Search PubMed⌕ Search

Biomedical subjects

Y D Kim

Publications and source records attributed to Y D Kim.

At least 91 records · Page 5Linked to original sources
PubMed1993

Comparison of the effect of zopiclone and brotizolam on sleep EEG by quantitative evaluation in healthy young women.

We studied the effect of brotizolam (BRO) (0.25 mg) and zopiclone (ZPC) (7.5 mg) on the sleep electroencephalograms (EEG) of seven healthy young women (ages 20-21 years). In addition to conventional sleep scoring, we performed spectral analysis of EEG wave forms using the Fast Fourier Transformation (FFT) method. Four weeks following two consecutive polysomnographic recordings with placebo administration (for baseline data), polysomnography with BRO or ZPC administration was performed on the subjects who were then crossed over to polysomnography with ZPC or BRO, respectively, 1 week later. Total rapid eye movement (REM) time was decreased on the ZPC and BRO nights and REM latency was prolonged on the ZPC night compared with baseline (BL) night. Other parameters, however, were not significantly different between the drug nights and the BL night. There were also no differences in standard scoring results between both drug nights. FFT analysis revealed significant differences in total power density percentage and mean power density percentage in both nonrapid eye movement (NREM) and REM sleep between ZPC and BRO nights and between both drug nights compared to the BL night. Total power density and mean power density per epoch showed significant decreases in the theta band (6.0-8.0 Hz) and sigma band (12.0-14.0 Hz) on the ZPC night versus the BRO night or BL night during specific NREM periods. The results of this study corroborate previous reports that suggest computer-aided quantitative electroencephalography aids in differentiating specific effects of hypnotics and other central-nervous-system-acting agents on the sleep EEG.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Anaesthetic modification of regional myocardial functional adjustments during myocardial ischaemia: halothane vs fentanyl.

During myocardial ischaemia, functional compensation occurs by non-ischaemic regions of the left ventricle (LV). Anaesthetics may affect compensation by altering contractility, metabolism and perfusion. This was studied in dogs anaesthetized with fentanyl (150 micrograms kg-1 loading dose and 100 micrograms kg-1 h-1) or 0.75% and 1.5% halothane and subjected to left anterior descending artery (LAD) occlusion. After 15 min of anterior wall ischaemia, cardiac output, mean arterial pressure and LV maximum dP/dt were diminished in the 1.5% halothane but not in the 0.75% halothane or fentanyl groups. In all groups, stroke volume decreased, LV end-diastolic pressure increased and anterior wall function deteriorated (measured as systolic shortening, peak systolic intramyocardial pressure (IMP), regional wall stroke work (RSW) and slope of preload recruitable stroke work curve (Mw)) with ischaemia. Functional changes in the lateral (non-ischaemic) wall were different between groups. Regional function during occlusion in this area improved with fentanyl (mean (SEM) IMP, RSW and Mw increased by 23 (2)%, 37 (3)% and 69 (7)%, respectively), was relatively well maintained with 0.75% halothane and diminished with 1.5% halothane.

Anesthesia, Inhalation↗
PubMed1992

One-year monkey heart xenograft survival in cyclosporine-treated baboons. Suppression of the xenoantibody response with total-lymphoid irradiation.

