Multiple lesions of osteonecrosis depicted by magnetic resonance imaging.
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Adult↗
Biomedical subjects
N Sugano
Publications and source records attributed to N Sugano.
Enhancement of an Mg(2+)-dependent nuclease activity in rat liver cells exposed to cisplatin.
An Mg(2+)-dependent deoxyribonuclease activity was highly purified from a 0.6 M NaCl extract of rat-liver nuclei. The template primer activity assay with a Klenow polymerase suggested that this nuclease plays a role in incision/excision of cisplatin-modified DNA strands to form single-strand gaps. In another experiment, rat-liver (Ac2F) cells were cultured in the presence of cisplatin. A 0.6 M NaCl extract was prepared from the cultured-cell nuclei and subjected to the activity blotting analysis [Seki et al. (1993) J. Chromatography 618, 147-166]. The nuclease activity of the extract was enhanced in response to cisplatin, but not in the presence of cycloheximide. These results imply that cisplatin-DNA lesions induce the Mg(2+)-dependent deoxyribonuclease activity in Ac2F cells to provide priming sites for the repair synthesis.
Animals↗
Experimental studies on a new bioactive bone cement: hydroxyapatite composite resin.
We developed hydroxyapatite composite resin (CAP) as a new type of bioactive bone cement. CAP is composed of 80% w/w hydroxyapatite granules (mean particle size: 2 microns) and bis-phenol-A glycidyl methacrylate-based resin. The setting time is 5 min and the peak curing temperature during polymerization is 46 degrees C. In this study, the mechanical strength of CAP and the biological behaviour of the CAP-bone interface were examined. The compressive strength of CAP was 260 MPa and this was about three times greater than that of commercial polymethylmethacrylate (PMMA) bone cement. The tensile strength and fracture toughness of CAP also exceeded those of PMMA cement. CAP was implanted into the femoral condyles of rabbits. Two weeks later, new bone formation was already seen on the surface of the CAP implants. At 8 wk, bone was growing directly onto the surface of the CAP implants and no intervening fibrous tissue could be observed at the CAP-bone interface. These results show that CAP is a promising material which possesses superior mechanical strength and the biological property of achieving direct contact with bone.
Animals↗
Study on thrombus formation and the course of healing after sclerotherapy for varicose veins of the leg (preliminary report).
Varicose veins of the leg with saphenous trunk incompetence have been treated surgically. However, recently we have switched to sclerotherapy, and the preliminary results have been satisfactory. We examined varicosities in the leg by color-coded duplex scanning to evaluate venous incompetence and the results of sclerotherapy. Our sclerotherapy procedure was performed as follows: the varicosed branches were punctured and less than 5 ml of 3% polidocanol was injected with the patient's legs raised; an elastic bandage was applied for 3-7 days. Before sclerotherapy, saphenous incompetence was detected in 31 out of 32 limbs. One to two weeks after sclerotherapy, 22 limbs with greater saphenous trunk incompetence were re-examined. The saphenous trunk was occluded with thrombus and saphenous incompetence had diminished in 16 limbs, and there was excellent sclerosis of the distal varicosities. The saphenous trunk was not sclerosed in six limbs. The varicosity was sclerosed in two out of these six limbs. We followed up the healing course of the saphenous vein thrombosis in nine limbs for up to 6 months. Six recanalizations of the saphenous veins were observed, however, clinically the distal varicosity did not recur in any of these limbs. Sclerotherapy appears to be a clinically useful method capable of replacing surgery.
Adult↗
Spongy metal Lübeck hip prostheses for osteoarthritis secondary to hip dysplasia. A 2-6-year follow-up study.
Between May 1987 and December 1990, 66 hips in 59 patients with osteoarthritis secondary to hip dysplasia underwent cementless total hip arthroplasty with a spongy metal Lübeck hip prosthesis (S+G Implants, Lübeck, Germany) that had a fully porous-surfaced short stem made of cased cobalt-chrome-molybdenum alloy. Sixty-five hips in 58 patients were prospectively followed for 2-6 years (mean, 43 months). Patient age at operation ranged from 29 to 63 years (mean, 51 years). The Merle d'Aubigné hip score improved from 7.8 before surgery to 16.9 at the final follow-up evaluation. All hips were rated as either excellent (63%) or good (37%). Mild thigh pain was recognized in only three hips (5%) at 6 months after surgery, but it disappeared within 2 years. Serial roentgenograms showed stable fixation with bone ingrowth in all hips, that is, bone densification in contact with the implant and trabecular connection to the endosteal surface. The authors found no migration of the implant or circumferential radiolucency. Moderate osteopenia, presumably due to stress shielding, was seen in only four hips (6%). Acetabular bone-grafting performed in 31 hips gave successful support to the socket. Cancellous bone chips grafted to small defects showed excellent remodeling. The authors conclude that the spongy metal Lübeck hip prosthesis contributed to lower rates of thigh pain and migration than cementless prostheses.
