Three-dimensional analysis of maxillary dentition during molar distalization with clear aligners under different movement designs: an in vitro experiment / 中华口腔医学杂志

Objective: To investigate the three-dimensional force in the maxillary dentition under different movement designs for molar distalization with clear aligners Methods: Three groups were designed: simultaneous movement group (simultaneous distalization of maxillary first and second molars), second molar movement group (distalization of maxillary second molars) and first molar movement group (distalization of maxillary first molars). Ten clear aligners were made in each group, and the displacement was designed to be 0.2 mm. A force sensing device was established to measure the three-dimensional force on the upper dentition with the clear aligner. The device contained a model of the maxillary dentition consisting of 14 teeth, each tooth connected to an individual sensor. After the clear aligner was fitted, the data of 14 sensors were collected and analyzed using computer analysis software. The moving teeth were taken as the target teeth, and the rest of the teeth were anchorage. The data of the three-dimensional force in the three groups in each tooth position were measured and compared. Results: The sagittal forces on the first and second molars in the simultaneous movement group were (5.61±0.94) and (5.81±1.08) N, respectively, which were significantly smaller than those of the target teeth in the same position in other groups (P<0.05). The second molars in the first molar movement group received a sagittal reaction force, which was (-6.73±1.99) N. The anterior teeth in the three groups were all subjected to sagittal reaction force, and the force value was in a range of (-3.33 to 0.46) N. In the coronal direction, the second premolars of the simultaneous movement group received the reaction force in the palatal direction, and the force value was (-2.17±1.06) N. The first molars in the second molar movement group were also subjected to palatal reaction force of (-1.99±0.70) N. The second molars and second premolars in the first molar movement group were also subjected to palatal reaction force, which were (-2.85±0.57) and (-1.85±0.74) N, respectively. Compared with the sagittal and coronal forces, the target teeth and anchorage teeth in the three groups were less stressed in the vertical direction. Conclusions: The first and second molars distalized simultaneously, the correction force in the sagittal direction was relatively small. When first molar was moved distally alone, a greater reaction force in the sagittal direction was exerted on the second molar. Buccal displacement of the adjacent anchorage teeth should be designed to counteract the palatal reaction force on the anchorage teeth as the molars moved distally.

An additional augmentative locking compression plate combined with bone graft for treatment of aseptic subtrochanteric fracture nonunion after intramedullary nailing / 中华创伤骨科杂志

Objective:To investigate the efficacy of an additional augmentative locking compression plate combined with bone graft for aseptic subtrochanteric fracture nonunion after intramedullary nailing.Methods:From October 2016 to October 2019, 32 patients (25 males and 7 females) were treated at Department of Orthopedics, The Sixth People's Hospital Affiliated to Shanghai Jiaotong University for aseptic subtrochanteric fracture nonunion after intramedullary nailing. Their ages ranged from 27 to 68 years (average, 50.5 years) and their nonunion time from 9 to 24 months (average, 12.2 months). According to the Weber-Cech classification for nonunions, 9 cases belonged to the highly vascular type and 23 to the ischemic type. With the original intramedullary nails retained, all patients were fixated with an additional augmentative locking compression plate before simultaneous autologous iliac bone grafting. All patients were followed up regularly for fracture union, function of the affected hip and complications.Results:The 32 patients were followed up for 6 to 24 months (average, 12.9 months). All nonunions obtained clinical and imaging union. The clinical union time ranged from 3 to 8 months (average, 5.2 months), and the imaging union time from 6 to 10 months (average, 7.4 months). At the last follow-up, the therapeutic efficacy was evaluated as excellent in 28 cases and as good in 4, giving a good to excellent rate of 100%(32/32), according to the Sanders scoring for post-traumatic hip joint; the efficacy was evaluated as excellent in 21 cases, as good in 10 cases and as fair in one, giving a good to excellent rate of 96.9%(31/32), according to the Harris hip scoring. No such complications occurred as infection or loosening or breakage of internal fixation.Conclusion:An additional augmentative locking compression plate combined with bone graft is a reliable and effective treatment for aseptic subtrochanteric fracture nonunion after intramedullary nailing.