The shortage of cadaveric human organs for transplantation could be alleviated by the use of xenografts. Long-term (> one-year) survival of xenografts in humans or experimental animals has not been achieved with previous immunosuppressive protocols. Poor results in xenotransplantation compared with allotransplantation have been attributed to a more potent antibody response rather than to cell-mediated responses. To investigate these issues a concordant heterotopic cardiac xenograft model was developed in conjunction with cyclosporine and/or total-lymphoid irradiation. Concordant models permit examination of xenoantigen induced antibody and cell-mediated responses since preformed humoral factors (in discordant models) do not cause hyperacute rejection. Four groups of baboon recipients received cervical heart transplants from cynomolgous monkeys. Group I (n = 2), untreated, mean survival (MS) = 6 days; group II (n = 5), CsA and methylprednisolone, MS = 25 days; group III (n = 3), preoperative TLI, MS = 29 days; group IV (n = 6), preoperative TLI and CsA+MP, MS = 255 days (> 77, > 108, > 142, 184, > 480, 540 days). Heart xenografts of CsA-MP-treated recipients appear to be destroyed predominantly by antibody (IgM)-mediated processes whereas cell-mediated rejection is likely the major reaction in TLI-treated recipients. CsA-MP-treated recipients had early immunohistochemical evidence of antibody and complement-mediated rejection (deposition of IgM and complement but not IgG on heart xenografts). In contrast IgM and complement deposits were not detected on heart xenografts in TLI- and TLI-CsA-treated recipients. IgG xenoantibodies were only detected on the two rejected heart grafts of TLI-CsA-treated recipients. CsA-MP-treated recipients rapidly developed high xenoantibody titers (1:256 to 1:512) that immediately preceded rejection. In contrast, TLI-treated animals developed lower levels of xenoantibody (< or = 1:8) and TLI-CsA-treated recipients had no detectable xenoantibody during the initial three months after transplantation (and titers no greater than 1:8 thereafter.) The lack of xenoantibody was likely not due to a generalized inhibitory effect of the immunosuppressants on B cell function since all classes of serum immunoglobulins were in the normal range. Intragraft cytolytic lymphocyte activity was detected in rejecting TLI- and TLI-CsA-treated recipients but could not be detected in xenografts of CsA-MP-treated recipients. One explanation for these data is that TLI (either directly or indirectly) induces a state of specific B cell unresponsiveness to monkey xenoantigens, thereby preventing IgM mediated rejection in the third week after transplantation.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1992

Brief ischemia-reperfusion induces stunning of endothelium in canine coronary artery.

BACKGROUND: Brief ischemic episodes that induce stunning of the myocardium may also induce stunning of the coronary endothelium. To test this hypothesis, we examined both in vivo and in vitro responses of canine coronary arteries exposed to brief ischemia. METHODS AND RESULTS: Functional recovery of the endothelium was examined in vivo during reperfusion after 15 minutes of ischemia. Vasodilatory responses to acetylcholine were severely impaired during the first hour of reperfusion but gradually improved over a 90-minute period after ischemia. The vasoconstrictive response to U46619 was enhanced for the first 30 minutes of reperfusion and returned to normal within 60 minutes. In vitro vasomotor responses to potassium chloride, acetylcholine, bradykinin, and sodium nitroprusside were examined in isolated segments of canine coronary arteries preexposed in vivo to brief ischemia (10-30 minutes) and 20 minutes of reperfusion. The results showed enhanced contractile responses and blunted endothelium-dependent but not endothelium-independent vasodilatory responses of arterial rings subjected to 10 minutes of ischemia. Twenty and 30 minutes of ischemia completely impaired endothelium-dependent vasodilation. When reperfusion was extended to 120 minutes after 15 minutes of ischemia, vasodilatory responses to acetylcholine had recovered by almost 90%. Examination of endothelial integrity by transmission electron microscopy after 10-15 minutes of ischemia revealed no evidence of structural damage. Twenty and 30 minutes of ischemia induced cytoplasmic vacuolation, partial detachment of endothelium, and swelling of cytoplasmic organelles. CONCLUSIONS: These data support the hypothesis that brief ischemia-reperfusion induces stunning of endothelium in which endothelium-dependent vasodilatory function is impaired temporarily without morphological damage.

Acetylcholine↗
PubMed1992

Comparison of thromboxane synthetase inhibitor and methylprednisolone effects on protamine responses in dogs.

