Biomedical subjects

K Shino

Publications and source records attributed to K Shino.

At least 19 recordsLinked to original sources

PubMed2003

Comparison between the cross-sectional area of bone-patellar tendon-bone grafts and multistranded hamstring tendon grafts obtained from the same patients.

This study intraoperatively compared the cross-sectional area (CSA) and graft-tunnel fit of bone-patellar tendon-bone (BTB) and multistranded hamstring tendon (STG) grafts harvested from the same patient. Twenty-two patients with a mean age of 26 years were the subjects of the study. Each BTB graft was harvested from the central third of the patellar tendon. Tripled or quadrupled semitendinosus tendon with or without gracilis tendon was used as a STG graft. CSAs of both grafts in the same patients were intraoperatively measured using a custom-made area micrometer during primary ACL reconstruction and revision surgery or during combined ACL and PCL reconstruction. Graft-tunnel fit was calculated by dividing the CSA of the graft by that of the tibial bone tunnel. The average CSA of STG grafts was significantly greater than that of BTB grafts. The average value of graft-tunnel fit for the STG grafts% was also greater than that of the BTB grafts%. Thus STG grafts have a larger CSA and closer graft-tunnel fit than BTB grafts in a clinical setting.

Adolescent↗

PubMed2001

Survey on occupational health management of VDT workers among 84 Japanese companies.

This survey of 84 companies described the present status of occupational health management of VDT workers in Japan, in relation to the official Guideline (Guidelines on Occupational Health for VDT Work, 1985). The majority admitted 80% or more of their workers engage in VDT works. Four hours of VDT work per day was widely used as a criteria for the eligibility to the VDT health examination. Some specific measurement was performed at health examination among 54.8% of the companies. The most popular item was "near vision." A larger number of follow-up measures was performed with ophthalmic cases than with muscloskeletal cases. From these findings, with consideration to the results of the preceding literatures, we made 8 suggestions for the on-going revision of the Guideline: 1) including recommendation for flat panel display and portable computers, 2) widening target of VDT health education also to general workers, 3) clarification of the categorization of VDT workers, 4) offering practical measures to secure off VDT period, 5) use of subjective symptoms to screen high-risk workers, 6) supply of the latest scientific information on each measuring item, 7) periodical revision to provide state-of-the-art management, and 8) clear statement of the purpose and limitation of the Guideline.

Computer Terminals↗

PubMed2001

Single- versus bi-socket anterior cruciate ligament reconstruction using autogenous multiple-stranded hamstring tendons with endoButton femoral fixation: A prospective study.

PURPOSE: This prospective study was conducted to compare the single-socket and the bi-socket anterior cruciate ligament (ACL) reconstruction techniques in terms of outcome. TYPE OF STUDY: Nonrandomized control trial. METHODS: There were 160 consecutive patients with unilateral chronic ACL insufficiency who underwent endoscopic single- or bi-socket ACL reconstruction alternately using multiple-stranded medial hamstring tendon and EndoButton (Smith & Nephew, Andover, MD) femoral fixation. All patients underwent the same postoperative rehabilitation protocol. Of them, 106 patients (57 single, 49 bi) were available for 2-year follow-up. RESULTS: According to the IKDC Knee Ligament Evaluation Form, 23 patients (40%) of the single-socket group were subjectively graded as normal, 30 (53%) as nearly normal, and 4 (7%) as abnormal. Twenty-six patients (53%) of the bi-socket group were graded as normal, 21 (43%) as nearly normal, and 2 (4%) as abnormal (P =.19). The mean side-to-side anterior laxity difference (KT-1000 manual maximum force) was 0.9 +/- 1.8 mm for the single-socket group and 0.7 +/- 1.2 mm for the bi-socket group (P =.44). Fifty-three of 57 patients (93%) in the single-socket group and all patients in the bi-socket group showed anterior laxity differences of +/-3 mm or less (P =.12). There were no differences in thigh muscle strength between the groups. CONCLUSIONS: Both single- and bi-socket ACL reconstruction using autogenous multiple-stranded hamstring tendons with EndoButton fixation provided satisfactory anterior stability, and there were no statistically significant differences in subjective results or measured restored stability between the 2 groups.

Adolescent↗

PubMed2001

Single- versus two-femoral socket anterior cruciate ligament reconstruction technique: Biomechanical analysis using a robotic simulator.