Adult↗
Prognostication of osteonecrosis of the femoral head in patients with systemic lupus erythematosus by magnetic resonance imaging.
To detect and prognosticate osteonecrosis of the femoral head in the preradiographic stage, 60 patients with systemic lupus erythematosus who had normal hip radiology were followed prospectively for a mean period of 5 years (range, 3-7 years) using magnetic resonance imaging (MRI). The first MRI scans showed a low intensity band in the femoral head of normal fat intensity on T1 weighted images in 16 hips of 9 patients. The MRI findings were used to classify the lesions into three categories. Type A (six hips): the lesions occupied the medial one third or less of the weight bearing portion. Type B (two hips): the lesions occupied the medial two thirds or less of the weight bearing portion. Type C (eight hips): the lesions occupied more than the medial two thirds of the weight bearing portion. At the final followup, all of the Type A and one of the Type B hips were classified as being in Stage 1, and one Type B and two Type C hips had progressed to Stage 2. The MRI appearance of six Type C hips had changed from a band to an inhomogeneous pattern with the femoral head progressing to collapse on radiographs 2-5 years after the diagnosis of systemic lupus erythematosus. The remaining hips, which had been classified as normal at the first MRI, maintained a normal appearance, except for one hip that developed a Type A lesion. The presence of a low intensity band on T1 weighted images was an early specific finding of osteonecrosis of the femoral head, and extensive lesions demarcated by band images signified a poorer prognosis in systemic lupus erythematosus patients. If no MRI abnormalities appeared after 1 year of the startup treatment for systemic lupus erythematosus, there was little risk of femoral head collapse based on the subsequent clinical course of the patients followed in the current study.
Adolescent↗
Ectopic ossification associated with osteoid osteoma in the acetabulum. A case report.
Ectopic bone formation was associated with osteoid osteoma in the anterior rim of the acetabulum. A factor, which has been speculated to be secreted from the nidus and is responsible for increased osteoblastic activity, also seemed to have the capacity to stimulate young mesenchymal cells to differentiate into an osteogenic pathway. A case of a 35-year-old woman with osteoid osteoma, which caused ectopic ossification adjacent to the nidus, is presented.
Acetabulum↗
Prognostication of nontraumatic avascular necrosis of the femoral head. Significance of location and size of the necrotic lesion.
After reviewing the radiographs of 149 hips with nontraumatic avascular necrosis of the femoral head (ANFH), a method for evaluating the prognosis in patients with ANFH in its early stages was devised. The evaluation was made primarily by classifying the radiographic features of each involved femoral head according to the location and size of its necrotic lesion. In a group of 120 hips, massive collapse occurred without exception in cases where both of the following criteria were true. First, in a standing position, the necrotic lesion involved more than the medial one third of the weight-bearing surface from the anteroposterior view. Second, from the lateral view, the lesion occupied more than 43% of the total area of the femoral head. However, in 29 hips, the extent and size of necrosis was less than the above, and no massive collapse occurred during the follow-up period of three to 15 years (average, 5.2 years). In these 29 hips, function was preserved. These data suggest that hips with a high risk for collapse can be reliably selected during the early stages of ANFH.
Adrenal Cortex Hormones↗
Properties of a DNA-binding protein from rat nuclear scaffold fraction.
Our previous work [Hibino et al. (1992) Biochem. Biophys. Res. Commun. 184, 853-858] has shown that a highly repetitive component in rat nuclear DNA forms a sequence-directed bend to have the binding affinity for the nuclear scaffold protein, P130. In the present experiment, the mobility shift DNA-binding assay suggested that the formation of the repetitive component-P130 complex is based on some cooperative mode of interaction. The DNase I footprint analysis revealed that the major binding region of this protein in the DNA is located near the center of the 370-bp XmnI repeat which has a strongly bent overall structure. These results imply that a nuclear scaffold protein such as P130 binds to sequence-directed bend(s) in a highly repetitive DNA to play an important role in construction of a higher-order chromatin structure.
