Biomedical subjects

K Shino

Publications and source records attributed to K Shino.

At least 19 recordsLinked to original sources

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

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↗

PubMed1997

Effect of freeze-drying or gamma-irradiation on remodeling of tendon allograft in a rat model.

Freezing or freeze-drying and gamma-irradiation are techniques currently used for processing tendon allografts. However, it is still unknown how these processing methods affect graft remodeling. In this study, we used a rat patellar tendon transplantation model to investigate the effect of various processing methods on remodeling by quantifying loss of collagen labeled with a radioactive isotope. The grafts were divided into the following four groups according to the processing method: fresh-frozen, freeze-dried, fresh-frozen and gamma-irradiated, or freeze-dried and gamma-irradiated. The percentage of donor collagen, calculated from hydroxyproline content and radioactivity level, was used as an indicator of graft remodeling. At 2 weeks, the level of donor collagen in the fresh-frozen group was 62%; in the freeze-dried group, 59%; in the fresh-frozen and irradiated group, 57%; and in the freeze-dried and irradiated group, 44%. At 4 weeks, the percentage of donor collagen remaining in grafts decreased to 38% in the fresh-frozen group, 19% in the freeze-dried group, 27% in the fresh-frozen and irradiated group, and 12% in the freeze-dried and irradiated group. Finally, at 12 weeks, the levels were 19% in the fresh-frozen group, 20% in the freeze-dried group, 15% in the fresh-frozen and irradiated group, and 6% in the freeze-dried and irradiated group. The percentages of donor collagen in the freeze-dried and the fresh-frozen and irradiated groups were significantly lower than that in the fresh-frozen group at 4 weeks. The values for the freeze-dried and irradiated group were significantly lower than those for the fresh-frozen and irradiated group at 4 and 12 weeks. These data suggest that freeze-drying, freeze-drying followed by gamma-irradiation, and fresh-freezing followed by gamma-irradiation temporarily accelerate graft remodeling.

Animals↗

PubMed1997

Temporal and spatial expression of transforming growth factor-beta in the healing patellar ligament of the rat.

We investigated the temporal and spatial expression of transforming growth factor-beta in the healing patellar ligament of the rat by immunohistochemistry. The mid-portion of the medial half of the patellar ligament in 14-week-old male Wistar rats was cut transversely with a scalpel. On day 1 after ligament injury, diffuse staining for transforming growth factor-beta was observed in the extracellular matrix filling the wound, and the staining in the adjacent ligament tissue was as weak as it was in the normal ligament. On day 3, the intensity of the diffuse extracellular staining decreased, and the staining was observed in correspondence with the cellular distribution in the wound site and in the adjacent uninjured ligament tissue. On day 7, the intense staining was widely distributed over the whole length of the ligament tissue. On day 28, the staining for transforming growth factor-beta was still observed at the wound site and in the adjacent uninjured ligament tissue, where the staining was reduced in intensity but still stronger than it was in the normal ligament. On day 56, the expression of transforming growth factor-beta was still detectable at the wound site; however, in the adjacent uninjured ligament tissue, it had almost subsided to the normal level. The results of the present study suggest that ligament healing may be accompanied by extensive changes in the expression of transforming growth factor-beta over the whole length of ligament tissue.

Animals↗

PubMed1997

Avulsion fracture of the anteromedial bundle of the anterior cruciate ligament.

The avulsion fracture of the tibial attachment site of the anterior cruciate ligament is relatively rare among adults. Although partial avulsion fracture of this site is very rare, complex forces exerted on the knee joint could produce this type of fracture. We report on an adult patient with an avulsion fracture of the attachment site of anteromedial bundle of the anterior cruciate ligament associated with injuries of lateral and medial collateral ligament and fibular fracture. We speculate varus stress in a flexed knee coupled with rotation between the femur and tibia caused this type of injury.

Adult↗

PubMed1997

Remodeling of allogeneic and autogenous patellar tendon grafts in rats.

