ABSTRACT
<p><b>OBJECTIVE</b>To investigate the clinical significance of BRAF-V600E mutation in children with Langerhans cell histiocytosis (LCH).</p><p><b>METHODS</b>Real-time fluorescence quantitative PCR was used to detect BRAF-V600E mutation in paraffin-embedded tissue samples from 26 children with LCH. A retrospective analysis was performed for the association of BRAF-V600E mutation with clinical features and prognosis of children with LCH.</p><p><b>RESULTS</b>Of the 26 children, 25 received standard chemotherapy, with a 2-year overall survival (OS) rate of 100% and a 2-year event-free survival (EFS) rate of 88%. Of the 26 pathological samples, 18 (70%) came from bone tissue, and the positive rate of BRAF-V600E mutation reached 50% (13/26). The positive rate of BRAF-V600E gene mutation was not associated with age, sex, affected organ, clinical classification, early treatment response, recurrence, and 2-year OS and EFS rates of the children with LCH (P>0.05), but it was associated with clinical grouping of LCH (P<0.05).</p><p><b>CONCLUSIONS</b>Children with LCH tend to have a high OS rate and a high incidence rate of BRAF-V600E mutation. BRAF-V600E mutation is associated with clinical grouping of LCH.</p>
Subject(s)
Adolescent , Child , Child, Preschool , Female , Humans , Infant , Male , Histiocytosis, Langerhans-Cell , Classification , Genetics , Mortality , Mutation , Proto-Oncogene Proteins B-raf , Genetics , Retrospective StudiesABSTRACT
Objective By developing a novel endoscopic succession closing device to overcome the shortcomings of existing devices that cannot deploy several clips at one time,to perform structural analysis on different clamp structures and to validate their performances in tissue closure through finite element analysis.Metbods Comparative analyses of 3 clamp structures,namely,the aligning tooth structure (original,clamp A),the staggered tooth structure (clamp B),a combination structure with page break angle and staggered tooth (clamp C),were performed to analyze pressure and its distribution on tissues when clamping the stomach wall.Displacement of 7.5 mm was then applied on the clamps to simulate the effect from operating procedures of the device and tissue kick-back.Results The maximum stresses of the clamp A and B were located on the first pair of teeth which was closest to the rotating shaft,with the stress of 10.39 kPa and 10.11 kPa,respectively.The maximum stress (11.35 kPa) of the clamp C was located on the second pair of teeth.For clamp A and B,the longer the distance to shaft,the larger pressure on stomach tissues.While for clamp C,the pressure on device-tissue interface showed little change along the path.Under tensile displacement,clamp A and B slipped off from the tissue when displacements reached to 5.0 mm and 6.5 mm,respectively,while clamp C did not slip off.Conclusions Clamp with page break angle and staggered tooth can exert the uniform maximum pressure to tissues and provide a larger contact area away from the rotating shaft,thus improving the anti-slippage and performance of the novel endoscopic closing device.
ABSTRACT
Objective By developing a novel endoscopic succession closing device to overcome the shortcomings of existing devices that cannot deploy several clips at one time,to perform structural analysis on different clamp structures and to validate their performances in tissue closure through finite element analysis.Metbods Comparative analyses of 3 clamp structures,namely,the aligning tooth structure (original,clamp A),the staggered tooth structure (clamp B),a combination structure with page break angle and staggered tooth (clamp C),were performed to analyze pressure and its distribution on tissues when clamping the stomach wall.Displacement of 7.5 mm was then applied on the clamps to simulate the effect from operating procedures of the device and tissue kick-back.Results The maximum stresses of the clamp A and B were located on the first pair of teeth which was closest to the rotating shaft,with the stress of 10.39 kPa and 10.11 kPa,respectively.The maximum stress (11.35 kPa) of the clamp C was located on the second pair of teeth.For clamp A and B,the longer the distance to shaft,the larger pressure on stomach tissues.While for clamp C,the pressure on device-tissue interface showed little change along the path.Under tensile displacement,clamp A and B slipped off from the tissue when displacements reached to 5.0 mm and 6.5 mm,respectively,while clamp C did not slip off.Conclusions Clamp with page break angle and staggered tooth can exert the uniform maximum pressure to tissues and provide a larger contact area away from the rotating shaft,thus improving the anti-slippage and performance of the novel endoscopic closing device.
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Objective To analyze the relationship of closed staple height with tissue damage and compression pressure, so as to provide theoretical references and guidance for the surgeon to choose the appropriate staple cartridge and height, as well as improve the safety of operation. Methods The finite element model of stapled colorectal end-to-end anastomosis was established based on analysis of staple-tissue interaction. Large intestine tissues with different wall thicknesses (1.0-1.5 mm) were compressed by closed staples with 4 different height to compare changes in stress distributions and average radial pressure. Results When the tissues were compressed by closed staple with height of 1.0, 1.1, 1.2 and 1.5 mm, respectively, the average radial stress of compressed tissues with wall thicknesses of 1.2, 1.3, 1.4, and 1.5 mm were 56.0, 58.6, 59.7 and 57.3 kPa, respectively, which was close to the optimal compression pressure. Stress concentrations were found in contact area of the staple and tissues，with the maximum stress being 2 783, 1 750, 1940 and 2 030 kPa, respectively. Conclusions Tissue damage cannot be completely avoided in anastomotic surgery, and stress concentration is generally located near contact region of the staple and tissues. The optimal closed staple height ranges in 50%-60% of the uncompressed tissue height.
