Risk Factors Analysis and Prevention Strategy of Renke Space Edema Complicated with Vocal Cord Adhesion After CO2 Laser Resection / 中山大学学报(医学科学版)

ObjectiveTo investigate the prevention strategy of bilateral vocal cord adhesion after simultaneous Renke space edema resection under CO2 laser. MethodsSeventy patients who underwent CO2 laser resection of bilateral Renke space edema of vocal cords from June 2018 to June 2021 in our hospital were retrospectively selected for this study. According to their postoperative vocal cord adhesion， patients were divided into vocal cord adhesion group （35 cases） and silent band adhesion group （35 cases）， and the general data of the two groups were compared. Multivariate logistic regression analysis was used to evaluate the risk factors for postoperative vocal cord adhesion. The prediction model of postoperative morbidity risk of vocal cord adhesion was established by using chisquared automatic interaction detection （CHAID） classification tree algorithm， and the application value of the model was evaluated by benefit graph and index graph. ResultsMultivariate analysis showed that surgical range and depth of Ⅱ， laser power≥5 W and anterior connection involvement were the risk factors for postoperative vocal cord adhesion ［OR 95%CI： 6.113 （2.346， 17.451）； 5.214 （1.469， 15.263）； 18.651 （1.689， 36.203）］. The classification tree model showed that anterior articulation involvement was an important predictor of postoperative vocal cord adhesion （76.92%； χ2=11.993， P=0.001）， and the benefit graph and index graph showed good models. ConclusionClinical attention should be paid to surgical scope and depth， laser power and anterior union involvement， and timely prevention strategies should be formulated to reduce the risk of vocal cord adhesion in patients.

Research progress on molecular mechanism of epigallocatechin-3-gallate against cancer and its application / 中草药

Epigallocatechin-3-gallate (EGCG), as one of the main components of green tea, has a variety of biological activities. Both in vitro and in vivo experiments widely demonstrate that EGCG has anticancer activities. The molecular mechanism of EGCG against cancer was much complicated, and EGCG suppressed tumor cell proliferation and/or induced cell apoptosis through multi-pathways. This paper reviewed the anticancer molecular mechanism of EGCG, including EGCG anti-oxidantion, prooxidation, retardant of tumor cell cycle, inhibition of tumor cell angiogenesis, inducement of cancer cell apoptosis, and regulation of microRNA, summarized the research progress of three strategies for improving bioavailability of EGCG: nano-packaging technology, synergistic application and molecular modification, and looked into research and development on anticancer activity of EGCG.

The microcirculation load influence based on numerical simulation for two-way fluid-structure coupling of the aorta / 医用生物力学

Objective To investigate the coupling relationship between microcirculation loads and other arterial structure, so as to build a reasonable hemodynamic model. Methods Based on the two-way fluid-structure interaction hemodynamic model, a three-way fluid-structure-microcirculation load interaction hemodynamic model was built by considering the influence of microcirculation loads. Four cases were calculated according to different load and elastic modulus. The inlet condition was set as transient single pulse velocity inlet, and the outlet condition was set as free exit. Results The blood pressure always maintained within 80-120 mmHg (1 mmHg= 0.133 kPa) in the whole flow field. The diastolic pressure was finally raised to physiological blood pressure by increasing the total amount of the stored flow. With the increase of elastic modulus in vascular wall, the blood pressure maintained within 65-140 mmHg. With the increase of microcirculation resistance, the blood pressure maintained within 128-166 mmHg. Microcirculation load impeded the flow and reallocated the pressure in the artery. Conclusions It is necessary to consider the influence of microcirculation loads for construction of the hemodynamic model, which has an important clinical significance in analyzing pathogenesis of the circulatory system diseases.

Study on urodynamics of SUI patients based on fluid-structure interaction model / 医用生物力学

Objective Aiming at solving the problem of the middle-aged and old women suffering from stress urinary incontinence (SUI), which can seriously affect their physical and mental health, the numerical study on urodynamics in pelvic floor of the female urinary system is conducted. Methods According to the characteristics of interaction coupled between urine and pelvic organizations, the SUI urine dynamics model was established based on computational fluid dynamics. Thus, the stress, strain and displacement of the urine system, and the pressure or velocity distributions in the urine flow, were analyzed. Results The stress, strain and displacement of elastic structure in the urinary system fluctuated with time，which played the important role in the mechanical mechanism of SUI. Conclusions It is not only necessary but also available to apply the fluid-structure interaction model to study the urinary system of SUI, and the urodynamic simulations can provide the theoretical foundation and technological method for the prediction and assessment of SUI diseases in clinic.