Neutralization of heparin anticoagulation by protamine produces catastrophic hemodynamic reactions in some patients. Using a canine model, we tested effects of thromboxane synthetase inhibition (CGS-13080) and glucocorticoid pretreatment on the cardiorespiratory effects of protamine. In control dogs, protamine decreased mean arterial pressure and cardiac output and increased mean pulmonary artery pressure, systemic and pulmonary vascular resistances (SVR, PVR), and airway pressure. Both CGS-13080 and methylprednisolone ameliorated some effects of protamine. CGS-13080 infusion decreased mean pulmonary artery pressure, SVR, and airway pressure after protamine injection relative to controls. Cardiac output and PVR were unaffected by the drug, whereas the decrease in mean arterial pressure was prolonged. Plasma thromboxane A2 metabolite (TXB2) concentrations were lower and prostacyclin metabolite (6-keto PGF1 alpha) concentrations were higher compared with that of controls. These experiments support a role for TXA2 in the response to protamine. Methylprednisolone pretreatment produced larger cardiac output and lower airway pressure after protamine injection compared with controls. Mean arterial pressure was improved, but not significantly. Mean pulmonary artery pressure, SVR, and PVR were not different from that of controls; TXB2 and 6-keto PGF1 alpha were unaffected. The effects of methylprednisolone appear unrelated to arachidonic acid metabolism, as TXB2 and 6-keto PGF1 alpha levels were unaffected.

6-Ketoprostaglandin F1 alpha↗
PubMed1991

A case of localization-related epilepsies suspected of panic disorder.

Some localization-related epilepsies have autonomic symptoms as well as psychic symptoms. As these symptoms are similar to those of panic disorder, it is important to discriminate between the two disorders. In such cases, VTR-polygraphic examination is necessary for the correct diagnosis.

Amygdala↗
PubMed1991

Hemangiopericytoma of the lacrimal sac.

Hemangiopericytomas are soft tissue tumors composed of pericapillary pericytes. These tumors are rare in the lacrimal sac. To the author's knowledge, only four previous cases of these tumors occurring in the lacrimal sac have been reported. A primary hemangiopericytoma of the lacrimal sac in a 34-year-old female is reported. Total excision with the surrounding tissue appears to be the treatment of choice for this tumor.

Adult↗
PubMed1991

Successful management of mechanical complications following acute myocardial infarction--a case report.

Rupture of the heart as a complication of myocardial infarction is one of the most common causes of in-hospital mortality. Rupture of the free wall of the ventricle or interventricular septum has a poor prognosis when treated conservatively. So, rupture of the heart after infarction requires prompt diagnosis and early surgical repair despite the high overall incidence of early operative mortality before hemodynamic deterioration and multiorgan failures develop. Rupture of the left ventricle results in pseudoaneurysm if the overlying pericardium adhers to the surface of the heart. Pseudoaneurysms which rarely develop after infarction, tend to rupture. Their presence alone is an indicator for operation because of the very poor prognosis following rupture. We experienced successful management of 2 rare complications after acute myocardial infarction: ventricular septal defect and pseudoaneurysm. The first patient was a 49-year-old man who had an apical septal defect. His electrocardiogram showed Q wave in leads V2-V6, II, III, and aVF but a coronary angiogram showed normal findings. He was successfully treated by patch closure of the septal defect. The second patient was a 65-year-old female who had false aneurysm of the left ventricle. She had neither chest pain nor abnormality on the electrocardiogram. A coronary angiogram showed complete occlusion of the distal circumflex artery. Under cardiopulmonary bypass, the neck of the aneurysmal sac was successfully closed with a prolene suture.

Aged↗
PubMed1989

Determination of intrinsic association constant of mouse monoclonal IgM antibody to human hepatitis B surface antigen.

