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Biomedical subjects

C J Wang

Publications and source records attributed to C J Wang.

At least 91 records · Page 5Linked to original sources
PubMed2000

Two-stage operation for treatment of a large dissecting popliteal cyst after failed total knee arthroplasty.

A symptomatic popliteal cyst after total knee arthroplasty (TKA) is rare, occurring most frequently as a result of intra-articular knee pathology. We present a case of a large dissecting popliteal cyst 7 years after TKA with symptoms of severe calf pain and functional disability. The symptomatic cyst was excised completely in a first-stage operation, and the severely worn TKA was corrected by a second-stage surgical procedure. The patient in this report was pain free and had satisfactory range of knee motion 5 years after the index revision TKA, without recurrence of effusion or popliteal cyst formation.

Aged↗
PubMed2000

Antibiotic-impregnated autogenic cancellous bone grafting is an effective and safe method for the management of small infected tibial defects: a comparison study.

OBJECTIVE: Bone grafting plays an important role in reconstructing infected tibial nonunions. The effects of antibiotic-impregnated bone grafting in infection elimination and bone incorporation was reported in this retrospective study. METHODS: Ninety-six patients treated for infected tibial nonunions were evaluated. These patients were managed with local antibiotic bead therapy and staged antibiotic-impregnated autogenous cancellous bone graft or pure autogenous cancellous bone graft. Patients were randomized to antibiotic-impregnated bone grafting or bone grafting-only groups on the basis of whether the admission date was odd or even. Patients were divided into two groups (antibiotic-impregnated bone grafting group and pure cancellous bone grafting group), according to the procedure used in preparing the bone grafts. The antibiotic-impregnated bone grafting group included 37 men and 9 women whose average age was 36 years (range, 17 to 72 years). The average follow-up period was 4.8 years. By using the Cierny-Mader staging classification of chronic osteomyelitis, 32 of 46 patients (70%) were stage 4A, and 14 of 36 patients (30%) were stage 4B. The pure cancellous bone grafting group included 39 men and 11 women whose average age was 37 years (range, 18 to 72 years). The average follow-up period was 4.5 years (range, 4 to 6 years). Thirty-nine of 50 patients (78%) were stage 4A, and 11 of 50 patients (22%) were stage 4B. The bone defects in both groups ranged from 2 to 4 cm. RESULTS: Wound healing and bony union were achieved in the antibiotic-impregnated bone grafting group. Only two patients had recurrent infections. The infection arrest rate was 95.6%. However, 9 of 50 patients in the pure cancellous bone grafting group had recurrent infections. The infection arrest rate was 82%. The antibiotic-impregnated bone grafting group had significantly superior results (95.6% vs. 82% chi2 test, p < 0.05) in infection elimination than the pure cancellous bone grafting group. CONCLUSION: After 4 to 6 years of follow-up, our results suggest that the use of impregnating antibiotics have no adverse effects on autogenic cancellous bone graft incorporation and could help to eliminate infection effectively.

Adolescent↗
PubMed2000

Effect of N-(biphenylyl-methyl)imidazole, a type 1 angiotensin II receptor inhibitor, on the contractile function of the rat corpus cavernosum.

