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Biomedical subjects

J Y Ko

Publications and source records attributed to J Y Ko.

At least 19 recordsLinked to original sources
PubMed2001

Induction chemotherapy with mitomycin, epirubicin, cisplatin, fluorouracil, and leucovorin followed by radiotherapy in the treatment of locoregionally advanced nasopharyngeal carcinoma.

PURPOSE: Survival in advanced nasopharyngeal carcinoma (NPC) is compromised by distant metastasis. Because mitomycin is active against hypoxic and G0 cells, which may help to eradicate micrometastasis, we investigated the effect of mitomycin-containing cisplatin-based induction chemotherapy. PATIENTS AND METHODS: Recruited for this study were American Joint Committee on Cancer (AJCC) 1992 staging system stage IV NPC patients with the following adverse features: obvious intracranial invasion, supraclavicular or bilateral neck lymph node metastasis, large neck node (> 6 cm), or elevated serum lactate dehydrogenase (LDH) level. Patients were given three cycles of chemotherapy before radiotherapy. The chemotherapy comprised a 3-week cycle of mitomycin, epirubicin, and cisplatin on day 1 and fluorouracil and leucovorin on day 8 (MEPFL). RESULTS: From January 1994 to December 1997, 111 patients were recruited. The median follow-up period was 43 months. The actuarial 5-year overall survival rate was 70% (95% confidence interval [CI], 60% to 80%; n = 111). For patients having completed radiotherapy (n = 100), the 5-year locoregional control rate was 70% (95% CI, 55% to 84%) and the distant metastasis-free rate was 81% (95% CI, 73% to 89%). The 5-year distant metastasis-free rate of N3a and N3b disease of AJCC 1997 staging system were 79% (95% CI, 62% to 95%) and 74% (95% CI, 60% to 89%), respectively. By Cox multivariate analysis, high pretreatment serum LDH level (P = .04) and neck nodal enlargement before radiotherapy (P = .001) were adverse prognostic factors of survival. CONCLUSION: The good 5-year survival of N3 disease supports the effectiveness of induction MEPFL in the primary treatment of advanced NPC. Further investigation to incorporate concurrent chemoradiotherapy is warranted.

Adolescent↗
PubMed2001

Information circulation in a two-mode solid-state laser with optical feedback.

A two-mode solid-state laser subjected to a delayed optical feedback is studied. Simultaneous random switchings between stable and chaotic antiphase spiking oscillations featuring the establishment of causal (drive response) relationships among modes have been demonstrated by a proposed information circulation analysis of an experimental time series. The observed phenomenon has been well reproduced by numerical simulations of two-mode laser equations with uncorrelated modal phase fluctuations.

Journal Article↗
PubMed2001

Quantum-noise-induced order in lasers placed in chaotic oscillation by frequency-shifted feedback.

A kind of chaotic oscillations featuring random switching between sustained relaxation oscillations (RO) and spiking oscillations (SO) has been demonstrated in lasers with frequency-shifted feedback. The presence of stochastic frequency locking between two periodicities of RO and SO motions and selective quantum-noise-induced ordering of chaotic spiking oscillations is demonstrated theoretically and experimentally.

Journal Article↗
PubMed2001

Guidewire-induced coronary artery perforation treated with transcatheter injection of polyvinyl alcohol form.

We describe a first case of successful transcatheter management of guidewire-induced distal coronary artery perforation and impending cardiac tamponade, which developed during percutaneous coronary angioplasty, with transcatheter injection of polyvinyl alcohol form. This method may be an effective alternative in the management of distal coronary artery perforation requiring surgical repair.

Angioplasty, Balloon, Coronary↗
PubMed2001

Acute septic arthritis of the hip in children.

Thirty-three cases of acute septic arthritis of the hip in children were treated at our hospital from 1986 to 1997. The average follow-up period was 6 years (range 2-11 years). In 17 cases the right hip was affected, and in 16 the left hip. The average duration of symptoms was 5 days (range 1-14 days). Microorganisms were isolated from the blood, joint aspirate, or surgical specimens in 25 cases (76%). Staphylococcus aureus was the most common bacteria found (44%). Those patients with S. aureus infection were older than 1 year of age. There was no significant difference in the final outcome between the younger and the older age groups. Twenty-six out of 33 patients (89%) had a satisfactory outcome. Satisfactory results can also be expected with arthrocentesis and medical treatment if the diagnosis is made early, and antibiotic treatment affords a good clinical response. Four out of 7 cases with an unsatisfactory result were associated with osteomyelitis of the proximal femur. The two most important factors associated with poor results included a delay of definite treatment lasting longer than 5 days and the presence of osteomyelitis of the proximal femur.