The differences in remodeling among frozen allografts, frozen autografts, and fresh autografts were investigated using a patellar tendon transplantation model in 2 different strains of rats. In this study, isografting (transplantation among the same strain inbred animals) was adopted as an autograft model. This method makes it possible to set up a frozen autograft model. Evaluation included mechanical properties determined during tensile failure tests, cross sectional area, histologic findings, and collagen fibril distribution. Recipient rats were euthanized at 4, 8, 12, and 24 weeks after transplantation (n = 5, in each group and in each period). The frozen allografts showed significantly less tensile strength than did the frozen autografts at 4 weeks, but this difference was transient and diminished by 8 weeks. The tensile strength of the fresh autografts was significantly greater than that of the frozen autografts at 8 weeks or the frozen allografts at 8 and 12 weeks. It was suggested that freeze thawing has adverse effects on the remodeling of fresh autografts in this extraarticular graft model. The cross sectional area for each type of graft at each posttransplantation period was about twice as large as that before transplantation. The collagen fibril profile of the frozen allografts was similar to that of the frozen autografts. However, the fresh autografts showed a greater number of large diameter fibrils and a lesser number of small diameter fibrils than did the other 2 frozen groups.

Animals↗

PubMed1997

Osteoclastogenesis in iliac bone marrow of patients with rheumatoid arthritis.

OBJECTIVE: To investigate osteoclastogenesis in bone marrow cells from patients with various pathogenic backgrounds known to induce osteoporosis, to identify specific factors that may cause generalized osteoporosis in patients with rheumatoid arthritis (RA). METHODS: Bone marrow blood was obtained from 59 women, 36 with RA and 23 without RA. Patients with RA were classified as severe (26) and mild RA (10: 5 patients with and 5 without corticosteroid therapy). The non-RA subjects were divided into 3 groups, premenopausal (7), menopausal (8), and elderly (8). As a marker of bone resorption, the pyridinoline crosslinked telopeptide domain of type I collagen (ICTP) concentration in the bone marrow supernatant was measured by radioimmunoassay. The bone marrow cells were cultured 14 days in the presence or absence of autologous bone marrow supernatant; then the number of tartrate resistant acid phosphatase positive multinucleated cells (TRAP positive MNC) was counted as an indicator of osteoclastogenesis. RESULTS: ICTP concentration of the bone marrow supernatant and the number of TRAP positive MNC showed remarkable enhancement in some patients with severe RA, but these features were not observed in the 3 control groups. CONCLUSION: Increased bone resorption and enhanced osteoclastogenesis were specifically observed in the iliac bone marrow of patients with RA, especially those with severe RA. These phenomena can be considered to accompany generalized osteoporosis in RA.

Adult↗

PubMed1996

Transient introduction of a foreign gene into healing rat patellar ligament.

We investigated the in vivo introduction of a reporter gene into healing rat patellar ligaments using the hemagglutinating virus of Japan (HVJ)-liposome-mediated gene transfer method. The mid-portion of the medial half of the patellar ligament was cut transversely with a scalpel in 14-wk-old male Wistar rats. A HVJ-liposome suspension containing beta-galactosidase (beta-gal) cDNA was injected directly into the injured site and pooled in the fascial pocket covering the injured site 3 d postoperatively. Thereafter, beta-gal-labeled cells were observed in the wound site accounting for 3% of the wound cells on the first day, 2% on the third, 7% on the seventh, 6% on the 14th, 2% on the 28th, and 0.2% on the 56th day after injection. The beta-gal-labeled cells were initially localized in and adjacent to the wound site, but they were observed spreading into the ligament substance away from the wound on the seventh day after injection. On day 28, beta-gal-labeled cells were observed throughout the length of the ligament substance. With double-labeling for marker antigens for monocyte/macrophage (ED-1) and for collagen I aminopropeptide (pN collagen I), it was revealed that fibroblastic (pN collagen I-positive) cells accounted for 63% and monocyte/macrophage lineage cells for 32% of the beta-gal-labeled cells in the day 7 wound. On day 28, they formed 58 and 35% of the beta-gal-labeled cells in the wound, respectively. Thus, we succeeded in introducing the beta-gal gene into healing rat patellar ligament. Moreover, labeling of the transfected cells made it possible to identify a biological event, namely that the cells in and around the wound site infiltrate into the uninjured ligament substance and come to populate the whole length of the ligament substance as repair progresses. These results suggest that ligament healing may involve not only the repair of the wound site itself but also extensive cellular infiltration of ligament substance adjacent to the wound.

