The correlation between the severity of hypoxic-ischemic brain damage in neonatal rats and subsequent abnormal neurobehavior / 中国新生儿科杂志

Objective:To assess the severity of hypoxic-ischemic brain damage (HIBD) in neonatal rats and predict the occurrence of subsequent neurobehavioral abnormalities after brain injury by scoring and magnetic resonance imaging (MRI).Methods:7-day-old of 60 Sprague-Dawley (SD) rats were randomly divided into control group (14 rats), sham operation group (14 rats) and HIBD model group (32 rats). HIBD model was established by right common carotid artery dissection with Rice-Vannucci method and hypoxia. Within 24 h after modeling, the rats in the model group were evaluated by general condition score and Longa score, and the surviving rats with moderate and severe HIBD were selected for the experiment. 24 h after modeling, 5 rats of the model group were randomly selected for 2,3,5-triphenyltetrazole chloride staining to verify cerebral infarction. 1 week after modeling, 6 rats from each group were randomly selected for hematoxylin-eosin staining to observe HIBD brain injury. 4 weeks after modeling, 4 rats were randomly selected from the control group and the sham operation group, and 8 rats from the remaining model group were used to evaluate the volume of brain damage by MRI. 5-6 weeks after modeling, the remaining 8 rats from each group were subjected to the Cylinder test, and at 13 weeks, they underwent the Morris water maze test to evaluate their neurobehavior.Results:In HIBD model group, 19 rats with moderate to severe HIBD were selected from 32 rats. 24 h after modeling, cerebral infarction was verified in all rats, indicating moderate to severe HIBD. Brain tissue pathology observed 1 week after modeling revealed predominantly gray matter brain damage. MRI showed that 7 out of 8 rats had moderate to severe HIBD. Compared to the control and sham operation groups, the model group exhibited a significant decrease in the usage rate of the left forelimb in the Cylinder test at 5-6 weeks after modeling ( P<0.05), and the latency period in Morris water maze test was significantly prolonged at 13 weeks after modeling ( P<0.05), and the times of crossing platform quadrant were significantly reduced ( P<0.05). There was no significant difference in the right brain injury volume between 24 h and 4 weeks model group ( P>0.05). The brain injury volume in model group was negatively correlated with the usage rate of left forelimb in cylinder test at 5-6 weeks and the times of crossing platform quadrant in Morris water maze test at 13 weeks ( P<0.05), and positively correlated with latency period in Morris water maze test at 13 weeks ( P<0.05). Conclusions:Within 24 h of HIBD modeling, the severity of brain injury can be preliminarily predicted by general condition score and Longa score. 4 weeks after modeling, in the chronic phase of brain injury, MRI was proved to be an excellent predictor for mid-term and long-term neurobehavioral abnormalities in HIBD rats.

Numerical Simulation on Aerodynamic Drag Reduction Evaluation of Vortex Generators Designed for Sprint Garment / 医用生物力学

Objective To investigate the effect from circumferential distribution angle of forwards wedge vortex generators on aerodynamic drag reduction during flow around a cylinder, so as to provide theoretical evidences for low drag sprint garment design. Methods Forwards wedge vortex generators were reconstructed based on the NIKE’s AeroBalde. Given that the individual parts of an athlete body can be treated as multiple cylinders with varied dimensions and positions, 48 forwards wedge vortex generators were distributed as four columns on windward side of the cylinder, which were symmetrical with the YOZ plane. When the air flowed through the cylinder at the speed of 32 km/h, large eddy simulation was carried out on the computational domains which were properly meshed with polyhedral mesh to investigate the drag force, flow filed and pressure distributions. Results It was effective for drag reduction of the cylinder induced by airflow when two columns of forwards wedge vortex generators were circumferential distributed in the range of 55°-75°and the circumferential internal angle between two columns was in the range of 10° or 15°. The pressure distribution on leeward side of the cylinder was apparently changed after surface modification, which minimized the pressure drag dominant in aerodynamic drag. The drag reduction mechanism was that micro-vortices were generated downstream after flow through the forwards wedge vortex generators, which resulted in an early transition to critical flow with low drag force. Conclusions Effective aerodynamic drag reduction is achieved if forwards wedge vortex generators are properly distributed. The research findings can provide guidance for wind tunnel test and low drag sprint garment design.