PURPOSE: Although anterior cruciate ligament (ACL) reconstruction with multistrand autogenous hamstring tendons has been widely performed using a single femoral socket (SS), it is currently advocated to individually reconstruct 2 bundles of the ACL using 2 femoral sockets (TS). However, the difference in biomechanical characteristics between them is unknown. The objective of this study was to clarify their biomechanical differences. TYPE OF STUDY: This is a cross-over trial using cadaveric knees. METHODS: Seven intact human cadaveric knees were mounted in a robotic simulator developed in our laboratory. By applying anterior and posterior tibial load up to +/- 100 N at 0 degrees, 15 degrees, 30 degrees, 60 degrees, and 90 degrees of flexion, tibial displacement and load were recorded. After cutting the ACL, the knees underwent ACL reconstruction using TS, followed by that using SS, with 44 or 88 N of initial grafts tension at 20 degrees of flexion. The above-mentioned tests were performed on each reconstructed knee. RESULTS: The tibial displacement in the TS technique was significantly smaller than that in the SS at smaller flexion angles in response to anterior and posterior tibial load of +/- 100 N, and the in situ force in the former was significantly greater than that in the latter at smaller flexion angles. Furthermore, in the TS technique, the posterolateral graft acted dominantly in extension, while the anteromedial graft mainly resisted against anterior tibial load in flexion. However, in the SS technique, the anteriorly located graft functioned more predominantly than the posteriorly located graft at all flexion angles. CONCLUSIONS: The ACL reconstruction via TS using quadrupled hamstring tendons provides better anterior-posterior stability compared with the conventional reconstruction using a single socket.

Aged↗

PubMed2001

Endoscopic reconstruction of the anterior cruciate ligament with quadrupled hamstring tendons. A correlation between MRI changes and restored stability of the knee.

A total of 30 patients who underwent endoscopic reconstruction of the anterior cruciate ligament using quadrupled hamstring tendons, through a single drill hole in the femur, had MRI 24 to 28 months after operation. In 18 patients the scans revealed that both the anterior and posterior portions of the graft ran in parallel from the inside of the femoral to the tibial tunnel. In 12, the posterior bundle had moved anteriorly and the anterior bundle could not be identified at the anterodistal border of the femoral tunnel. The mean difference in the anterior laxity, when compared with the contralateral knee, was 2.0+/-1.7 mm and 4.3+/-2.8 mm for the two types, respectively. Damage to the anterior bundle may occur when using the endoscopic technique because of biomechanical disadvantages, including concentration of loading and repetitive bending stress in the anterior bundle at the opening of the femoral tunnel.

Adolescent↗

PubMed2001

Human meniscus cell: characterization of the primary culture and use for tissue engineering.

Human meniscus cells from 47 surgically excised menisci were grown in primary culture. Cell proliferation and morphologic features were evaluated in three different culture media. Human meniscus cells showed three distinguishable cell types in monolayer culture: elongated fibroblastlike cells, polygonal cells, and small round chondrocytelike cells. These cells proliferated in Dulbecco's modified Eagle's medium, but by Day 7, elongated fibroblastlike cells became predominant. Cells did not proliferate in Ham's nutrient mixture-F-12. In a mixture of Ham's nutrient mixture-F-12 and Dulbecco's modified Eagle's medium, cells proliferated, maintaining their morphologic features and their ability to express messenger ribonucleic acids for aggrecan and Types I, II, and III collagen. Hyaluronan enhanced cellular proliferation without altering morphologic features or chondroitin sulfate production. Cultured human meniscus cells attached to a porous collagen sponge after cell seeding. Gene transfer was successful and an introduced gene was expressed by the cells, indicating that human meniscus cells can undergo gene manipulation. The finding that cells collected from small surgical specimens of human meniscus could be cultured, propagated, and seeded onto a collagen scaffold holds promise for the development of a cell-based, tissue engineered collagen meniscus.

Adolescent↗

PubMed2000

Decorin antisense gene therapy improves functional healing of early rabbit ligament scar with enhanced collagen fibrillogenesis in vivo.

Injured ligaments heal with scar tissue, which has mechanical properties inferior to those of normal ligament, potentially resulting in re-injury, joint instability, and subsequent degenerative arthritis. In ligament scars, normal large-diameter collagen fibrils have been shown to be replaced by a homogenous population of small collagen fibrils. Because collagen is a major tensile load-bearing matrix element and because the proteoglycan decorin is known to inhibit collagen fibrillogenesis, we hypothesized that the restoration of larger collagen fibrils in a rabbit ligament scar, by down-regulating the proteoglycan decorin, would improve the mechanical properties of scar. In contrast to sense and injection-treated controls, in vivo treatment of injured ligament by antisense decorin oligodeoxynucleotides led to an increased development of larger collagen fibrils in early scar and a significant improvement in both scar failure strength (83-85% improvement at 6 weeks; p < 0.01) and scar creep elongation (33-48% less irrecoverable creep; p < 0.03) under loading. This is the first report that in vivo manipulation of collagen fibrillogenesis improves tissue function during repair processes with gene therapy. These findings not only suggest the potential use of this type of approach to improve the healing of various soft tissues (skin, ligament, tendon, and so on) but also support the use of such methods to better understand specific structure-function relationships in scars.