Animals↗

PubMed1996

The remodelling process of allogeneic and autogenous patellar tendon grafts in rats: a radiochemical study.

In order to study the remodelling of collagen fibres of transplanted tendons, one-half of the patellar tendon of the knee in 54 rats was replaced with a radioisotope (3H-proline)-labelled patellar tendon procured from a donor rat. Three transplantation models were used in this study: fresh-frozen allograft, fresh-frozen autograft (fresh-frozen isograft), and fresh autograft (fresh isograft). The percentage of old collagen was calculated as an indicator of collagen turnover from the amount of hydroxyproline and the radioactivity level of 3H-hydroxyproline in the transplanted tendons at 4, 12 and 24 weeks postoperatively. Histological evaluation was also performed at 2, 4, 12 and 24 weeks. At 4 weeks, the percentage of old collagen in the grafts from the fresh-frozen allograft group was significantly lower than in the autograft groups (20% vs. 48%). Although the percentage of old collagen in the fresh-frozen autograft group had decreased to the same level as in the fresh-frozen allograft group by 12 weeks (approximately 10%), the value was still high in the fresh autograft group at 12 weeks and remained higher (38%). Histologically, at 2 weeks, the cellularity in the fresh-frozen allograft was higher than in the fresh-frozen autograft. After 4 weeks, however, no significant difference was found between these two groups. In the fresh autograft group, the cellularity was lower than in the fresh-frozen groups at all times. In conclusion, the collagen turnover rate in the fresh-frozen allograft was the most rapid of the three transplantation models based on hydroxyproline turnover.

Animals↗

PubMed1996

Results of isolated meniscal repair evaluated by second-look arthroscopy.

Thirty-six isolated torn menisci in 35 patients (average age, 24 years) which had been repaired arthroscopically using an inside-out technique were evaluated by second-look arthroscopy. The time from meniscal repair to second-look arthroscopy ranged from 2 to 10 months with a mean of 5 months. The indications for meniscal repair were a longitudinal or oblique tear located at the outer half of the meniscus. Twenty (56%) were graded as excellent, 10 (28%) as good, and 6 (16%) were graded as poor. Neither age nor length of time between injury and repair affected meniscal healing. The medial meniscal repairs showed better results than the lateral repairs (rate of excellent results: medial, 82%; lateral, 44%; P < .01, chi-squared test). The rate of excellent results for those with normal meniscal bodies at the time of repair was 79%, which was significantly higher than that seen in the cases with deformed and/or superficial damage to the meniscal body (36%; P < .05, chi-squared test).

Adolescent↗

PubMed1996

A simple and secure anchoring system for Caspari's transglenoid multiple suture technique using a biodegradable poly-l-lactic acid button.

To manage a difficulty in tying sutures over the infraspinatus fascia when using Caspari's transglenoid multiple suture technique, we developed a new anchoring system using a biodegradable poly-L-lactic acid (PLLA) button and investigated its clinical efficacy in 28 patients who were followed-up for more than 2 years postoperatively (mean, 26.5 months). Twenty-four patients had Bankart lesions and 4 had detachment of the superior glenoid labrum. The mean age at operation was 22.1 years. The PLLA button measured 8 x 8 x 1.2 mm and had two holes. After multiple sutures were inserted by the routine Caspari technique (mean, 7.3 sutures), the sutures were divided into 2 bundles, passed through the holes in the button, and tied over it on the posterior scapular neck under traction. The arm was immobilized in a Velpeau bandage for 3 weeks after Bankart repair and for 1 to 2 weeks after superior labral repair. The results of Bankart repair were excellent in 13 patients, good in 7, and poor in 4 according to Rowe's rating scale (success rate, 83%), while the outcome of superior labral repair was excellent in 3 and good in 1 according to our own criteria. All 4 patients who showed a poor outcome were contact athletes who developed resubluxation postoperatively. There were no complications, but transient damages to the suprascapular nerve occurred in 2 patients. In conclusion, the PLLA button provided simple and secure suture fixation for the Caspari technique.

