Biomedical subjects

S L Jen

Publications and source records attributed to S L Jen.

6 recordsLinked to original sources

PubMed2000

Far lateral lumbar disc herniation.

BACKGROUND: Far lateral lumbar disc herniation is an uncommon condition that may compress the nerve root outside the vertebral canal and in its extraforaminal course. The traditional midline interlaminar approach for the exploration of far lateral lumbar disc herniation is often difficult because the intervertebral articulation obviates a direct view of the course of the extraspinal nerve. In this report, we present two surgical approaches for the treatment of far lateral lumbar disc herniation: the paramedian muscle-splitting microtechnique and the enlarged midline approach. METHODS: Eight patients with far lateral lumbar disc herniation were found among 160 lumbar disc operations in 160 patients. According to computed tomography results, we divided patients with far lateral lumbar disc herniations into two groups; the extraforaminal and foraminal groups. Clinical presentation, imaging studies and surgical approach were thoroughly reviewed. RESULTS: Three patients in the extraforaminal group underwent the paramedian muscle-splitting microtechnique. Two patients in the foraminal group underwent the enlarged midline approach. The other three were operated on before the introduction of the paramedian muscle-splitting microtechnique and the enlarged midline approach. One of these patients who underwent the traditional interlaminar approach with resection of the lateral portion of facet joint, received additional instrumentation and fusion for the prevention of further instability. All had good results and no further surgical treatment was necessary. CONCLUSIONS: The incidence of far lateral lumbar disc herniation was 5% of all surgically treated disc herniations at our institution. For the extraforaminal group, the paramedian muscle-splitting microtechnique is the surgical route of choice. For the foraminal group, the enlarged midline approach is better than the traditional, interlaminar approach in saving the facet joint and preventing postoperative instability.

Adult↗

PubMed1998

Differentiating syndrome X from coronary artery disease by treadmill exercise test in patients with chest pain and exercise-induced myocardial ischemia.

Even though the underlying mechanisms of myocardial ischemia may be different, it is difficult to differentiate syndrome X from coronary artery disease (CAD) by means of the treadmill exercise test in elderly patients with chest pain and exercise-induced myocardial ischemia. One hundred sex- and age-matched patients-42 with syndrome X and 58 with CAD-were studied. Another 10 subjects with atypical chest pain, negative treadmill exercise test, and normal-appearing coronary angiograms served as controls. We evaluated the difference in exercise performance between patients with syndrome X and CAD, and the treadmill exercise test was undertaken with modified Bruce protocol within 2 weeks before coronary angiography. Parameters including time to 1 mm ST segment depression (STD), exercise duration (ED), heart rate (HR), systolic blood pressure, rate-pressure product (RPP), and percentage of age-predicted maximum HR (% HR) at different stages of the test were measured and then compared among the three groups of patients. Compared with CAD patients, syndrome X patients had significantly higher HR, % HR, and RPP at the time of 1 mm STD and at peak exercise. The time to 1 mm STD and ED were longer in syndrome X than in CAD patients. However, ED was shorter and HR, % HR, and RPP at peak exercise were similar in syndrome X patients as compared with control subjects. The new criterion of combined ED (> or =315 seconds) and RPP at peak exercise (> or =24,000 beats x mmHg/min) was found to be highly specific (86%) and moderately sensitive (64%) in differentiating syndrome X from CAD patients. The positive likelihood ratio for this criterion was 4.57 and negative likelihood ratio was 0.42. In conclusion, syndrome X patients had better exercise performance than CAD patients, but less ED and similar workload when compared with control subjects. The new criterion proposed in this study may provide a quick and simple way to differentiate syndrome X from CAD in a group of aged and predominantly male patients with chest pain and positive treadmill exercise test.

Adult↗

PubMed1998

Differential glucose tolerance in dipper and nondipper essential hypertension: the implications of circadian blood pressure regulation on glucose tolerance in hypertension.

OBJECTIVE: The goals of this study were to compare glucose tolerance in dipper and nondipper hypertensive patients and to explore the cause of glucose intolerance in essential hypertension. RESEARCH DESIGN AND METHODS: A total of 50 patients <45 years old who had essential hypertension were recruited and studied by 24-h blood pressure monitoring and an oral glucose tolerance test (OGTT). Autonomic function was assessed with spectral analysis of heart rate variability RESULTS: Dipper hypertensive patients (n=25) had lower nocturnal blood pressure than nondipper (n=25) patients. During OGTT, postprandial glucose levels were higher in the nondippers at 0, 90, and 120 min (all P < 0.05). Nondippers had a higher fasting insulin/glucose ratio than was apparent in normal control subjects. Despite higher postprandial glucose levels, nondippers had lower postprandial insulin levels. These results suggest that nondippers were insulin resistant and that their pancreatic beta-cell function was impaired. For all patients, nocturnal reduction of blood pressure was inversely related to total glucose levels under the OGTT curve and was positively related to postprandial insulin levels. Daytime heart rate did not differ between the dippers and nondippers, but nocturnal heart rate was higher in the nondippers, suggesting that nocturnal sympathetic activities were higher among the nondippers. Spectral analysis of heart rate variability suggests that the nondippers had lower parasympathetic activities and unbalanced sympathetic/parasympathetic outflow. CONCLUSIONS: These findings indicate that nondipper hypertensive patients are more glucose intolerant than are dipper patients. The abnormalities of glucose metabolism in nondippers could be explained by insulin resistance and beta-cell dysfunction. The results of spectral analysis suggest that abnormal autonomic outflow may represent a possible link between hypertension and associated metabolic dysfunction.