Animals↗

PubMed2000

Comparison of eccentric and concentric screw placement for hamstring graft fixation in the tibial tunnel.

Interference screw fixation of four-strand hamstring grafts for ACL reconstruction has recently been introduced. By this method, the interference screw is placed in the tibial and femoral tunnels eccentric (adjacent) to the bundled limbs of the graft. In order to maximize the graft to tunnel contact to promote biological fixation, it is proposed to place the screw concentrically in the tunnel, in the middle of the four limbs of the graft, pressing each limb of the graft into the tunnel wall. This would be difficult to do in the proximal, folded end of the four limb graft situated in the femoral tunnel but can be done easily in the tibial tunnel. The purpose of this study was to evaluate the effect of screw placement on the stiffness, yield load, and ultimate load of hamstring graft fixation in the tibial tunnel. Five pairs of human knees were used for the study. Pull out tests were performed using an MTS system, pulling along the axis of the tibial tunnel. Tibial fixation stiffness was greater using concentric screw placement (P < 0.05) although there was no statistical difference in yield load, slippage, or ultimate load.

Anterior Cruciate Ligament↗

PubMed2000

The gravity sag view: a simple radiographic technique to show posterior laxity of the knee.

We introduce a simple radiographic technique of taking a "gravity sag view" to show sagittal laxity secondary to posterior cruciate ligament injury. Side-to-side differences of the tibia-femur step-off measured with these radiographs have proved to be useful parameters for evaluating posterior laxity. This radiographic technique is recommended instead of routine lateral radiographs taken with the knee kept recumbent.

Humans↗

PubMed2000

Reconstruction of the lateral ligaments of the ankle using solvent-dried and gamma-irradiated allogeneic fascia lata.

We have described a method of anatomical reconstruction of the lateral ligaments of the ankles with instability using allogeneic fascia lata dried with solvents and sterilised with gamma irradiation. Twenty ankles of 20 patients were assessed objectively and subjectively after a mean follow-up of 4.2 years (3.1 to 10). The result was excellent in 12 (60%), good in seven (35%) and fair in one (5%); none had a poor result. Stress radiography showed that the angle of talar tilt improved from 12.3+/-4.2 degrees (mean +/- SD) to 5.9+/-3.0 degrees and that the anterior drawer distance decreased from 9.2+/-3.9 mm to 4.4+/-2.5 mm. Neither infection nor limitation of movement occurred after operation. Fascia lata allografts provide a good alternative to autogenous grafts such as the peroneus brevis tendon.

Adolescent↗

PubMed1999

Direct in vivo gene transfer to healing rat patellar ligament by intra-arterial delivery of haemagglutinating virus of Japan liposomes.

BACKGROUND: Manipulation of ligament healing has been a major focus of orthopaedic research. In recent years, gene transfer to healing ligament appears to be a feasible method for manipulating the healing process. In this study, we investigated the feasibility of gene transfer to healing rat patellar ligament by intra-arterial delivery. METHODS: An attempt was made to transfer a reporter gene (Escherichia coli, beta-galactosidase gene) to healing rat patellar ligament using the haemagglutinating virus of Japan (HVJ) liposome-mediated gene transfer method. Three days after cutting the patellar tendons of 25 14-week-old male Wistar rats, HVJ-liposome complexes containing beta-galactosidase (beta-gal) cDNA were injected into the femoral artery of 15 Wistar rats as the experimental group. HVJ liposomes without DNA were injected into the femoral artery of 10 Wistar rats as the control group. Three rats from the experimental group and two control rats were killed 3, 7, 14, 28 and 56 days after the injection. RESULTS: After X-gal staining, the rate of transfection in the experimental group (mean +/- SEM) was found to be 12.1% +/- 0.590%, 8.7% +/- 0.217%, 10.2% +/- 0.227%, 3.2% +/- 0.247% and 0.7% +/- 0.060% at post-injection days 3, 7, 14, 28 and 56 respectively. In control sections the number of blue-stained cells were very few at any point. CONCLUSION: We succeeded in introducing a reporter gene into healing rat patellar ligament by infra-arterial delivery of HVJ-liposome complexes. This method appears to have the potential to be applicable for soft-tissue healing studies and also healing studies of other tissues and organs.