Assessment strategies for drug permeability during drug discovery and development / 药学学报

Permeability is a key factor in the bioavailability of oral drugs. Therefore, in the early stage of drug discovery, accurate and efficient evaluation of drug permeability is essential. The parallel artificial membrane permeability assay (PAMPA) with Caco-2 cells model was used by the industry as early evaluation methods. At present, the Ussing chamber rat model is also widely used. This review summarizes the human data for the in vivo single-pass perfusion technique (Loc-I-Gut) – the gold standard, and then focuses on the basic principles, experimental operation, and efficiency of the three in vitro methods, with correlation to the effective permeability coefficient (Peff) and fractional absorbed (Fa) in man. We provide recommendations for the use of proper permeability methods at different stages in drug discovery and development.

Analytical Solution and Finite Element Analysis of Coronary Stent under Vascular Systolic Pressure / 医用生物力学

Objective To deduce analytic solution of the displacement and stress distributions for the coronary stent based on reasonable assumptions, and to investigate the influence from the wave number of support bars on stress distributions by combining the results of finite element analysis. Methods A local cylindrical coordinate system was established to deduce analytical solution of the displacement and stress components of the periodic support bar of the rectangular-wave type vascular stent under vascular systolic pressure. The support bar model was established by using ANSYS, to calculate the numerical results of stress analysis. By analyzing the consistency of stress curves obtained from the two methods, the accuracy and applicability of analytical solutions were verified. The influence from the number of wave crests for support bars on the stress under systolic pressure was investigated by analytic solution. Results The analytical stress curves were basically in conformity with those from the ANSYS results. When the number of wave crests was 6, there were both tensile and compressive stresses in circumferential direction of the cross bar. Conclusions When the number of wave crests was 6, such stents could effectively prevent restenosis in blood vessels during working. The derived analytical solution could be used to analyze mechanical properties of one-cycle support bars of rectangular-wave type stent, and the research findings provided a new idea to further recognize and study the stress distributions on coronary stent to reduce the restenosis rate of interventional therapy.

Correlation study on mobile phone addiction and sleep quality of military medical students / 第二军医大学学报

Objective: To investigate the relationship between mobile phone addiction and sleep quality of military medical students, so as to provide evidence for improving their mental health. Methods: A total of 237 cadets from freshman to senior majored in medicine were tested by the Pittsburgh sleep quality index (PSQI) scale and mobile phone addiction tendency scale (MPATS). Results: Eventually, 227 valid questionnaires were collected, with the effective response rate being 95.8%. The mean score of PSQI was 5.78±2.26, and the mean score of MPATS was 38.65±11.32. Females had a worse sleep quality than male military medical students (6.12±2.11 vs 5.49±2.35, P < 0.05). Junior cadets had the highest MPATS score (42.51 ± 10.81). The score of PSQI was positively correlated with the score of MPATS among military medical students (r 0.280, P<0.01). Regression analysis showed that mobile phone addiction had significant impact on sleep quality of military medical students (P < 0.01). Conclusion: Mobile phone overuse has a negative impact on sleep quality among military medical students, especially in females. It is necessary to strengthen the management mobile phone use among junior cadets.