Design and Verification of Isokinetic Muscle Strength Rehabilitation Training Equipment Based on Oil Resistance / 中国医疗器械杂志

This study designed an isokinetic muscle strength rehabilitation training equipment, based on oil resistance. The equipment detected joint angles during movement through displacement sensors to measure the angular velocity in real-time. Then it can achieve flow resistance adjustment and constant velocity movement, based on the flow area of the proportional valve calculated by PID algorithm and the deviation between the set speed and the measured speed. The equipment can also collect muscle strength during exercise through force-sensitive sensors to achieve real-time and accurate assessment of muscle strength. Moreover, the study preliminarily certificated the isokinetic motion the results showed that the mean error of peak torque test is less than 5%, and the correlation is between 0.89 and 0.92 (

Long-term Results of Arcuate Keratotomy in Femtosecond Laser-assisted Cataract Surgery

PURPOSE: To investigate the long-term follow-up results of arcuate keratotomy in femtosecond laser-assisted cataract surgery. METHODS: The medical records of 78 patients (99 eyes) with corneal astigmatism >0.5 diopters (D) who underwent arcuate keratotomy concurrent with femtosecond laser-assisted cataract surgery were retrospectively reviewed. Uncorrected and corrected visual acuities and keratometric and higher order aberration outcomes were compared preoperatively and 2 years postoperatively. RESULTS: The mean uncorrected visual acuities and corrected visual acuities changed from 0.55 ± 0.31 D and 0.33 ± 0.26 D, preoperatively to 0.13 ± 0.19 D and 0.07 ± 0.09 D, 2 years postoperatively. The mean preoperative corneal astigmatism was −1.15 ± 0.66 D. This was reduced to −0.79 ± 0.38 D at 1–2 days after surgery (p < 0.001), followed by no significant change for 2 years. The mean target-induced astigmatism was 1.15 ± 0.66 D preoperatively, and the mean surgically-induced astigmatism and difference vector were 0.69 ± 0.43 D and 0.83 ± 0.48 D, 2 years postoperatively. The mean correction index was 0.68 ± 0.45, 2 years postoperatively. There was no significant difference in higher order aberrations except 4 mm and 6 mm total higher order aberrations and 6 mm trefoil between preoperatively and 2 years postoperatively. CONCLUSIONS: Arcuate keratotomy concurrent with femtosecond laser-assisted cataract surgery is a safe and effective way to reduce corneal astigmatism which remained stable over 2 years of follow-up with below moderate astigmatism.

Approaches to segment stent area from Intravascular Optical Coherence Tomography

Abstract Introduction Cardiovascular diseases (CVD) have been the focus of research in recent years due to its high mortality rate. It is estimated that 17.5 million people died of CVD in 2012, from which 7.4 million were due to coronary heart disease (CHD). In order to monitor CHD patients and avoid waste of specialists' time, this study proposes the development of a method that segments the area contained by stent struts from Frequency Domain Intravascular Optical Coherence Tomography (the latest technology to view vessels internally) of coronary arteries. Methods The novelty of this study is to find areas comprised by stent struts using two optimal strategies that are robust even with false positives and false negatives detection of stent struts. The first one uses an ellipse fitting algorithm and the other uses a cylinder fitting algorithm. Results Both strategies obtained similar accuracy results close to 98% of true positives, but the cylinder technique showed a run time of at least 50 times higher than the ellipse technique. Conclusion The methods were executed on 443 images with different characteristics showing robustness and usefulness in the medical area.

Clinical analysis of asthenopia caused by wearing inappropriate glasses in college students / 国际眼科杂志(Guoji Yanke Zazhi)

Abstract?AlM: To proposed control measures by exploring visual fatigue caused by college students wearing inappropriate glasses.?METHODS:A total of 124 cases of asthenopia patients underwent optometry students audition, checked the original spectacles;TOPCON-CL100 computer center was used to checked the original mirror glasses ( glasses, the distance between the optical center);with near vision as the standard examination table nearly with vergence and regulation near point, and checked the visual function.?RESULTS: All 124 cases ( 248 eyes ) had refractive errors, 77% were spherical mirror and 69% column mirror with error≧±0. 50D, and the pupil center distance from the lens had significant difference ( U= 5. 27, P<0. 01), 87% of the lens away from the heart for more than 2mm, 62% of mainly due to visual fatigue had glasses inappropriate.? CONCLUSlON: Students wearing inappropriate spectacle asthenopia is caused by one of the main scientific wearing glasses can effectively control asthenopia.

