Biomedical subjects

W L Lee

Publications and source records attributed to W L Lee.

At least 73 records · Page 4Linked to original sources

PubMed1999

Changes of the insulin-like growth factor I system during acute myocardial infarction: implications on left ventricular remodeling.

In vitro and in vivo experiments have shown important biological actions of insulin-like growth factor I (IGF-I) in heart. The aims of this study were to determine the changes in circulating IGF-I and IGF-binding proteins (IGFBPs) during acute myocardial infarction (AMI) and to explore the relationship between IGF-I levels and myocardial remodeling and function after AMI. Thirty-four patients with acute Q-wave AMI and 17 matched controls were investigated in this study. Compared to normal subjects, free IGF-I and IGFBP-3 were significantly elevated, and IGFBP-1 was decreased upon AMI. Myocardial remodeling occurred after AMI in these patients. The day 2, 3, and 7 total IGF-I levels were inversely related to day 7 left ventricular (LV) end-diastolic, end-systolic diameters (r = -0.395 to -0.516) and LV mass (r = -0.487 to -0.661). Moreover, total IGF-I levels were positively related to LV ejection fraction (r = 0.402-0.453). Compared to the healthy survivors, those patients with poor outcomes had lower total IGF-I levels immediately after AMI. Most healthy survivors had total IGF-I levels greater than 137 ng/mL, but all patients with poor outcome had total IGF-I levels less than 137 ng/mL. Thus, AMI is associated with significant alterations in the IGF-I system. A higher total IGF-I level immediately after the onset of AMI is associated with better myocardial remodeling and ventricular function.

Echocardiography, Doppler↗

PubMed1999

Ovarian tumors complicating pregnancy. Emergency and elective surgery.

OBJECTIVE: To retrospectively evaluate the different effects and characteristics of ovarian surgery performed under emergency conditions and electively during pregnancy and to search for risk factors contributing to emergency ovarian surgery. STUDY DESIGN: Between 1980 and 1996, 174 patients undergoing adnexal surgery during pregnancy or the puerperium were reviewed at Veterans General Hospital-Taipei. Of these 174 patients, 32 underwent emergency surgery (group A), while 142 patients underwent elective surgery (group B). In order to search for differences between the emergency and elective operations, patients in both groups were analyzed, with particular emphasis on the characteristics and outcome of pregnancy. RESULTS: In contrast to elective operations, there were five distinct aspects of emergency surgery. First, half of them occurred in the first trimester. Second, they contributed to 75% (9/12) of the total fetal wastage and 85.7% (6/7) of spontaneous fetal loss (P = .00016). Third, tumor sizes (11.1 +/- 4.2 cm) were significantly larger than those found (8.3 +/- 3.76 cm) in the elective surgery group (P < .05). Fourth, tumors less than 5 cm never caused symptoms requiring surgery. Fifth, an increasing incidence of completely extirpative surgery and general anesthesia was noted (P < .005). Incidence of tumors greater than 10 cm during pregnancy increased with malignancy (P = .0295) and before emergency surgery (P = .00001). CONCLUSION: We could remove ovarian tumors greater than 10 cm in diameter or with a teratoma component at earlier stages of pregnancy (after the seventh week of gestation) to avoid unpredictable complications. This reduces the risks of malignancy and emergency surgery. There was no evidence of increasing risk of fetal loss when surgery was performed after the seventh week of gestation.

Adult↗

PubMed1999

Relationship between hormone receptor concentration and tumor shrinkage in uterine myoma after treatment with a GnRHa.

BACKGROUND: Uterine myomas are benign tumors of the uterus, occurring in up to 25% of women of reproductive age. We examined the possible causes for different degrees of volume reduction in patients with uterine myomas who received gonadotropin-releasing hormone agonist (GnRHa) treatment by investigating the hormone receptors at the end of GnRHa treatment. METHODS: This trial was designed as a prospective study of five premenopausal women presenting with symptomatic uterine myoma. All patients were treated with a subcutaneous injection of goserelin depot 3.6 mg every four weeks for 16 weeks. Clinical examinations, hormonal evaluation and ultrasound determinations were performed before, during and after treatment. At the end of the treatment period, all patients underwent myomectomy. The concentrations of the unbound progesterone receptors and estrogen receptors were evaluated. RESULTS: The volume of the uterine myoma decreased by 21% to 65%. The percentage of decrease in volume of treated uterine myomas was found to negatively correlate with the concentration of unbound progesterone receptors (r2 = 0.92, p = 0.008). This percentage was not significantly correlated with the concentration of unbound estrogen receptors (r2 = 0.02, p = 0.84). CONCLUSIONS: The limited data available suggested that the volume decrease of uterine myomas in GnRHa-treated patients is partly dependent on the concentrations of unbound sex-hormone receptors in the uterine myomas.