Animals↗

PubMed1998

Expression of peroxisome proliferator-activated receptor alpha (PPAR alpha) in primary cultures of human vascular endothelial cells.

The peroxisome proliferator-activated receptor (PPAR) is a member of the steroid nuclear receptor superfamily. Three types of PPARs have been described in humans: PPAR alpha, PPAR beta, and PPAR gamma. Here we investigated the levels of PPAR alpha mRNA in primary cultures of human umbilical venous endothelial cells (HUVEC), human umbilical arterial endothelial cells (HUAEC), human coronary arterial endothelial cells (HCAEC), and human aortic endothelial cells (HAEC), using the reverse transcriptase-polymerase chain reaction (RT-PCR). The HUVEC, HAEC, and HCAEC, but not the HUAEC, showed relatively low expression of PPAR alpha in comparison with liver, which was used as a positive control. Moreover, the partial sequences of the PCR-amplified products from HUVEC, HAEC, and HCAEC were similar to that of the PPAR alpha from human liver. The expression of PPAR alpha in cultured HAEC, which were induced by dexamethasone, was inhibited by insulin. In addition, PPAR alpha expression was also increased by benzafibrate or eicosapentaenoic acid with the physiological concentration. These results suggest that the PPAR alpha in endothelial cells may have the same physiological role as the expression of PPAR alpha in the liver.

Aorta↗

PubMed1998

Effect of alignment of the transplanted graft extracellular matrix on cellular repopulation and newly synthesized collagen.

This study examines the effect of alignment of the transplanted graft extracellular matrix on cellular repopulation and new collagen synthesis. The lateral half of the patellar tendon was harvested as a tendon graft from Lewis rats and frozen at -80 degrees C. In order to maintain the original alignment of the graft extracellular matrix, the graft was transplanted to a same size defect in the patellar tendon of other Lewis rats (group I). For controls, the graft was transplanted in a lax condition after excision of only the distal half of the lateral side of a patellar tendon (group II). After transplantation, six animals in each group were killed at 3, 7, 14, and 28 days. Cellular repopulation was assessed by using fibrillar-actin (F-actin) labeling with rhodamine-phalloidin, and new collagen synthesis was detected by means of a polyclonal antibody against type III collagen aminopropeptide (pN collagen III). Collagen fibril profiles were observed under the transmission electron microscope. On the 3rd day after transplantation, no specific fluorescence was detected in either group. Specific labeling for F-actin and pN collagen III, however, was observed at both ends of the graft in both groups at 1 week and throughout the graft at 2 weeks after transplantation. Consistent with the actin bundles' orientation, pN collagen III was aligned parallel to the longitudinal axis of the graft in group I. Collagen fibrils with a smaller diameter, mixed evenly and everywhere with a larger diameter, increased gradually in group I. However, smaller collagen fibrils in group II increased more slowly and were distributed unevenly. In summary, the dense collagen arrangement in the native patellar tendon determined the alignment of the repopulating cells, and the distribution of newly synthesized collagen might be affected by the actin cytoskeleton within the repopulating cells.

Actins↗

PubMed1998

Cross-sectional area measurement of the semitendinosus tendon for anterior cruciate ligament reconstruction.

We measured the cross-sectional area (CSA) of the semitendinosus tendon (SMT) in 79 anterior cruciate ligament (ACL)-injured patients using magnetic resonance imaging (MRI) to scrutinize their appropriateness for ACL grafts. Measurements of the CSAs of the SMT with MRI were closely correlated with intraoperative direct measurement (y = 0.697). The mean CSAs of the SMT measured with MRI ranged from 6.3 to 15.0 mm2 with a mean of 10.1+/-2.1 mm2. The CSA of the SMT measured with MRI proved to be a useful indicator to determine preoperatively whether the SMT graft would be of adequate dimensions (7 mm or more in diameter, 60 mm or more in length) for ACL reconstruction. If the CSA of the SMT was more than 11 mm2, a sufficiently thick and long graft could be prepared with a tripled or quadrupled SMT in 89% of cases. We conclude that tissue CSA measurements using MRI could potentially be implemented as a useful tool for determining the most appropriate donor autograft tissue preoperatively, thus minimizing harvest-site morbidity.

Adolescent↗

PubMed1998

Early biological effect of in vivo gene transfer of platelet-derived growth factor (PDGF)-B into healing patellar ligament.

