dose irradiation of bone chips preserves the <i>in vitro</i> activity of bone-conditioned medium

Low‐level laser therapy enhances the number of osteocytes in calvaria bone defects of ovariectomized rats

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