Chemical constituents of lipophilic parts in water extrct from stem of Mahonia fortunei / 中草药

Objective To study the chemical constituents of lipophilic parts in water extracts from the stem of Mahonia fortunei. Methods The compounds were isolated and purified by repeated column chromatography on silica gel and high performance liquid chromatography, and their structures were determined by spectroscopic data analysis. Results Thirty-eight compounds were obtained from lipophilic parts in water extracts from the stem of M. fortunei and identified as maltol (1), 3-hydroxy-4-methoxyphenylethanol (2), syringylethanone (3), 1-hydroxy-3-(4-hydroxy-3-methoxyphenyl)-2-propanone (4), α-hydroxypropiosyringone (5), corydaldine (6), zhebeiresinol (7), vanillic acid (8), springic acid (9), noroxyhydrastinine (10), (+)-syringaresinol (11), episyringaresinol (12), schisandrin (13), neoechinulin A (14), 8-oxyjatrorrhizine (15), 8-oxyberberine (16), 5-hydroxymaltol (17), methyl-5- hydroxy-2-pyridinecarboxylate (18), vomifoliol (19), 2,3-dihydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanone (20), oleracein E (21), acortatarin A (22), 5-epi-acortatarin A (23), 5-(methoxymethyl)-1H-pyrrole-2-carbaldehyde (24), (+)-lyoniresinol (25), (−)-secoisolariciresinol (26), ciwujiatone (27), protocatechuic acid (28), adenosine (29), 3,4,5-trimethoxyphenyl-1-O-β-D- glucopyranoside (30), 2-(4-hydroxy-3-methoxyphenyl) ethyl-O-β-D-glucopyranoside (31), tortoside B (32), oldhamioside (33), (+)-syringaresinol-4′-O-β-D-glucopyranoside (34), episyringaresinol-4′-O-β-D-glucopyranoside (35), berberine (36), 3,4,5-trimethoxyphenyl-(6′-O-syringoyl)-O-β-D-glucopyranoside (37), and salidroside (38), respectively. Conclusion Compounds 3—7, 13—15, 17—19, 21—27, 29, 31, 33, and 38, are isolated from the genus Mahonia for the first time. Moreover, the nuclear magnetic resonance data of compound 15 is assigned for the first time.

Preliminary application experience of GuidezillaTM guide extension catheter during complex coronary percutaneous coronary intervention procedure / 中国介入心脏病学杂志

Objective To evaluate the clinical safety and efficacy of GuidezillaTM guide extension catheter during complex coronary percutaneous coronary intervention(PCI). Methods A total of 13 patients were included in the studywho presented with complex coronary lesions during PCI. Stents or balloons could not be delivered to these complex lesions with conventional approach and GuidezillaTM guide extension catheters were used. Results Among these 13 patients,there were 7 CTO lesions,7 calcified lesions, 6 tortuous lesions,8 diffuse lesions,8 distal lesions and 8 lesions with pre-existing stents. PCI success rate was 100% .In one patient,GuidezillaTM guide extension catheter was obstructed which were relieved after stent implantation. There was no major adverse cardiac event(MACE) during follow-up.Conclusions The GuidezillaTM guide extension catheter was safe and effective for PCI of complex coronary artery lesions.

Quality control of human chorionic gonadotrophin subunit dissociation / 药学学报

Human chorionic gonadotrophin (hCG), a glycohormone widely used in treatment of infertility, is a heterodimer composed of an alpha-and a beta-subunit. The heterodimer could be dissociated during production and storage with an impact on its bioactivity. A CE-SDS method for quantitative analysis of hCG subunit dissociation was established in this study by optimization of a variety of method conditions including sample preparation buffer compositions, incubation temperature, separation voltage, and capillary temperature. This method was validated for good sensitivity, linearity, precision, and accuracy for both α-and β-subunit. CE-SDS also showed much better precision and accuracy than SDS-PAGE. The method was successfully used in both recombinant hCG (r-hCG) produced by cell culture and hCG (u-hCG) derived from urine. The CE-SDS method was used in the study of hCG development and stability. Therefore, it is an useful tool for the quality control of hCG.

