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Biomedical subjects

D S Kim

Publications and source records attributed to D S Kim.

At least 145 records · Page 8Linked to original sources
PubMed2000

Risk factors for the development of hemodynamically significant cardiac arrhythmias in patients with mechanical ventilation.

PURPOSE: The purpose of this article was to identify the risk factors related to development of hemodynamically significant cardiac arrhythmias in patients with mechanical ventilation. MATERIALS AND METHODS: Holter recording and echocardiogram were performed within 24 hours of ventilator initiation in patients on mechanical ventilation (MV) owing to respiratory failure (RF) from various reasons. RESULTS: From 68 patients, hemodynamically significant cardiac arrhythmias were detected in 18 patients (26.5%). Initial mean arterial pressure, maximal heart rate, and initial pH were identified as risk factors for hemodynamically significant cardiac arrhythmias. Additionally, the patients with pressure-controlled ventilation as an initial ventilatory mode developed hemodynamically significant cardiac arrhythmias less frequently than the patients with other modes (15.8% vs. 40%, P = .03). In multivariate analysis, initial mean arterial pressure (< 70 mm Hg, odds ratio [OR]: 5.5; 95% confidence interval [CI]: 1.2 to 24.2, P = .026), maximal heart rate (> 120/min, OR: 19.7; 95% CI: 2.0 to 190.9, P = .01), and pressure-controlled ventilation (OR: 0.13; 95% CI: 0.03 to 0.55, P = .006) were associated with the development of hemodynamically significant cardiac arrhythmias. CONCLUSIONS: These findings suggest that during the early stages of mechanical ventilation with acute respiratory failure, hemodynamically significant cardiac arrhythmias are directly associated with tachycardia (> or = 120/min), initial MAP (<70 mm Hg), and, inversely, the initial use of pressure-controlled ventilation.

APACHE↗
PubMed2000

Aromatase and sulfatase inhibitors from Lepiota americana.

From an edible mushroom Lepiota americana Pk., (Agaricaceae), 2-aminophenoxazin-3-one that inhibited aromatase at IC50 = 5.7 microM and 3 beta-hydroxy-5,8-epidioxyergosta-6,22-diene that inhibited sulfatase at IC50 = 0.9 microM were isolated. Neither 2-aminophenoxazin-3-one was active against sulfatase nor was 3 beta-hydroxy-5,8-epidioxyergosta-6,22-diene active against aromatase.

Agaricales↗
PubMed2000

Pneumocystis carinii pneumonia associated with a rapid reduction of cortisol level in a patient with ectopic ACTH syndrome treated by octreotide and ketoconazole.

A case is herein reported of pneumocystis carinii pneumonia in a 60-year-old female patient with ectopic production of ACTH at a position 2 cm superior to her right clavicle, revealed in an octreotide scan. Her extremely high plasma ACTH and cortisol levels (460 pg/ml and 80 microg/dl, respectively) were markedly decreased with the combined treatment of octreotide (300 microg/d) and ketoconazole (600 mg/d). As her serum cortisol concentration decreased, pneumocystis carinii pneumonia occurred on the third day of treatment. A secondary E. coli infection was superimposed and the patient died of disseminated intravascular coagulation and adult respiratory distress syndrome. This case suggests that primary prophylaxis for pneumocystis carinii infection should be initiated before cortisol lowering therapy, especially when the plasma cortisol concentration is excessively high, and that early adjunctive glucocorticoid therapy can reduce the acute mortality in patients with endogenous Cushing's syndrome and Pneumocystis carinii pneumonia. This case study would also like to point out that plasma ACTH and cortisol levels were decreased effectively by the combination of octreotide and ketoconazole in this instance of ectopic ACTH syndrome.

ACTH Syndrome, Ectopic↗
PubMed2000

Suppression of collagen-induced arthritis with histone H1.

Besides roles in nucleus mediating the condensation of DNA into chromatin, the involvement of histones in autoimmune diseases, hormone regulation, and killing leukemia cells has been reported. In order to investigate the functions of histones on an autoimmune disease, histone H1 was injected into collagen-induced arthritis (CIA) mice. A dramatic suppression of CIA by histone H1 was observed at a dose of 1 mg/kg bodyweight of mouse. In addition, the increased level of anti-inflammatory cytokine IL-10 was detected in cultured splenocytes from the mouse treated with histone H1. These findings suggest that histone H1 suppresses the collagen-induced arthritis, possibly by increasing the level of IL-10 production.

Animals↗
PubMed2000

Arrangement of orientation pinwheel centers around area 17/18 transition zone in cat visual cortex.