Acute Disease↗
PubMed2001

Topiramate treatment of bipolar spectrum disorders: a retrospective chart review.

The objective of this paper was to determine if topiramate is effective as treatment for bipolar spectrum disorders in a naturalistic setting. All charts of outpatients treated with topiramate (n = 76) were reviewed, and clinical response was assessed retrospectively using the Clinical Global Impressions Scale for Improvement. Mild improvement was seen in 47% (n = 36) and moderate-to-marked improvement in 13% (n = 10). Responders received a higher mean dose (180 mg/day) than did nonresponders (83.2 mg/day, p = 0.002). Topiramate dose was also higher in those who lost weight (138.3 mg/day) than in those who did not (70 mg/day, p = 0.007). Weight loss was experienced by 50% of the sample, with a mean loss of 14.2 lbs. Side effects were reported by 82% (n = 62) of the population, including cognitive effects, sedation, parasthesias, nausea, insomnia, headache, and dizziness. Adverse effects led 36% (n = 27) of the total sample to discontinue treatment with topiramate. Topiramate led to significant weight loss in about half of this bipolar population, while also improving mood symptoms at least mildly in most patients. Topiramate response and weight loss were both dose-related, with efficacy, in particular, associated with higher doses (mean = 180 mg/day) than frequently used in current clinical practice.

Adult↗
PubMed2001

Diabetes and the associated incidence of subclinical atherosclerosis and coronary artery disease: Implications for management.

BACKGROUND: We sought to examine the prevalence, sensitivity, and specificity of coronary calcium (CC), a marker of atherosclerosis, in a population of symptomatic and asymptomatic diabetic persons. METHODS: We used electron beam tomography (EBT) to quantitate CC in 168 symptomatic (chest pain or anginal equivalent) persons with diabetes who underwent coronary angiography and then compared this with a cohort of 155 asymptomatic persons with diabetes. RESULTS: In the 168 symptomatic diabetic persons, 124 (74%) had obstructive coronary artery disease (CAD) by angiography. Receiver-operator characteristic curve analysis was used to maximize sensitivity and specificity for obstructive CAD (>50% stenosis), which established a CC score of 102 as optimal. With use of this cut point, EBT has a sensitivity of 77% and a specificity of 77% for detecting obstructive CAD. Of the 155 asymptomatic diabetic persons, 72% had CC and 48% had a CC score >102. The presumed prevalence of obstructive disease (on the basis of EBT scores and prevalence of CC) among asymptomatic diabetic persons is quite high (as high as symptomatic persons without diabetes). Analyzing the 323 diabetic patients demonstrated no significant age difference in CC scores between women and men. CONCLUSIONS: This study confirms that higher CC scores should be used in diabetic patients to improve the specificity of CC to determine obstructive disease. EBT can allow a noninvasive diagnosis of CAD before clinical presentation, allowing for more therapy for those in which CC is detected. These results suggest that asymptomatic diabetic persons have the same atherogenic burden of those patients with CAD without diabetes. The high prevalence of CC in asymptomatic persons with diabetes supports the need for aggressive management of diabetes and associated risk factors.

Adult↗
PubMed2001

Treatment of lateral epicondylitis of the elbow with shock waves.

In a prospective clinical study, the effectiveness of shock wave treatment for lateral epicondylitis in 56 elbows in 53 patients (27 men and 26 women) with an average age of 46 years was investigated. Three patients received treatment for both elbows. Each elbow was treated with 1,000 impulses of shock waves at 14 kV. A 100-point scoring system was used for evaluation including 40 points for pain, 30 points for function, 20 points for strength, and 10 points for elbow motion. The intensity of pain was measured using a visual analogue scale from 0 to 10. The overall results were 13.2% excellent, 44.7% good, 36.8% acceptable, and 5.3 unchanged in 35 patients with 12 weeks followup; 30.8% excellent, 42.3% good, and 26.9% acceptable in 25 patients with 24 weeks followup. Considerable improvement was observed from 6 weeks to 6 months after the treatment. None of the patients' symptoms became worse. The results of nine patients who also received a second treatment were good in three patients, acceptable in five patients, and unchanged in one patient. There was no device-related problems, systemic, or local complications. Shock wave therapy may offer a new and safer nonoperative treatment for patients with lateral epidoncylitis of the elbow.