Preliminary application experience of GuidezillaTM guide extension catheter during complex coronary percutaneous coronary intervention procedure / 中国介入心脏病学杂志

Objective To evaluate the clinical safety and efficacy of GuidezillaTM guide extension catheter during complex coronary percutaneous coronary intervention(PCI). Methods A total of 13 patients were included in the studywho presented with complex coronary lesions during PCI. Stents or balloons could not be delivered to these complex lesions with conventional approach and GuidezillaTM guide extension catheters were used. Results Among these 13 patients,there were 7 CTO lesions,7 calcified lesions, 6 tortuous lesions,8 diffuse lesions,8 distal lesions and 8 lesions with pre-existing stents. PCI success rate was 100% .In one patient,GuidezillaTM guide extension catheter was obstructed which were relieved after stent implantation. There was no major adverse cardiac event(MACE) during follow-up.Conclusions The GuidezillaTM guide extension catheter was safe and effective for PCI of complex coronary artery lesions.

Closed suction drainage or non-drainage for total knee arthroplasty: a meta-analysis / 中华外科杂志

<p><b>OBJECTIVES</b>To investigate the different effects of closed suction drainage and non-drainage for total knee arthroplasty(TKA) and to provide reference information for the choice of clinical treatment.</p><p><b>METHODS</b>Randomized controlled trials (RCTs) of closed suction drainage versus non-drainage for TKA were collected from the Cochrane Library, PubMed, EMBase, Springer, CBM, CNKI, VIP and WANFANG database. Methodological quality of the RCTs was independently assessed using the Consolidated Standards of Reporting Trials (CONSORT) checklist. Data analysis was performed by RevMan Version 5.1.6 based on the methods recommended by the Cochrane Collaboration.</p><p><b>RESULTS</b>Twenty-one RCTs without bias were finally enrolled, and 1920 enrolled knees were identified into drainage group (979 knees) and non-drainage group (941 knees). A lower incidence of soft tissue ecchymosis was demonstrated in the closed suction drainage group (OR = 0.30, 95%CI: 0.24 - 0.49); however, compared with the non-drainage group, more loss of blood (MD = 320.03, 95%CI: 235.31 - 404.76) and more need of homologous blood transfusion (OR = 1.83, 95%CI: 1.26 - 3.29) were found in the closed suction drainage group. In addition, there were no significant differences of postoperative infection (OR = 0.53, 95%CI: 0.22 - 1.32), deep venous thrombosis (OR = 1.00, 95%CI: 0.46 - 2.18), and the joint range of motion (MD = -0.04, 95%CI: -1.11 - 1.02) between the two groups.</p><p><b>CONCLUSION</b>Based on the current evidence, no obvious advantage is demonstrated for closed suction drainage, in comparison with non-drainage for TKA.</p>

Myxoid adrenal cortical tumor: report of four cases / 中华医学杂志(英文版)

Myxoid adrenocortical neoplasms are rare. Surgical resection of the mass is the first-line therapy. Here we reported a total of four patients, aged 44–66 years, diagnosed with myxoid adrenocortical tumor. The clinical characteristics and immunohistochemical features of the tumor are discussed in the current literature.