In the primary visual cortex of higher mammals, orientation preferences are represented continuously except for singular points, so-called pinwheel centers. In spite of the uniqueness of orientation pinwheel centers, very little is known about the pattern of their arrangement. In this study we examined the arrangement of orientation pinwheel centers in the cat visual cortex by optical imaging of intrinsic signals. Our results demonstrate that orientation pinwheel centers are arranged in a unique geometric pattern around the area 17/18 transition zone: pinwheel centers of the same type are arranged in rows parallel to the transition zone, and rows of clockwise and counterclockwise pinwheel centers are arranged alternately. We suggest that the areal border imposes a strong restriction on the pattern formation of orientation preference maps in the visual cortex.

Animals↗
PubMed2000

Posterior segment neovascularization associated with acute ophthalmic artery obstruction.

PURPOSE: To report previously unrecorded ocular neovascularization associated with acute ophthalmic artery obstruction (AOAO) that presents clinical manifestations of acute concomitant obstruction of the retinal and posterior ciliary circulations. METHODS: This report documents the clinical, fluorescein angiographic, and histopathologic findings in two patients with AOAO followed by posterior segment neovascularization. RESULTS: Ophthalmoscopic findings showed whitening of the posterior pole, arterial attenuation, and a pale optic disk. Serial fluorescein angiograms showed a nearly total shutdown of choroidal and retinal perfusion, degeneration of the retinal pigment epithelium and choriocapillaris, and eventual development of a huge neovascular frond at the posterior pole. Histopathologic examination of the enucleated eyeball showed inner retinal necrosis caused by central retinal artery obstruction, degeneration of the outer retina with choriocapillaris obstruction caused by impairment of choroidal circulation, and a thick preretinal neovascular frond at the posterior pole. CONCLUSIONS: These results suggest that AOAO can induce ocular neovascularization, which to the authors' knowledge has not yet been reported.

Acute Disease↗
PubMed2000

Effects of pH and trace minerals on long-term starvation of Leuconostoc mesenteroides.

Laboratory experiments have definitively shown that exopolymer-producing bacteria have the potential to modify the flow of fluids in oil reservoirs to enhance oil production. Once injected into the reservoir, they will be subjected to a wide range of pH values and to starvation resulting from nutrient depletion. For successful field implementation it is necessary to have a fundamental understanding of these effects on the viability of bacteria. This paper addresses the effects of pH and trace minerals on cell viability of Leuconostoc mesenteroides during carbon source depletion. Two different carbon sources were used to grow cells before transferring the cells to starvation conditions: sucrose and a combination of glucose and fructose. These substrates were chosen because L. mesenteroides produces a significant amount of water-insoluble exopolymers (dextran) under sucrose-fed conditions, which may enhance cell survival under harsh conditions. The effects of dextran on the cell viability were tested at different pH values with and without trace minerals. The rate of cell death followed an exponential-decay law for different values of the solution pH. The optimal solution pH for survival was pH 5, whereas cells died rapidly at pH 3 and below and at pH 13 and above. The sucrose-fed cells showed a greater viability than cells fed glucose and fructose for all pH ranges tested. The results indicated that water-insoluble exopolymers help cells survive for longer periods of time under starvation conditions. The effects of trace minerals on cell culturability were tested at two pH values, 4.5 and 7. For both cases, cells showed a greater culturability (smaller decay rate constant) in the presence of trace minerals than without trace minerals. It was also found that the effects of trace minerals on cell culturability were greater for glucose-fructose-fed cells than for sucrose-fed cells. The Michaelis pH function theory was used for comparing the relationships between the cell decay rate and pH.

Biofilms↗
PubMed2000

A tetrodotoxin-producing Vibrio strain, LM-1, from the puffer fish Fugu vermicularis radiatus.

Identification of tetrodotoxin (TTX) and its derivatives produced from a Vibrio strain in the intestine of the puffer fish Fugu vermicularis radiatus was performed by thin-layer chromatography, electrophoresis, high-performance liquid chromatography, and gas chromatography-mass spectrometry, together with a mouse bioassay for toxicity. It was demonstrated that the isolated bacterium produced TTX, 4-epi-TTX, and anhTTX during cultivation, suggesting that Vibrio strains are responsible for the toxification of the puffer fish.

Animals↗
PubMed2000

Acute cerebral phaeohyphomycosis due to Wangiella dermatitidis accompanied by cerebrospinal fluid eosinophilia.

We report a case of cerebral phaeohyphomycosis due to Wangiella dermaitidis in an immunocompetent adult man. His cerebrospinal fluid (CSF) showed pleocytosis with a high eosinophil count but without peripheral blood eosinophilia. The present case suggested that this black yeast-like fungus should be included when the causes of CSF eosinophilia are considered, even though it is an extremely rare pathogen.