Antineoplastic Agents, Hormonal↗

PubMed1999

The neurological manifestations of Nipah virus encephalitis, a novel paramyxovirus.

A novel Hendra-like paramyxovirus named Nipah virus (NiV) was the cause of an outbreak among workers from one abattoir who had contact with pigs. Two patients had only respiratory symptoms, while 9 patients had encephalitis, 7 of whom are described in this report. Neurological involvement was diverse and multifocal, including aseptic meningitis, diffuse encephalitis, and focal brainstem involvement. Cerebellar signs were relatively common. Magnetic resonance imaging scans of the brain showed scattered lesions. IgM antibodies against Hendra virus (HeV) were present in the serum of all patients. Two patients recovered completely. Five had residual deficits 8 weeks later.

Adult↗

PubMed1999

Mature teratoma with secondary infection: case report.

Mature teratoma (dermoid cyst) is a common disorder in women of reproductive age. Sometimes the tumor is complicated by torsion, rupture, and malignant change. However, it rarely presents with fever. We present a 38-year-old woman with an intermittent fever for 30 days, who received occasional medical treatment without improvement. She was to our clinic for evaluation and treatment; however, fever persisted for three days without clinical improvement. No definite infection source could be identified except the presence of a huge pelvic tumor. The patient underwent exploratory laparotomy and an ovarian dermoid cyst with infection was noted. Pathology review revealed mature teratoma with superimposed infection by Escherichia coli. Fever impressively subsided on the fifth postoperative day. Although the majority of patients suffering from fever initially search for medical treatment at primary clinics, rare conditions such as persistent fever should be consulted by specialists to make differential diagnosis. Mature teratoma is rarely superimposed by infection and rarely causes fever. Furthermore, the possibility of fever caused by tubo-ovarian abscess (TOA) is often missed in patients with history of tubal ligation since there is a lower incidence of TOA in these unique patients. However, based on this case report, we should be alert whenever long-term fever is noted. Prompt surgical treatment for extirpation and an appropriate antibiotic treatment would be the choice of treatment in such cases.

Adult↗

PubMed1998

Parasympathetic withdrawal antedates dynamic myocardial ischemia in patients with syndrome X.

This study was to evaluate the dynamic changes in cardiac autonomic control preceding electrocardiographic (ECG) myocardial ischemia in patients with syndrome X. Twenty-four-hour ambulatory ECG was obtained in 34 consecutive patients in a drug-free state. Fourteen (41%) of them, aged 58.8+/-13.5 years, presented a total of 19 ischemic episodes, mean duration 12.4+/-19.8 min (ranged 1 to 90 min). Heart rate variability was measured for 24 h; for 3 min and 30 min before, and during the 15 min (in five 3-min intervals) immediately antedating ST segment depression; and for another 3 min after ST segment back to normal. There were significant progressive shortenings in sinus cycle lengths over the 30 min preceding myocardial ischemia (-30 vs -3 minute, 822+/-32 ms vs 637+/-23 ins, P<0.05; a decrement of 22.5%). The sinus cycle lengths lengthened after ischemia ceased. High frequency activity, pNNSO and rMSS.D. were significantly reduced from the -30 min baseline to a nidus in the last 3 min before ischemia (P<0.05), whereas low frequency band and low/high frequency ratio did not present significant change. These findings strongly argue that cardiac autonomic control, especially vagal withdrawal, is involved in the pathogenesis of dynamic myocardial ischemia in syndrome X.

Adult↗

PubMed1998

Changes of autonomic tone before the onset of paroxysmal atrial fibrillation.