Efficacy of arterial duct stenting in neonatal pulmonary atresia with intact ventricular septum / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the feasibility and efficacy of arterial duct stenting in neonates with pulmonary atresia and intact ventricular septum.</p><p><b>METHODS</b>Eleven neonatal pulmonary atresia with intact ventricular septum patients received arterial duct stenting in our hospital from December 2007 to September 2010 were involved in this study. The average age was (8.20 +/- 2.90) days (ranged from 3 to 13 days). The average weight was (3.41 +/- 0.29) kg (ranged from 3.00 to 3.88 kg). The stents were selected according to digital subtracted angiography measurements. After checking for correct position by angiography, the balloon was inflated to expand the stent to desired diameter. Oxygen saturation was monitored, echocardiography was measured and stent diameter and location were observed by chest Xray. Patients were followed up at 1, 3, 6 and 12 months post procedure.</p><p><b>RESULTS</b>Stents were successfully implanted in all 11 patients. The preoperative peripheral oxygen saturation was (63.27 +/- 8.47)%, while increased to (82.73 +/- 5.59)% after alprostadil application and to (86.18 +/- 3.19)% after operation (all P < 0.01). After the operation, the peripheral oxygen saturation was higher than alprostadil application (P < 0.05). The intraoperative narrowest diameter of patent ductus arteriosus was (1.69 +/- 0.37) mm, the length was (16.72 +/- 2.37) mm. The internal diameter of implant stents was 4 mm, the length was (20.18 +/- 3.40) mm. After the operation, surgical B-T shunt operation was performed in one patient due to stent shift and pulse oxygen saturation decrease. One patient died post operation with unknown reason, another patient received stent balloon dilatation due to pulse oxygen saturation decrease at 4 months after the surgery. Pulmonary atresia with intact ventricular septum surgeries were performed in 2 patients at 5 and 7 months after stent implantation.</p><p><b>CONCLUSION</b>The neonatal pulmonary atresia with intact ventricular septum arterial stent implantation was a feasible and effective procedure and this method could be used as preferred treatment in pulmonary atresia and intact ventricular septum for neonates.</p>

Percutaneous balloon pulmonary valvuloplasty for critical pulmonary stenosis in infants under 6 months of age and short and medium term follow-up / 中华儿科杂志

<p><b>OBJECTIVE</b>To evaluate the effect and results of short and medium periods of follow-up of percutaneous balloon pulmonary valvuloplasty for critical pulmonary stenosis of neonates and infants under 6 months of age.</p><p><b>METHODS</b>Between January 2002 and December 2008, 34 consecutive patients aged from 13 to 175 days with critical pulmonary valvular stenosis underwent percutaneous balloon valvuloplasty. Patients records, catheterization data, angiograms and echocardiograms were reviewed. Patients were followed up for 6 months to 4 years (mean 25.5 months) by means of clinical examination and Doppler echocardiography.</p><p><b>RESULTS</b>The pulmonary valvuloplasty was accomplished in 32 (94%) of 34 attempts. Immediately after dilation, right ventricular systolic pressure (RVSP) decreased from (96 ± 28) mm Hg (1 mm Hg = 0.133 kPa) (49 ± 20) mm Hg (P < 0.01), the transvalvular peak to peak systolic gradient (ΔP) decreased from (89 ± 25) mm Hg to (25 ± 12) mm Hg (P < 0.01), and the right ventricular/aortic systolic pressure ratio decreased from 1.2 ± 0.5 to 0.7 ± 0.3 (P < 0.01). One patient died because of cardiac tamponade following rupture of the pulmonary valve annulus, 2 patients developed pericardial effusion, 3 patients had infundibular spasm, 3 patients had a pre-dilation by small balloon and 1 patient had weakened femoral artery pollex. After a follow up period of 6 months to 4 years 3 of 31 patients lost to follow-up. Repeat valvuloplasty was performed in 5 patients (3 neonates), no patient required surgery, and the other 23 patients did not undergo further intervention, a mean peak systolic Doppler gradient of (20 ± 13) mm Hg was found and no significant pulmonary regurgitation was seen.</p><p><b>CONCLUSIONS</b>Percutaneous balloon pulmonary valvuloplasty was effective and safe for the treatment of critical pulmonary stenosis of neonates and infants under 6 months of age with good short and medium term results.</p>

Analysis of Defense Mechanism in 40 Patients with Obsessive-Compulsive Disorder / 中国康复理论与实践