Adult↗
PubMed2000

Magnetic resonance studies of brain function and neurochemistry.

In the short time since its introduction, magnetic resonance imaging (MRI) has rapidly evolved to become an indispensable tool for clinical diagnosis and biomedical research. Recently, this methodology has been successfully used for the acquisition of functional, physiological, and biochemical information in intact systems, particularly in the human body. The ability to map areas of altered neuronal activity in the brain, often referred to as functional magnetic resonance imaging (fMRI), is probably one of the most significant recent achievements that rely on this methodology. This development has permitted the examination of functional specialization in human and animal brains with unprecedented spatial resolution, as demonstrated by mapping at the level of orientation and ocular dominance columns in the visual cortex. These functional imaging studies are complemented by the ability to study neurochemistry using magnetic resonance spectroscopy, allowing the determination of metabolic processes that support neurotransmission and neurotransmission rates themselves.

Animals↗
PubMed2000

Closing volume influences the postural effect on oxygenation in unilateral lung disease.

In normal adults, both blood flow and ventilation are distributed preferentially to the dependent lung zones. In adults with unilateral lung disease, arterial oxygenation improves when they are positioned with their good lung down because of improved matching of ventilation and perfusion. When the closing volume is increased, dependent airways are closed during tidal breathing, so that reduced ventilation-perfusion ratio and hypoxia develops and ventilation is preferentially distributed to the upper lung zones. We undertook an observational study on the effects of lateral recumbency on arterial oxygenation in adult patients with unilateral lung disease and tested the hypothesis that oxygenation in lateral recumbency might be influenced by an increase in closing volume. Arterial blood gases were analyzed in the supine, right and left lateral decubitus positions and the AaPO(2) was calculated in 44 randomly selected patients 49.9 +/- 18.7 yr of age with unilateral pneumonia (23 cases) or pulmonary tuberculosis (21 cases). In 26 patients, individual Pa(O(2)) with the normal lung in the dependent position was higher than that with the diseased lung; the opposite was true for 18 patients. The difference in Pa(O(2)) and AaPO(2) between the two positions was statistically significant in both groups. In 16 patients (10 men and six women 49.2 +/- 18.2 yr of age), we measured closing volume and determined the fractional ventilation to each lung by (133)Xe lung scan in the three positions. In these 16 patients, the difference in Pa(O(2)) between the normal and the diseased lung in the dependent position was related significantly to the difference in the fractional ventilation going to the normal lung between the dependent and the supine position (r = 0.642, p = 0. 007). The latter was related significantly to the % predicted closing volume (CV/VC) (r = -0.597, p = 0.015). This study has shown that closing volume, as well as posture, might be involved in determining oxygenation in lateral recumbency in patients with unilateral lung disease.

Adolescent↗
PubMed2000

An optimal dose of perfluorocarbon for respiratory mechanics in partial liquid ventilation for dependent lung-dominant acute lung injury.

BACKGROUND: Despite increasing knowledge about partial liquid ventilation (PLV), the optimal dose of perfluorocarbon (PFC) is not yet established. Because there exist normal regions in the lung with ARDS and because PLV in the normal lung results in worsened gas exchange, we postulated that the optimal dose of PFC for PLV may be less than the functional residual capacity (FRC) dose in the lung with limited disease. DESIGN AND SETTING: Animal study at the Asan Institute for Life Sciences, Seoul, Korea. SUBJECTS: Twelve rabbits in which dependent lung-dominant lung injury was created by a modified saline solution lavage. INTERVENTIONS: PLV performed at six different doses of perfluorodecalin in sequence (3, 6, 9, 12, 15, and 18 mL/kg every 15 min). MEASUREMENTS AND RESULTS: Our modified saline solution lavage induced atelectasis and hemorrhage confined to the dependent lung with severe hypoxia (PaO(2)/fraction of inspired oxygen = 37 +/- 6 mm Hg). Peak airway pressure (Ppeak) and inspiratory pause pressure (Ppause) with PLV were lower at doses of 3 to 15 mL/kg (all p < 0.05), but not different at a dose of 18 mL/kg, when compared with gas ventilation. Ppeak increased at doses of 12, 15, and 18 mL/kg, when each was compared with the preceding PFC dose. At increasing PFC doses, the change in the elastic component of airway pressure (Ppause after minus Ppause before) was negative until the dose of 9 mL/kg, but was positive at doses of 12 mL/kg and above. The change in the resistive component ([Ppeak minus Ppause] after minus [Ppeak minus Ppause] before) was negative until the dose of 6 mL/kg, but was positive at the dose > or = 9 mL/kg. CONCLUSION: Respiratory mechanics during PLV for dependent lung-dominant lung injury were optimal at a PFC dose less than the FRC.

