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Biomedical subjects

K Urabe

Publications and source records attributed to K Urabe.

At least 37 records · Page 2Linked to original sources
PubMed2001

A new concept for precise patella resection in total knee arthroplasty.

We developed a new patella-cutting guide that simplifies proper alignment and enables resection of the correct thickness of bone. This guide consists of a central shaft, two support frames, and a ring. The ring consists of upper and lower disks, with a slot between the disks. The central shaft and the lower disk have holes for fixation pins. The distance from the distal end of the central shaft to the lowest level of the slot is 8 mm. Bone of the same thickness as that of the patellar component can be automatically resected using this guide. A feeler gauge is inserted through the slot, and the periarticular region is felt. This procedure enables the guide to be set at the correct angulation. A laboratory study using fresh-frozen cadaver patella specimens and a clinical study showed that proper alignment and proper resection were achieved using this guide.

Arthroplasty, Replacement, Knee↗
PubMed2000

Anatomic variations should be considered in total knee arthroplasty.

The effect of anatomic variations on the operative techniques used in total knee arthroplasty (TKA) was assessed. In 133 Japanese patients with medial osteoarthritis (OA), six parameters were measured on anteroposterior radiographs of the lower extremities taken with the patients in the supine position. The results showed that the characteristics of the knees were bowing of the femoral shaft and proximal tibia vara, with lateral offset of the tibial shaft with respect to the center of the tibial plateau. The angle between a perpendicular to the mechanical axis and the tangent to the distal femoral condyles can be used in determining the external rotation of the femoral component. This angle was more than 3 degrees in 20% of the patients. The femoral component should therefore be externally rotated more than 3 degrees relative to the posterior condylar line in such patients. Because the center of the tibial plateau is located medial to the central line of the tibial shaft in knees with medial OA, the central point of the tibial articular surface should not be used for alignment of the tibial component. The medial offset stem of the tibial component may impinge against the medial wall. Anatomic variations should be evaluated before TKA is attempted.

Aged↗
PubMed2000

CD1a+, CD3+, CD4+, CD8+, CD68+ and cutaneous lymphocyte-associated antigen-positive cells in Bowen's disease.

BACKGROUND: Bowen's disease (BD) is a squamous cell carcinoma in situ that rarely invades into the underlying dermis. However, little is known about its immunohistology. Objectives To evaluate the relationship between the cytological properties of the tumour cells in BD and the host immune response. METHODS: We examined the expression of p53, proliferating cell nuclear antigen (PCNA) and Ki67 antigen, and the number of mitotic cells, together with the number of intratumoral and dermal infiltrating CD1a+, CD3+, CD4+, CD8+, CD68+ and cutaneous lymphocyte-associated antigen (CLA)+ cells in 18 cases of genital BD. RESULTS: When compared with normal genital skin (n = 10), there was a significantly higher number of mitotic cells as well as higher expression of p53+, PCNA+ and Ki67+ cells in BD. There was significant mutual correlation between CD3+, CD4+ and CD68+ cells in the tumoral epidermis. The number of CD1a+ Langerhans cells significantly decreased in BD epidermis; however, dermal CD1a+ cells were increased. Interestingly, numbers of dermal CD1a+ cells significantly correlated with those of intratumoral CD3+, CD4+ and CD68+ cells. In situ hybridization for human papillomavirus (HPV) demonstrated that HPV-infected BD had significantly less infiltration of intratumoral CD3+ cells and CLA+ cells. CONCLUSIONS: The present data suggest that dermal CD1a+ cells may participate in the immune surveillance and that HPV infection may interfere with the intratumoral infiltration of CLA+ cells in BD.

Antibody Formation↗
PubMed2000

Tibial tubercle malposition in patellar joint instability: a computed tomograpy study in full extension and at 30 degree flexion.

We evaluated the tibial tubercle position in knees with patellar instability. CT in full extension and at 30 degree flexion was used in 18 knees with instability and 18 control knees. Scans were taken at the level of the femoral epicondyles, tibial tubercle and distal tibia. We found that in full extension, the tibial tubercle was in a more lateral position in the unstable than in the control knees. At 30 degree flexion, the tibial tubercle in the unstable knees rotated internally, but it was never within the normal range. CT scans taken in full extension and at 30 degree flexion seem to be of value for ascertaining the degree of tibial tubercle malposition during knee flexion in patellar instability.

Adolescent↗
PubMed2000

Clinical features of multiple epiphyseal dysplasia expressed in the knee.