Monte Carlo simulation for elastic modulus of double-stranded DNA biofilm / 医用生物力学

Objective To investigate elastic modulus of double-stranded DNA (dsDNA) biofilm adsorbed on microcantilever substrate. Methods Parsegian’s empirical potentials based on mesoscopic continuum liquid crystal theory was employed to describe the interaction energy among coarse-grained DNA cylinders; Monte Carlo method was used to simulate the distribution pattern of DNA chains before and after loading. The thought experiment method combined with the compression bar model in the sense of macroscopic continuum mechanics was adopted to predict the elastic modulus of DNA biofilm. Results The elastic modulus of dsDNA biofilm ranged from 0.1 MPa to 80 MPa. Conclusions It was found out that the classic hypothesis with uniform hexagonal pattern may underestimate the elastic modulus of DNA biofilm when compared with that in random pattern. Moreover, either the increase of packing density or the decrease of buffer salt concentration will help to enhance elastic modulus of DNA biofilm. These results have great significances in further understanding the mechanical properties and regulation rules of DNA biofilm related with clinical work.

Determination method of dynamic viscosity of methylcellulose / 中国药学杂志

OBJECTIVE: To solve the existing problems of the determination method of dynamic viscosity of methylcellulose in Chinese Pharmacopoeia (2010 edition): METHODS: By virtue of concentric cylinder rheometer, the experiment probes into the influence of shear rate, temperature measurement, the yield value, thixotropic, etc. on the rheological properties of samples, and identifies then the optimum temperature and shear rate of the samples. RESULTS: The optimum conditions were established as temperature of (20±0.1)°C and shear rate of 80 s-1. CONCLUSION: This method is simple and accurate with good repeatability. It can be applied to determine the viscosity of methylcellulose.

Analysis of photoastigmatic keratectomy with the cross-cylinder ablation.

Aim: The aim was to evaluate the safety and efficacy of the “cross-cylinder” technique in the correction of astigmatism. Setting and Design: A prospective interventional study from a university eye department was conducted. Material and Methods: The photoastigmatic refractive keratectomy (PARK) using the “cross-cylinder” technique was performed in 102 eyes of 84 patients with at least 0.75 D of astigmatism. The study population was divided into two groups: in the first group the preoperative astigmatic power ranged from –0.75 D to –3.00 D (group 1), in the second group it ranged from –3.25 D to –6.00 D (group 2). Group 1 included 82 eyes of 67 patients (29 males and 38 females) with a mean cylinder power of –1.90 ± 0.63 D, group 2 included 20 eyes of 17 patients (13 males and 4 females) with a mean cylinder power of -4.28 ± 0.76 D. All eyes were targeted for emmetropia. The results were evaluated using Calossi's vector analysis method. Six-month postoperative outcomes are presented. Results: Six months after PARK the mean sphere for the entire cohort was +0.28 ± 0.75 D (range +2.5 to –2 D), the mean cylindrical power was +0.33 ± 0.51 D (range +2.5 to –1.25 D) and the mean spherical equivalent refraction was +0.73 ± 0.81 D (range +1.75 to –2 D). Conclusions: The cross-cylinder technique may be safely used with predictable results for the correction of astigmatism.

Development of agar diffusion method for dosage of gramicidin / Desenvolvimento do método de difusão em agar para dosagem de gramicidina