The relationship between autonomic nerve system and the onset of paroxysmal atrial fibrillation (PAF) is still controversial. Furthermore, no prior studies have compared heart rate variability (HRV) between PAF patients with (organic) or without (idiopathic) underlying cardiac diseases. The purpose of this study was to assess the alteration of autonomic tone by analyzing HRV immediately before the onset of atrial fibrillation. This study included 57 patients (M/F: 34/23, 66+/-22 years) with frequent attacks of PAF. All cases underwent 24-h ambulatory Holter monitoring; each patient had one or more episodes of sustained PAF (>30 s). A period of sinus rhythm 40 min was allowed for accurate assessment of HRV over these periods. Spectral HRV was expressed as low (0.04-0.15 Hz) and high (0.15-0.40 Hz) frequency components (LF, HF), and L/H ratio at 2-min intervals over a 40-min period before the onset of PAF. According to HRV, three subtypes were classified; onset of PAF accompanied with increased HF component and decreased L/H ratio was designated as vagal type; decreased HF component and increased L/H ratio was designated as sympathetic type, and the other episodes which did not belong to vagal or sympathetic type were designated as non-related type. In group I (idiopathic PAF, n=30): 63 episodes of PAF were found and vagal type was predominant (41/63, 63.5%); HF increased significantly before the onset of AF. In group II (organic PAF, n=27): 58 episodes of PAF were found and sympathetic type was predominant (39/58, 67.2%); L/H ratio increased before AF onset. None of the three subtypes showed significant circadian distributions in group I and II patients. Changes of HRV before the onset of PAF were not universal; most of the patients with idiopathic PAF were vagal dependent and most of the patients with organic PAF were sympathetic dependent.

Aged↗

PubMed1998

Cellular correlates of long-term sensitization in Aplysia.

Although in vitro analyses of long-term changes in the sensorimotor connection of Aplysia have been used extensively to understand long-term sensitization, relatively little is known about the ways in which the connection is modified by learning in vivo. Moreover, sites other than the sensory neurons might be modified as well. In this paper, several different biophysical properties of sensory neurons, motor neurons, and LPl17, an identified interneuron, were examined. Membrane properties of sensory neurons, which were expressed as increased excitability and increased spike afterdepolarization, were affected by the training. The biophysical properties of motor neurons also were affected by training, resulting in hyperpolarization of the resting membrane potential and a decrease in spike threshold. These results suggest that motor neurons are potential loci for storage of the memory in sensitization. The strength of the connection between sensory and motor neurons was affected by the training, although the connection between LPl17 and the motor neuron was unaffected. Biophysical properties of LPl17 were unaffected by training. The results emphasize the importance of plasticity at sensory-motor synapses and are consistent with the idea that there are multiple sites of plasticity distributed throughout the nervous system.

Animals↗

PubMed1998

Differential expression and association of calcium channel alpha1B and beta subunits during rat brain ontogeny.

Calcium functions as an essential second messenger during neuronal development and synapse acquisition. Voltage-dependent calcium channels (VDCC), which are critical to these processes, are heteromultimeric complexes composed of alpha1, alpha2/delta, and beta subunits. beta subunits function to direct the VDCC complex to the plasma membrane as well as regulate its channel properties. The importance of beta to neuronal functioning was recently underscored by the identification of a truncated beta4 isoform in the epileptic mouse lethargic (lh) (Burgess, D. L., Jones, J. M., Meisler, M. H., and Noebels, J. L. (1997) Cell 88, 385-392). The goal of our study was to investigate the role of individual beta isoforms (beta1b, beta2, beta3, and beta4) in the assembly of N-type VDCC during rat brain development. By using quantitative Western blot analysis with anti-alpha1B-directed antibodies and [125I-Tyr22]omega-conotoxin GVIA (125I-CTX) radioligand binding assays, we observed that only a small fraction of the total alpha1B protein present in embryonic and early postnatal brain expressed high affinity 125I-CTX-binding sites. These results suggested that subsequent maturation of alpha1B or its assembly with auxiliary subunits was required to exhibit high affinity 125I-CTX binding. The temporal pattern of expression of beta subunits and their assembly with alpha1B indicated a developmental pattern of expression of beta isoforms: beta1b increased 3-fold from P0 to adult, beta4 increased 10-fold, and both beta2 and beta3 expression remained unchanged. As the beta component of N-type VDCC changed during postnatal development, we were able to identify both immature and mature forms of N-type VDCC. At P2, the relative contribution of beta is beta1b > beta3 >> beta2, whereas at P14 and adult the distribution is beta3 > beta1b = beta4. Although we observed no beta4 associated with the alpha1B at P2, beta4 accounted for 14 and 25% of total alpha1B/beta subunit complexes in P14 and adult, respectively. Thus, of the beta isoforms analyzed, only the beta4 was assembled with the rat alpha1B to form N-type VDCC with a time course that paralleled its level of expression during rat brain development. These results suggest a role for the beta4 isoform in the assembly and maturation of the N-type VDCC.

