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Biomedical subjects

Y S Hwang

Publications and source records attributed to Y S Hwang.

At least 73 records · Page 4Linked to original sources

Experience of anesthesia for transthoracic endoscopic sympathectomy in palmar hyperhidrosis--110 cases.

Transthoracic endoscopic sympathectomy (TES) is an effective treatment for palmar hyperhidrosis. We review our experience and discuss the anesthetic technique and perioperative complications encountered in 110 patients undergoing TES for palmar hyperhidrosis. All patients were monitored with EKG, NIBP and pulse oximetry (SPO2) during the operation. The trachea was intubated with a single lumen endotracheal tube and ventilation was controlled manually. 100% inspired oxygen was necessary during TES to avoid hypoxia. One patient developed sudden cardiac arrest during electrocauterization of the left sympathetic chain and two patients required underwater drainage for hemothorax. Minimal pneumothorax was diagnosed in 4 patients and all cases resolved spontaneously without active treatment.

Adolescent↗

Comparison of the electrophysiologic effects of oral sustained-release and intravenous verapamil in patients with paroxysmal supraventricular tachycardia.

The electrophysiologic effects of intravenous verapamil (0.15 mg/kg) and oral sustained-release verapamil (verapamil-SR) (240 mg once daily for 7 days) were studied in 17 patients with paroxysmal supraventricular tachycardia (SVT). Ten patients had atrioventricular (AV) nodal reentrant tachycardia and 7 had AV reciprocating tachycardia involving an accessory AV pathway. Both preparations significantly prolonged anterograde effective refractory period of the AV node and depressed the retrograde AV nodal conduction system. The sinus cycle length, and atrial and ventricular effective refractory periods were prolonged after oral verapamil-SR. Furthermore, oral verapamil-SR depressed retrograde accessory pathway conduction which was not interfered with by intravenous verapamil. Intravenous verapamil and oral verapamil-SR prevented induction of sustained SVT in 12 of 17 (71%) and 10 of 17 (59%) patients, respectively. Follow-up study with oral verapamil-SR 240 mg once daily in 15 patients for 19 +/- 6 months revealed that among the 8 patients without induction of sustained SVT, 7 have been free of symptomatic arrhythmia; only 1 patient had occasional SVT attacks. For the 7 patients with induction of sustained SVT, 3 patients failed to respond to oral verapamil-SR, 1 patient became symptom free, and the remaining 3 patients had less frequent SVT attacks. Thus, immediate intravenous verapamil testing predicts the electrophysiologic results of oral verapamil-SR therapy, and oral verapamil-SR once daily may be used for long-term prophylaxis of SVT with better patient compliance.

Administration, Oral↗

Efficacy of once-daily lisinopril monotherapy in systemic hypertension.

Lisinopril is a new, long-acting angiotensin-converting enzyme inhibitor formulated for once-daily treatment of hypertension. This study assessed the 24-h efficacy and tolerability of lisinopril in Chinese patients with mild to moderate hypertension of World Health Organization Stages I to II. A total of 30 patients aged 30 to 60 years (mean 47 +/- 9) entered a 2-week washout period. All patients had ambulatory diastolic blood pressure (BP) > 90 mmHg and were given active treatment with lisinopril for 4 to 7 weeks. The dose of lisinopril was titrated from 10 to 40 mg daily (at 8-9 A.M.). In each patient, 24-h ambulatory blood pressure (BP) monitoring (SpaceLabs 90202) was performed twice, once before and once following treatment. Mean 24-hour systolic/diastolic BPs after lisinopril were significantly decreased compared with baseline values (132 +/- 12/86 +/- 7 vs. 150 +/- 11/98 +/- 7 mmHg; p < 0.0005/0.0005). The average dose of lisinopril was 14.5 +/- 5 mg daily after a titration period of 5 weeks of treatment. Mean daytime (6 A.M. to 6 P.M.) BP decreased from 152 +/- 11/100 +/- 8 to 134 +/- 12/87 +/- 8 mmHg (p < 0.0005/0.0005) and nighttime (6 P.M. to 6 A.M.) BP from 147 +/- 14/95 +/- 9 to 128 +/- 14/83 +/- 8 mmHg (p < 0.0005/0.0005). BP reduction was more pronounced during the night. Before treatment, the circadian variation showed a peak BP at 11 A.M. and nadir at 3 P.M. After treatment, significant BP reduction (p < 0.0005/0.0005) was seen throughout the 24-h period.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Central core disease--a case report.

