1.The bionic artificial joint capsule study (1)--mechanics simulation.
Shihu SU ; Jianhua ZHANG ; Dehua TAO
Journal of Biomedical Engineering 2007;24(1):120-123
In this paper, a three-dimensional finite element analysis (FEA) model was created for bionic artificial joint with joint capsule. Finite element method (FEM) was used to calculate and simulate mechanics distribution of the joint capsule under different thickness of the joint capsule, different loading, and different angular displacements. The results of the simulation show that the maximum stress is created in the joint area between artificial joint capsule. And the effect of the thickness of the artificial joint capsule on the stress magnitude and distribution is depend on motion model. On standing situation, the maximum stress decreases with the increase of the thickness of joint capsule. However, on walking situation, the maximum stress increases with the increase of the thickness of joint capsule. Whatever conditions simulated, the maximum stress of the artificial joint capsule is not over the limit of the material strength (9.97 megapascals). All the large stress, which gained from the simulation under different situations, locates at the interface between the capsule and the artificial joint. This is because the artificial joint and the capsule transfer loading each other at the interface. At the same time, supporting area of the capsule at the location of the interface is minimum for the whole vesicle. The stress concentration is inevitable at the interface due to the model structure. This result will offer guidance for the optimum joint structure of the capsule and the artificial joint.
Arthroplasty, Replacement, Knee
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Biomechanical Phenomena
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Computer Simulation
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Finite Element Analysis
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Humans
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Imaging, Three-Dimensional
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Joint Capsule
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physiology
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Knee Joint
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physiology
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surgery
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Knee Prosthesis
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Models, Biological
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Stress, Mechanical
2.Hypoxia-reoxygenation induced apoptosis of cardiomyocytes and the effect of nitric oxide
Feng ZHANG ; Xiaoxing LUO ; Tao ZHANG ; Jianjun XIE ; Chen LI ; Dehua ZHAO ;
Chinese Pharmacological Bulletin 1987;0(03):-
AIM To study hypoxia reoxygenation induced apoptosis of neonatal rat cardiomyocytes and the roles of nitric oxide in this process. METHODS Cultured neonatal rat cardiomyocytes were divided into two groups. Cells of one group were cultured in an incubator of 950 mL?L -1 N 2 and 50 mL?L -1 CO 2 for 16 h, 32 h and 48 h followed by normal incubation for 6h to form the cell model of hypoxia reoxygenation injury.Cells of another group were cultured in the same hypoxia condition for 16 h, 32 h and 48 h. Before they were put in normal condition for 6 h, NO donor SNAP was added to the media to form the final concentration of 100 ?mol?L -1 . Apoptosis was detected by TUNEL and flow cytometer. RESULTS Apoptotic cells were detected by TUNEL after hypoxia of 16 h, 32 h and 48 h followed by 6 h reoxygenation and the apoptotic rates of cardiomyocytes were (5 5?0 7)%, (11 0?1 1)% and (14 2?1 6)% respectively detectedby flow cytometer. The apoptotic rates of myocardiums with SNAP were (3 2?0 7)%, (7 8?0 7)% and (10 9?1 0)% respsctively. CONCLUSION The apoptotic rates of cardiomyocytes undergoing hypoxia reoxygenation injury increase with time of hypoxia; NO can inhibit apoptotic rates of cardiomyocytes in this pathological process and thus may have a protective effect on cardiomyocytes.
3.A Sampling Survey on the Distribution of Oncomelania Snails in Zhejiang Province
Liyong WEN ; Wei ZHENG ; Mingdong ZHU ; Dehua YAN ; Jishun YANG ; Lulu GAO ; Junhu CHEN ; Jianfeng ZHANG ; Liling YU ; Lijun LIN ; Haiquan TAO
Chinese Journal of Parasitology and Parasitic Diseases 1997;0(06):-
Objective To find out current distribution of Oncomelania snails and Schistosoma infection in snails in Zhejiang Province, so as to improve the project of schistosomiasis control. Methods Investigation spots were selected by stratified cluster sampling method, 100 villages of 34 counties were selected from 7 106 villages of 55 counties as survey spots. Synchronously systematic and environmental samplings were used for the survey. Snails were dissected to determine the infection status and spots with sham snails were set to assess the quality of the survey. Results The result showed that snails were found in 223 strips, 1 572 frames and 73 300 m 2 area in 32 villages of 21 counties. Snails were found in an area covering 72 640 m 2 in 29 villages of 18 counties in hilly region, which accounted for 99.1% of total snail habitats. The significantly larger area with snails was revealed in hilly region than that in water network region (t=3.04, P
4.Genetic analysis of a 45,X male fetus.
Yan ZENG ; Dehua CHENG ; Jian ZHAO ; Feiyan QIAN ; Jiaming FAN ; Ting WANG ; Tao ZHANG
Chinese Journal of Medical Genetics 2020;37(10):1176-1178
OBJECTIVE:
To analyze the prenatal diagnosis procedure for a 45,X male fetus.