@#Objective To explore the characteristics of defense mechanism in patients with obsessive-compulsive disorder(OCD).Methods Outpatients diagnosed as OCD were tested by Yale-Brown obsessive Compulsive Scale. Among them, 40 patients with score beyond or equal to 16 were selected as research group. 33 healthy individuals were selected as normal group. They were tested with Defense Style Questionnaire.Results ①The factor score of immature defense mechanisms in the OCD group is much higher than that in the normal group (P<0.01); the factor score of mature defense mechanisms in the OCD group is lower than that in the normal group (P<0.05); the factor score of middle defense mechanisms in the OCD group is much higher than that in the normal group (P<0.01). ②Passive aggression, acting out, splitting, regression, somatization in the immature defense mechanisms and relief, false altruism, isolation in the middle defense mechanisms are much more used by the OCD group than that in the normal group; but suppression and humor in the mature defense mechanisms are less used by the OCD group than that of the normal group(P<0.05 or P<0.01). ③Sublimation, suppression and consuming tendency are much more used in male patients than female ones in OCD group(P<0.05).Conclusion The patients with OCD tend to use the immature defense mechanisms and middle defense mechanisms, and there is some difference between male and female patients in using defense mechanisms.

Study on the height of marginal ridge to cusp in posterior teeth and its effect on brackets placement / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To measure the vertical height of mesio-distal marginal ridge to cusp in posterior teeth, which may be helpful to brackets positioning.</p><p><b>METHODS</b>The study groups comprised of 60 patients (30 men, 30 women, mostly aged 12-14 years) who underwent orthodontic treatment without tooth extraction and matched the Andrews normal occlusion standard after treatment. Study model of each patient was made. Three-dimensional laser measurer was used to evaluate the vertical height of mesio-distal marginal ridge to mesial cusp in posterior teeth. The data were stored in a personal computer and submitted to statistical analysis of paired t test.</p><p><b>RESULTS</b>No statistical significant difference was found in the same teeth between men and women. Not only in maxilla but also in mandible, there was no significant difference between the left and the right (P>0.05). The average vertical height of maxillary first premolars was (1.70+/-0.50) mm, the maxillary second premolars was (1.24+/-0.45) mm, and for maxillary first molars, the result was (0.83+/-0.40) mm. The difference between each result was statistically significant (P9< 0.01). The average vertical height of mandibular first premolars was (2.25+/-0.45) mm, the mandibular second premolars was (1.55+/-0.45) mm, and for mandibular first molars, the result was (1.18+/-0.40) mm. The difference between each result was statistically significant (P<0.0 1).</p><p><b>CONCLUSION</b>The vertical height of brackets position in posterior teeth should be considered to guarantee that mesio-distal marginal ridges of deferent posterior teeth located in the same plane, so that satisfying goal could be achieved, If the vertical height in the first molar was X mm, the vertical height in the second premolar should be (X+0.5) mm, and (X+1.0) mm might be suit for the first premolar.</p>

Single cell analysis of some deletion in dystrophin gene exons and gender determination by 3-plex nested PCR / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To set up a technique of single lymphocytes 3-plex nested PCR for dystrophin and SRY gene, and to evaluate the possibility of using this technique for preimplantation genetic diagnosis(PGD) of deleted Duchenne muscular dystrophy (DMD) with family history.</p><p><b>METHODS</b>Fifty single lymphocytes of a normal male and fifty of a normal female were obtained for detecting dystrophin gene(exon 51, exon 19, exon 48) and SRY gene by 3-plex nested PCR.</p><p><b>RESULTS</b>In the group of exon 51/exon 19/SRY, the amplification rates of exon 51, exon 19 and SRY in male were 96%, 94% and 94%; the amplification rates of exon 51 and exon19 in female were 94% and 94%, respectively. In the exon 48/exon 19/SRY group, the amplification rates of exon 48, exon 19 and SRY in male were 92%, 90% and 94%, the amplification rates of exon 48, exon 19 in female were 94% and 92%, respectively.</p><p><b>CONCLUSION</b>The technique of single lymphocytes 3-plex nested PCR for dystrophin and SRY gene established in this study is highly sensitive, specific and reliable, and is suitable for PGD of deleted DMD with family history.</p>