The purpose of this study is to clarify the clinical features of the knee affected by multiple epiphyseal dysplasia. Thirty-one cases of multiple epiphyseal dysplasia were reviewed. Of the patients, 11 were male and 20 were female. The average age at onset of symptoms was 22.5 years. The average age at initial visit to the authors' hospital was 28.9 years. Radiographic findings showed epiphyseal abnormality of the knee in all but two (93%) cases. Irregularity, segmentation of the epiphysis, widening of the joint space, and genu valgum deformity were the dominant findings before epiphyseal closure. After epiphyseal closure, the most characteristic finding was a shallow femoral trochlear groove, which was observed in 56.5% of the cases. Other findings in adult patients included early onset osteoarthritic change, genu valgum, depression of the lateral tibial plateau, and multiple free bodies. However, there still is a possibility that multiple epiphyseal dysplasia exists, even if the patient lacks a shallow femoral trochlear groove. If genu valgum or varum, free bodies, and premature osteoarthritis are observed, one should evaluate other joints, keeping a diagnosis of multiple epiphyseal dysplasia in mind. Patients with knees that have a femoral trochlear groove of normal or near normal shape do exist, and premature osteoarthritic changes may develop in such patients.

Adolescent↗
PubMed2000

Outbreak of cryptosporidiosis after contamination of the public water supply in Saitama Prefecture, Japan, in 1996.

An outbreak of cryptosporidiosis occurred in Ogose Town, Saitama Prefecture. Japan, in June 1996. Of 12,345 respondents to a questionnaire sent to households in the town (population; 13,809), 8,812 (71.4%) reported an acute gastrointestinal illness some time between May and July. In addition, 274 traceable visitors at local inns, golf courses, and the like during this period and 54 employees from out of town were infected. Cases of cryptosporidiosis were estimated to 9,140. Of these, 2,856 subjects were treated at outpatient clinics and 24 subjects were hospitalized (some subjects counted twice). No deaths were attributed to the outbreak. Among the visitors to Ogose who were traced, 7 persons who stayed only one day during the outbreak and drank half a glass to 2 glasses (100 to 360 ml) of tap water had cryptosporidiosis confirmed by laboratory tests. The median incubation period for the 14 persons for whom this calculation was possible was 6.4 days (range, 5 to 8 days). Of 469 pupils reporting details of their fever and diarrhea, abdominal cramps, or these combined signs and symptoms, the median maximum body temperature was 37.8 degrees C (range, 36.7 to 40.3 degrees C). The duration of illness, reported by 608 of the pupils, was 5.2 days (range, 1 to 15 days), and that reported by 187 employees was 4.8 days (range, 1 to 18 days). The longest known time for discharge of oocysts after onset was 44 days. Blood was not found in the 609 stool specimens examined. The outbreak was caused by contamination of the town's potable water by Cryptosporidium parvum oocysts. The town's water treatment plant treated river water by coagulation, sedimentation, sand filtration, and chlorination. Contamination arose because of various natural and artificial factors: one was that the monthly precipitation in May was much lower than average, causing the river water level to drop. Another factor was heavy rainfall one night in May that increased water turbidity. The amounts of the coagulant added seemed to be insufficient. There are two inns, three public lavatories, and two small-scale wastewater treatment plants upstream 400 m and 1,200 m of the intake point of the town's water treatment plant. However, there are no farms with livestock in the area. We suggest that the location of the water treatment facilities was inappropriate, and that oocysts had circulated from the potable water to humans to sewage to the river and back to the potable water.

Adolescent↗
PubMed2000

[A case of acute urticaria from hydroxyzine hydrochloride used for preanesthetic medication].

We report a case of acute urticaria probably caused by hydroxyzine hydrochloride. A 66-year-old male was scheduled for cardiac cystectomy by thoracic endoscopy. The patient was premedicated with atropine and hydroxyzine intramuscularly 30 min before arrival in the operating room. Abrupt general exanthema was observed when intravenous infusion was started. Although his general condition was stable, the operation was postponed. Three days later, the skin test was performed using several drugs. Only hydroxyzine hydrochloride gave positive result. It is assumed that hydroxyzine hydrochloride may have caused his urticaria.

Acute Disease↗
PubMed1999

Inhibitory effects of activin-A on osteoblast differentiation during cultures of fetal rat calvarial cells.

Activin-A is a member of the transforming growth factor-beta (TGF-beta) superfamily and is expressed by osteoblasts. However, the role of activin-A on osteoblasts is not clearly understood. We examined the effects of activin-A on osteoblast proliferation or differentiation, and mineralization by the osteoblasts in the first subcultures of fetal rat osteoblasts obtained from calvarial bones. Exogenous activin-A led to impaired formation of bone nodules in a dose-dependent manner, although it did not influence cell proliferation using an MTT assay. This inhibitory effect depended upon the time at which activin-A was added to the culture media, and the effect was most significant when addition took place at the early phase of the culture. In addition, exogenous activin-A inhibited gene expression of type I procollagen, alkaline phosphatase, osteonectin, and osteopontin in the cultured cells using Northern blot analysis. The peak of osteocalcin mRNA was delayed. Gene expression for TGF-beta was not influenced by exogenous activin-A. The betaA subunit (activin-A) mRNA was detected during the early phase of this culture. These results indicate that activin-A inhibited early differentiation of the fetal rat calvarial cells, or osteoblasts.