METHODS:
A 31-year-old women underwent amniocentesis due to a moderate risk of trisomy 21. The fetal cells were subjected to chromosomal karyotyping, BACs-on-Beads (BoBs) assay, chromosomal microarray analysis and fluorescence in situ hybridization.
RESULTS:
Combined analyses revealed that the whole of Yp has translocated to 21p, which yielded a fetal karyotype of 45,X,dic(Y;21)(q11;p11).ishdic(Y;21)(SRY+,CEPY+;CEP21+).
CONCLUSION
BoBs and modified N-banding method are helpful for the diagnosis of 45,X male fetus with Yp translocation.
5.Genetic analysis of a fetus with mosaicism of 13q inversion duplication.
Tingting LUO ; Ming CHE ; Dehua CHENG ; Lifang ZHANG ; Tao ZHANG ; Yan ZENG
Chinese Journal of Medical Genetics 2022;39(1):76-80
OBJECTIVE:
To report on a case of mosaicism 13q inversion duplication, analyze its mechanism, and discuss the correlation between its genotype and phenotype.
METHODS:
Amniotic fluid and umbilical cord blood were collected at 23 and 32 weeks of gestation, respectively. Combined with G-banding chromosome karyotyping analysis, single nucleotide polymorphism array (SNP-array) and fluorescence in situ hybridization (FISH) were used to confirm the result.
RESULTS:
The karyotype of the fetus was determined as 47,XY,+inv dup(13)(q14.3q34)/46,XY. After careful counseling, the couple decided to continue with the pregnancy, and had given birth to a boy at 40 weeks' gestation. Except for a red plaque (hemangioma) on the nose bridge, no obvious abnormality (intelligence to be evaluated) was discovered.
CONCLUSION
To provide reference for clinical genetic counseling and risk assessment, the location and proportion of new centromere formation should be fully considered in the case of mosaicism 13q inversion duplication.
Amniocentesis
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Chromosome Inversion/genetics*
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Comparative Genomic Hybridization
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Female
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Fetus
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Humans
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In Situ Hybridization, Fluorescence
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Male
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Mosaicism
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Pregnancy
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Prenatal Diagnosis
6.Preliminary observation of new immobilization for total skin irradiation with helical tomotherapy
Senkui XU ; Wenyan YAO ; Jiang HU ; Yunfei XIA ; Dehua KANG ; Yalan TAO ; Xiaobo JIANG ; Jie LU ; Chengguang LIN
Chinese Journal of Radiation Oncology 2021;30(11):1183-1187
Objective:To preliminarily observe the feasibility of different immobilization techniques for total skin irradiation (TSI) using helical tomotherapy.Methods:Three eczema scrophuloderma patients treated with TSI in Sun Yat-sen University Cancer Center were immobilized with low-temperature thermoplastic in a prone position, diving suit combined with negative pressure vacuum bag in a supine position, low-temperature thermoplastic combined with vacuum bag in a supine position, respectively. Different immobilization effects were observed. The conformity index (CI) of the target area, heterogeneity index (HI) of the target area, and the mean dose (D mean) of the target area were calculated. Results:Three immobilization methods could achieve satisfactory immobilization effects, and all the dosimetric parameters of radiation treatment plans met the clinical requirements. The average set-up errors in the left and right, head and foot, and abdomen and back directions of three patients were (0.26±3.40) mm, (-2.63±4.63) mm and (6.13±4.86) mm, respectively. The CI, HI andD mean were0.56±0.09, 1.186±0.059 and (2586.56±63.28) cGy. Conclusions:Low-temperature thermoplastic or diving suits can be combined with vacuum bags for immobilization in TSI. The epidermal dose can be increased with bolus through the dose-building effect, which can provide a safe and reliable method for TSI in helical tomotherapy.
7.Prenatal diagnosis and genetic analysis of a special case with complex structural rearrangements of chromosome 8.
Yan ZENG ; Tingting LUO ; Feiyan QIAN ; Dehua CHENG ; Caiping CHEN ; Jiaming FAN ; Lifang ZHANG ; Tao ZHANG ; Hongmei LI ; Zhiqiang WU
Chinese Journal of Medical Genetics 2023;40(9):1181-1184
OBJECTIVE:
To present on a prenatally diagnosed case with complex structural rearrangements of chromosome 8.
METHODS:
Chromosome karyotyping, chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH) were carried out for a fetus with increased nuchal thickness.
RESULTS:
The karyotype of the amniotic fluid sample showed extra materials on 8p. FISH revealed a centromeric signal at the terminal of 8p with absence of telomeric signal. CMA revealed partial deletion of 8p23.3 [(208049_2256732)×1], partial duplication of 8p23.3p23.2 [(2259519_3016818)×3], and partial duplication of 8q [8q11.1q12.2(45951900_60989083)×3].
CONCLUSION
The complex structural rearrangements of chromosome 8 in this case has differed from the commonly seen inv dup del(8p).
