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Objective: Application of tomotherapy with megavoltage CT (MVCT)image-guided technique into craniospinal radiotherapy to analyzethe fixation effect of whole-body fixation plate.Methods: A retrospective analysis of 10 cases receiving craniospinalradiotherapy was performed. All patients were in supine position and were fixed with a whole-body fixation plate combined with thermoplastic mesh. The MVCTimages acquired before tomography were matched with the kilovoltage CT (KVCT) images, sothat the setup errors in six directions were detected. The tomography was performed if thematching result was satisfactory, otherwise the patient needed to be setup for the secondtime when the matching result was not accepted by the clinical radiation therapists.Results: A total of 159 MVCT scans was conducted in 10 patients. The average setup errorsin left-right (LR), cranial-caudal (CC), anterior-posterior (AP), pitch, roll and yaw directionswere (1.94 ± 1.44) mm, (2.98 ± 2.51) mm, (1.71 ± 1.87) mm, (0.73 ± 0.64) degrees, (0.30 ±0.26) degrees and (0.34 ± 0.31) degrees, respectively. The probability of second setup was3.14% (5/159).Conclusion: MVCT image-guided technique can significantly reduce the setup errors incraniospinal tomography. The fixation effect of the whole-body fixation plate is acceptable.
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BACKGROUND:Shape memory polymer is a new type of functional material. The applications of shape memory polymers in the biomedical field have increasingly been paid close attention. OBJECTIVE: To summarize the characteristics and applications of shape memory polymers. METHODS: SpringerLink and China Journal Ful text Database were searched for articles related to shape memory polymers. RESULTS AND CONCLUSION: As a new type of inteligence material, shape memory polymers have lots of advantages compared with shape memory aloy and shape memory ceramics, such as low density, light weight, low cost, high shape-recovery rate, easy to regulate the shape memory temperature, to dye, to shape and to be stimulated under expected switch temperature. Especialy for polyurethane, the structure-property relationships are extremely easy to control, the shape memory temperature can be set in a wide range from-30℃ to 70℃, and it has the biocompatibility. Due to these, shape memory polymers have great potentials in applications of biomedical engineering. But the comprehensive properties of the developed shape memory polymers are not satisfactory. For example, the polynorbornene has big recovery stress, fast recovery velocity and high recovery precision, but its relative molecular mass is very big, the molecularchain is long, and processing is difficult. Furthermore, most of shape memory polymers have smal recovery stress, slow recovery velocity, low recovery precision and unsatisfied repeat memory effect. The key problems for shape memory polymers include optimization of the function of shape memory and improvement of the comprehensive properties based on the technologies of molecular design and material modification.
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<p><b>OBJECTIVE</b>Through a simulation of interstitial fluid pressure (IFP), we developed an in vitro model to explore the change law of biological characteristics of adenoid cystic carcinoma (ACC) under different IFP.</p><p><b>METHODS</b>A pressure cooker was refitted into a controllable pressure device. Cultured ACC-2 cells were subdivided into different groups, namely, negative control (untreated ACC-2) and experimental group (stressed for 3, 6, 12, 24 h under pressure of 7.551, 7.649, 7.747 kPa). CCK-8 and immunofluorescence of Ki67 were used to reflect proliferation ability. Transwell chamber assay was performed to observe the invasion ability of cells.</p><p><b>RESULTS</b>The proliferation ability was positively correlated with treatment time, and the peak value was obtained after the cells were subjected to 7.649 kPa of stress for 24 h. The invasion ability of ACC-2 cells was upregulated under stress.</p><p><b>CONCLUSION</b>We successfully developed an in vitro model of IFP and found that high IFP can stimulate cell proliferation ability and upregulate invasion ability.</p>
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Humans , Carcinoma, Adenoid Cystic , Cell Proliferation , Extracellular Fluid , In Vitro Techniques , Salivary Gland NeoplasmsABSTRACT
<p><b>OBJECTIVE</b>To evaluate facial morphology characteristics of patients with unilateral complete cleft lip and palate (UCCLP) after cleft palate repair in different periods.</p><p><b>METHODS</b>46 nonsyndromic UCCLP patients were chosen as test group and divided into three kinds (under 4-year-old, 4-7-year-old, over 7-year-old) according to periods of palate repair. 38 age and gender matched non-clefts children were involved as control group. 26 cephalometric measurements were measured to evaluate facial morphology of four groups.</p><p><b>RESULTS</b>Compared with patients who received palate repair before 4-year-old, patients who received repair after 4-year-old had more protrusive ANS point (Ba-N-ANS, Ba-ANS) and less Y-axis angle. Patients who received palate repair after 7-yesr-old had greater A-PMP and ANS-PMP than patients who received palate repair before 4-year-old, patients who received palate repair before 7-year-old had smaller ANS-Me but after had no significant difference when compared with non-clefts.</p><p><b>CONCLUSION</b>Whenever palate repair is undertaken in the period of maxillary growth and development, patients' maxillary growth would be restrained, the delayed repair sample have better lower face height, maxillary protrusion, maxillary sagittal length and mandible growing direction when compared with the early repair sample, that is to say, the delayed repair sample have preferable head-face morphology.</p>