Animals↗
Purification and characterization of nuclear scaffold proteins which bind to a highly repetitive bent DNA from rat liver.
Our previous work (Hibino et al. (1992) Biochem. Biophys. Res. Commun. 184, 853-858) has shown that the binding affinities of a highly repetitive DNA component for rat nuclear scaffold proteins, P123 and P130, depend on the degree of sequence-directed bending of the helix axis. In the present experiment, these proteins have been purified and finally isolated by DNA-Sepharose column chromatography. The pI values of P123 and P130 were 7.2 and 8.1, respectively. The southwestern blotting revealed that a highly repetitive bent DNA (370-bp XmmI fragment) from rat liver binds readily to the isolated proteins under a hypotonic condition (50 mM NaCl) and that the level of the binding affinity for each protein was lowered with increasing NaCl concentration. The sedimentation analysis predicted that direct interaction between the XmnI fragment and P123 or P130 results in the formation of a complex which consists of two of the fragments and one molecule of the protein, alternatively, one of the fragment and three molecules of the proteins. Distamycin A, an antibiotic which binds specifically to AT-rich DNA, removed the bend in the XmnI fragment and inhibited binding of the fragment to P123 or P130, whereas neither removal of the bend nor binding inhibition was observed with chromomycin A3, an antibiotic specific for GC-rich sites in DNA. These results imply that AT-rich regions in a highly repetitive DNA component cause bending of the helix axis to be recognized by some of nuclear scaffold proteins.
Animals↗
Dome osteotomy of the pelvis for osteoarthritis secondary to hip dysplasia. An over five-year follow-up study.
We performed Kawamura's dome osteotomy of the pelvis, with simultaneous distal transfer of the greater trochanter on 101 hips in 91 patients with osteoarthritis secondary to hip dysplasia. The mean age at operation was 30 years (15 to 55), and follow-up was for a mean of 8.3 years (5 to 14). Clinical evaluation using the Merle d'Aubigné score showed 92% excellent or good results. Radiologically, 91 hips had good acetabular remodelling and showed no signs of progression of osteoarthritis. In ten hips the osteoarthritic process progressed despite the osteotomy and six of these eventually underwent total hip replacement. Factors which were significantly associated with a poor outcome included an advanced stage of osteoarthritis, valgus deformity of the proximal femur, old age at the time of operation and postoperative persistence of abductor insufficiency.
Adolescent↗
Total hip arthroplasty in the neglected congenital dislocation of the hip. A five- to 14-year follow-up study.
A retrospective study was performed on 34 hips of 28 patients with neglected congenital dislocation of the hip after cemented total hip arthroplasty (THA) using a straight-stem prosthesis in 21 and a curve-stem prosthesis in 13 hips. The mean age at operation was 49 years (28-72 years) and the mean follow-up period was 9.4 years (5.6-14 years). Functional evaluation using Merle d'Aubigné Hip Score showed 71% success rate. Radiographic loosening occurred in three femoral and eight acetabular components attributable to poor cementing in all stems and three sockets, and to dislocation due to trauma and graft collapse in two sockets. Marked acetabular deficiency showed increased incidence of socket loosening. Both types of prostheses showed the same statistical results. Localized endosteal osteolysis appeared in five hips at the sites of less than 1-mm cement thickness. Greater trochanter nonunion reduced the functional status evidenced by pain, limping, and a statistically significant Trendelenburg sign. Proper cementing, effective acetabular reconstruction, and prevention of trochanter nonunion can produce excellent long-term results.
Adult↗
Affinity of a highly repetitive bent DNA for nuclear scaffold proteins from rat liver.
A highly repetitive component in rat nuclear DNA was isolated by HindIII digestion and cloned. A self-ligated tandem dimer of the 370-bp cloned component was digested with each of DraI, HindIII and XmnI. The resulting 370-bp restriction fragments exhibited anomalously slow gel electrophoretic mobilities. Of them, the XmnI fragment had the slowest mobility. This suggested that sequence-directed bending of the helix axis is the strongest in this fragment. Moreover, the 370-bp restriction fragments had selective affinities for the nuclear scaffold proteins, P123 and P130. The affinity levels of XmnI fragment were higher than those of DraI or HindIII fragment. These results implied that the affinity of a highly repetitive component for the nuclear scaffold proteins depends on the degree of sequence-directed bending of the helix axis.