The effect of N-(biphenylyl-methyl)imidazole, losartan potassium, a newly developed antihypertensive type 1 angiotensin II receptor antagonist on the rat erectile function, was studied. Sexually active 9-week-old male spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats were given losartan 60 mg/kg intraperitoneal injections. Mean blood pressure (MBP) dropped significantly in both SHR and WKY rats (for SHR: from 140 +/- 8 to 114 +/- 5 mm Hg, p < 0.05, n = 8; for WKY: from 113 +/- 7 to 79 +/- 9 mm Hg, p < 0.05, n = 8). On the contrary, the intracavernous pressure (ICP) of SHR and WKY rats did not differ significantly from that of the corresponding controls receiving saline injections (p > 0.05, n = 8 for each group). For the chronic study, the rats were fed with losartan 30 mg/kg/day for 30 days. MBP decreased significantly in SHR but not in WKY rats (for SHR: from 137 +/- 7 to 113 +/- 5 mm Hg, p < 0.05, n = 8; for WKY: from 110 +/- 6 to 107 +/- 5 mm Hg, p > 0.05, n = 8). The ICP of the losartan-treated rats was not significantly different from that of control rats (p > 0.05, n = 8 for each group). In contrast, WKY rats receiving guanethidine 1 mg/kg/day for 30 days showed significantly decreased ICP. Angiotensin II (10(-9)-10(-5) M) and losartan (10(-9)- 10(-5) M) did not induce significant contractile responses of the cavernosal strip when tested in vitro. On the other hand, methoxamine 10(-4) M induced good contractile responses. In conclusion, the present study demonstrated that angiotensin II did not cause significant change in the contractile status of rat corpus cavernosum. Correspondingly, the type 1 angiotensin II inhibitor effectively lowered blood pressure but did not affect cavernosal contractile function, thus is useful clinically in the treatment of hypertensive disorders without significant detrimental effects on male sexual function.

Angiotensin Receptor Antagonists↗
PubMed2000

Improved PCR-based subtractive hybridization strategy for cloning differentially expressed genes.

An improved PCR-based subtractive hybridization strategy was used to clone apoptosis-related genes induced by all-trans retinoic acid (ATRA) from human promyelocytic leukemia cell line HL-60 cells. The protocol used the cap-finder method, long-distance PCR, streptavidin magnetic bead-mediated subtraction and spin column chromatography. Twenty-seven clones related to apoptosis were identified by reverse dot blot assay. Seventeen were known genes, of which seven have been reported to be apoptosis related. The remaining 10 were unknown genes, five of which were sequenced and named apr-1 to apr-5. apr-1, apr-2, apr-3 and TNF were reidentified by reverse dot blot, and it is suggested that they might be related to apoptosis. The results suggest that this strategy might be efficient for large-scale cloning of differentially expressed genes in target cells.

Apoptosis↗
PubMed2000

Laparoscopic extraperitoneal sacrospinous suspension for vaginal vault prolapse.

BACKGROUND: A new laparoscopic sacrospinous suspension procedure is described for the correction of vaginal vault prolapse using an extraperitoneal approach. This is the first report in the literature of the extraperitoneal approach. METHODS: We reviewed 12 women who had been treated in our hospital using this technique because of vaginal vault prolapse. These women had undergone hysterectomies (10 abdominal; 2 vaginal) between 5 and 22 years previously (mean, 12 years). After pre-laparoscopic preparation, a 10-mm trocar with a 10-mm zero-degree telescope was placed into the Retzius space. Using a direct air-distended method with a 20 mmHg insufflation pressure, Retzius and para-rectal spaces were created. The sacrospinous ligament could be easily identified and confirmed. A permanent suture was then inserted from the sacrospinous ligament to the vaginal vault to ensure that there was no space in between. RESULTS: This procedure was followed for all 12 patients. There were no major complications during surgery. Eleven women had no recurrence of vaginal vault prolapse during a follow-up period of 1 to 3 years (mean, 2.2 years). One patient developed recurrent vaginal vault prolapse; however, she subsequently underwent a successful colposacropexy by laparoscopy 23 months after the initial surgery. CONCLUSION: We modified the traditional sacrospinous fixation laparoscopically, following principles to restore the correct anatomic position of the vault. Laparoscopic extraperitoneal sacrospinous suspension can eliminate the procedure of opening and closing the peritoneum and avoid interference with the intestine during surgery. It can be used as an alternative to traditional genital suspension surgeries.

Aged↗
PubMed2000

Nasopharyngeal carcinoma with leptomeningeal dissemination: case report.