Age Factors↗

PubMed1998

Association of infantile convulsions with paroxysmal dyskinesias (ICCA syndrome): confirmation of linkage to human chromosome 16p12-q12 in a Chinese family.

We have studied one family of Chinese origin, in which benign infantile convulsions and paroxysmal choreoathetosis (of the dystonic form) were co-inherited as a single autosomal dominant trait. This association is specific to ICCA syndrome, which we have recently described in four French families. Some patients in the new family also exhibit recurrence of epileptic seizures at a much later age, making the ICCA syndrome in this family atypical. DNA samples isolated from this family of 22 members (9 affected) have been tested with genetic markers at chromosome 16p12-q12, in which region the ICCA syndrome has previously been linked. Confirmation of linkage to this pericentromeric region of human chromosome 16 has been obtained and no critical meiotic recombination event has been detected in the ICCA region. This result suggests that, in contrast to marked clinical heterogeneity, the association of infantile convulsions with paroxysmal dyskinetic movements could be genetically homogeneous.

China↗

PubMed1998

Use of a long-acting gonadotropin-releasing hormone agonist for treatment of steroid cell tumors of the ovary.

OBJECTIVE: To report a complete serologic response in a 50-year-old women who received long-acting gonadotropin-releasing hormone agonist (GnRH-A) therapy for steroid cell tumor of the ovary, not otherwise specified. DESIGN: Case report. SETTING: University hospital-based reproductive biology unit. PATIENT(S): A 50-year-old female patient exhibited persistent elevation of T (>2.0 ng/mL) after surgery for steroid cell tumor of the ovary, not otherwise specified, stage IIA for 3 months. This elevation suggested the presence of some residual active tumor. INTERVENTION(S): All tumor evaluations, including those for tumor markers, a thorough physical examination, imaging studies, and evaluations of nuclear medicine studies were negative except for elevated serum T levels. The patient was treated with GnRH-a between the fourth month and sixth month postoperatively. MAIN OUTCOME MEASURE(S): Serum levels of T and tumor survey. RESULT(S): The serum T levels returned to normal limits after administration of the first dose of GnRH-a. Follow-up of tumor survey was negative. The patient was alive and free of disease 26 months after treatment with GnRH-a. CONCLUSION(S): GnRH-a may be an alternative choice as adjuvant therapy for managing a persistent or recurrent hormone-producing steroid cell tumor of the ovary.

Antineoplastic Agents, Hormonal↗

PubMed1998

Steroid cell tumors of the ovary: clinical, ultrasonic, and MRI diagnosis--a case report.

Steroid cell tumors of the ovary are rare sex-cord neoplasms which account for less than 0.1% of all ovarian tumors. They have been divided into two subtypes according to their cell of origin as follows: stromal luteoma, and Leydig cell tumors, and a third subtype with lineage unknown is a steroid cell tumor, not otherwise specified (NOS). The clinical presentation may take many forms, including pain, abdominal distention and bloating, but perhaps the most interesting and noticeable presentations are those related to the hormonal activity and virilizing properties of the tumor. No radiological features of the steroid cell tumor, NOS have been presented in the literature. This report presents the MRI and ultrasonographic findings of a patient having steroid cell tumor, NOS, of the right ovary with metastasis to the uterus.

Female↗

PubMed1998

Differential expression and association of calcium channel subunits in development and disease.