Central core disease is a rare congenital myopathy characterized by the formation of "cores" that consist of abnormal arrangement of myofibrils inside the myofibers. We report a 5-year-old Korean girl who showed a fairly typical clinical course of non-progressive muscle weakness. Electrodiagnostic studies showed low-amplitude polyphasic electromyograph and normal nerve conduction velocity. Gastrocnemius muscle biopsy showed central cores in over 80% of the fibers on H&E section. Histochemistry revealed deficient or absent mitochondrial enzyme in the cores and type I predominance. Ultrastructurally both structured and non-structured cores were found separately or simultaneously in one fiber. This case is the first report in the Korean literature.

Child, Preschool↗

Hallervorden-Spatz syndrome in two siblings diagnosed by the clinical features and magnetic resonance imaging (MRI).

Hallervorden-Spatz syndrome (HSS) is a heredodegenerative disorder characterized by both progressive pyramidal and extrapyramidal signs, dysarthric speech, and mental deterioration. No diagnostic biochemical test is yet available, and diagnosis of HSS can be confirmed only at autopsy by the characteristic neuropathology including abnormal iron storage, disordered myelination, and loss of brain substance. We present two siblings with clinical features consistent with HSS, in whom magnetic resonance imaging (MRI) demonstrated the deposition of iron in the globus pallidus and the substantia nigra thus allowing an antemortem diagnosis of HSS.

Child↗

[The study of anatomic factors in difficult intubations].

Endotracheal intubation is a common procedure in anesthesia which can usually be accomplished easily. However if the attempt is unexpectedly difficult the patient may be seriously at risk. If all difficult airways can be predicted confidently in the pre-operative period, anesthesiologists can plan the safest and most effective way of managing tracheal intubation. The purpose of this study was to analyze not only the incidence, anatomic factors, immediate complications and management of difficult intubation cases but also the view obtained at laryngoscope which was graded according to the Cormack's and Lehane's description. Patients who received general anesthesia with endotracheal tube within 1 year's period from November 1, 1991 to October 31, 1992 in Show Chwan Memorial Hospital were collected. All difficult intubations were performed by senior anesthesiologists. 3925 patients were intubated, 92 cases were noted to have difficult intubations and their overall incidence were 2.3%. Among the 92 patients, those with 2 anatomic factors (41 patients, 44.6%) represented the majority for patients with difficult intubations. On the other hand, the four most common anatomic factors and their incidences in order of frequency included short neck (48.9%), protruding teeth (38.0%), receding mandible (27.2%) and limited opening mouth (26.1%). According to Cormack's and Lehane's laryngoscopic grading, the results were shown respectively as follow: 4 cases (4.4%) for grade 1;2 cases (2.2%) for grade 2;82 case (89%) for grade 3 and 4 cases (4.4%) for grade 4. We also found that tachycardia/hypertension (70.7%), bleeding (37.0%) and esophageal intubation (33.7%) were the three most frequent immediate complications during difficult intubations.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗

Sparganosis in the spinal canal with partial block: an uncommon infection.

A case of rare intraspinal sparganosis treated by surgical excision is described. In this 59-year-old male with paraparesis and voiding problem, an intradural mass was noted on myelogram. Magnetic resonance (MR) and computed tomographic appearance of spinal and associated cerebral lesion are illustrated and possible route of migration discussed. This represents, to our knowledge, the first MRI demonstration of intraspinal sparganosis reported in the literature.

Humans↗

Effects of thromboxane synthase and cyclooxygenase inhibition on PAF-induced changes in lung function and arachidonic acid metabolism.

PAF was administered as an intravenous bolus (0.1 micrograms/kg) to eight chronically instrumented awake sheep. The effects of pretreatment with an inhibitor of cyclooxygenase (meclofenamate) on PAF-induced changes in lung function were compared to those observed with a specific inhibitor of thromboxane synthase (DP1904). Each animal was studied four times in varied order: PAF alone, PAF + DP1904, PAF + meclofenamate, and DP1904 alone. Saline alone (control), DP1904 alone, and meclofenamate alone did not cause changes in any of the measured variables. DP1904 and meclofenamate significantly attenuated the PAF-induced fall in lung compliance, elevation in peak pulmonary artery pressure, and increased lung lymph flow. Both drugs abolished the PAF-induced increases in lung lymph thromboxane B2 concentrations. Meclofenamate, but not DP1904, blocked the rise in lymph 6-keto-PGF1 alpha. Although meclofenamate blocked the rise in lymph PGE2, DP1904 resulted in levels 2.7 times higher than PAF alone. We conclude that: (1) inhibition of thromboxane synthase is as effective as inhibition of cyclooxygenase in attenuating PAF-induced changes in lung function, and (2) thromboxane synthase inhibition results in augmented production of PGE2 following PAF administration in vivo.

