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Biomedical subjects

S Toh

Publications and source records attributed to S Toh.

At least 19 recordsLinked to original sources
PubMed2006

Pathophysiological role of endothelin in ectopic ossification of human spinal ligaments induced by mechanical stress.

Ossification of the posterior longitudinal ligament (OPLL) of the spine is characterized by progressive ectopic bone formation in the spinal ligament. To identify the genes related to ossification affected by mechanical stress during OPLL, analyses using cDNA microarray were carried out using cultured human spinal ligament cells that had been subjected to uniaxial cyclic stretching. Samples were obtained from a total of 14 patients: seven cervical or thoracic OPLL patients and seven control patients. Spinal ligament cells derived from tissues of OPLL (OPLL cells) and control (non-OPLL cells) patients were subjected to uniaxial sinusoidal cyclic stretching (0.5 Hz, 20% stretch) for various time periods (0-9 hours). cDNA microarrays revealed that ranges of distribution of both up- and downregulated genes evoked by cyclic stretching were significantly wider in OPLL cells than in non-OPLL cells. Increases in the mRNA expression of endothelin-1 (ET-1) as well as various marker genes related to ossification were also observed. mRNA expression of ET-1 and alkaline phosphatase was increased by mechanical stress in a time-dependent manner, while addition of ET-1 to static cultures of OPLL cells increased mRNA expression of alkaline phosphatase in a dose-dependent manner. During 9 hours of cyclic stretching, ET-1 release increased to about sixfold the amount observed in nonstretched cells. In non-OPLL cells, neither cyclic stretching nor ET-1 induced any increase in alkaline phosphatase expression. These results suggest that mechanical stress promotes the progression of ossification in OPLL cells through autocrine and/or paracrine mechanisms of ET-1.

Aged↗
PubMed2003

Uni-axial cyclic stretch induces Cbfa1 expression in spinal ligament cells derived from patients with ossification of the posterior longitudinal ligament.

Ossification of the posterior longitudinal ligament of the spine (OPLL) is characterized by ectopic bone formation in the spinal ligaments. Mechanical stress, which acts on the posterior ligaments, is thought to be an important factor in the progression of OPLL. To clarify this mechanism, we investigated the effects of in vitro cyclic stretch (120% peak to peak, at 0.5 Hz) on cultured spinal ligament cells derived from OPLL (OPLL cells) and non-OPLL (non-OPLL cells) patients. The mRNA expressions of Cbfa1 (an osteoblast-specific transcription factor), type I collagen, alkaline phosphatase (ALP), osteocalcin and integrin beta1 (a mechanotransducer) were increased by cyclic stretch in OPLL cells, whereas no change was observed in non-OPLL cells. The effects of cyclic stretch on the spinal ligament tissues derived from OPLL and non-OPLL patients were also analyzed by immunohistochemistry using an antibody against Cbfa1. The expression of Cbfa1 was increased by cyclic stretch at the center of the spinal ligament tissues of OPLL patients, whereas no change was observed in the tissues of non-OPLL patients. Furthermore, U0126, a specific inhibitor of MAPK kinase (MEK), suppressed the stretch-induced mRNA expressions of Cbfa1, ALP and type I collagen in OPLL cells. These results suggest that in OPLL cells, mechanical stress is converted by integrin beta1 into intracellular signaling and that Cbfa1 is activated through the MAP kinase pathway. Therefore, we propose that mechanical stress plays a key role in the progression of OPLL through an increase in Cbfa1 expression.

Aged↗
PubMed2003

Endoscopic treatment of delayed unions and nonunions with calcium phosphate paste.

We describe a new therapeutic procedure using a bone filler in a calcium phosphate paste (bone paste) for endoscopic surgery for delayed unions and nonunions. Guided by radiography, the site of nonunion was confirmed. Two portals were created toward the nonunion site and, through each portal, the tissue around the nonunion site was released. While confirming the site of nonunion under endoscopy, scar tissue at the nonunion was excised to expose the bone. Next, the bone paste was injected into the space between bone fragments. This therapeutic modality is indicated most favorably in cases of open fractures, in cases after replantation in which soft tissue is severely damaged but one wants to preserve as much soft tissue as possible, and in cases of nonunion with satisfactory fixation but insufficient callus formation.

Arthroscopy↗
PubMed2003

The Ishiguro extension block technique for the treatment of mallet finger fracture: indications and clinical results.

The results of extension block Kirschner wire fixation for the treatment of mallet fractures of the distal phalanx were retrospectively assessed in 65 consecutive patients. The indications for this technique were the presence of a large bone fragment, and palmar subluxation or the loss of joint congruity of the distal interphalangeal joint. Using the Wehbé and Scheider classification there were 27 type IB, 19 type IIB, 17 type IA, and 2 type IIA fractures. According to the Crawford rating system there were 46% excellent, 32% good, 20% fair and 2% poor results. We believe that this technique, when properly applied, produces satisfactory results.

Adolescent↗
PubMed2002

Treatment of soft tissue injuries to the dorsum of the metacarpophalangeal joint (Boxer's knuckle).

We retrospectively reviewed the surgical treatment for 16 cases of traumatic soft tissue injury to the metacarpophalangeal joint (Boxer's knuckle). A history of trauma was present in all cases and there was an associated extensor tendon dislocation in seven cases. Eight cases were initially treated conservatively, but their symptoms persisted. Intraoperative findings included rupture of the extensor hood or joint capsule in all cases. Surgical closure of the rupture of the joint capsule resulted in a successful outcome in all cases. We consider that conservative treatment of this injury may not be effective when the joint capsule of the metacarpophalangeal joint is ruptured. We recommend arthrography of the metacarpophalangeal joint to assist in the decision as to whether to proceed with surgical or conservative treatment.

Adolescent↗
PubMed2002

The carpal detachment injury of the triangular fibrocartilage complex.

Triangular fibrocartilage complex (TFCC) injuries were suspected clinically in 22 wrists of 21 patients, but arthrography and MRI assessments of this structure were normal. As conservative therapy for 2 months did not improve their symptoms, wrist arthroscopy was then performed. Although no abnormalities of the TFCC and ligaments were observed, meniscus homologue-like tissue which arose from TFCC was riding on the articular surface of the triquetrum. After resection of this soft tissue with a shaver and a punch, the symptoms disappeared in all cases. The arthroscopic findings suggested that a portion of TFCC that was originally attached to the ulnar side of the triquetrum had become detached.

Adolescent↗
PubMed2002

Distraction lengthening by callotasis in the hand.

The clinical results of 26 digits (18 patients) lengthened by distraction callotasis were evaluated and the factors which influenced healing were analysed. There were 14 men and four women, with a mean age of 39 years. All digits had suffered traumatic amputation. There were eight thumbs and 18 fingers. The level of the site of the osteotomy was at the proximal metaphysis in ten, the middle diaphysis in 13 and the distal metaphysis in three. Although the proposed length was achieved in 23 of the 26 digits, five required additional bone grafts. The rate of healing was 96 days/cm in the digits without complications such as callus fracture or poor callus formation, and 158 days/cm in those with complications. Lengthening at the proximal metaphysis gave a better result than at the diaphysis or distal metaphysis.

Adolescent↗
PubMed2001

Activation peptide of carboxypeptidase B and anionic trypsinogen as early predictors of the severity of acute pancreatitis.

BACKGROUND: Early prediction of severity is important in the management of patients with acute pancreatitis. The presence of activation peptides and certain pancreatic proenzymes in plasma and urine has been shown to correlate with severity. This study was designed to assess the value of measuring levels of the activation peptide of carboxypeptidase B (CAPAP) and of anionic trypsinogen. METHODS: Concentrations of CAPAP and anionic trypsinogen were measured in the urine and serum in 60 patients with acute pancreatitis. Preset cut-off levels were used to analyse the accuracy of the tests. Severity was classified retrospectively according to the Atlanta classification. RESULTS: Concentrations of CAPAP in urine and serum and of anionic trypsinogen in urine correlated with the severity of the pancreatitis. CAPAP in urine showed the highest accuracy. The overall accuracy was 90 per cent, with a positive predictive value of 69 per cent and a negative predictive value of 98 per cent. CONCLUSION: In this study, measurement of CAPAP in urine was an accurate way to predict the severity of acute pancreatitis, and was superior to assay of anionic trypsinogen in urine and serum. Measurement of CAPAP in urine may be of value in the management of individual patients with pancreatitis and in the selection of patients for therapeutic trials.