Animals↗
PubMed2000

Effects of oncostatin M on hormone release of rat pituitary cells in primary culture.

It has become increasingly clear that cytokines play an important role in modulating neuroendocrine regulation, especially in the secretion of corticotropin (ACTH) in the pituitary. Oncostatin M (OSM), a cytokine of IL-6 family has been reported to increase ACTH secretion and pro-opiomelanocortin (POMC) transcription in murine corticotroph pituitary tumor cells (AtT20 cells). The present study was undertaken to determine the effects of OSM on hormonal release in primary culture of rat pituitary cells. Growth hormone or prolactin release was not affected by OSM. OSM (1 nM) stimulated ACTH release (35.1% increase versus control, p<0.001) in dispersed pituitary cells of rat to a lesser extent than in AtT20 cells. Corticotropin releasing hormone (CRH) (10 nM) also induced a 2.3-fold increase of ACTH secretion (p<0.001), but co-treatment of OSM and CRH did not exhibit any synergistic effect on ACTH secretion. We conclude OSM has a stimulatory effect on ACTH secretion in normal rat pituitary cell cultures, and OSM acts mainly on corticotroph, supporting the potential role of OSM to modulate immune-endocrine regulation in the pituitary.

Adrenocorticotropic Hormone↗
PubMed2000

Serologic and histopathologic study of Chlamydia pneumoniae infection in atherosclerosis: a possible pathogenetic mechanism of atherosclerosis induced by Chlamydia pneumoniae.

Chronic infection and inflammation have recently been implicated as important etiologic agents for atherosclerosis in general and, in particular, ischemic heart disease. Several agents have been suggested as possible candidates for the chronic inflammation including cytomegalovirus, Helicobacter pylori and Chlamydia pneumoniae. We hypothesized that a vascular infection with C. pneumoniae may induce a chronic inflammatory reaction in the host vascular tissue and activated inflammatory cells may express inflammatory mediators such as cyclooxygenase-2 (COX-2) and matrix metalloproteinases (MMPs). At first, we evaluated the relationship between C. pneumoniae infection and atherosclerosis indirectly by serologic study, and then, to confirm our hypothesis, we performed an immunohistochemical study of atherosclerotic plaques. The seropositive rate of anti-Chlamydia pneumoniae IgG was higher in the disease group (Group I, 59.8%, n = 254) than in the negative control group (Group III, 47.4%, n = 97) (p = 0.041), but the anti-Chlamydia pneumoniae IgA was not different in seropositivity between the two groups (Group I, 64.6%; Group III, 57.7%). The simultaneous seropositive rates of both IgG and IgA were 56.7% in Group I and 43.3% in Group III (p = 0.033). In subgroups without the conventional risk factors of atherosclerosis, these findings were more prominent. Furthermore, we performed immunohistochemical staining on the atherosclerotic aortic tissues obtained from patients that were seropositive to C. pneumoniae (n = 5), by using antibodies to C. pneumoniae, COX-2, and MMP-9. The immunoreactivity for COX-2 and MMP-9 increased in the atherosclerotic plaques itself, predominantly in the surrounding area of immunoreactive C. pneumoniae. These findings support our hypothesis and C. pneumoniae may participate in a pathogenetic mechanism for atherogenesis or progression of atherosclerosis. The present study may open a promising perspective concerning future therapeutic trials of chronic inflammation related atherogenesis under pathophysiological conditions.

Aged↗
PubMed2000

Endoscopic mucosal resection with a ligation device for early gastric cancer and precancerous lesions: comparison of its therapeutic efficacy with surgical resection.

Endoscopic mucosal resection with a ligation device (EMR-L) has become important in the curative treatment of precancerous lesions and early gastric cancers (EGCs), but little is known of the long-term efficacy and survival rates of EMR-L compared with surgical resection. We analyzed the therapeutic efficacy and safety of EMR-L in cases of EGC and precancerous lesions and compared the results of EMR-L with those of gastrectomy in patients with EGC over the same periods. EMR-L was performed on 20 EGCs and 54 precancerous lesions including tubular adenomas with or without severe dysplasias in 74 patients. Macroscopic type, size and location of the lesion were determined by endoscope, and the depth of invasion in EGCs was determined by endoscopic ultrasonography and confirmed by pathologic examination of the resected specimens. All the EGC cases were endoscopically followed up for at least 18 months (range, 18-66 months). Patients were selected that underwent subtotal gastrectomy and the survival rates were compared with those that underwent EMR-L. Complete resection was made in a single EMR-L treatment session in 61 cases (82.4%; 91.5%, were precancerous lesions and 65% were EGCs). After a repeat trial of EMR-L, the total rate of complete resection of precancerous lesions and EGCs was 92.6% and 85.0%, respectively. The survival rate of EGCs showed that complete resection by EMR-L resulted in 2 and 5 year survival rates of 100% and 95%, which are comparable to those of surgery (100% and 100%). This study suggests that EMR-L is a technically simple, minimally invasive and highly safe and effective treatment modality for selective EGCs, and offers an alternative to surgical treatment.