ABSTRACT
By developing a novel endoscopic succession closing device to overcome the shortcomings of existing devices that cannot deploy several clips at a time, to perform structural analysis on different clamp structures and to validate their performances in tissue closure through finite element analysis. Methods Comparative analyses of three clamp structures, namely, the aligning tooth structure (original, clamp A), the staggered tooth structure (clamp B), a combination structure with page break angle and staggered tooth (clamp C), were performed to analyze pressure and its distribution on tissues when clamping the stomach wall. Displacement of 7.5 mm was then applied on the clamps to simulate the effect of the operating procedures of the device and tissue kick-back. Results The maximum stresses of the clamp A and B were located on the first pair of teeth which was closest to the rotating shaft, with the stress being 10.39 kPa and 10.11 kPa, respectively. The maximum stress (11.35 kPa) of the clamp C was located on the second pair of teeth. For clamp A and B, the longer the distance to shaft, the larger pressure on stomach tissues. While for clamp C, the pressure on device-tissue interface showed little change along the path. Under tensile displacement, clamp A and B slipped off from the tissue when displacements reached to 5 mm and 6.5 mm, respectively, while clamp C did not. Conclusions Clamp with page break angle and staggered tooth can exert the uniform max pressure to tissues and provide a larger contact area away from the rotating shaft, thus improving anti-slippage and performance of the novel endoscopic closing device.
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Objective To observe the changes of preoperative and postoperative retinal circulation time in partretinal laser photocoagulation (PRP) in patients with diabetic retinopathy (DR).Methods Together 16 patients (16 eyes) were collected as the subjects in this study,who was diagnosed as severe non-proliferative and proliferative DR by fundus fluorescein angiography (FFA) examination and had PRP indications for undergoing pan-retinal laser photocoagulation.Then retinal arterial and venous cir culation time in all patients was recorded using FFA before and 1 to 3 months after treatment.Meanwhile,it was necessary to observe the following variables,including the developing duration and complete filling time of the four branches of the retinal artery,as well as the duration of the laminar flow and complete filling time of the four branches of the venous artery,followed by calculating mean transition time of retinal artery,retinal capillary,retinal vein,retinal arteriovenous flow for comparison and analysis of changes in transit time of retina in different time-periods before and after treatment.Results The mean transition time of the retinal capillary in patient was (1.58 ± 0.99) s before treatment and (2.19 + 1.23)s after treatment,and the difference was statistically significant(P =0.011),but there was no significant difference in the mean transition time of the retinal artery,retinal vein and arteriovenous flow (all P ＞ 0.05).Conclusion The transit time of the retinal capillary at 1 to 3 months after PRP is significantly longer than that before treatment.
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Objective To observe the changes of preoperative and postoperative retinal circulation time in partretinal laser photocoagulation (PRP) in patients with diabetic retinopathy (DR).Methods Together 16 patients (16 eyes) were collected as the subjects in this study,who was diagnosed as severe non-proliferative and proliferative DR by fundus fluorescein angiography (FFA) examination and had PRP indications for undergoing pan-retinal laser photocoagulation.Then retinal arterial and venous cir culation time in all patients was recorded using FFA before and 1 to 3 months after treatment.Meanwhile,it was necessary to observe the following variables,including the developing duration and complete filling time of the four branches of the retinal artery,as well as the duration of the laminar flow and complete filling time of the four branches of the venous artery,followed by calculating mean transition time of retinal artery,retinal capillary,retinal vein,retinal arteriovenous flow for comparison and analysis of changes in transit time of retina in different time-periods before and after treatment.Results The mean transition time of the retinal capillary in patient was (1.58 ± 0.99) s before treatment and (2.19 + 1.23)s after treatment,and the difference was statistically significant(P =0.011),but there was no significant difference in the mean transition time of the retinal artery,retinal vein and arteriovenous flow (all P ＞ 0.05).Conclusion The transit time of the retinal capillary at 1 to 3 months after PRP is significantly longer than that before treatment.
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Objective To design a novel endoscopic successive hemostasis and closing device, and to validate whether the device can meet the needs of tissue closure by finite element analysis. Methods By using the novel device, the target tissue was clamped and the clip was then pushed to pierce the tissue. Under the compression between the clip and the inner side of the grasper, the thinner arms of the clip were forced to bend and close to stay in the tissue, and then the inverse displacement of 2 mm was applied on the clip. The elastic limit and tensile strength of the clip were set as 239.0 and 901.0 MPa, respectively. Results Deformation did not occur in the piercing process of the clip, with the maximum stress of 212.6 MPa. The deformed shape of the clip in the bending process matched its design expectation, with the maximum stress of 727.7 MPa. The maximum stress of the clip was 75.8 MPa under 2-mm inverse displacement. Material failure was not found in the bending process or with 2-mm inverse displacement, and the maximum stress in the whole process was 741.0 MPa. Conclusions The novel endoscopic successive hemostasis and closing device proposed in this study can deploy 4 clips at one time, together with an independent grasper for gathering tissues, which can shorten the reloading time and improve the accuracy of clip deployment. The effectiveness and safety of the device is also proved by using finite element method.