Nasopharyngeal carcinoma (NPC) is a highly prevalent malignancy in southeast China, Hong Kong, and Taiwan. Spread of this tumor is known to occur via three main routes, i.e., local invasion of adjacent structures, regional metastasis to neck nodes, and hematogenous metastasis to distant organs. In this report, we describe a rare case of NPC disseminated via the leptomeninges, so called meningeal carcinomatosis (MC). The patient was a 62 year-old man who presented with multiple cranial nerve palsies and a headache, and was diagnosed with NPC in August 1988. The primary tumor regressed completely after induction chemotherapy and radiation therapy. Computerized tomography (CT) 17 months after radiation therapy showed multiple enhanced nodules scattered along the temporal meninges. The nodules increased in number and size in the subsequent CT scan 4 months later. The patient declined further invasive procedures and oncologic treatments, and he expired at home 9 months after the development of MC. It is speculated that perineural invasion and access to the subarachnoid space was the major cause of MC in this case. The case, although rare, possibly highlights a rare route of tumor dissemination in NPC.

Carcinoma, Squamous Cell↗
PubMed2000

Cartilage repair by free periosteal grafts in the knees of pigs: a histologic study.

BACKGROUND AND PURPOSE: Periosteal grafts may result in cartilage formation and, therefore, have the potential to repair cartilage defects. We evaluated the histologic results of free periosteal grafts for the repair of full-thickness cartilage defects in pigs. METHODS: A free autogenous periosteal flap from the proximal tibia was grafted to a size-matched, full-thickness articular defect on the lateral femoral condyle of the knees of 12 pigs. The same defect on the medial femoral condyle was used as a control lesion. Biopsies were performed at 4, 8, and 12 weeks after grafting. RESULTS: The control lesions showed dense fibrous tissue with no evidence of cartilage-like tissues. The predominant tissues after grafting were mixtures of fibrous tissue, fibrocartilage, mesenchyme tissue, and occasional bone islands, but no cartilage tissue was identified. The tissue distribution did not change in the same knee from the week 4 to the week 8 biopsy; nonetheless, there were interindividual variations in tissue distribution. CONCLUSIONS: The results of this study do not support the use of free periosteal transplantation for full-thickness cartilage defects of the knee.

Animals↗
PubMed2000

Treatment of painful heels using extracorporeal shock wave.

BACKGROUND AND PURPOSE: Shock wave therapy has been shown to improve many tendinopathies at the tendon-bone junction. The purpose of this study was to investigate the safety and effectiveness of extracorporeal shock wave therapy for the treatment of painful heels. METHODS: Sixty-six patients, including 45 women and 21 men with an average age of 47.70 years (range, 19-75 years), were included in the study. Each patient received 1,000 impulses of shock waves at a 14-kV generator voltage at the affected site under local anesthesia. Twelve patients received a second treatment, and two patients received a third treatment. RESULTS: Of 58 patients with 6 weeks' follow-up, five (9%) were complaint-free, 21 (37%) were significantly better, 27 (47%) were slightly better, and five (9%) were unchanged. Of 41 patients with 12 weeks' follow-up, 11 (27%) were complaint-free, 22 (54%) were significantly better, seven (17%) were slightly better, and one (2%) was unchanged. The results at 12 weeks were much better than those at 6 weeks. The effect of shock waves on painful heels continued between 6 and 12 weeks. Twelve patients who did not respond favorably to the first treatment showed significantly better results after a second treatment. Two patients who had a third treatment also achieved satisfactory results. There were no device-related problems or systemic or local complications. CONCLUSIONS: Extracorporeal shock wave therapy is a new modality that is safe and effective in the treatment of painful heel spurs.

Adolescent↗
PubMed2000

Elective neck irradiation for nasopharyngeal carcinoma.

