The effect of sub-epineural platelet-rich plasma (PRP) on regeneration of the sciatic nerve in a rat model

Background: Peripheral nerve injury is one of the most challenging of modern surgical problem. Recent advances in understanding the physiological and molecular pathways demonstrated the important role of growth factors in peripheral nerve regeneration. Platelet-rich plasma (PRP) is a biological product that has many growth factors. The aim of this study was to investigate the effect of PRP in the regeneration of sciatic nerve crush in the rat model. Methods: In this experimental study that established in the animal lab of the Hazrat Fatemeh Hospital in Tehran from September to October 2013, Twenty-four healthy male Sprague-Dawley rats (200-250 g) were randomly divided into two groups. In all rats the sciatic nerve was cut and then carefully repaired by the tension free method under a light microscope. In group 1, after the repair, 0.05 μL of PRP was injected below the epineurium to the proximal and distal parts of the repaired area. In group 2 the same amount of normal saline was injected to the proximal and distal of the repaired area. After six weeks footprint analysis, neurophysiologic and histopathology evaluations were performed. Results: Significant differences existed between the two groups footprint analysis (P= 0.001). Also the nerve conduction latency test was significantly shorter in PRP group. (1.0233 ms in PRP group and 1.7375 ms in control) (P< 0.001). The average amplitude in the first group and the second group was 7.6250 mv (control) 6.3667 mv that does not show a statistically significant difference (P= 0.093). Significant differences between the two groups in the number of axons of the proximal portion of the study was not seen (P= 0.29). The parameters included number of axons of the proximal and the distal part of axons, the diameter of the distal and proximal axons in the two groups were compared. In the two groups there was statistically significant difference between the above parameters. (P= 0.298). Conclusion: It seems that PRP may have an important role in peripheral nerve regeneration and functional recovery after nerve laceration and repair. Further clinical evaluation recommended. © 2016, Tehran University of Medical Sciences. All rights reserved

The global burden of cancer attributable to risk factors, 2010–19: a systematic analysis for the Global Burden of Disease Study 2019

BACKGROUND: Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. METHODS: The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk–outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. FINDINGS: Globally, in 2019, the risk factors included in this analysis accounted for 4·45 million (95% uncertainty interval 4·01–4·94) deaths and 105 million (95·0–116) DALYs for both sexes combined, representing 44·4% (41·3–48·4) of all cancer deaths and 42·0% (39·1–45·6) of all DALYs. There were 2·88 million (2·60–3·18) risk-attributable cancer deaths in males (50·6% [47·8–54·1] of all male cancer deaths) and 1·58 million (1·36–1·84) risk-attributable cancer deaths in females (36·3% [32·5–41·3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20·4% (12·6–28·4) and DALYs by 16·8% (8·8–25·0), with the greatest percentage increase in metabolic risks (34·7% [27·9–42·8] and 33·3% [25·8–42·0]). INTERPRETATION: The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden