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Biomedical subjects

C Y Yen

Publications and source records attributed to C Y Yen.

At least 19 recordsLinked to original sources
PubMed2001

Signal transduction pathways and apoptosis in bacteria infected chondrocytes.

The mechanism underlying chronic destructive arthropathy after pyogenic arthritis is not clear. This study evaluated the role of apoptosis in Staphylococcus aureus infected human articular chondrocytes and investigated the signal transduction pathways activated by bacterial infection. Chondrocytes cultured in monolayer were challenged with bacteria for 6 h and were analyzed after incubation for 2, 18, and 24 h. Chondrocytes showed morphologic and biochemical evidences of apoptosis after infection and the following incubation period. Although treatment with extensive washing and vancomycin could ameliorate the amount of apoptosis from 31% to 15% at 2 h, from 48% to 23% at 18 h, and from 58% to 33% at 24 h, the infected samples with treatment still had higher amount of apoptosis than the un-infected controls (ANOVA P < 0.001). Accompanying with the increasing amount of apoptosis, the caspase activity was upregulated in bacteria infected samples and remained high in samples with treatment (ANOVA P < 0.05). Signal transduction pathways activated by bacterial infection were assessed by co-transfection technique. After infection, the c-Jun N-terminal kinase, extracellular signal-regulated kinase, and cyclic AMP-dependent protein kinase activities were elevated by 7.6-, 7.3-, and 3.2-fold, respectively, compared to the uninfected controls. The data support the hypothesis that human chondrocytes will undergo apoptosis after infection by a single organism. Apoptosis and activated intracellular kinase activities may be related to the pathogenesis of post-infectious destructive arthropathy.

Apoptosis↗
PubMed2001

Reconstruction of posttraumatic long bone defect with free vascularized bone graft: good outcome in 48 patients with 6 years' follow-up.

We analyzed our clinical results in 48 patients (40 men) treated during 1990-1993 with free vascularized bone-graft reconstruction for bone defects, the follow-up being an average 6 (5-8) years. The bone defects were located in the femur (10), tibia (32), humerus (2), and forearm (4). We performed 41 fibula transfers, 4 iliac transfers, and 3 rib transfers in these patients. 3 patients required early revision surgery due to venous thrombosis. The average time needed for radiographic bone union was 4.2 months. Bone transfers to the lower extremity showed significantly more hypertrophy than those in the upper extremity. The functional outcome was good in 43 patients.

Adolescent↗
PubMed2001

Treatment of distal clavicle fracture using Kirschner wires and tension-band wires.

BACKGROUND: Nonunion frequently follows distal clavicle fracture. Traditional pinning methods using the through acromioclavicular articulation may result in osteoarthritic changes or ankylosis. This study introduces a direct pinning technique in which the acromioclavicular joint is spared. METHODS: Twelve patients with displaced distal clavicle fractures received open reduction and fixation with Kirschner wires (K-wires) and tension-band wires, from May 1996 to March 1997. The indication for surgery was type IIa fracture or fracture with displacement. Unrestricted passive and active range of motion was performed as soon as possible after the operation. Stretching and exertional exercises were permitted after radiographs showed an osseous union and after the implants were removed. RESULTS: Eleven patients achieved osseous union with painless full motion. Union time ranged from 3 to 6 months. One patient suffered from more comminuted fracture because of a fall 2 months after operation. This patient received a revision surgery with distal clavicle resection and coracoclavicle reconstruction. Symptomless ossification around the coracoclavicle ligament was noted on radiographs in one patient. The ossification did not progress after the 9-month follow-up. CONCLUSION: Edwards reported a rate of 45% delayed union and 30% nonunion in type II fractures. Several techniques had been described in the relevant literature. In our practice, fixation with Kirschner wires and tension-band wires has been successful in the treatment for displaced distal clavicle fracture.

Accidental Falls↗
PubMed2000

Vascularized island pedicle iliac bone grafting for avascular necrosis of the femoral head.

BACKGROUND: Nontraumatic avascular necrosis of the femoral head is a common disorder causing disability of the hip joint. The methods for optimally treating this disease in active young patients are still controversial. In this study we investigated the surgical outcome of vascularized pedicle iliac bone grafting for treating nontraumatic avascular necrosis of the femoral head. METHODS: Between 1994 and 1999, we treated 100 cases of avascular necrosis of the femoral head with vascularized pedicle iliac bone grafting. Thirty-nine hips in 33 patients were followed-up longer than 24 months. These patients included 30 men and 3 women, with an average age of 40 years. Steinberg's classification and Ohzono's types were used to categorize the diseased hips. The clinical results were evaluated using Charnley's modification of Merle d'Aubigne and Postel's numeric classification. RESULTS: Of the 33 patients, 82% were satisfied with their decision to have vascularized pedicle iliac bone grafting for avascular necrosis of the femoral head. No serious complications arose during this study. The average operation time for vascularized pedicle iliac bone grafting was 3.5 hours for one team. The rate of conversion to replacement arthroplasty was 10.3% (4 of 39 patients). CONCLUSION: Vascularized pedicle iliac bone grafting is a useful alternative treatment option for patients with avascular necrosis of the femoral head.