Adult↗

PubMed1997

Suprasellar meningiomas: analysis of 32 cases.

BACKGROUND: Suprasellar meningiomas originating from the tuberculum sellae, diaphragma sellae and planum sphenoidale are uncommon. Tumors of these regions can cause insidious visual loss and often remain undiagnosed until they have enlarged substantially or the symptoms have become aggravated. Previous reports have identified tumor size and duration of symptoms as the major factors determining the patient outcome. METHODS: Between 1984 and 1995, at the Department of Neurosurgery, Neurological Institute of Veterans General Hospital-Taipei, 32 patients with histopathologically identified meningiomas originating from the suprasellar region received surgical tumor removal. In this study, the records and clinical data of these patients are retrospectively analyzed. RESULTS: Tumor sizes ranged from 1.4 to 6.4 cm (average 3.4 cm) in diameter. The age of the patients ranged from 15 to 70 years (average 49 years), with the highest number of patients in their 50s. The male to female ratio was 7:25, with female predominance in all age groups. The presenting symptoms were mostly visual loss (87.5%) and the duration of symptoms ranged from 2 months to 35 years (average 4.25 years). Prognosis was evaluated according to the tumor size and duration of symptoms. Results showed that prognosis was favorably affected by a tumor size of 3.0 cm or less, and symptom duration of one year or less. CONCLUSIONS: In this series, patients with a tumor size of 3 cm or less and patients with a duration of symptoms for one year or less had a better visual outcome, higher total removal rates, lower mortality rates and lower recurrence rates.

Adolescent↗

PubMed1997

Efficacy and safety of fenofibrate or gemfibrozil on serum lipid profiles in Chinese patients with type IIb hyperlipidemia: a single-blind, randomized, and cross-over study.

BACKGROUND: The purpose of the study was to evaluate the effects and safety of fenofibrate or gemfibrozil on plasma lipid profiles in Chinese patients with type IIb hyperlipidemia. METHODS: Patients with previously diagnosed type IIb hyperlipidemia were initially evaluated in this single-blind, randomized, cross-over study. Only those who had persistent hyperlipidemia after a two-month diet control period were included. The patients were randomized to either fenofibrate 100 mg tid or gemfibrozil 600 mg bid for three months, then shifted to alternate drug for another three months after a two-month washout period. During the whole 10-month period, a prudent diet was maintained. Each patient was followed up at Out-patient Clinic regularly for diet interview, compliance and possible adverse events. RESULTS: A total of 12 patients, 11 males and 1 female, completed the whole study. After a three-month treatment of fenofibrate, there was significant reduction in plasma total cholesterol (22.7%, p < 0.001), total triglycerides (43.2%, p < 0.001), and low-density lipoprotein (LDL)-cholesterol (25.7%, p = 0.001). Serum high density lipoprotein (HDL) cholesterol was also increased by 30.2% (p = 0.055). On the other hand, only total triglyceride was significantly reduced by 36.5% (p = 0.005) with gemfibrozil treatment. There was no significant change of serum total, HDL- and LDL-cholesterol after the three-month treatment of gemfibrozil. Besides, serum uric acid and alkaline phosphatase were significantly reduced with fenofibrate but not with gemfibrozil treatment. There was no obvious adverse event noted during each treatment period with either drug. CONCLUSIONS: The findings suggest that in Chinese patients with type IIb hyperlipidemia, both fenofibrate and gemfibrozil can safely and significantly reduce serum triglyceride. Fenofibrate, but not gemfibrozil, could also reduce serum total cholesterol, LDL and uric acid. The results were compatible with the findings of previous studies in western patients with hyperlipidemia.

Adult↗

PubMed1996

Different exercise performance between aged patients with syndrome X and those with coronary artery disease.

BACKGROUND: Both patients with coronary artery disease (CAD) and those with syndrome X (anginal chest pain, exercise-induced myocardial ischemia, normal coronary angiogram and no evidence of coronary spasm) have ischemic electrocardiogram (ECG) during exercise. However, the difference of ECG change during treadmill exercise test in these two patient groups has rarely been studied. METHODS: In this prospective study, we evaluated and compared the changes of hemodynamics and 12-lead ECG during treadmill exercise test by modified Bruce protocol in 29 patients with syndrome X and 46 patients with CAD. RESULTS: As compared with CAD patients, syndrome X patients had significantly higher heart rate, higher systolic blood pressure and higher rate-pressure product at 1mm ST depression and peak exercise. The time to 1mm ST depression (304 +/- 128 vs 254 +/- 92 seconds, p = 0.06) and total exercise duration (463 +/- 108 vs 331 +/- 111 seconds, p < 0.001) were also longer in syndrome X than in CAD patients. However, coronary flow reserves, obtained from 20 syndrome X patients and 9 CAD patients, did not differ between both groups. (2.3 +/- 0.6 vs 2.5 +/- 0.6, p = NS) CONCLUSIONS: Patients with syndrome X had higher ischemic threshold and better exercise tolerance than CAD patients though coronary flow reserve was similar between them. During exercise, more work-load as well as metabolic demands was required for the development of similar degree of myocardial ischemia in these aged syndrome X patients as compared with CAD patients.

Aged↗