Effect of Ramp on Joint Moment of Attendants during Manual Control of Wheelchairs

Objective@#This study aimed to predict the injury risk to attendants by simulating and analyzing the joint moment that occurs during wheelchair transportation for five different ramp ratios and five different velocities. Method: Three-dimensional musculoskeletal models and rigid structure of a standard wheelchair were developed using the AnyBody Modeling System. The ramp ratio was set to 1：6 (the steepest), 1：8, 1：10, 1：12, and 1：14 (the gentlest). The wheelchair speeds were set to 0.4, 0.5, 0.6, 0.7, and 0.8 m/s. Both the uphill and downhill movement conditions were investigated. @*Results@#Most of the joint moments that occur in the wrist joint, elbow and shoulder while driving uphill increased or decreased proportionally to the slope and speed of the ramp. However, the external moment of the wrist occurring downhill was largely influenced by the slope, and the joint moment of the shoulder showed a dynamic pattern of change in the middle of the ramp in spite of constant driving speed. @*Conclusion@#The influence that occurs during deceleration while wheelchair driving on a ramp is primarily on the proximal shoulder joint, and the influence of the release control in the middle of driving primarily causes loads on the distal wrist and forearm. A high risk of damage exists because the moment change value of the load on the shoulder joint is relatively large and increases with inclination. The increase in wrist abduction moment for deceleration while driving downhill also suggests the possibility of damage.

Clinical Outcomes of Distraction Osteogenesis in Fourth Brachymetatarsia / 대한정형외과학회잡지

Purpose@#Brachymetatarsia is a relatively rare disease that is characterized by one or more metatarsals shorter than the adjacent metatarsal bones by 5 mm or more. Corrective treatment is done, not only for cosmetic purposes but also to improve function. The aim of this study was to evaluate radiologic and clinical results after distraction osteogenesis using external fixators for the fourth brachymetatarsia. @*Materials and Methods@#From January 2005 to September 2018, 45 patients (60 cases) with brachymetatarsia who underwent distraction osteogenesis using external fixators and who were followed up for at least 6 months were studied retrospectively. At the final follow-up, the application time of the external fixator was measured and the percentage of lengthening, healing index, complication, and the patient’s satisfaction were analyzed. The patient’s satisfaction was evaluated using the American Orthopedic Foot and Ankle Society (AOFAS) scores, based on the level of stiffness, pain, function, and alignment. @*Results@#The average gain in length and the percentage increase in the fourth metatarsals were 13.8 mm and 30.0%, and the mean followup period was 14.2 months after the removal of the external fixator. Bony union was obtained in the metatarsal bones in almost all the cases except for one case of non-union. According to the AOFAS score, 39 cases were rated excellent, and 6 cases were good at the final follow-up. The patients showed satisfactory cosmetic and functional results. Complications were pin site infections in 3 cases, all improved by oral antibiotic administration and dressing for about 2 weeks. Decreased sensation of the distal phalanx occurred in one case, and there was one case of non-union where we performed revision with an autogenous bone graft. In one case metatarsal joint subluxation occurred due to angular deformity, for which corrective osteotomy was performed. @*Conclusion@#Satisfactory results were obtained after distraction osteoplasty using external fixation for the treatment of the fourth brachymetatarsia.

Comparison of Mechanical Allodynia and Recovery of Locomotion and Bladder Function by Different Parameters of Low Thoracic Spinal Contusion Injury in Rats