BACKGROUND: This study was conducted to evaluate the effectiveness of elective neck irradiation (ENI) for nasopharyngeal carcinoma (NPC), and to analyze factors associated with ENI failure. METHODS: A radiation port covering the side of a neck without gross nodal metastasis was qualified for evaluation of the effectiveness of ENI. From 1988 through 1992, a total of 261 patients with N0 (130 cases), N1 (91 cases), and N3 (40 cases) NPCs were studied. All patients were irradiated with 60Co teletherapy or 10 MV x-ray to a total dose of 46.8 Gy/26 fractions, followed by a boost treatment to the primary site to a total dose of 64.8 to 75.6 Gy/36-42 fractions. All ENI ports received irradiation to a dose of 46.8 to 60.8 Gy. The duration of follow-up was 6 to 10 years, with a median of 8.1 years. Factors associated with to the risk of ENI failure were analyzed. RESULTS: (1) The overall 5-year actuarial local control rate and actuarial survival rate were 74% and 63%, respectively. (2) Among the 261 cases in which ENI treatment was used, the treatment failed in 12 cases, accounting for a crude ENI failure rate of 5%. The overall 5- and 10-year cumulative risk of ENI failure was 5% and 7%, respectively. (3) Time from the start of treatment to ENI failure ranged from 9 to 66 months, with a median of 17 months. (4) Of the 12 patients for whom EMI failed, 11 (92%) had recurrence in the upper neck, and one in the lower neck. (5) Existence of prior failure at the primary site was the only factor significantly correlated with the risk of ENI failure (p < 0.001). The 5-year cumulative risk of ENI failure for patients with local failure vs. those without was 16% vs. 1% (p < 0.0001). CONCLUSION: Moderate-dose ENI was highly effective in the control of subclinical disease in the neck for NPC. ENI failure was closely associated with prior failure at the primary site, implying that local primary tumor failure may lead to an increased potential for metastasis to the neck.

Adult↗
PubMed2000

Intracortical osteosarcoma: report of a case.

Intracortical osteosarcoma is the rarest anatomic variation of osteosarcoma. There have been only 12 cases reported in the English-language literature. We present a case of osteosarcoma in an 18-year-old Taiwanese man that originated within the cortex of the tibial diaphysis. The initial radiograph revealed a lytic mass confined to the cortex, mimicking a benign bone lesion. Histopathologic examination of the biopsy specimen showed an osteoblastic osteosarcoma mingled with some fibroblastic foci. He underwent en bloc resection, and a metallic prosthetic intercalary stem was used to replace the larger bone defect. Adjuvant chemotherapy was administered before and after the operation. He was free of disease during 40 months of follow-up. A review of all reported cases of intracortical osteosarcoma revealed that the initial method of treatment plays an important role in local recurrence and distant metastasis. Local excision and curettage leads to the worst results. The outcomes of more recently reported cases have improved because of early awareness of the possibility of malignancy and advances in chemotherapy. However, whether patients with intracortical osteosarcoma have a different prognosis from those with conventional osteosarcoma cannot be determined, because of the small number of intracortical osteosarcoma cases available for analysis.

Adolescent↗
PubMed2000

Deep vein thrombosis after total knee arthroplasty.

BACKGROUND AND PURPOSE: The incidence of deep vein thrombosis (DVT) after total knee arthroplasty (TKA) in the Asian population is probably higher than is commonly assumed by clinicians. The purpose of this study was to investigate the incidence of DVT after TKA in a southern Taiwanese population and to determine whether routine prophylaxis against DVT is indicated. MATERIALS AND METHODS: The incidence of DVT was investigated in 107 ascending venograms performed in 105 knees in 102 patients after TKA. Observations were made and interpreted by orthopedic radiologists blinded to the clinical condition of the patients. The correlation of DVT with the medical conditions, anesthesia type, and local physical findings were analyzed. RESULTS: The overall incidence of DVT after TKA was 63.6% (68/107); 95.6% (63/68) of cases involved the distal veins in the calf and only 4.4% (3/68) involved the proximal vein at the popliteal level. There was no higher incidence of thrombosis in the femoral and iliac veins, and no pulmonary embolism. Approximately 70% of patients with DVT were symptomatic and required treatment. There was no statistically significant correlation of DVT with medical condition, including diabetes mellitus, hypertension, body weight, varicosity, history of thromboembolic disorder and congestive heart failure, or the type of anesthesia or bone cement used. There was a positive correlation of DVT with local physical findings including calf girth enlargement, leg edema, and skin discoloration, and a negative correlation with findings including Homans' sign, cord induration, venous engorgement, and knee effusion. CONCLUSION: The incidence of DVT after TKA in this southern Taiwanese cohort was similar to that in Western populations, and higher than is commonly assumed by clinicians at this facility. However, the rate of proximal thrombosis and pulmonary embolism was much lower than in previous studies from Western populations. The majority of cases of DVT involved the veins in the calf; approximately 70% of patients were symptomatic and required treatment.