Gramicidin, an antimicrobial peptide active against Gram positive bacteria, is commonly used in pharmaceutical preparations for topical use. Considering that only the turbidimetric method has been described in the literature, the present study sought to develop and validate an agar diffusion method for the dosage of gramicidin. The method was developed and validated using the Kocuria rhizophila ATCC 9341 as a test microorganism. Two designs were used: a 3x3 parallel-line model, and a 5x1 standard curve. The validation demonstrated that the method follows the linear model (r²= 0.994), presenting a significant regression between the zone diameter of growth inhibition and the logarithm of the concentration within the range of 5 to 25.3 µg/mL. The results obtained for both designs were precise, having a relative standard deviation (R.S.D.) for intra-day precision of 0.81 for the 3x3 assay and 1.90 for the 5x1 assay. For the inter-day precision, the R.S.D. was 1.35 for the 3x3 and 2.64 for the 5x1. The accuracy was verified and results confirmed to be accurate, having a tolerance interval of 95 percent, which lay within permitted limits and appropriate trueness. In addition, the method was considered selective, with limit of detection and upper and lower limits of quantification of 2.00, 5.00 and 25.3 µg/mL, respectively. No difference in precision between the designs used in the agar diffusion method was evident (p>0.05). The method proved to be appropriate for the microbiological dosage of the raw material gramicidin.

A gramicidina, um peptídeo antimicrobiano ativo contra bactérias Gram positivo, é utilizada em preparações farmacêuticas de uso tópico. Neste trabalho procurou-se desenvolver e validar outro método para o doseamento de gramicidina tendo em vista que somente o método turbidimétrico é descrito. O método de difusão em ágar foi desenvolvido e validado utilizando como microrganismo teste Kocuria rhizophila ATCC 9341. Foram utilizados dois delineamentos: retas paralelas 3x3 e curva padrão 5x1. A validação demonstrou que o método segue o modelo linear (r²= 0,994) havendo regressão significativa entre o diâmetro dos halos de inibição e o logaritmo da concentração na faixa de 5,00 a 25,3 µg/mL. Os resultados obtidos por ambos os delineamentos foram precisos apresentando desvio padrão relativo (DPR) para precisão intra-dia de 0,81 para ensaio 3x3 e de 1,90 para ensaio 5x1. Para a precisão inter-dias o DPR foi de 1,35 para 3x3 e de 2,64 para 5x1. A exatidão foi verificada e os resultados foram exatos apresentando intervalo de tolerância a 95 por cento dentro dos limites permitidos e veracidade adequada. O método foi seletivo com limites de detecção e quantificação inferior e superior iguais a 2,00, 5,00 e 25,3 µg/mL, respectivamente. Não foi observada diferença entre a precisão dos delineamentos empregados no método de difusão em ágar (p>0.05). O método se mostrou adequado para a dosagem microbiológica de gramicidina matéria-prima.

Influence of calcinable cylinders cast in cobalt-chromium alloy on the passivity of implant-supported frameworks / Influência de cilindros calcináveis fundidos em cobalto-cromo na passividade de próteses implanto-suportadas

Purpose: This study aimed to determine the effect of using calcinable cylinders on the passivity of a framework that simulates a three-unit fixed partial prosthesis on two implants. Methods: Two 3.75 x 10 mm external hex implants were used, with their abutments set on a steel base forming the master model. Ten cobalt-chromium alloy frameworks were manufactured by the induction casting technique. Two groups were established: Group 1 used premachined cylinders to cast five frameworks; Group 2 used plastic calcinable cylinders to cast five frameworks. Passivity evaluation was accomplished by using strain gauges placed in the cervical and occlusal regions of the framework pontics. The measurement was performed during screwing of the second prosthetic screw with a torque of 10 Ncm. Data were analyzed by Student's t test (α = 0.05). Results: The mean (standard deviation) values were 39.16 (24.74) mV/V for Group 1 and 43.76 (21.13) mV/V for Group 2. There was no statistically significant difference between groups (P = 0.815). Conclusion: The results suggest that the use of calcinable cylinders had a similar degree of passivity compared to the use of premachined prosthetic cylinders.

Objetivo: Este trabalho avaliou a influência da utilização de cilindros calcináveis no grau de passividade de infra-estruturas que simulam uma prótese parcial fixa de três elementos sobre dois implantes. Metodologia: Foram utilizados dois implantes de hexágono externo de 3,75 mm×10 mm, com seus respectivos pilares intermediários, fixados numa base de aço, formando o modelomestre. A partir disto, foram fabricadas dez infra-estruturas em liga de cobalto-cromo através da técnica de fundição por indução. Foram criados dois grupos: Grupo 1 utilizando cilindros pré-usinados para a fabricação de cinco infra-estruturas; Grupo 2 cinco infra-estruturas fundidas com cilindros de plástico calcináveis. Para avaliação da passividade foram utilizados extensômetros colados na região oclusal e cervical do pôntico das infra-estruturas. A medição foi realizada no momento do aperto do segundo parafuso protético com torque de 10Ncm. Os dados foram analisados pelo teste t de Student (α=0,05). Resultados: As médias (desvio-padrão) dos grupos foram de 39,16 (24,74) mV/V no Grupo 1 e 43,76 (21,13) mV/V no Grupo 2. Não houve diferença estatisticamente significante entre os grupos (P=0,815). Conclusão: Considerando-se as limitações deste trabalho, sugere-se que o uso de cilindros calcináveis obtém o mesmo grau de passividade que o uso de cilindros pré-usinados.