BACKGROUND: The present study was designed to examine the functional recovery following spinal cord injury (SCI) by adjusting the parameters of impact force and dwell-time using the Infinite Horizon (IH) impactor device. METHODS: Sprague-Dawley rats (225-240 g) were divided into eight injury groups based on force of injury (Kdyn) and dwell time (seconds), indicated as Force-Dwell time: 150-4, 150-3, 150-2, 150-1, 150-0, 200-0, 90-2 and sham controls, respectively. RESULTS: After T10 SCI, higher injury force produced greater spinal cord displacement (P < 0.05) and showed a significant correlation (r = 0.813) between the displacement and the force (P < 0.05). In neuropathic pain-like behavior, the percent of paw withdrawals scores in the hindpaw for the 150-4, 150-3, 150-2, 150-1 and the 200-0 injury groups were significantly lowered compared with sham controls (P < 0.05). The recovery of locomotion had a significant within-subjects effect of time (P < 0.05) and the 150-0 group had increased recovery compared to other groups (P < 0.05). In addition, the 200-0 and the 90-2 recovered significantly better than all the 150 kdyn impact groups that included a dwell-time (P < 0.05). In recovery of spontaneous bladder function, the 150-4 injury group took significantly longer recovery time whereas the 150-0 and the 90-2 groups had the shortest recovery times. CONCLUSIONS: The present study demonstrates SCI parameters optimize development of mechanical allodynia and other pathological outcomes.

Induction of Hepatic Microsomal Cytochrome P450 by Styrene in Rat / 대한산업의학회지

The effects of styrene on the induction of cytochrome P-450s (P450), (P4501A1/2, P4502B1/2 and P4502El) and activities of other related enzymes were investigated in the male Sprague Dawley rats which were treated with styrene 500 (S1), 1,000 (S2) 1,500 (S3) mg/kg in olive oil intraperitoneally once a day for two days and sacrificed for the preparation of liver microsomes after 24 hrs. 1. The contents of total protein and P450 in the microsomes derived from the styrene treated groups were slightly higher than those from the control group except those from the 53 group (1,500 mg styrene/kg body weight) . The decreases in microsomal protein contents was prominent in the S3 (p<0.05), but the P450 contents was increased significantly in the S2 (p<0.05). 2. The activities of NADPH-P450 and NADH b5 reductase in hepatic microsomes derived from the treated groups were significantly increased in the treated groups(p<0.05). 3. The activities of PROD were also prominently increased with the treatment of styrene except in 53 group, but the activity of EROD was decreased by styrene treatment. The activities of pNPH in the styrene treated groups were higher than that of the control group (p<0.05). 5. Western blotting with monoclonal antibodies against P4502B1/2 isozymes showed the presence of P4502B1/2 in hepatic microsomes from the rats treated with styrene, and the increase in the densities of immunoblots were corelated with the dosages of styrene. The blot densities against P4501A1/2 and P4502El were slightly increased in the styrene treated groups compared with the control group. These results suggested that styrene could primarily induce P4502B1/2 as major and P4501A1/2 and P4502El in minor forms for the metabolism of styrene in rats.

Induction of Hepatic Microsomal Cytochrome P450 by Styrene in Rat / 대한산업의학회지

The effects of styrene on the induction of cytochrome P-450s (P450), (P4501A1/2, P4502B1/2 and P4502El) and activities of other related enzymes were investigated in the male Sprague Dawley rats which were treated with styrene 500 (S1), 1,000 (S2) 1,500 (S3) mg/kg in olive oil intraperitoneally once a day for two days and sacrificed for the preparation of liver microsomes after 24 hrs. 1. The contents of total protein and P450 in the microsomes derived from the styrene treated groups were slightly higher than those from the control group except those from the 53 group (1,500 mg styrene/kg body weight) . The decreases in microsomal protein contents was prominent in the S3 (p<0.05), but the P450 contents was increased significantly in the S2 (p<0.05). 2. The activities of NADPH-P450 and NADH b5 reductase in hepatic microsomes derived from the treated groups were significantly increased in the treated groups(p<0.05). 3. The activities of PROD were also prominently increased with the treatment of styrene except in 53 group, but the activity of EROD was decreased by styrene treatment. The activities of pNPH in the styrene treated groups were higher than that of the control group (p<0.05). 5. Western blotting with monoclonal antibodies against P4502B1/2 isozymes showed the presence of P4502B1/2 in hepatic microsomes from the rats treated with styrene, and the increase in the densities of immunoblots were corelated with the dosages of styrene. The blot densities against P4501A1/2 and P4502El were slightly increased in the styrene treated groups compared with the control group. These results suggested that styrene could primarily induce P4502B1/2 as major and P4501A1/2 and P4502El in minor forms for the metabolism of styrene in rats.