Adult↗
PubMed2001

Treatment of calcifying tendinitis of the shoulder with shock wave therapy.

In a prospective clinical study, the effectiveness of shock wave treatment for calcifying tendinitis in 31 shoulders in 29 patients (14 women and 15 men) with an average age of 52 years was assessed. Each shoulder was treated with 1,000 impulses of shock waves at 14 kV. A 100-point Constant score system was used for evaluation. The overall results of 20 patients (21 shoulders) with 12 weeks followup were no complaints in 23.8%, significantly improved in 38.1%, some improvement in 14.3%, and unchanged in 23.8%. Considerable improvement was observed between 6 and 12 weeks. The results of seven patients with 24 weeks followup were no complaints in two patients, significantly improved in three, and unchanged in two patients. Radiographs showed complete elimination of the calcium deposits in six patients (28.6%), incomplete elimination in two patients (9.5%), and three patients (14.3%) had fragmentation of the calcium deposits. There was no recurrence of calcium deposits observed at 24 weeks. There was a correlation between the functional improvement and the elimination of calcium deposits. There were no device-related problems, systemic or local complications. Low-energy shock wave therapy may offer a new and safer additional nonoperative treatment for patients with calcifying tendinitis of the shoulder.

Adult↗
PubMed2001

Factors affecting the overall survival after salvage surgery in patients with recurrent nasopharyngeal carcinoma at the primary site: experience with 60 cases.

OBJECTIVE: To analyze the factors affecting overall survival after salvage surgery in patients with recurrent nasopharyngeal carcinoma at the primary site after a full course of radiotherapy. DESIGN: Retrospective analysis of 60 consecutive patients treated by surgical resection of the recurrent tumors, with a mean follow-up of 43.1 months (range, 19-96 months). SETTING: Academic tertiary referral center. RESULTS: The overall survival and locoregional relapse-free survival were 56% and 60% at 2 years, respectively, and 30% and 40% at 5 years. Twenty-nine (81%) of 36 patients died with uncontrolled local disease. The T stage of the recurrent tumors appeared to be an important prognostic factor. Age, sex, pathologic findings, and disease-free interval (time between previous radiotherapy and local recurrence) were not significant prognosis-affecting factors by the log-rank test. Multivariate analysis showed that patients with recurrent tumors of undifferentiated carcinoma, sarcoma, or small cell carcinoma had unfavorable prognoses. Uncontrolled local disease and the emergence of distant metastasis predicted grave results as well. Postoperative irradiation showed some benefit to patients, but the difference was not statistically significant. CONCLUSIONS: The T stage of the recurrence was the prominent prognosis-affecting factor in patients with recurrent nasopharyngeal carcinoma who received salvage surgery. Patients with local recurrence should be carefully selected for the salvage surgery. We recommend this surgery for patients with rT1, rT2, or limited rT3 lesions. The results of surgical resection in terms of local control and overall survival were slightly better than those of high-dose reirradiation, with fewer late complications.

Adult↗
PubMed2000

A probability prediction rule for malignant cervical lymphadenopathy using sonography.

BACKGROUND: Our purpose was to weigh various sonographic parameters as predicting malignant cervical lymphadenopathy and build a reliable prediction rule. METHODS: One hundred and eighty-nine cervical lymph node lesions from 125 consecutive patients were used for building the prediction model. Sonographic variables, including 15 morphologic features of B-mode, 5 vascular parameters of color Doppler mode, along with age and sex, were analyzed with multivariate logistic regression to evaluate the joint effect of a set of independent variables. A prediction rule for malignant lymphadenopathy was established, and prospective validation was assessed on a new group consisting of 100 lymph nodes from another 60 consecutive patients. RESULTS: The association of heterogeneous content, long transverse diameter, pathologic vascular pattern, high vascular density, and older age provided the most robust prediction value. Scoring scale was designed as 1x (age) + 2x (vascularity index) + 3x (short axis) + 4x (vascular pattern) + 4x (internal echo) according to the parameter estimates of multivariate logistic regression analysis. Cut-off value of score >==10 as malignancy resulted in 89.2% sensitivity and 85.2% specificity. Prospective validation also showed satisfactory results (sensitivity, 82.9%; specificity, 86.2%). CONCLUSIONS: By measuring only 4 sonographic parameters and age, this prediction rule could provide the physician a nonconfusing and reliable probability reference for managing cervical lymphadenopathy.