Birth of healthy children after preimplantation diagnosis of beta-thalassemia / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Clinical programs for preventing beta-thalassemia are presently based on prospective carrier screening and prenatal diagnosis. This paper report an achievement of a pregnancy with unaffected embryos using in vitro fertilization and embryo transfer (IVF-ET), in combination with preimplantation genetic diagnosis (PGD), for a couple at risk of having children with beta-thalassemia.</p><p><b>METHODS</b>A couple carrying different thalassemia mutations, both a codon 41 - 42 mutation and the IVS II 654 mutation, received standard IVF treatment, with intracytoplasmic sperm injection, embryo biopsiy, single cell polymerase chain reaction (PCR) and DNA analysis. Only unaffected or carrier embryos were transferred to the uterine cavity. After confirmation of pregnancy, a prenatal diagnosis was performed.</p><p><b>RESULTS</b>Of a total of 13 embryos analyzed for beta-globin mutations, PGD indicated that 2 were normal, 3 were affected, and 6 were carriers. Diagnosis could not be made in the other 2 embryos. Three embryos were transferred to the uterus on the third day after oocyte retrieval. Ultrasonography revealed a twin pregnancy with one blighted ovum. The prenatal genetic diagnosis revealed that both fetuses were unaffected, and two healthy boys were born, confirming the results of PGD.</p><p><b>CONCLUSIONS</b>We developed a single-cell based primer extension preamplification (PEP)-PCR assay for the detection of beta-thalassemia mutations. The assays were efficient and accurate at all stages of the procedure, and resulted in the birth of PGD-confirmed beta-thalassemia free children in China. PEP was used here in PGD for beta-thalassemia.</p>

Preimplantation genetic diagnosis for beta-thalassemia using whole genome amplification / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To achieve pregnancy with unaffected embryo using in vitro fertilization and embryo transfer (IVF-ET) and preimplantation genetic diagnosis(PGD) for the couples at risk of having children with beta-thalassemia.</p><p><b>METHODS</b>A couple carrying different thalassemia mutations of codon 41/42 and codon IVS2 position 654 received standard IVF treatment and intracytoplasmic sperm injection, embryo biopsy, single cell polymerase chain reaction and DNA analyses, and only the unaffected or carrier embryos were transferred to uterus. Pregnancy confirmation, and prenatal diagnosis were done at 20 week's gestation.</p><p><b>RESULTS</b>A total of 13 embryos were analyzed in the IVF cycle. PGD indicated that 2 were normal 18.1 , 3 were affected 27.3 , and 6 were carriers 54.5 ; diagnosis was not possible in 2. Three embryos were transferred to uterus on the third day after oocyte retrieval. Ultrasonography showed twin pregnancy with one blighted ovum. The prenatal diagnoses revealed that both fetuses were unaffected, one normal baby and one carrier were born.</p><p><b>CONCLUSION</b>These studies represent the successful application of PGD for beta-thalassemia in China.</p>

Reflections on surgical operation to treat cancer after a long term follow-up survey / 解放军医学杂志

Objective To review and reflect the development and achievement in surgical therapy for cancer in 20th century, and to inquire and foresee the objectives and tasks of the study on tumor surgery in 21st century. Methods Based on the data of a long term follow-up survey of more than 3000 cancer patients who had undertaken thoracic or abdominal operations, and also on a review, analysis, evaluation and reflection of clinical cases accumulated for 40 years, clinical experiences of both positive and negative aspects were summed up, a few new personal ideas and knowledge were raised. Results It was found that: (1) Postoperative recurrence and metastases played as the key factors which affected the curative effect. Therefore therapies and procedures to control postoperative recurrence and metastases are vital in improving the curative effect. (2) Improvement on curative effect of cancer surgery can be hardly expected if no breakthrough in basic researches is made. Conclusion Experimental and clinical researches should be aimed at the radical cure of postoperative recurrence and metastases, so as to improve the surgical treatment of malignancies in the future.