Utilizing 808 nm laser for sensitizing of melanoma tumors to megavoltage radiation therapy.

Melanotic melanoma has high content of melanin and laser can destroy melanin-containing cells through thermal effect. In this study, the therapeutic effect of 808 nm laser therapy was investigated on B16-F10 melanoma tumor growth and tumor-bearing mice survival time. In addition, as laser can destroy melanin as the main cause of melanoma radioresistance, the effect of laser administration to enhance radiation therapy efficacy at B16-F10 cancer cells was evaluated in vitro and in vivo. Laser therapy (1 W/cm2 × 4 min) could cause significant (P < 0.05) inhibition of melanoma tumors' growth (~ 61%) and about three times increase of the tumor-bearing mice survival time in comparison with no-treatment group. In addition, the mice which were treated with 1 W/cm2 × 4 min laser administration plus 6 Gy megavoltage radiation therapy exhibited ~ 68% lesser tumors' volume and 27 days increase of survival time in comparison with 6 Gy irradiated tumor-bearing mice. Also, significantly higher (P < 0.05) tumor necrosis percentage was observed at the histopathological slides of 1 W/cm2 × 4 min laser + RT treated mice tumors (57 ± 12%) in comparison with radiation therapy group (31 ± 10%). Therefore, not only laser therapy can inhibit melanoma tumors' growth per se but also its combination with radiation therapy can cause a significant enhancement of radiation therapy efficacy. The laser administration can be used as a radiosensitizing method for melanotic melanoma radiation therapy.

The relationship between cross-sectional area of multifidus muscle and disability index in patients with chronic non-specific low back pain.

BACKGROUND: Nonspecific low back pain (NSLBP) is a common problem that may have an effect on the level of functional ability. Imaging techniques indicated the degeneration of multifidus muscles in patients with low back pain. But its relationship with disability in NSLBP is unclear. OBJECTIVE: To assess the relationship between changes in multifidus muscle morphology in MRI as paraclinical data with changes in the level of disability as clinical data in patients with CNLBP, whose MRI studies are normal. Moreover, the relationship between multifidus CSA and its thickness was determined. DESIGN: Cross-sectional study. METHODS: A total of 45 subjects with CNLBP participated in this study. Multifidus muscle thickness and cross-sectional area (CSA) for both sides in L4-L5 and L5-S1 levels were measured with MRI and Image J software. Level of disability was assessed with Roland-Morris disability index. RESULTS: There was no significant relationship between multifidus muscle's CSA or thickness variations among the L4-L5 and L5-S1 levels and disability index score. Furthermore, Pearson's test showed significant positive relationship between thickness and CSA of muscles (p˂0.05). CONCLUSION: The relationship between lumbar multifidus Thickness and disability in CNLBP with normal MRI study, is not proven in this study. Multifidus muscle thickness in L4-L5 or L5-S1 level can be representative of its CSA in patients with CNLBP and normal MRI.

A study on the effects of general fatigue on head and neck proprioception in healthy young adults.

BACKGROUND: Fatigue is one of the factors causing disturbance in proprioception which can be manifested in two ways: general and local. Due to the important role of cervical proprioception on body stability and posture, research on the effects of general fatigue on proprioception helps to better understand its mechanism and to improve the strategies to prevent injury. Therefore, the aim of this study was to identify the effects of general fatigue on head and neck proprioception in young healthy adults. MATERIAL AND METHODS: This clinical study was done by implementing pre- and post-test measurements in 112 young healthy subjects aged between 18-30 years and able to walk at a speed of 10Km for 5 minutes. They were randomly divided into an experimental and control group. The patients in the control (not exposed to a general fatigue task) and experimental (exposed to a general fatigue task) groups were matched for age, height and weight. In the first step, the zero absolute reposition angle of the head and neck was measured in all participants. Then the subjects in the experimental group did a five-minute run on the treadmill to achieve the level of general fatigue, following which the head and neck reproduction angle was measured in all subjects for the second time. RESULTS: There was a statistical significant difference between pre- and post-test absolute angular error in the experimental group; however, there was no noticeable difference between the pre- and post-test data in the control group. CONCLUSIONS: 1. General fatigue increased the repositioning angular error of head and neck. 2. Neck proprioception decreased due to general fatigue. 3. General fatigue increased the risk of neck injury.