Efficacy of different LASIK mode for the correction of mixed astigmatism / 眼科

Objective To compare the efficacy and predictability of sphere-cylinder-combined LASIK and two-zone cross-cylinder LASIK for the correction of moderate and high astigmatism.Design Prospective,comparative case series.Participants 40 eyes of 35 patients with mixed astigmatism undergoing LASIK.Methods All patients were treated with Visx Star IV LASIK system.20 eyes of 19 cases were used for sphere-cylinder combined LASIK mode and 20 eyes of 16 cases for two-zone-cross-cylinder LASIK mode.All sub- jects were followed more than 6 months.Main Outcome Measures Uncorrected visual acuity (UCVA),best spectacle-corrected visual acuity (BSCVA),spherical diopter,residual astigmatism and corneal thickness.Results For the patients who received two-zone-cross-cylinder LASIK mode,the UCVA at 6 months after surgery was 0.5 or above,and 13 eyes (65.0%) were 1.0 or above. For the patients who received sphere-cylinder-combined LASIK mode,the UCVA at 6 months after surgery was 0.5 or above,and 11 eyes (55.0%) was 1.0 or above (P=0.683).The residual astigmatism for the patients received sphere-cylinder-combined LASIK mode was (1.15?1.00)D,while for the patients received cross-cylinder LASIK mode was (1.13?0.62)D(P=0.045).The remotion depth of cornea for sphere-cylinder-combined LASIK mode and cross-cylinder LASIK mode was (36.73?13.12)?m and (15.60?6.85)?m,respectively (P= 0.031).Condusion The UCVA,residual astigmatism and corneal thickness after surgery in two-zone-cross-cylinder LASIK mode were better than that in sphere-cylinder-combined LASIK mode for the correction of moderate and high astigmatism.

Influence of different fixation targets in accuracy of Jackson cross cylinder examination / 吉林大学学报(医学版)

Objective To evaluate the influence of black dots,isolated line above the best correct visual acuity and multiple lines containing the best correct visual acuity in the accuracy of Jackson cross cylinder examination.Methods Forty students were chosen(11 males,29 females,between 24 to 29 years old).Routine examination of phoropter was used to check under the maximum plus to maximum visual acuity(MPMVA) status.The sequence of three fixation targets was chosen randomly.Astigmatism chart was used to judge the best one when the different results were obtained.Results Among the 80 eyes of 40 students,12 eyes were spherical(the cylinder degree below 0.25 DC).The response of three fixation targets was the same in 19 eyes(27.9%),23 eyes(33.8%)were sensitive to the black dots target,14 eyes(20.6%)were sensitive to the isolated line above the best correct visual acuity,12 eyes(17.6%) were sensitive to multiple lines containing the best correct visual acuity.Kruska Wallis Test was used to detect the difference among three groups.No significant difference was found(?2 =4.026,P=0.134).Conclusion According to the efficiency of examination,communication and judgment,black dots target is recommended although no difference is detected among three fixation targets.