Aged↗
PubMed1999

Computed tomography findings of bony regeneration after radiotherapy for nasopharyngeal carcinoma with skull base destruction: implications for local control.

PURPOSE: To evaluate the response of bony destruction (BD) of the skull base following radiotherapy in nasopharyngeal carcinoma (NPC) and investigate the implications of bony regeneration (BR) on local control and its related factors. METHODS AND MATERIALS: Ninety patients with NPC with skull base destruction clearly demonstrated on computed tomography (CT) were reviewed. These patients have completed the prescribed treatment and received regular CT follow-up. A total of 338 sets of CT images of the head and neck were reviewed. The tumor response and the appearance of BR in the previous destructive part of the skull base were recorded and analyzed. The tumor response was divided into complete, partial, or no response. BR was defined as recalcification or sclerotic change with partial or complete healing in the previous osteolytic bony defect. Local failure was confirmed either by pathological or merely by imaging studies showing progression of tumor in consecutive radiological pictures. RESULTS: The distribution of specific sites of bony destruction (BD) in these patients included the sphenoid bone (68%), paracavernous sinus area (48%), petrous apex (47%), clivus (44%), pterygoid plates (20%), and others (7%). The CT showed 57 patients (63%) had BR. All were observed within 1 year after treatment. Sixty-two patients (69%) had complete tumor response after treatment. Analyzed by logistic regression method, tumor response after treatment was found to have a statistically significant correlation with BR (p = 0.0004). Most BR (55/57) was demonstrated in patients with complete tumor response. The 3-year actuarial local control rate was 54 % in these patients. The local control was quite different in the comparison of patients with BR versus those with persistent BD (77% vs. 21%, p < 0.0001). Multivariate analysis showed that patients with complete tumor response or with BR on imaging had statistically better local control than those without either of the two findings (p < 0.05). CONCLUSION: Appearance of BR at previous destructive skull base following radiotherapy for NPC patients could be clearly demonstrated on CT. Bony regeneration significantly correlated with treatment response and local control. Although the underlying significance of BR was unknown, to predict the outcome after treatment, the appearance of BR shown on CT may imply the complete eradication of tumor in this area.

Adolescent↗
PubMed1999

Postoperative radiotherapy in early stage carcinoma of the uterine cervix: treatment results and prognostic factors.

PURPOSE: The objective was to investigate the effect of pathologic parameters and other variables on treatment outcome for patients with International Federation of Gynecology and Obstetrics (FIGO) stage IB, IIA cervical carcinoma, as well as to assess the morbidities attributable to radical surgery combined with postoperative radiotherapy. MATERIALS AND METHODS: Between January 1980 and June 1994, 179 women with FIGO stage IB, IIA carcinoma of the uterine cervix were treated with radical hysterectomy and postoperative irradiation. The median follow-up of alive patients was 6.8 years. All patients received 44-60 Gy external irradiation. One hundred fifty-nine patients received 3-10 Gy intracavitary brachytherapy. The data were analyzed for overall survival, disease-free survival, pelvic control, and treatment-related complications. RESULTS: The 5-year overall survival rate, disease-free survival rate, and pelvic control rate for the 179 patients were 72, 74, and 90%, respectively. The 5-year overall survival rate was 81% for patients without pelvic lymphadenopathy and 53% for those with pelvic lymphadenopathy (P = 0.0000). Other independent prognostic factors for overall survival included tumor differentiation and the interval between operation and initiation of radiotherapy. For the endpoint of disease-free survival, pelvic lymph node status, tumor differentiation, the duration of interruption of radiotherapy, and the interval between operation and radiotherapy were of independent prognostic significance. As pelvic control was concerned, the 5-year pelvic control rate was 90% and only the duration of interruption of radiotherapy was noted as an independent predictor of pelvic control. Distant metastases were noted in 43 patients (24%); the most common sites were lung (10%), liver (6%), and bone (6%). The overall 5-year intestinal and urinary complication-free rate was 66 and 82%, respectively. The overall incidence of grade 3 or above late rectal and urinary sequelae was 10%. For patients sustaining leg lymphedema after radiotherapy, there was higher incidence of severe leg cellulitis which warranted antibiotics treatment. CONCLUSION: These prognostic factors should be considered in patient counseling and treatment planning. Based on these factors, a more aggressive treatment to improve survival in these subsets of high-risk patients might be justified. New therapeutic regimens and modalities aimed to overcome treatment failure should be investigated.