Female
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Pregnancy
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Humans
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Chromosomes, Human, Pair 8/genetics*
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In Situ Hybridization, Fluorescence
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Gene Rearrangement
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Prenatal Diagnosis
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Centromere
8.Replacing a smaller-size catheter after tubularized incised plate urethroplasty may decrease postoperative urethral complications
Wei RU ; Daxing TANG ; Dehua WU ; Yong HUANG ; Chang TAO ; Guangjie CHEN ; Xiaohao WANG ; Lei GAO ; Yiding SHEN ; Jia WEI
Chinese Journal of Urology 2019;40(3):220-223
Objective To investigate the effect of replacing a smaller-size catheter after tubularized incised plate (TIP) urethroplasty on postoperative urethral complications.Methods The data of 116 hypospadias patients underwent TIP urethroplasty performed by the same urologist in our hospital from January 2014 to December 2017 were retrospectively analyzed.The age of patients ranged from 0.5-15.4 years,with the median age of 1.5 years.Meatal location was distal in 47 (39.5%),midshaft in 62 (52.1%) and proximal in 10(8.4%) patients.Unhealthy urethral plate occurred in 49 (42.2%) patients.F8 catheter was used for urethroplasty in 92 (79.3 %) patients,F10 in 17 (14.7%),and F12 in 7 (6.0%).According to the pattern of urinary diversion,patients were divided into two groups.Conventional catheter group in 56 patients (group A):the catheter was chosen in as large size as possible for urethroplasty without tension.Replace a smaller-size catheter group in 60 patients (group B):replace a smaller-size catheter after urethroplasty on the basis of group A.There were no statistically significant differences in age,meatal location and catheter size between the two groups (P > 0.05).Results The mean follow up was 23 months (range 6-66 months).There were 73(62.9%) cases of orifice overflow during indwelling catheterization.There were 5 (4.3%) patients needed further reoperation result from postoperative urethral complications,including 4 cases of fistula and 1 case of meatal stenosis.The process of replacing a smaller-size catheter after urethroplasty in group B was simple and without adverse reactions.There were 15 (26.8%) cases of orifice overflow in group A and 58 (96.7%) in group B.There were statistically significant differences in orifice overflow between the two groups (P < 0.05).There were 5 (8.9%) cases of postoperative urethral complications in group A and 0 case in group B.There were statistically significant differences in postoperative urethral complications (P < 0.05).Conclusions The process of replacing a smaller-size catheter after TIP urethroplasty in was simple and subsequently contributed to less postoperative urethral complications.The results of replacing a smaller-size catheter after TIP urethroplasty were superior to that of no replacing conventionally.
9.Diagnosis and treatment of urethral mucosa prolapse in female children
Fan YANG ; Yiding SHEN ; Chang TAO ; Guangjie CHEN ; Dehua WU ; Yong HUANG ; Zheming XU ; Daxing TANG
Chinese Journal of Urology 2019;40(8):611-614
Objective To review the clinical characteristics of urethral prolapse in female children and summarize our experience of treatment.Methods A retrospective analysis of the clinical characteristics of 102 patients with urethral prolapse from January 2007 to December 2017 was conducted at The Children's Hospital of Zhejiang University School of Medicine.The age of the patients ranged from 8-156 months with an median of 80 months.The presenting symptoms in the 102 girls were:bleeding in 57 patients (55.9%),mass in 31 patients (30.4%),and dysuria/urinary frequency,urgent and pain in 14 patients (13.4%).In all,58 patients were managed conservatively with Sitz baths as their masses were small,39 underwent prolapse reduction under topical anesthesia and Sitz baths because their mass were large,and 5 patients were treated by excision of the prolapsed urethral mucosa with four-quadrant excisional technique because thrombosed urethral prolapse at first visit.Results A total of 89 patients were cured after conservative treatment (87.3%),8 patients were converted to surgical treatment because frequent recurrence with conservative treatment.No urethral stricture,active hemorrhage and recurrent were found in 13 patients after operation.Conclusions The most common clinical manifestations of urethral prolapse are urethral mass and bleeding.Most patients can be cured by conservative treatment.The patients whose symptoms were severe or suffered from frequent recurrence of urethral prolapse should be managed with surgical excision.
10.Recent advances in the treatment of persistent Müllerian duct syndrome
Hongjuan TIAN ; Dehua WU ; Wei RU ; Daxing TANG ; Chang TAO
Chinese Journal of Urology 2022;43(8):628-631
Male sex differentiation is driven by 2 hormones produced by the fetal testis, testosterone and anti-Müllerian hormone(AMH), responsible for the regression of müllerian ducts in male fetuses. Mutations inactivating AMH or its receptor AMHR2 lead to the persistent müllerian duct syndrome(PMDS) in otherwise normally virilized 46, XY males. Further assessment was carried out when suspicion of PMDS arose from physical examination which revealed that the testis crossed to the contralateral side of the body. Further examination include ultrasound, AMH concentration, karyotype, and gene sequencing. Once PMDS is considered, there is no need to perform the gonads biopsy. The optical surgery methods include one-stage cryptorchidism and hernia curation, and at the same time.Stripping/destroying the mucosa of the retained müllerian remnants to reduce the risk of malignancy and, simultaneously, to prevent the damage to vas deference.