Animals↗

Is sick sinus syndrome an adenosine-mediated disease? Effects of intravenous aminophylline on sick sinus node function after pharmacologic autonomic blockade.

To assess the effects of intravenous aminophylline on the sinus node, 12 patients with clinical and Holter monitor-documented sick sinus syndrome were studied (1) during the control state, (2) after pharmacologic autonomic blockade and (3) 5 min after intravenous administration of aminophylline. The effects of aminophylline on sinus node function were compared with those after pharmacologic autonomic blockade. No significant improvement of sinus node function was found after intravenous aminophylline administration with a mean sinus cycle length and a mean maximum CSRT of 968 +/- 218 and 1832 +/- 1036 ms, respectively. The mean serum theophylline level was 10.9 +/- 1.7 micrograms/ml. Since aminophylline is an adenosine receptor antagonist, these findings suggest that intrinsic adenosine may not play an important role in pathogenesis in patients with chronic and advanced sick sinus syndrome.

Adenosine↗

Phase II Radiation Therapy Oncology Group study of hormonal cytoreduction with flutamide and Zoladex in locally advanced carcinoma of the prostate treated with definitive radiotherapy.

In patients with locally advanced (bulky) carcinoma of the prostate, definitive radiotherapy is associated with a high rate of local recurrence. The Radiation Therapy Oncology Group (RTOG) has conducted several studies evaluating hormonal cytoreduction (used as an induction regimen) as a means of improving the local control rate. RTOG 85-19 tested an induction regimen consisting of a depot LH-RH agonist (Zoladex) and an antiandrogen (flutamide). Eligible patients were those with bulky primary lesions (stage B2 and C) with disease confined to the pelvis. Zoladex was administered every 29 days via a subcutaneous injection. Flutamide was given by mouth in a dose of 250 mg t.i.d. Administration of the drugs was initiated 2 months prior to start of radiotherapy and was terminated at completion of the radiotherapy course. Radiotherapy consisted of 180-200 rad/day, 4,400-4,500 rad to the regional lymphatics, and 6,500-7,000 rad to the prostate. The primary aim of the study was to evaluate the effectiveness and toxicity of the combined (hormonal cytoreduction plus definitive radiotherapy) regimen. Thirty-one patients were accessioned; 30 are analyzable. The drug-related toxicity appears acceptable. It included appearance of diarrhea before initiation of radiotherapy in two patients, nausea during the 2nd week of drug administration in two patients, and skin rash in three patients. These phenomena appear to be related to flutamide. Hot flashes were recorded in 17 patients. With a minimum follow-up of 2 years, clearance of the primary lesions (by clinical examination) was documented in 28 of 30 patients. During the 1st year, two of 30 patients died (of unrelated causes) with residual palpable tumors. The observed toxicity appears acceptable and the response rate encouraging. A phase III study comparing the tested regimen against radiotherapy alone appears warranted.

Buserelin↗

Structure and expression of the rice glutelin multigene family.

A near full-length cDNA and three genomic clones for rice (Oryza sativa L.) glutelin were isolated and studied. Based on nucleic acid sequence and Southern blot analyses, the three isolated glutelin genomic clones were representative members of three gene subfamilies each containing five to eight copies. A comparison of DNA sequences displayed by relevant regions of these genomic clones showed that two subfamilies, represented by clones Gt1 and Gt2, were closely related and evolved by more recent gene duplication events. The 5'-flanking and coding sequences of Gt1 and Gt2 displayed at least 87% homology. In contrast, Gt3 showed little or no homology in the 5'-flanking sequences upstream of the putative CAAT boxes and exhibited significant divergence in all other portions of the gene. Conserved sequences in the 5'-flanking regions of these genes were identified and discussed in light of their potential regulatory role. The derived primary sequences of all three glutelin genomic clones showed significant homology to the legume 11 S storage proteins indicating a common gene origin. A comparison of the derived glutelin primary sequences showed that mutations were clustered in three peptide regions. One peptide region corresponded to the highly mutable hypervariable region of legume 11 S storage proteins, a potential target area for protein modification. Expression studies indicated that glutelin mRNA transcripts are differentially accumulated during endosperm development. Promoters of Gt2 and Gt3 were functional as they direct transient expression of chloramphenicol acetyltransferase in cultured plant cells.

Amino Acid Sequence↗