Changes in Astigmatism after Surgical Repair of Epiblepharon or Ptosis: A Vectorial-analytic Approach

PURPOSE: To analyze the changes of astigmatism and keratometric cylinder by using the scalar and vector analysis method in children who had undergone surgery for epiblepharon or ptosis. METHODS: The study subjects were 142 eyes of 79 patients who had undergone surgery for epiblepharon or ptosis. We examined the cycloplegic refractive error and keratometric astigmatism by auto-refractometry before and 2 months after surgery. Astigmatic changes were analyzed through the scalar and vector analysis method. RESULTS: The mean age of the patients was 5.27+/-2.18 years of age, and the male to female ratio was 35: 44. There were 98 eyes of 49 patients in the epiblepharon surgery group, 28 eyes of 22 patients in the ptosis surgery group, and 16 eyes of 8 patients in the epiblepharon and ptosis surgery (combined surgery) group. The epiblepharon surgery group demonstrated a decrease in with-the-rule astigmatism, and the changes in magnitude (p<0.001) and vector (p<0.05) of keratometric cylinder were statistically significant. The ptosis surgery group demonstrated an increase in with-the-rule astigmatism and the changes in magnitude and vector of astigmatism were statistically significant (both p<0.01). The combined surgery group demonstrated an increase in with-the-rule astigmatism and the changes in vector of astigmatism and magnitude of keratometric cylinder were statistically significant (both p<0.05). CONCLUSIONS: Our results showed significant astigmatic change in eyes that underwent surgery for epiblepharon or ptosis. Therefore, careful cycloplegic refraction is necessary after epiblepharon or ptosis surgery.

The Efficacy of Multi-Zone Cross-Cylinder Method for Astigmatism Correction

The purpose of this study is to assess the efficacy of the multi-zone cross-cylinder method as compared with the single method for astigmatism correction using LASIK. This prospective study enrolled 40 patients (52 eyes) who underwent the cross-cylinder method using LASIK, and 52 patients (60 eyes) who underwent the single method using LASIK: all patients were given a diagnosis of complex myopic astigmatism from the department of ophthalmology of this hospital between January 2002 and July 2003. Preoperatively, the mean spherical equivalent refraction was .3.85 +/- 1.13 D in the cross-cylinder group and .4.05 +/-1.20 D in the single method group (p = 0.23). The mean cylinder was .2.05 +/-1.58 D in the cross-cylinder group and .1.95 +/-1.12 D in the single method group (p = 0.31). 6 months after treatment the results were a mean spherical equivalent refraction of .0.26 +/-0.30 D in the crosscylinder group and -0.34 +/-0.35 D in the single method group (p = 0.13). The mean cylinder was .0.38 +/-0.29 D in the cross-cylinder group and .0.45 +/-0.30 D in the single method group (p = 0.096). There were no statistically significant differences between the two groups. The mean BCVA was not different from mean preoperative BCVA in both groups (i.e., 0.98 +/-0.10, 0.96 +/-0.25, p = 0.86). Postoperatively, patient complications that included night halo, glare and corneal haze were not noted in either group. In conclusion, the results of cross-cylinder method are no different from the single method for the correction of a complex astigmatism. In the future, studies will have to be conducted to assess the efficacy of the cross-cylinder method in consideration of those factors that can affect the postoperative outcome.

Hemostasis with a Flat Plastic Cylinder Derived from Disposable Syringe During Dermatologic Procedures / 대한피부과학회지

Dermatologists frequently perform a number of procedures without the aid of an assistant and have sometimes difficulty to obtain hemostasis during the biopsy or other minor surgery. A flat plastic cylinder made of a disposable syringe effectively stops bleeding and procedures are easily carried out with a clean surgical field. It is believed to be inexpensive, durable and easy to be sterilized.

Development of Upgraded Cortical Impact Model(Part I: Mechanics)

OBJECTIVE: Head trauma model is important and essential to development of new therapeutic modality. We present a upgraded head trauma model for experimental animals. METHODS: Using pneumatic cylinder, solenoid valve, linear variable differential transformer(LVDT) and load cell, we developed "Chung-Ang University Hospital Model 1.0(CAUH-1)" based on controlled cortical impact model. RESULTS: Changing pressure, impact velocity could be controlled up to 4m/sec. Using solenoid valve, we could control dwell time precisely. Real time impact force could be measured with load cell. CONCLUSION: Controlling dwell time, impact velocity, depth of deformation, this model would reproduce variable degrees of head injury. This model is so precise and versatile that it would be useful in diverse animal experimental researches.