Biomechanical properties of the complete mandibular subperiosteal implant under different bite loads / 医用生物力学

Objective To investigate biomechanical properties of the complete mandibular subperiosteal implant under four different bite loads, and provide some references for the personalized implant design in clinical cases. Methods Based on the three-dimensional model of human mandible, two kinds of matching complete mandibular subperiosteal implants, meshy base (implant 1) and zonary base (implant 2), were established, respectively. Stress distributions of both the two implants under four different bite loads were calculated and compared. Results The maximum stress of implant 1 was 230.42 MPa under the load Ⅳ and that of implant 2 was 311.11 MPa under the load Ⅰ. The stress distributions and maximum stress showed that the implant with meshy base had better resistance to the vertical loads, while the implant with zonary base had better resistance to the horizontal loads. Conclusions Rational arrangement for the number of posts and the distance between posts can effectively control the stress of implants. Posts should be placed in a vertical direction with the alveolar bone to avoid amplifying the horizontal component. In addition, posts should be well bounded to the bases, so that the stress on the bottom of posts won’t be at a high level. The complete denture should be guaranteed to contact at several spots during centric, protrusive and lateral bites to keep occlusion balance and decrease the maximum tensile stress on the contact surface.

Viscoelasticity of porcine acellular dermal matrix / 医用生物力学

Objective To evaluate the viscoelastic properties of porcine acellular dermal matrix (PADM) by comparison and analysis on physical parameters of the skin. Methods Full-thickness skin defects were performed on the back of white rabbits as wound models, and randomly divided these wounds into 3 groups according to different methods of skin grafting: PADM group (autogenous skin and PADM were grafted to the surface of the wound), TS group (autogenous skin was grafted in situ), NS group (normal skin as the control). Experiments on the stress-strain relationship of the implanted skin in the three groups were conducted. Results The curves of stress relaxation, creep, and stress-strain relationship showed that under a given stress, PADM group had the lowest strain, NS group had the highest strain, while the strain of TS group was in between the PADM and NS group. Conclusions The skin viscoelasticity mechanical model is a four-parameter solid model. When the skin wounds are grafted by using PADM which may have poor elasticity, its recovery capacity after deformation is also poor, and this is in agreement with the clinical results.

Nonlinear numerical model analysis of circumferential stress on human aortic arch / 医用生物力学

Objective To provide reference for understanding the stress state of the aortic arch，select the appropriate constitutive relation, further analyze the biomechanical properties of human aortic arch so as to offer the biomechanical basis for treating aortic arch in clinic. Method Under two different constraints(the first constraint: the constraint along with the direction of ascending aorta; the second constraint: the ascending aorta could move freely, but the end was closed with a hemisphere), three constitutive relationships (linear constitutive, exponential function constitutive, M-R constitutive) and two loads(10.67 kPa and 26.66 kPa), the circumferential stress on human aortic arch were studied by the finite element method, and the results were also discussed. Results The models under two constraints were established and the contour plot of circumferential stress and its distribution along the arc of aortic arch under two constraints, three constitutive relationships and two loads were obtained respectively. Conclusions The exponential function constitutive model could reflect the mechanical properties of aortic arch more comprehensively and the mechanical properties of aortic arch could be reflected more factually under the second constraint.

Research progress on second-hit in malignant lymphomagenesis-- review / 中国实验血液学杂志

Stem/progenitor cells contribute to normal development of organs, but their mutation may lead to many human diseases including cancer. Stem/progenitor cells and some of the cancer cells have the same abilities of self-renewal and differentiation, suggesting that tumors were initiated from mutated stem/progenitor cells, the cancer stem/progenitor cells. The recent studies on the origin of the non-Hodgkin's lymphomas has proved that the second-hit aggravates gene mutation in lymphocytic progenitor cells, leading to the generation of lymphoma. This review summarizes the current advances in the studies of the second-hit at stem/progenitor cells in oncogenesis of B-cell non-Hodgkin's lymphoma.