Voltage-gated calcium channels (VDCC) are essential to neuronal maturation and differentiation. It is believed that important signaling information is encoded by VDCC-mediated calcium influx that has both spatial and temporal components. VDCC are multimeric complexes comprised of a pore-forming alpha1 subunit and auxiliary beta and alpha2/delta subunits. Changes in the fractional contribution of distinct calcium conductances to the total calcium current have been noted in developing and differentiating neurons. These changes are anticipated to reflect the differential expression and localization of the pore-forming alpha1 subunits. However, as in vitro studies have established that beta regulates the channel properties and targeting of alpha1, attention has been directed toward the developmental expression and assembly of beta isoforms. Recently, changes in the beta component of the omega-conotoxin GVIA (CTX)-sensitive N-type VDCC have indicated differential assembly of alpha1B with beta in postnatal rat brain. In addition, unique properties of beta4 have been noted with respect to its temporal pattern of expression and incorporation into N-type VDCC complexes. Therefore, the expression and assembly of specific alpha1/beta complexes may reflect an elaborate cellular strategy for regulating VDCC diversity. The importance of these developmental findings is bolstered by a recent study which identified mutations in the beta4 as the molecular defect in the mutant epileptic mouse (lethargic; lh/lh). As beta4 is normally expressed in both forebrain and cerebellum, one may consider the impact of the loss of beta4 upon VDCC assembly and activity. The importance of the beta1b and beta4 isoforms to calcium channel maturation and assembly is discussed.

Animals↗

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

Insulin-like growth factor I modulates induction of apoptotic signaling in H9C2 cardiac muscle cells.

Insulin-like growth factor I (IGF-I) is an important survival growth factor that has been shown to inhibit apoptosis, but the effects of IGF-I on apoptotic signaling remain largely unknown. To investigate IGF-I actions on apoptosis of H9C2 cardiac muscle cells, we have defined the effects of IGF-I on Bcl-2, Bax, caspase 3, DNA fragmentation, and cell survival. The abundance of Bcl-2 and Bax was determined with immunoblotting, and the activities of caspase 3 were assayed with the labeled substrate DEVD-p-nitroanilide. The occurrence of apoptosis was determined by electrophoresis of labeled DNA fragments and by in situ terminal deoxynucleotidyl transferase UTP nick end labeling assay. We found that apoptosis of H9C2 cells, induced by serum withdrawal and doxorubicin, was associated with the induction of Bax and the activation of caspase 3. IGF-I partially inhibited Bax induction, caspase 3 activation, DNA fragmentation, and enhanced cell survival. Interestingly, there is a compensatory rise in the abundance of Bcl-2 upon serum withdrawal and doxorubicin treatment, and IGF-I stimulation resulted in decreased induction of Bcl-2. These results suggest that serum withdrawal- and doxorubicin-induced apoptosis of H9C2 cells probably in part resulted from induction of Bax and caspase 3, and IGF-I inhibited apoptosis by attenuating Bax induction and caspase 3 activation.

Apoptosis↗

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↗

PubMed1998

Creutzfeldt-Jakob disease presenting with visual blurring, diplopia and visual loss: Heidenhain's variant.

Focal electroencephalographic abnormalities as described in Heidenhain's variant of Creutzfeldt-Jakob disease are uncommon. We report a 73-year-old male presenting with visual symptoms, right hemianopia and rapidly progressive dementia. Myoclonus was synchronous with generalised periodic epileptiform discharges on electroencephalography (EEG). In addition, there were periodic focal sharp waves at the left occipital region. Diffusion-weighted magnetic resonance brain images showed slightly increased signal intensity in the occipital parasagittal area, left more than right. 14-3-3 protein was detected in the cerebrospinal fluid. The patient died within 5 months of presentation.

Aged↗

PubMed1998

Fever of unknown origin in the puerperium. A case report.

BACKGROUND: Postpartum fever is a common problem for obstetricians, but fever of unknown origin (FUO) occurring in the puerperium may be relatively unfamiliar and a challenge to the majority of obstetricians. CASE: A 29-year-old woman had a FUO detected during the puerperium. Despite serial examinations and therapeutic trials, the fever persisted for three weeks without a clinical improvement or definite infection source. The presence of a huge uterine myoma was observed. The patient finally underwent myomectomy, and a pathology review revealed a cellular leiomyoma associated with massive infarction and acute inflammation. The fever subsided substantially on the third day postoperatively. CONCLUSION: Although a uterine leiomyoma as a cause of fever in the puerperium is not new, rarely does it cause prolonged fever. It should be taken into consideration in pregnant women known to have uterine myomas during pregnancy and in the puerperium, especially if FUO develops. Nonsteroidal antiinflammatory drugs can be a tool for making the differential diagnosis in such a patient, and exploratory laparotomy can be delayed until an emergency condition occurred, especially important during pregnancy.

Adult↗