Adolescent↗

PubMed1996

Arthroscopic posterior cruciate ligament reconstruction using hamstring tendons: one-incision technique with Endobutton.

The one-incision surgical technique using autogenous hamstring tendons with Endobutton (Acufex Microsurgical Inc. Mansfield, MA) femoral end fixation for posterior cruciate ligament reconstruction is described. This technique avoids a second incision on the femoral side, and is adaptable to various graft materials (autogenous or allogeneic bone-patellar tendon-bone, hamstring, or Achilles tendon.

Arthroplasty↗

PubMed1996

Bone marrow stromal cells contribute to synovial cell proliferation in rats with collagen induced arthritis.

OBJECTIVE: To observe the migration of bone marrow stromal cells into the joint cavity and the contribution of such cells to synovial proliferation in rats with collagen induced arthritis (CIA). METHODS: After bone marrow stromal cells preliminarily labeled with fluorescent dye or 3H thymidine accumulated in the bone marrow of splenectomized rats by intraperitoneal injection, the migration of labeled stromal cells in rats with CIA was analyzed by liquid scintillation counting, autoradiography, and fluorography. RESULTS: In splenectomized control rats, labeled bone marrow stromal cells were mostly found in the bone marrow and not in the synovium. Over 2 weeks after immunization, labeled stromal cells were microscopically found migrating directly into the joint cavity through the area between the articular margin and the synovial insertion (the bare zone). Labeled stromal cells were mainly found in the sublining layers of proliferating synovial tissue. CONCLUSION: At the onset of CIA, bone marrow stromal cells migrated from the bone marrow into the affected joint cavity and seemed to contribute to synovial proliferation.

Animals↗

PubMed1995

Large molecule fraction of plasma separated with polyethylene glycol in treatment of chronic relapsing thrombotic thrombocytopenic purpura.

Plasma exchange and plasma infusion are effective in the treatment of patients with thrombotic thrombocytopenic purpura (TTP). It has been proposed that some component in normal plasma may be deficient in TTP patients. In this experiment normal plasma was fractionated and an effective fraction for the treatment of TTP was sought. Plasma was fractionated with 5% polyethylene glycol and a large molecule fraction was obtained which was composed mainly of proteins and lipoproteins with molecules larger than that of IgG. The fraction was dissolved in physiological saline and infused in two patients with chronic relapsing TTP who had been successfully treated periodically with plasma infusion. Peripheral platelet counts and serum LDH levels were measured, and the efficacy of the treatment was assessed. Infusion of the large molecule fraction elevated platelet counts and lowered the LDH level. However, the efficacy of the large molecule fraction was 25 to 50% that of plasma. Components in the fraction may have been inactivated partially during preparation. We propose that the large molecule fraction contains factors which are effective in some patients with TTP.

Adolescent↗

PubMed1995

Arthroscopic repair for a flap tear of the posterior horn of the lateral meniscus adjacent to its tibial insertion.

A flap tear of the posterior horn of the lateral meniscus adjacent to its tibial insertion combined with acute rupture of the anterior cruciate ligament was successfully repaired arthroscopically by a combination of advancement of the tip of the flap into a drill hole created in the tibia and an inside-out stacked suture technique using Henning instrumentation in two cases. However, the long-term function of the repaired menisci, which was reduced several millimeters in circumferential length, is still unknown.

Adolescent↗