Adolescent↗
PubMed2000

Comparison of echocardiography and electron beam tomography in differentiating the etiology of heart failure.

BACKGROUND: The clinical manifestations in patients with ischemic cardiomyopathy are often indistinguishable from those in patients with primary dilated cardiomyopathy (DCM). Clinicians often base work-up of patients with heart failure on echocardiographic wall motion abnormalities; however misclassification can lead to unnecessary coronary angiography. HYPOTHESIS: The study was undertaken to evaluate the diagnostic ability of echocardiography and electron beam tomography (EBT) to differentiate between ischemic and nonischemic cardiomyopathy. METHODS: The accuracy of EBT and echocardiography was compared in 111 patients undergoing coronary angiography for the evaluation of heart failure. The presence of coronary calcification (CC) by EBT or segmental wall motion abnormalities by echocardiography was used as evidence of coronary-induced cardiomyopathy. RESULTS: Of 63 patients, 61 (97%) with obstructive coronary artery disease had CC by EBT. This sensitivity was significantly higher compared with 43 of 63 patients (68%) with segmental wall motion abnormalities by echocardiography (p < 0.001). Of 48 patients without obstructive coronary artery disease by angiography, 39 (81%) had no CC by EBT and 35 (73%) had no segmental wall motion (global hypokinesis) by echocardiography (p = 0.33). The overall accuracy of EBT to differentiate ischemic from nonischemic cardiomyopathy was 90%, significantly higher than echocardiography (70%, p < 0.001). CONCLUSION: This double-blind study demonstrates that the presence of CC by EBT is superior to that of segmental wall motion abnormalities by echocardiography to distinguish ischemic from nonischemic cardiomyopathy. This modality may prove to be an important diagnostic tool when the etiology of the cardiomyopathy is not clinically evident.

Adult↗
PubMed2000

Surgical treatment of muscular torticollis for patients above 6 years of age.

Eighteen patients with congenital muscular torticollis, aged 6-22 (average 11) years, underwent surgical releases of the contractive bands. There were 8 boys and 10 girls. Preoperative open mouth radiograph of the odontoid process in 16 patients showed asymmetry of articular facets of the axis and tilt of the odontoid process to the side of the torticollis. Sixteen patients received bipolar releases, the others received distal releases. After the operation, a neck collar was applied and an exercise program was started. At an average follow-up of 5 years and 7 months, there were excellent or good results in 10 patients. All of the patients except 2 showed improvement of the facial asymmetry and all except 1 had a satisfactory range of motion of the neck. One patient underwent a second operation due to recurrence. The follow-up radiographs showed improvement of the tilt of the odontoid process, but the asymmetry of the articular facets of the axis persisted. We suggest that bipolar release is the treatment of choice for congenital muscular torticollis in patients of more than 6 years of age. To determine the influence of a bipolar release on the functions of the cervical spine, longer follow-up intervals are needed.

Adolescent↗
PubMed2000

Usefulness of the C1 transverse process as a reference guide in the dissection of the upper lateral neck.

In this investigation we dissected 3 cadavers with the lateral cervical approach to assess the usefulness of the transverse process of the atlas (TPA) as a reference guide in the upper lateral neck. Our results indicate that all the important structures in this space can be identified systematically. Lateral to the TPA sits the posterior belly of the digastric muscle, the stylohyoid muscle, and the occipital artery. Anterior to the TPA, the styloid process can be exposed. The internal jugular vein and cranial nerves X, XI, and XII sit between the styloid process and the TPA. Superior to the TPA, tracing the carotid sheath upward, the carotid canal and jugular foramen can be reached. Anteroinferior to the jugular foramen, the hypoglossal nerve emerges from the cranial cavity through the hypoglossal canal. Posterior to the TPA, the suboccipital triangle can be recognized. Within the triangle, the vertebral artery and its accompanying venous complex can be identified.