Activins↗
PubMed1999

Inhibition of endochondral ossification during fracture repair in experimental hypothyroid rats.

Using a rat fracture model, we investigated the effects of a decrease in serum levels of thyroid hormone on the fracture-repair process. Rats were divided into the following groups: (a) controls, (b) those treated with methimazole for the duration of the experiment, and (c) those treated with methimazole and L-thyroxine, receiving both for the same duration. Three weeks after the initiation of pharmacologic treatment, closed femoral fractures were produced. The formation of cartilage tissue in the fracture callus in all rats was not obviously different on day 7 after fracture. In the rats treated with methimazole, differentiation from proliferating to hypertrophic chondrocytes in the fracture callus was less advanced and vascular invasion was clearly inhibited on day 12. Gene expression of alkaline phosphatase and osteocalcin in the callus was significantly lower in these rats than in the controls on days 10, 12, and 14. The mechanical properties of the fracture callus were also significantly weaker in these animals than in the controls on day 21, resulting in impaired fracture repair. These results demonstrate that hypothyroidism inhibits endochondral ossification, resulting in an impaired fracture-repair process. L-thyroxine replacement in the rats treated with methimazole caused the impaired repair process to revert to normal. These results indicate that thyroid hormone is one of the critical systemic factors for fracture repair.

Alkaline Phosphatase↗
PubMed1999

Radiological assessment of the position of the tibial tuberosity by means of a marking wire in knees with patellofemoral arthritis.

OBJECTIVE: To assess the usefulness of a new axial radiographic technique in knees with patellofemoral arthritis (PF-OA). DESIGN AND PATIENTS: After a marking wire had been attached to the skin on the tibial tuberosity so that the wire matched the width of the patellar tendon, an axial radiograph was taken at 30 degrees of flexion in 16 normal knees and 14 PF-OA knees in which computed tomographic analysis had revealed a laterally positioned tibial tuberosity at 30 degrees of flexion. The distance of the marking wire from the lateral condyle and from the patellar groove was compared between the two groups. RESULTS: The marking wire was located significantly laterally in PF-OA knees compared with normal knees. CONCLUSION: An axial radiograph with a marking wire on the tibial tuberosity is useful for assessing the position of the tibial tuberosity in PF-OA knees.

Aged↗
PubMed1999

A new, all-inside technique for meniscus repair.

A new method for arthroscopic meniscal repair using sutures with multiple knots was developed, and its mechanical strength was evaluated. Sutures are passed arthroscopically through the torn meniscus using a needle with a cleft in its tip, and when the needle is withdrawn, knots are placed both in the meniscus and the joint capsule. Our method does not require additional skin incisions and can be performed for repair of posterior tears. Furthermore, this all-inside technique minimizes the risk of popliteal neurovascular injury. Biomechanical analysis using bovine menisci showed that the maximum frictional force between the suture and meniscus was greater than the maximum strength of a suture itself. Our method is simple and rapid, making it easy to insert multiple sutures to achieve adequate stability.

Animals↗
PubMed1999

Changes in knee alignment after total knee arthroplasty.

Changes in limb alignment after total knee arthroplasty were evaluated in 20 knees replaced with the Miller Galante knee system. The mean follow-up period was 87.4 months. Seventeen of the 20 knees were in the varus position on the initial postoperative radiographs, but the alignment significantly changed to become even more aligned toward varus during the follow-up period. The thickness of the ultra-high-molecular-weight polyethylene (UHMWPE) also decreased significantly in the medial femorotibial joint. The wear of the UHMWPE possibly changed the alignment, and the postoperative alignment had a positive correlation with the wear rate. The components should be implanted so that the mechanical axis intersects the center of the components to prevent worsening of alignment as well as to minimize any such wear.

Aged↗
PubMed1999

Therapeutic effects of LK 423, a phthalimido-desmuramyl-dipeptide compound, on dextran sulfate sodium-induced colitis in rodents through restoring their interleukin-10 producing capacity.