Adenocarcinoma↗
PubMed1999

Recalcitrant bicipital radial bursitis.

Three of 12 nonrheumatoid patients with bicipital radial bursitis had recurrent and recalcitrant symptoms and underwent operative treatment. Preoperative computed tomogram showed an anterior distended synovial cyst at the level of the radial tubercle. Magnetic resonance imaging provided a superb demonstration of a bicipital radial bursa which communicated with the elbow joint below the annular ligament. Surgical exploration revealed a valvular mechanism between the distended bursa and the joint cavity. Excision of the distended bursa and closing the capsular defect lead to excellent results. An antecubital cyst resulting from an acute or chronic tear of the anterior capsule at the sacciform recess may communicate with the bicipital radial bursa and become the cause of recurrent and recalcitrant symptoms.

Adult↗
PubMed1999

Recurrent cervical carcinoma after primary radical surgery.

OBJECTIVE: This study was undertaken to investigate prognostic factors in patients with recurrent cervical carcinoma who had undergone a primary radical hysterectomy and pelvic lymphadenectomy. STUDY DESIGN: A retrospective analysis of 177 patients with recurrent cervical carcinoma after radical hysterectomy and pelvic lymphadenectomy for stage IB to II disease at a single institution was performed to evaluate clinicopathologic parameters, time to recurrence, pattern of failure, use of salvage therapy, and survival after recurrence. RESULTS: The 5-year survival rate from diagnosis of recurrence in this series was 10.1%. Survival after recurrence was significantly decreased in patients with pelvic lymph node metastasis at primary surgery and adenocarcinoma-adenosquamous carcinoma histologic type. Patients with extravaginal recurrences receiving chemoradiation for recurrent cervical carcinoma had significantly better outcomes than those receiving radiation alone. Six patients who had a distant relapse at a sole site had prolonged survival after salvage therapy, which was accomplished by chemoradiation, surgery plus radiotherapy, or surgery alone. CONCLUSIONS: Our results demonstrate the benefit of adding chemotherapy to radiotherapy in the treatment of recurrent cervical carcinoma. Salvage multimodality treatment should be offered to selected patients who have isolated relapse at a single distant site.

Adenocarcinoma↗
PubMed1999

Endoscopic management of injured bowel using the automatic stapler.

Bowel injury is a rare but potentially fatal complication of laparoscopy if it is unrecognized at the time of the procedure. Once a bowel injury is identified, it must be repaired by either laparoscopy or laparotomy. The Endo GIA 30 stapler is effective for achieving large-vessel hemostasis and facilitating laparoscopic procedures, and is reported safe for laparoscopic hysterectomy. It was used successfully in two women to repair extensive bowel injuries.

Adult↗
PubMed1999

Postoperative radiotherapy for supratentorial malignant gliomas.

From January 1988 to December 1996, sixty-five patients with histologically confirmed supratentorial malignant gliomas were treated with postoperative radiation therapy in our department. They were subjected to this analysis according to different clinical and pathologic parameters. The overall 1-year, 2-year survival rate was 57% and 23%, respectively. With univariate analysis, age, postoperative Karnofsky performance status, duration of symptoms, multiplicity of lesions and the extent of surgery were identified as significant prognostic factors. With multivariate analysis, postoperative Karnofsky performance status and the extent of surgery continued to show independent prognostic significance on overall survival.

Combined Modality Therapy↗