Cervical Atlas↗
PubMed2000

Herpes zoster oticus treated with acyclovir and prednisolone: clinical manifestations and analysis of prognostic factors.

Herpes zoster oticus is a cranial polyneuropathy with facial nerve involvement as its main feature. The prognosis of the facial palsy is usually poor. Thirty patients with herpes zoster oticus suffering from facial palsy were admitted for parenteral acyclovir and oral prednisolone. Multiple regression analysis of improvement of facial palsy showed three significant covariates: age, multiple nerve palsies, and the initial grading of the palsy. The recovery of the facial palsy treated with acyclovir and prednisolone was good, and possibility of a good outcome was greater when the initial grade of the palsy was higher. Multiple nerve palsies and age had negative effects on the improvement.

Acyclovir↗
PubMed2000

Intravascular ultrasound findings of negative arterial remodeling at sites of focal coronary spasm in patients with vasospastic angina.

BACKGROUND: There are few data about the intravascular ultrasound (IVUS) findings in patients with vasospastic angina, especially regarding patterns of vascular remodeling. METHODS AND RESULTS: Coronary spasm was documented by angiography and electrocardiographic evidence of ischemia in 36 patients after administration of ergonovine (cumulative doses up to 350 microg). After relief of spasm with 1000 microg of intracoronary nitroglycerin, quantitative angiography and IVUS imaging were performed and analyzed by standard methods. The 36 focal spasm sites were compared with the proximal and distal reference segments. The angiographic baseline minimum lumen diameter measured 1.78 +/- 0.66 mm, which decreased to 0.66 +/- 0.38 mm with ergonovine provocation (P <.0001), increased to 2.66 +/- 0.64 mm after intracoronary nitroglycerin (P <.0001 compared with baseline and after ergonovine), and did not change after IVUS imaging (2.66 +/- 0.63, P =.9). By IVUS, atherosclerotic lesions were observed at all coronary spasm sites; the mean plaque burden measured 56% at the spasm site and 35% at the reference. Spasm site plaque composition was hypoechoic in 31 and hyperechoic, noncalcific in 5; there was no calcium. The mean eccentricity index (maximum divided by minimum plaque thickness) was 6.7. Positive remodeling (spasm site arterial area greater than proximal reference) was present in 5; intermediate remodeling (proximal reference greater than spasm site greater than distal reference arterial area) was present in 7; and negative remodeling (spasm site arterial area less than distal reference) was present in 24. CONCLUSIONS: Sites of vasospasm in patients with variant angina showed characteristics of early atherosclerosis, except for an unusually high incidence of negative arterial remodeling.

Adult↗
PubMed2000

Dysphagia after radiotherapy: endoscopic examination of swallowing in patients with nasopharyngeal carcinoma.

Dysphagia is a late sequela compromising the lives of more than one fourth of patients with nasopharyngeal carcinoma (NPC) who survive long after radiotherapy. By using fiberoptic endoscopic examination of swallowing as a modality for dysphagia evaluation, we were able to easily recognize the functional and anatomic changes in 31 dysphagic NPC patients. The majority of patients were found to aspirate after the act of swallowing (77.4%). Seventeen (54.8%) had tongue atrophy, and 9 (29%) had vocal cord palsy. Dysfunctions such as dry mouth (45.2%), velopharyngeal incompetence (58%), premature leakage (41.9%), delay or absence of swallow reflex (87.1%), poor pharyngeal constriction (80.6%), pharyngeal residue retention (83.9%), penetration or aspiration (93.5%), and silent aspiration (41.9%) were noted in these patients. Multiple dysfunctions were demonstrated in each patient. Abnormality of pharyngeal constriction and/or aberrant upper esophageal sphincter function played the major role in the postswallow aspiration of these irradiated NPC patients. Clinically compromised patients (weight loss of > or =5 kg in 1 year or pneumonia) had more of the above anatomic and functional impairments. The radiation dosage and volume bore no correlation to the time of symptom onset, or to the occurrence of functional changes.

Adult↗