Analysis of clinical characteristics of gastrointestinal cancer in Heilongjiang province, China 1998 to 2007 / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To provide basic information for epidemiological research of gastrointestinal (GI) malignant tumors.</p><p><b>METHODS</b>Data of GI cancer diagnosed in 15 hospitals of Heilongjiang province between January 1998 and December 2007 were analyzed retrospectively. The data mainly involved the age of onset, initial symptoms, pathological types, clinical staging and types of surgical procedure.</p><p><b>RESULTS</b>Gastric cancer was the most common type (45.8%) among the 33,540 GI cancer cases, then were rectal cancer (27.3%) and colon cancer (26.8%). Right colon cancer cases were more common than the left ones (1.3:1.0), particularly in people over 80 (2.1:1.0). Only 1.3% of colorectal cancer could be found in age under 30 years old. In patients aged 50 to 70, advanced gastric cancer accounted for 70.6%, advanced colon cancer 73.4% and advanced rectal cancer 72.4%. Well-moderately differentiated adenocarcinoma in early gastric cancer was 49.7%, early colon cancer 77.3% and rectal cancer 83.2%. Patients undergone radical excision in early gastric cancer accounted for 69.1%, advanced gastric cancer 79.9%, left colon cancer 91.9%, right colon cancer 83.9% and in rectal cancer for 88.3%.</p><p><b>CONCLUSIONS</b>People aged 50 to 70 tend to get GI cancer in Heilongjiang province. Gastric cancer is the most common GI cancer. Radical excision is the main choice of therapy.</p>

Reconstruction of a finite element model of intracranial aneurysms based on CT images / 中华神经医学杂志

Objective To establish a three-dimensional (3D) finite element model of intracranial aneurysms based on CT images for three-dimensional simulation of the hemodynamics in the aneurysms. Methods CT angiographic (CTA) images of the intracranial aneurysms were obtained using a GE Lightspeed 16-slice spiral CT with the slice thickness of 0.625 mm at the interval of 0.5 mm. The original Dicom format images were directly imported using the Mimics software. Threshold-based combined with manual segmentation of the images was carried out to acquire the region of interest including the aneurysm and parent artery, followed by 3D calculations of the images. The 3D model was remeshed and exported as an area mesh file to Ansys. The area-based file was then converted into an IGES file in Ansys, and exported to the Ansys workbench software to generate the volumetric mesh for further homodynamic study. Results A 3D finite element model of intracranial aneurysm was established, and the area mesh file could be directly introduced into Ansys software to allow homodynamic study of the aneurysm. Conclusion The application of thin-layer CT scanning and the Dicom standard allows more accurate reconstruction of the 3D finite element model of intracranial aneurysms. The Mimics software can greatly improve the efficiency ofintracranial aneurysm model reconstruction.

Significance of nerve growth factor low affinity receptor p75 in the formation of traumatic neuroma / 中华显微外科杂志

Objective To observe the expression and distribution the low affinity receptor p75 of nerve growth factor in the traumatic neuroma and investigate its significance and relationship with the growth of peripheral nerve and the formation of the traumatic neuroma.Methods Fifty-one cases of traumatic neuro- ma were collected and were divided into four groups according to its course,i.e,groupⅠ(less than one month),groupⅡ(1～3 months),groupⅢ(3～6 months) and groupⅣ(more than six months).Fifteen cases of normal nerve samples were harvested as the control group(n=15).Immunohistochemical studies were performed to observe the expression of p75.the expression level was detected by the computer graph analysis system.Results There was no significant expression of p75 in the normal nerve while in the four studied groups,significant expression of p75 waspositively observed.The level of p75 was weak in the early time and achieved its peak in three months,but the high level state was maintained even after six months.The one-way ANOVA statistic analysis manifests that there were no significant differences of the expression of p75 among the groupⅡ,ⅢandⅣ(P＞0.05),but the differences among the groupⅠand the latter three groups were signifi- cant (P＜0.05).p75 was mainly distributed in the Schwans cell.Conclusion p75 is expressed in the traumatic neuroma and may play an important role in the modulation progress of the formation of traumatic neu- roma with an unknown mechanism.

MRI Diagnosis of Intracranial Meningiomas (An Analysis of 63 Cases) / 实用放射学杂志

Objective To study the relationship between the MRI features and pathological types of intracranial meningiomas. Methods MRI findings of intracranial meningiomas in 63 cases proved by operation and pathology were analyzed retrospectively.Results Of 63 cases,62 cases were singular and one case was multiple lesions. The lesions were located in frontal,parietal and occipital regions nearby the convexity of the brain in 30 cases,in sellar region in 10,at sphenoidal crest in 8 , at olfactory sulcus in 5 and at other regions in 10. Isointense or slightly hypointense signal on T 1WI was found in 87.27% cases of meningiomas . On T 2WI, tumors had isointense or slightly hyperintense signal in 69.84%, obviously hyperintense signal in 19.05%,heterogenous texture signal in 7.94% and slightly low intense signal in 3.17%. Pathological type was included meningiomas meningothelial(n=29), meningiomas fibrous(n=11) , meningiomas psammomatous(n=8),angioblastic meningiomas (n=5) and meningiomas angiomatous(n=10). Conclusion It is great value in diagnosis of meningiomas with MRI. Meningiomas angiomatous show effecting of blood-vessel flowed empty with MR imaging.