The ultracentrifugation technique utilizing Airfuge was employed to determine the intrinsic association constant of mouse monoclonal IgM antibodies to human hepatitis B surface antigen (HBsAg). The IgM antibody was reduced to Fab fragments by tryptic digestion in the presence of mercaptoethanol, followed by two passages over a Sephacryl S-200 column. The centrifugation conditions were optimized to sediment Fab-HBsAg complexes, leaving the unbound Fab in the supernatant. The analyses of the binding data by Scatchard and Sips methods yielded good agreement, and the intrinsic association constants ranged from 0.13 to 5.3 X 10(7) (l/mol) for three IgM antibodies. The heterogeneity indices deduced from the Sips analysis were 1.0. The present protocol would allow determination of the intrinsic association constant for the binding of a multivalent antibody to a comparatively large antigen bearing multiple combining sites.

Animals↗
PubMed1989

Molecular characterization of the epitope in prostate and breast tumor-associated PR92 antigen.

In our previous report, monoclonal antibody PR92 has defined prostate- and breast tumor-associated PR92 antigen. The molecular nature of PR92 antigen, especially the epitope involved in specific interaction with PR92 monoclonal antibody, is described. PR92 antigen was purified from the cell extract or tissue culture medium of prostate cancer cell line DU145 by means of monoclonal antibody-coupled Sepharose 4B affinity chromatography, followed by a Sephacryl S-500 chromatography. Physical and chemical characterization, coupled with high-performance liquid chromatography, determined that PR92 antigen is a glycoprotein with a molecular weight of about 470,000, comprising repeating subunits of about 44,000. Sialic acid was found to form a critical part, while D-galactose and N-acetylgalactosamine were also involved, in the epitope structure. PR92 antigen is rich in serine, threonine, proline, glycine, and alanine and poor in aromatic amino acid residues. The carbohydrate moieties may be predominantly O-linked to polypeptide chains which contribute directly or indirectly to maintain the integrity of the epitope. Elucidation of the molecular nature of PR92 antigen may help understand the mechanism of shedding into the body fluids during tumor progression.

Amino Acids↗
PubMed1989

Primary endobronchial granular cell myoblastoma.

Granular cell myoblastoma is a common lesion of uncertain histogenesis. It commonly affects the tongue, breast, and subcutaneous tissues. However, its occurrence in the tracheobronchial tree is rare. Although generally a benign lesion, isolated malignant granular cell myoblastoma as well as its coexistence with other primary bronchogenic carcinomas has been documented. In spite of recent anecdotal reports advocating endoscopic removal of this lesion, we believe definitive surgical excision is a more rational choice of treatment.

Bronchi↗
PubMed1989

Effects of hypothermia and hemodilution on oxygen metabolism and hemodynamics in patients recovering from coronary artery bypass operations.

The coexistence of hypothermia and hemodilution in patients in the intensive care unit immediately postoperatively after coronary artery bypass graft operations presents concerns regarding the adequacy of hemodynamics and oxygen metabolism. We evaluated the hemodynamic status and oxygen metabolism during the postoperative recovery period in six patients with moderate hemodilution (hematocrit value 34% +/- 3%) and in eight patients with marked hemodilution (hematocrit value 23% +/- 2%). All patients were well sedated and paralyzed with pancuronium bromide during the study period, during which their body temperature was slowly returning toward normal. In both groups, cardiac index at 34 degrees C was about 40% lower than at 37 degrees C. This was associated with 50% higher systemic vascular resistance and 30% lower oxygen availability to tissue. Oxygen consumption, however, was proportionally lower (45%) and coronary perfusion pressure was higher (28%) at 34 degrees C than at 37 degrees C; thus neither mixed venous nor coronary sinus blood oxygen saturation was compromised under hypothermic conditions. Although the trends in hemodynamic changes were similar in both groups, cardiac indices in patients with marked hemodilution were higher than cardiac indices in those with moderate hemodilution at all temperatures. This observation indicates that the hemodilution-induced rise in cardiac index remains intact even under hypothermic conditions. Under the conditions we studied, hypothermia with or without hemodilution had no significant adverse effects on hemodynamics and oxygen metabolisms of the whole body or of the heart.

Aged↗