Animals↗
Rotational osteotomy for non-traumatic avascular necrosis of the femoral head.
We reviewed 41 hips in 40 patients at three to 11 years (average 6.3 years) after Sugioka transtrochanteric rotational osteotomy for non-traumatic avascular necrosis of the femoral head. The clinical results were excellent or good in 23 hips (56%) and the radiological success rate was 56%. Failure was due to fracture of the femoral neck, nonunion of the osteotomy, secondary collapse, or osteoarthritis. Nonunion and femoral neck fracture were more common after the use of the large screws described by Sugioka than with AO blade plates. Secondary collapse was significantly more common when less than one-third of the posterior articular surface was intact (p = 0.002). Postoperative degenerative changes were seen in cases with stage III avascular necrosis. We conclude that success depends to a large extent on the amount and stage of necrosis of the femoral head, but that careful technique and the use of AO hip plates may increase the likelihood of a satisfactory result.
Adult↗
Action of a nuclease from rat nuclei on UV-irradiated DNA.
An Mg(2+)-dependent nuclease was highly purified from rat-liver nuclei. The nuclease activity was enhanced in ultraviolet light (UV)-irradiated dsDNA, but not in unirradiated dsDNA. Irrespective of UV irradiation, ssDNA was readily cleaved by this enzyme. UV-irradiated plasmid DNA was incubated with this enzyme and subjected to the template primer activity assay with a Klenow polymerase. With increasing incubation time, the activity was enhanced in the circular-relaxed and linear forms, but not in the superhelical form. These results implied that this enzyme excises UV-damaged sites in dsDNA to form single strand gaps for repair synthesis.
Animals↗
Pulmonary embolism after total hip replacement in a patient who had an ovarian cyst. A case report.
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Endometriosis↗
[Conservative treatment of acute deep vein thrombosis of lower extremities].
To evaluate conservative treatment for acute deep vein thrombosis (DVT) of lower extremities, 56 limbs of 53 patients (29 men and 24 women, age ranging 20 to 77 years, mean age of 50.1 years) were reviewed. Only three patients underwent thrombectomy of restricted iliac venous regions by Fogarty catheter within 24 hours of the onset and their symptoms were relieved immediately after operation with good follow-up condition. Forty-five limbs were treated conservatively. Among 45 limbs, 15 limbs were treated within 7 days of symptom's onset using heparin and urokinase for 6-10 days followed by oral anticoagulant. Forty-seven percent of the patients were freed from their symptoms within one year. However 30 limbs received conservative therapy after 7 days of the onset showed 23% recovery from their symptoms within one year and in extensive thrombosis recovery was only 14%. We concluded that conservative treatment for DVT was effective if it was started within 7 days of the onset, and thrombectomy of ilio-femoral regions might be more effective than conservative treatment under the same condition.
Acute Disease↗
Bipolar prosthetic replacement for the treatment of avascular necrosis of the femoral head.
Eighty-three hips in 66 patients with nontraumatic avascular necrosis of the femoral head (ANFH) showing evidence of severe collapse or secondary osteoarthritic changes were treated with surgical implantation of bipolar hip prostheses either with or without cement fixation of femoral stems. The cases were observed for more than three years (range, three to ten years seven months; average, five years seven months) and assessed in terms of functional and roentgenographic results. These data were compared with the results of classic hemiarthroplasties using fixed head prostheses (Austin-Moore-type with curved or straight stem) that were performed at the authors' institutions before 1980. The results confirm that the clinical outcome is improved with use of the bipolar prosthesis. Satisfactory results (a score of 80 or greater on a hip function scoring system proposed by the Japanese Orthopaedic Association) were maintained throughout the follow-up period in most cases (71 of 83 hips) with the bipolar prosthetic replacements. In a group of patients with unsatisfactory results (12 hips), proximal migration of prosthetic head was seen in two cases. The incidence of proximal migration of bipolar heads, including those exhibiting minimal movement, was significantly lower when compared with that observed in an Austin-Moore-type head-fixed prosthesis group (7/83 versus 12/19) during a comparable postoperative follow-up period. It is noteworthy that the proximal migration of the bipolar head was not progressive, and, in most cases observed more than five years, the cartilaginous spaces of acetabulum were preserved, whereas in the Austin-Moore-replaced group, the migration was evident and progression occurred within three years of surgery.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