Anterior Interbody Fusion using a Horizontal Cylinder Cage in a Degenerative Lumbar Spine / 대한정형외과학회잡지

PURPOSE: To evaluate the surgical effect of anterior interbody fusion using a horizontal cylinder cage in a degenerative lumbar spine. MATERIALS AND METHODS: We evaluated 16 patients (at 20 levels) who received anterior interbody fusion using a horizontal cylinder cage in a degenerative lumbar spine or in secondary segmental lumbar instability following decompression at the same level from May 1997 to May 1998. Preoperative, postoperative, and follow-up radiographs were taken to compare the posterior disc height, neuroforaminal area, and the neuroforaminal volume. Fusion rates and clinical results were also reviewed. RESULTS: Posterior disc height (mm), neuroforaminal area (mm2) and neuroforaminal volume (mm3) were increased and maintained during the follow-up period. Radiological fusion was noted in 17 levels (85%) at a postoperative 1 year. Satisfactory clinical results were also obtained in 17 levels (85%). CONCLUSION: Anterior interbody fusion using a horizontal cylinder cage might be an effective method in the surgical treatment of degenerative lumbar spine or secondary segmental lumbar instability.

THE EFFECTS OF FABRICATION AND TIGHTENING METHODS OF GOLD CYLINDER ON THE PRELOAD OF THE IMPLANT ABUTMENT / 대한치과보철학회지

The purpose of this study was to evaluate the effects of fabrication and tightening methods of gold cyliner on the preload of the standard abutment. Three linear strain gauges (KFR-02N-120C1-23, Kyowa, Japan) were mounted longitudinally on the 5.5mm Standard abutment (Nobel Biocare, Sweden) and three kinds of gold cylinders such as, as-received gold cylinder, gold cylinder after casting, and plastic cylinder after casting with type IV gold alloy were connectedd over the top of the standard abutment. Two kinds of tightening methods, such as manual torque with handheld screwdriver and electronic torque using Electronic torque controller were used to generate preload on the abutment. The result were as follows 1. The preload generated by tightening cast plastic cylinder with handheld screw driver, was the lowest among the six groups. 2. The preload generated by cast plastic cylinder was lower than those by gold cylinders regardless of the tightening methods. 3. The electronic torque controller produced higher torque values than the handheld screwdriver.

Titanium Mesh Cylinder as an Anterior Strut in Reconstructive Spinal Surgery / 대한척추외과학회지

STUDY DESIGN: A retrospective study. OBJECTIVES: To evaluate the efficiency of titanium mesh cylinder as an anterior strut in reconstructive spinal surgery. SUMMARY OF LITERATURE REVIEW: Biomechanically, 80 to 85% of the axial forces on the upright spine are distributed through the anterior column. Reconstruction of the anterior column using load sharing construct is essential for normal spinal biomechanics in various anterior column deficiency conditions. Titanium mesh cylinder as an anterior strut has advantages in these surgical conditions, and may be an effective alternative to strut bone graft. MATERIALS AND METHODS: From October 1993 to May 1998, 22 patients received reconstructive spinal surgery using titanium mesh cylinder-bone graft composite. Average follow up period was 3(1/2)years(range: 1(1/2)to 6 years). 20 of them were male and 2 were female and average age was 45 years(range: 21 to 69 years). The diagnoses were kyphosis/kyphoscoliosis, burst fracture/ fracture-dislocation, revision surgery, tumor, and multiple thoracic HNP. Radiographs were taken preoperatively, postoper-atively at 2 weeks, 4, 6, 9, 12, 18, 24 months, and yearly thereafter, these were read for change of sagittal angle correction, anterior bony fusion, settling of the titanium mesh cylinder-bone graft composite, or instrument failure. RESULTS: Radiologic union between titanium mesh cylinder & vertebra appeared at (1/2)to 1 (1/2)years follow-up period. 81.8%(18 of 22 cases) showed definite bony trabeculation, and 18.2%(4 of 22 cases) showed immature bony trabeculation. Sagittal angle correction loss was measured by average 7.6 .(range: 5 .to 9 .) in 8 of 22 cases, all of which appeared at 4 months to 1 year follow-up period. Correction loss was associated with penetration of spikes of titanium mesh cylinder into endplates of adjacent vertebral bodies until internal rings contact endplates, but was not accompanied with implant failures, dislodgement or migration of titanium mesh cylinder. CONCLUSIONS: Titanium mesh cylinder can be used as a good substitute of anterior strut in combination with rigid spinal fixa-tion in reconstructive spinal surgery.