A new phthalimido compound, N-[2-(2-phthalimidoethoxy)acetyl]-L-alanyl-D-glutamic acid (CAS 142489-47-2, LK 423), was examined for its possible activity to modulate levels and species of cytokines in mice carrying a specific inflamed organ. Colonic inflammation was induced in mice by giving 5% dextran sulfate sodium (DSS) solution as drinking water. The capacity of spleen cells obtained from the DSS-inflamed mice to produce interleukin-10 (IL-10) in response to mitogen was significantly reduced when compared with the capacity of spleen cells from intact mice. Treatment of the mice administered DSS by subcutaneous multiple injections with a low dose of LK423 resulted in delaying the progression to full-blown inflammation in the colon. The mitogen-stimulated spleen cells obtained from the LK423-treated mice yielded significantly greater amounts of IL-10 and IL-6 than the untreated DSS group, and the peritoneal cells from the LK423-treated mice produced significantly lower levels of tumor necrosis factor alpha (TNF alpha). Based on this prophylactic effect of LK423 in the murine colitis model, its therapeutic effect was examined in rats in which colitis had been induced by feeding 3% DSS for 12 days. Intracolonic administration of LK423 to these rats for 7 days resulted in diminishing the ulcerative area in the colon. The immunological characteristics of this new compound are discussed from the point of view of its possible application as a therapeutic agent for inflammatory bowel diseases (IBD) and other inflammatory diseases.

Adjuvants, Immunologic↗
PubMed1999

Knee stability in posterior cruciate ligament retaining total knee arthroplasty.

Anteroposterior knee laxity was evaluated in 14 patients (19 knees) who had posterior cruciate ligament retaining total knee arthroplasty using the Miller Galante I prosthesis. The followup ranged from 87 to 118 months (average, 105.9 months), and the measurements were done using the KT-2000 arthrometer. The mean anteroposterior displacement with the knees with Miller Galante I prostheses was 10.1 mm at 30 degrees flexion and 8.1 mm at 75 degrees flexion. In the 15 knees with Miller Galante I prostheses with flexion greater than 90 degrees, seven had less stability at 75 degrees than at 30 degrees flexion. These knees were considered to have a nonfunctional posterior cruciate ligament, and they had a worse Knee Society score (81.1) than did the other eight knees with Miller Galante I prostheses (89.9). There were four knees in which the flexion was less than 90 degrees. In this study, approximately half of the knees with posterior cruciate ligament retaining total knee arthroplasty did not have good anteroposterior stability in flexion an average of 9 years after surgery.

Aged↗
PubMed1999

Expression of insulin-like growth factor I messenger ribonucleic acid in developing osteophytes in murine experimental osteoarthritis and in rats inoculated with growth hormone-secreting tumor.

Osteophytes are one of the characteristic features of osteoarthritis and are often found in acromegalic arthropathy. The aim of this study was to investigate insulin-like growth factor I (IGF-I) involvement in osteophyte formation. One percent collagenase solution was injected into murine knee joints as an osteoarthritis model. In a different animal group, GH-secreting tumor cells were inoculated s.c. to the rat thigh as an acromegaly model. A series of osteophyte formation was examined histologically. IGF-I messenger RNA was detected using the in situ hybridization method. Type I IGF receptors were detected immunohistochemically. In the osteoarthritis model, osteophyte formation appeared as synovial or perichondral cell proliferation adjacent to the articular cartilage on day 5, followed by cartilage formation on day 7 and endochondral ossification on day 14. In the acromegaly model, synovial or perichondral cell proliferation was observed 4 weeks after inoculation, followed by osteophyte formation at 8 weeks. In both models, IGF-I messenger RNA and type I IGF receptor were coexpressed by proliferating synovial or perichondral cells, proliferating chondrocytes, and osteoblasts within the developing osteophytes. These results suggest that IGF-I regulated the initiation and development of osteophyte formation in both models in an autocrine and/or paracrine fashion.

Animals↗
PubMed1999

Posterior tibial slope in the normal and varus knee.

Posterior tibial slope was evaluated in 30 normal and 30 varus knees using magnetic resonance imaging. The mean tibial posterior slope in the medial plateau was 10.7 degrees (range: 5 degrees - 15.5 degrees) in the normal knees and 9.9 degrees (range: 1.5 degrees - 19 degrees) in the varus knees. The mean tibial posterior slope in the lateral plateau was 7.2 degrees (range: 0 degrees - 14.5 degrees) in the normal knees and 6 degrees (range: 1 degrees - 13 degrees) in the varus knees. Although these differences were not statistically significant, there was a large range in the posterior tibial slope in both groups. When 10-mm thickness of bone was resected in the middle of the lateral plateau in total knee arthroplasty, the thickness of the bone resection in the anterior and posterior part of the lateral plateau was measured. The presumed thickness of bone was 10.1 mm (range: 7.3-13.9 mm) in the anterior part and 7.5 mm (range: 5-10.3 mm) in the posterior part. A large range in the measured thickness of bone also was detected in the varus knees. These results suggest that the shape of the proximal tibia varies among individuals and that the cutting angle should be determined in each case to avoid any mismatch of the patient's posterior slope of the tibia after implantation.

Case-Control Studies↗