Adult↗
PubMed1998

Chronic refractory tibia osteomyelitis treated with adjuvent hyperbaric oxygen: a preliminary report.

BACKGROUND: Refractory osteomyelitis is a serious disease that fails to respond to aggressive medical and surgical treatment. A plethora of alternative therapies have evolved. Hyperbaric oxygen has been proven to enhance bone and soft tissue healing in many in vitro and in vivo studies. This article presents the preliminary results of adjunctive hyperbaric oxygen therapy in patients with refractory osteomyelitis. MATERIALS AND METHODS: Fifteen patients who were diagnosed with refractory tibia osteomyelitis were treated prospectively with adjunctive hyperbaric oxygen therapy, aggressive surgical debridement, and parenteral antibiotic treatment. The effectiveness was evaluated with an average follow-up of 17.2 months. RESULTS: The hyperbaric oxygen therapy averaged 26 daily sessions. Successful treatment was achieved in 13 patients (86%). The mean length of treatment was 45 days. The preliminary results are comparable with other series. CONCLUSION: Hyperbaric oxygen is effective as an adjunct to aggressive medical and surgical management in refractory osteomyelitis. A precise clinical staging system for patient selection and treatment organization is imperative to successful outcome.

Adolescent↗
PubMed1998

Inferior dislocation of the glenohumeral joint combined with the compartment syndrome of the upper arm: case report.

Compartment syndromes occurring in the forearm and leg are not infrequent. However, reports of compartment syndrome of the upper arm are conspicuously rare. Inferior dislocation of the shoulder combined with compartment syndrome has rarely been reported in the literature. We report our experience with a patient with inferior dislocation of the glenohumeral joint combined with compartment syndrome of the upper arm. A 29-year-old man had traumatic inferior dislocation of the glenohumeral joint combined with severe swelling of the shoulder and upper arm. After close reduction, the shoulder and upper arm were still tensely swollen. Compartment pressure of the upper arm was measured using a digital manometer (Quick Pressure Monitor 295-1, Stryker) and remained very high, thus, fasciotomy was performed. After debridement and skin graft, the arm healed without sequelae. When a patient has a fracture dislocation of the shoulder joint associated with a swollen arm, compartment syndrome of the upper arm should be included as a differential diagnosis. Detecting the compartment pressure can confirm the diagnosis of compartment syndrome objectively.

Adult↗
PubMed1997

Purification and partial amino acid sequence of a novel protein of the reticulocalbin family.

Binding proteins in neuronal membranes for a phospholipase A2 with presynaptic neurotoxicity have been purified. Three polypeptides of 87, 65, and 50 K Da were obtained from the synaptic membrane fraction of guinea pig brain utilizing an immobilized crotoxin (a phospholipase A2) column. For large scale purification, porcine brain was used instead, and two polypeptides of 50 and 18 K Da were found. The 65 and 18 K polypeptides may represent hitherto unidentified components of the crotoxin-binding proteins. Partial N-terminal amino acid sequence and a partial sequence for an internal peptide fragment have been determined for the 50 K polypeptide. Search of protein data bank reveals that this polypeptide or protein is a novel member of the reticulocalbin family of calcium-binding proteins.

Amino Acid Sequence↗
PubMed1997

Hyperbaric oxygen in the treatment of diabetic foot infection.

BACKGROUND: Although hyperbaric oxygen therapy to treat diabetic foot lesions has been approved for insurance reimbursement in Taiwan, its clinical application has not yet been well accepted. This study evaluated multiple healing predictive factors in patients with diabetic foot infections to determine the usefulness of adjunctive hyperbaric oxygen in the treatment of such patients. METHODS: From March 1995 to May 1996, we treated 31 diabetic patients presenting with infected foot lesions with a regimen of adequate metabolic control, frequent wound debridement and hyperbaric oxygen therapy. Age, gender, leukocyte count, total lymphocyte count, hemoglobin, erythrocyte sedimentation rate (ESR), c-reactive protein (CRP), glycosylated hemoglobin Alc (HbAlc), albumin, ankle-brachial index, types of bacterial cultures and number of debridements were compared between successful and failed treatments. Independent t-test and Fisher's exact test were used to identify the prognostic factors associated with outcome of treatment. RESULTS: The mean age of the patients was 63.0 +/- 9.7 years (range 43 to 81). The mean number of hyperbaric oxygen therapies was 35.3 +/- 21.8 treatments (range 5 to 83). Of the 31 patients, 6 received below knee amputation, and 25 had their foot preserved or achieved a lower level of amputation. Elevated leukocyte count and low ankle-brachial index were significantly related to poor outcome. CONCLUSIONS: In the treatment of diabetic foot infection, adjunctive hyperbaric oxygen therapy seems to be a useful tool to enhance wound healing provided that there are preserved circulation and controlled infection.