Acute Disease↗
PubMed2001

Arthroscopic diagnosis and treatment of dorsal wrist ganglion.

Thirty-seven patients with dorsal wrist ganglia underwent arthroscopic resection. The mean follow-up was 20 months, and no complications were encountered. The ganglia were classified into three types according to their arthroscopic appearance. This classification helps to determine the amount of dorsal capsular resection required.

Adolescent↗
PubMed2001

One-bone forearm formation using vascularized fibula graft for massive bone defect of the forearm with infection: case report.

Massive long-bone defects of greater than 6 cm are difficult to treat with conventional bone grafts, and other methods are sometimes recommended, such as vascularized bone grafts or bone transport using the Ilizarov external fixator. The combination of local infection with a massive bone defect exacerbates the problem, and provides an even more negative prognosis. The authors treated a large bone defect of the forearm with local infection, using a one-bone forearm formation with a large vascularized fibula graft. They attached an adequate amount of muscle fascia to the vascularized fibula, which was useful not only for coverage of the skin defect, but also for treatment of the local infection. Twenty months after surgery, elbow and hand functions were maintained, and the patient had no disturbance of hand function in daily activities, although rotation of the forearm was sacrificed.

Bone Wires↗
PubMed2001

Ipsilateral pedicle vascularized fibula grafts for reconstruction of tibial defects and non-unions.

Between October 1983 and August 1998, 31 patients with non-union or bone defect of the tibia have undergone 32 vascularized fibula transfers to reconstruct lower legs. Of these 32 vascularized fibula transfers, there were 19 pedicle transfers from the ipsilateral leg. There were 17 males and two females. The average patient age was 53 (21 to 84) years old. All patients achieved good bone reconstruction. All patients are currently able to walk without a brace, except for one. As to major complications, three of these 19 had delayed union, with only one postoperative fracture. In the cases with delayed union or fractured grafted fibulas, the periods to walking without a brace were longer than in the cases without such major complications. From the results, the ipsilateral pedicle vascularized fibula graft appears to be a useful option for reconstruction of tibial defects.

Adult↗
PubMed2001

Combining free vascularized fibula graft and the Ilizarov external fixator: recent approaches to congenital pseudarthrosis of the tibia.

The present study compares a recent approach for congenital pseudarthrosis of the tibia, combining a free vascularized fibula graft and an Ilizarov external fixator. Between 1984 and 1993, seven vascularized fibula grafts were performed. In the first six cases, casts or unilateral external fixators were applied, and five of these cases were complicated by fractures of the graft, necessitating secondary procedures or long-term immobilization. The mean follow-up was 12.1 years. Five patients can now walk unassisted, and one uses a brace only outdoors. On average, a brace was required for 18 months. In the recent Ilizarov external fixator case, the fixator was removed after 4 months and a brace was unnecessary at 10 months. There was no leg-length discrepancy, severe ankle deformity, or fracture of the grafted fibula 7 years postoperatively. Combining a free vascularized fibula graft with an Ilizarov external fixator is recommended for this condition.

Child, Preschool↗
PubMed2001

Tardy posterolateral rotatory instability of the elbow due to cubitus varus.