To define the early biological effect of in vivo introduction of the PDGF-B gene on the healing of ligaments, a HVJ-liposome suspension containing platelet-derived growth factor (PDGF)-B cDNA was injected directly into the injured patellar ligament of 14-week-old male Wistar rats. Rats were killed at 1, 4 and 8 weeks for the morphological analysis of angiogenesis by laminin immunohistochemistry and of collagen deposition by Masson's Trichrome staining and collagen I immunohistochemistry. PDGF-B gene transfer caused the enhanced expression of PDGF in healing ligament up to 4 weeks after transfection, leading to an initial promotion of angiogenesis and subsequent enhanced collagen deposition in the wound. Enhanced and accelerated matrix synthesis in the PDGF-B gene introduced healing ligament suggests that this gene transfer technique may be a potentially useful tool for improving soft tissue repair.

Animals↗

PubMed1998

A comparison of in vivo gene delivery methods for antisense therapy in ligament healing.

To determine the most efficient in vivo delivery method of oligonucleotides for antisense therapy in ligament healing, fluorescence-labelled phosphorothioate oligodeoxynuleotides (ODN) were introduced into 12 rabbit ligament scars 2 weeks after injury using haemagglutinating virus of Japan (Sendai virus: HVJ)-conjugated liposomes. We compared the efficiency of cellular uptake of fluorescence as a percentage of all cells in each scar using three delivery procedures: (1) direct free-hand injection into the ligament scar using a conventional syringe; (2) systematic direct sca injection using a repeating 10 microliters dispenser and a square mesh grid system; and (3) injection into the feeding (femoral) artery. Results showed that there was a significant difference in fluorescence uptake by scar cells on day 1 after injection between the three delivery methods: (1) direct free-hand, 9.7 +/- 7.6% (average +/- s.d.); (2) systematic direct, 58.4 +/- 15.9%; and (3) intra-arterial, 0.2 +/- 0.1%. Systematic direct injection was most efficient and it resulted in 25.9 +/- 13.0% of scar cells being labeled at 7 days after transfection. We then introduced antisense ODN for the rabbit proteoglycan, decorin, into ligament scars with this delivery method and confirmed a significant inhibition of decorin mRNA expression in antisense-treated scar tissues in vivo both at 2 days (42.3 +/- 14.7% of sense control +/- s.d.; P < 0.0025) and 3 weeks (60.5 +/- 28.2% of sense control +/- s.d.; P < 0.024) after treatment, compared with sense ODN-treated scars. Decorin was significantly suppressed also at protein level in antisense-treated scars at 4 weeks (66.6 +/- 35.7% of sense control +/- s.d.; P < 0.045) after treatment. These results demonstrate that in vivo transfection efficiency in ligament scars is 'delivery system dependent' and that introduction of antisense ODN for the small proteoglycan, decorin, with this delivery method can lead to significant suppression of its expression over 3 weeks both at mRNA and protein levels. Thus, an effective model for the potential manipulation of scar composition and quality in ligament healing has been established.

Animals↗

PubMed1998

Solvent-dried and gamma-irradiated tendon allografts in rats. Mechanical and morphological evaluation.

We examined solvent-dried, gamma-irradiated (SD-R) allografts and fresh-frozen (FF) allografts mechanically and morphologically. Before transplantation, FF grafts were more than six times stronger than SD-R grafts. After four weeks, the tensile strength was about the same in both groups. At 24 weeks only collagen fibrils of small diameter were observed in the SD-R grafts while in FF grafts fibrils of small and intermediate diameter were seen. Clinically, we suggest that SD-R grafts could be used as a favourable alternative to FF grafts if care was taken regarding their initial mechanical weakness.

Actin Cytoskeleton↗

PubMed1998

Articular cartilage repair. Rabbit experiments with a collagen gel-biomatrix and chondrocytes cultured in it.

To repair a full-thickness articular cartilage defect in rabbit knees, we developed a technique of using a collagen gel hardened by cultured allogeneic chondrocytes in it. The gel-chondrocyte composite accumulated an intense metachromatic matrix, and had elasticity and stiffness enough to be shaped easily after 2 weeks' culture in vitro. It was implanted into full-thickness articular cartilage defects. Histologic evaluation was performed up to 6 months after surgery, using a histologic grading scale composed of 5 categories. In the gel-chondrocyte composite implanted group, good repair was observed from as early as 1 day up to 6 months. On the other hand, in the empty control group, no repair was observed 1 day to 2 weeks after the defects were made. At 4 weeks, some repair occurred, but even at 6 months the repair was not good.

Animals↗