Adult↗
PubMed1996

In vivo immunosuppressive effect and the decreasing expression of MHC class II antigens by purine nucleoside phosphorylase inhibitor 8-amino-9-benzylguanine in recipient tissues of canine renal allograft rejection.

8-Amino-9-benzylguanine (8-ABG), a potent purine nucleoside phosphorylase inhibitor, was administered to dogs for 10 days following single renal transplantation. A significant prolongation of graft survival was observed in the groups treated with 100 and 150 mg kg/day of 8-ABG per os compared with the control group that was not treated with any immunosuppressant. Expression of major histocompatibility complex (MHC) class II antigens (Ag) was investigated in the normal kidney(s) and renal allografts of mongrel dogs after single renal transplantation. The 8-ABG was administered to the normal and renal allografted dogs and no detectable MHC class II Ag in the normal kidneys was found. During acute rejection, the MHC class II Ag was expressed on the renal tubular epithelium and glomerular vascular endothelium in graft kidneys. The intensity of the MHC class II Ag expression was correlated to the severity of rejection. This abnormal expression of MHC class II Ag on allograft kidney was suppressed by 8-ABG treatment. Our results suggest that MHC class II Ag expression can be induced on the renal allografts during acute rejection. This abnormal expression of MHC class II Ag may serve as a specific index for diagnosis of kidney allograft rejection. That 8-ABG can suppress abnormal expression of MHC class Ag on allografted kidney and prolong graft survival indicates that 8-ABG may provide an alternative approach for the development of a potential new immunosuppressant.

Animals↗
PubMed1990

Simultaneous renal cell carcinoma and angiomyolipoma in a kidney--a case report and literature review.

Renal cell carcinoma (RCC) is the most common tumor of the kidney. Angiomyolipoma is frequently present in the patient who has the stigma of tuberous sclerosis. We reported a case of a 39-year-old female, without the stigma of tuberous sclerosis, who was admitted on account of a firm, huge, fixed and palpable mass over the left flank region for one week. After radical nephrectomy, the pathological report was renal cell carcinoma, granular cell type, associated with angiomyolipoma. The literature concerning this unusual case is reviewed.

Adult↗
PubMed1989

[Histochemical studies on the healing after partial excision of tongue. Regeneration and restoration of the muscular tissue].

After a partial excision of tongue of rats, regeneration and restoration of the muscular tissue in the vicinity of the exact region and the anterior regions treated, and the non-treated region, were particularly assessed from 3 days to 20 weeks after treatment and compared with those of controls histologically, enzyme-histochemically and immunohistochemically. The results were obtained as follows: 1. Histopathological findings 1) Atrophy or disappearance of the residual muscular fibers adjacent to the exact region was observed after treatment and an arrangement of the muscular fasciculi became more irregular as the fibers were gradually restored from 4 weeks, although regenerative fibers with a slight irregularity were seen from 3 days up to even 20 weeks after treatment. 2) Atrophy and the sparse arrangement of the muscular fibers of the anterior region were observed at the initial stage. However, they gradually recovered from 4 weeks after treatment and became similar to those of controls 8 weeks after treatment. 3) Atrophy of the non-treated region was occurred in muscular fibers 3 days after treatment and the muscular fasciculi with the irregular arrangement was dispersely observed, although the arrangement was gradually recovered from 2 weeks and became similar to that of controls from 4 weeks after treatment. 2. Enzyme histochemical findings 1) SDH (1) The activity in the residual muscular fibers adjacent to the exact region was weak at the initial stage, although the activity was restored to the control level from 4 weeks after treatment. The regenerated muscular fibers began to show less activity from 1 week, although the activity became similar to that of controls from 8 weeks after treatment. (2) The activity in the muscular fiber anterior to the region was less at the initial stage, but began to be restored from 2 weeks and recovered to the control level from 4 weeks after treatment. (3) The activity in the muscular fibers at the non-treated region became less 3 days and 1 week after treatment, but similar to that of controls from 2 weeks after treatment. 2) LDH: It showed similar changes to SDH. 3) ACP: (1) The weak activity was seen in the residual muscle fibers adjacent to the exact region, and the relatively strong activity was observed in a few muscular fibers 3 days and 1 week after treatment. (2) In the anterior region, a weak activity was seen at the initial stage, but not 2 weeks after treatment.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