BACKGROUND: Cubitus varus has long been considered merely a cosmetic deformity. The purpose of this paper is to demonstrate a causal relationship between cubitus varus and instability of the elbow. METHODS: In twenty-four patients (twenty-five limbs) with a cubitus varus deformity following a pediatric distal humeral fracture or resulting from a congenital anomaly (three limbs of two patients), tardy posterolateral rotatory instability of the elbow developed approximately two to three decades after the deformity occurred. All patients presented with lateral elbow pain and recurrent instability. The average varus deformity was 15 degrees (range, 0 degrees to 35 degrees ). Surgery was performed in twenty-one patients (twenty-two limbs). Treatment consisted of reconstruction of the lateral collateral ligament and osteotomy in seven limbs, ligament reconstruction alone in ten, osteotomy alone in four, and total elbow arthroplasty in one. RESULTS: In three patients, the triceps muscle was dynamically stimulated intraoperatively to contract while resisting extension of the elbow. This produced posterolateral rotatory subluxation of the elbow, which was reversed by corrective osteotomy and lateral transposition of a portion of the medial head of the triceps that originally had been attached to the elongated, deformed medial aspect of the olecranon. At an average of three years (minimum, one year) after the operation, the result was good or excellent for nineteen of the twenty-two limbs that had undergone an operation; three limbs had persistent instability. CONCLUSIONS: With cubitus varus, the mechanical axis, the olecranon, and the triceps line of pull are all displaced medially. The repetitive external rotation torque on the ulna permitted by these deformities can stretch the lateral collateral ligament complex and lead to posterolateral rotatory instability. Thus, cubitus varus deformity secondary to supracondylar malunion or congenital deformity of the distal part of the humerus may not always be a benign condition and may have important long-term clinical implications. Operative correction can relieve symptoms of instability. The indications for preventive corrective osteotomy remain to be determined.

Adolescent↗
PubMed2000

Traumatic boutonniere deformity of the thumb.

We report three patients who presented 3 to 8 months after sustaining a closed injury to the dorsoradial aspect of the metacarpophalangeal joint of the thumb. All three patients had an extensor lag of the metacarpophalangeal joint and paradoxical hyperextension of the interphalangeal joint. There were no collateral ligament injuries. The patients required surgical treatment which included advancement and reattachment of the extensor pollicis brevis insertion and imbrication of the dorsoradial capsule to restore the anatomical alignment of the extensor pollicis longus. Surgical treatment of dorsoradial injuries to the thumb metacarpophalangeal joint may be required for injuries that result in subluxation of the extensor pollicis longus tendon and a boutonnière deformity of the thumb.

Adolescent↗
PubMed2000

Vascularized free flaps for reconstruction after resection of congenital arteriovenous malformations of the hand.

Between 1981 and 1996, the authors performed reconstructions with vascularized free flaps in four patients with congenital arteriovenous malformations of the hand. This series included one man and three women, whose ages at the time of surgery ranged from 20 to 57 years, with an average of 41 years. All were categorized as fast-flow type B malformations. The locations of the arteriovenous malformations were the thumb only, thumb to palm, index to palm, and thumb and index to palm. In all cases, free vascularized flaps (two dorsalis pedis, one wrap-around, and one peroneal) were utilized to replace the resected abnormal skin lesions. Follow-up ranged from 1 year to 18 years and 9 months, with an average of 7 years. All flaps survived with no complications, and all patients were relieved of their preoperative symptoms. One patient unfortunately committed suicide for unknown reasons. The authors recommend that complete resection be carried out whenever possible. When skin is involved, repair should be carried out with a free flap. Based on the good results achieved in the case followed-up for over 18 years, vascularized free flaps proved very useful for the treatment of arteriovenous malformations.

Adult↗
PubMed2000

Severely displaced scaphoid fracture treated by arthroscopic assisted reduction and osteosynthesis.

The severely displaced scaphoid fracture, when combined with a scapholunate dissociation, is a very rare condition that commonly is treated by open surgery. The authors present a case treated by arthroscopic-assisted closed reduction, using percutaneous pinning for the scapholunate dissociation and a Herbert/Whipple screw insertion for the scaphoid fracture. The patient was able to return to work four months after surgery. At twenty-seven months after surgery, both the patient's grip power and range of motion in the wrist were acceptable. The authors recommend this procedure as a minimally invasive operation.

Adult↗