Adult↗
PubMed2000

Apoptosis of peripheral blood mononuclear cells in Kawasaki disease.

OBJECTIVE: Kawasaki disease (KD) is an acute systemic vasculitis characterized by marked depletion of peripheral lymphocytes in the acute stage of the disease. We evaluated the degree of apoptosis of peripheral blood mononuclear cells (PBMC) in KD and investigated whether the Fas-Fas ligand system is involved in inducing apoptosis in KD. METHODS: Fifteen patients with KD were classified into 2 groups, Group KW1 (initial stage of disease, or fever < 5 days) and Group KW2 (fulminant stage of disease, or fever > 5 days). PBMC were isolated and after 5, 24, and 48 h incubation stained and analyzed by flow cytometry. The levels of serum soluble Fas were measured by ELISA. mRNA expression of Fas ligand was evaluated by reverse transcription polymerase chain reaction. RESULTS: The degree of apoptosis at 24 h was 20.2 +/- 5.6% in Group KW1, higher than that of normal (p < 0.05) and febrile controls (p < 0.01); and 10.8 +/- 2.8% in Group KW2, lower than that of normal (p < 0.01) and febrile controls (p < 0.01). At 48 h the degree of apoptosis was 37.7 +/- 4.2% in Group KW1, significantly higher than normal (p < 0.01) and febrile controls (p < 0.01); and 17.1 +/- 5.6% in Group KW2, lower than normal (p < 0.01) and febrile controls (p < 0.01). The mean level of serum soluble Fas in the acute stage of KD was 0.45 +/- 0.26 ng/ml, significantly lower versus the subacute stage (1.06 +/- 0.40 ng/ml) (p < 0.01). FasL of mRNA was expressed in PBMC of all patients with acute stage KD. whereas no expression was noted in the subacute stage of disease. CONCLUSION: Marked decrease of peripheral blood lymphocytes in acute stage KD may be caused by the upregulated apoptosis of lymphocytes; Fas-Fas ligand may be involved in this upregulation.

Acute Disease↗
PubMed2000

The value of interleukin-12 as an activity marker of pulmonary sarcoidosis.

BACKGROUND: Sarcoidosis is characterized by hyperactivity of T-helper lymphocytes and recent studies showed that they were mainly Th1 cells. IL-12 is a major cytokine inducing Th1 differentiation of naive T cells. This study was performed to test whether IL-12 can be a marker for disease activity and possibly a prognosis in sarcoidosis. METHODS: IL-12 levels of BALF (BALF-IL-12) and conditioned medium of alveolar macrophages (AM) were measured by ELISA in 36 patients with pulmonary sarcoidosis (14 males and 22 females, mean age: 39.6 +/- 11.0 years) and eleven normal controls. Clinically, 16 patients had active sarcoidosis and 20 had an inactive disease. RESULTS: BALF-IL-12 of sarcoidosis patients (41.3 +/- 43.9 pg/ml) was significantly higher than that of normal controls (2.5 +/- 0.4 pg/ml) (p < 0.001). The patients with active disease (71.3 +/- 54.3 pg/ml) had a higher BAL-IL-12 level than those with inactive disease (17.3 +/- 13.8 pg/ml) (p = 0.0001). It had a significant correlation with the number of T4 cells (p = 0.0001), total cell number, number and percentage of lymphocytes (p = 0.0001) and AM (p = 0.001) in BALF. It was also significantly correlated with soluble ICAM-1 levels in serum (p = 0.0001) and BALF (p = 0.002), and ICAM-1 expression of AM (p = 0.001). Furthermore the patients whose condition worsened without therapy had a significantly higher initial BALF-IL-12 level than the patients whose condition improved spontaneously. The AM of sarcoidosis secreted significantly more IL-12 (133 +/- 177 pg/ml) than AM of controls (68.3 +/- 43.7 pg/ml) (p = 0.038). CONCLUSION: Our data suggest that the BALF-IL-12 level can be used as a marker of the activity of pulmonary sarcoidosis and possibly prognosis.

Adult↗