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Biomedical subjects

H Shin

Publications and source records attributed to H Shin.

At least 55 records · Page 3Linked to original sources
PubMed1999

Supercritical fluid extraction of microcystins from cyanobacteria.

A new method for the fast extraction of microcystins RR and LR in cyanobacterium was developed using supercritical CO2. The microcystins were successfully extracted with aqueous methanol modified supercritical fluid (90% CO2, 9.0% methanol, 1.0% water). The method developed here has several advantages over solid-phase extraction sample preparation for the analysis of microcystins. Sample handling steps are minimized, thus reducing possible losses of analytes and saving analysis time. No organic solvent extractions are involved in this method, and no cleanup steps are employed.

Chromatography, High Pressure Liquid↗
PubMed1999

TRAF family proteins interact with the common neurotrophin receptor and modulate apoptosis induction.

The common neurotrophin receptor, p75(NTR), has been shown to signal in the absence of Trk tyrosine kinase receptors, including induction of neural apoptosis and activation of NF-kappaB. However, the mechanisms by which p75(NTR) initiates these intracellular signal transduction pathways are unknown. Here we report interactions between p75(NTR) and the six members of TRAF (tumor necrosis factor receptor-associated factors) family proteins. The binding of different TRAF proteins to p75(NTR) was mapped to distinct regions in p75(NTR). Furthermore, TRAF4 interacted with dimeric p75(NTR), whereas TRAF2 interacted preferentially with monomeric p75(NTR). TRAF2-p75(NTR), TRAF4-p75(NTR), and TRAF6-p75(NTR) interactions modulated p75(NTR)-induced cell death and NF-kappaB activation with contrasting effects. Coexpression of TRAF2 with p75(NTR) enhanced cell death, whereas coexpression of TRAF6 was cytoprotective. Furthermore, overexpression of TRAF4 abrogated the ability of dimerization to prevent the induction of apoptosis normally mediated by monomeric p75(NTR). TRAF4 also inhibited the NF-kappaB response, whereas TRAF2 and TRAF6 enhanced p75(NTR)-induced NF-kappaB activation. These results demonstrate that TRAF family proteins interact with p75(NTR) and differentially modulate its NF-kappaB activation and cell death induction.

Apoptosis↗
PubMed1999

Prognosis of Marfan and non-Marfan patients with cystic medial necrosis of the aorta.

The characteristics and prognosis of patients with cystic medial necrosis of the aorta were reviewed. Subjects were 46 patients who underwent aortic and/or aortic valve surgery between August 1965 and October 1994. All had histologically documented cystic medial necrosis including 22 Marfan patients. The patients with Marfan syndrome were substantially younger (median age, 32 vs 50 years; p < 0.05), and experienced annulo-aortic ectasia more frequently {81% (17/22) vs 46% (11/24); p < 0.05} than those without the syndrome. Sixty-eight percent (15/22) of the Marfan patients and 63% (15/24) of the non-Marfan patients experienced complications with aortic dissection, although not to a significant degree. The hospital mortality rate was 14% (3/22) in the Marfan group and 21% (5/24) in the non-Marfan group, which was also not significant. Of the 38 survivors, developments in the health of 37 were completely followed-up until October 1997. The cardiovascular event-free rate for Marfan patients at 10 years (28%) was lower than that for non-Marfan patients (68%, p = 0.057), whereas the actuarial survival rates at 10 years were nearly equal (72% for the Marfan patients and 74% for the non-Marfan patients). Reoperation was the first cardiovascular event in 77% (10/13) of the Marfan patients and in 14% (1/7) of the non-Marfan patients (p < 0.05). Cardiovascular event was the main cause of late death both for Marfan patients (80%; 4/5) and for non-Marfan patients (86%; 6/7). In conclusion, independent of the presence of Marfan syndrome, careful follow-up is necessary for patients with cystic medial necrosis of the aorta to eliminate serious late complications.

Adolescent↗
PubMed1999

Effect of storage temperature on cell viability in cryopreserved canine aortic, pulmonic, mitral, and tricuspid valve homografts.

We determined how long cryopreserved aortic, pulmonic, mitral, and tricuspid valve homografts could be stored in a deep freezer (-80 degrees C) without compromising fibroblast viability. Valves harvested from 20 anesthetized mongrel dogs were grouped into nonfrozen control, frozen and stored in liquid nitrogen (-196 degrees C), and frozen and stored in a deep freezer (-80 degrees C). Frozen groups were divided into subgroups and stored for 2, 4, 8, or 12 weeks. A leaflet of each valve was divided into three fragments, and fibroblast viability was analyzed by flow cytometry. Cell viability was defined as staining by fluorescent diacetate but not by propidium iodide. The viability of untreated control valves from all four sites was about 70%, decreasing to about 50% when treated with low doses of antibiotics. The viability of frozen valves stored in liquid nitrogen was about 45% without a significant difference among storage periods. The viability of valves frozen and stored in a deep freezer was significantly lower than for the liquid nitrogen group at 2 weeks for the mitral valve and at 4 weeks for other valves. These results suggest that homografts can be stored in a deep freezer for up to 2 weeks without deterioration.

Animals↗
PubMed1999

Surgical angioplasty of left main coronary stenosis complicating supravalvular aortic stenosis.

We successfully treated obstruction of the main coronary artery, not aortic valve leaflet adhesion to the intimal shelf, complicating supravalvular aortic stenosis by modifying the Brom aortoplasty. An autologous pericardial patch was used to enlarge the left main coronary artery as well as the stenotic aorta. This modification allows simple and effective restoration of coronary blood flow, while maintaining the Brom procedure's merit of achieving anatomic geometry of the aortic root in such patients.

Adolescent↗
PubMed1999

GTPase activity and biochemical characterization of a recombinant cotton fiber annexin.

A cDNA encoding annexin was isolated from a cotton (Gossypium hirsutum) fiber cDNA library. The cDNA was expressed in Escherichia coli, and the resultant recombinant protein was purified. We then investigated some biochemical properties of the recombinant annexin based on the current understanding of plant annexins. An "add-back experiment" was performed to study the effect of the recombinant annexin on beta-glucan synthase activity, but no effect was found. However, it was found that the recombinant annexin could display ATPase/GTPase activities. The recombinant annexin showed much higher GTPase than ATPase activity. Mg2+ was essential for these activities, whereas a high concentration of Ca2+ was inhibitory. A photolabeling assay showed that this annexin could bind GTP more specifically than ATP. The GTP-binding site on the annexin was mapped into the carboxyl-terminal fourth repeat of annexin from the photolabeling experiment using domain-deletion mutants of this annexin. Northern-blot analysis showed that the annexin gene was highly expressed in the elongation stages of cotton fiber differentiation, suggesting a role of this annexin in cell elongation.

Adenosine Triphosphatases↗
PubMed1999

[A case of Chlamydia pneumonia and systemic lupus erythematosus (SLE) pleurisy].

A 40-year-old female was admitted with right chest pain. SLE was absent from her past history, although she complained of polyarthralgia in winter. Atypical pneumonia/pleuritis was suspected by chest X-ray film, showing a nodular shadow in the right lower field and moderate pleural effusion. Chlamydia pneumonia was diagnosed by elevated anti-C. psittsci antibody, while characteristics of pleural fluid revealed serositis accompanied by SLE because of the high titered anti-DNA antibody and the low titered complement. She was cured by clarithromycin and subsequent administration of prednisolone and cyclophosphamide.

Adult↗
PubMed1999

Thrombin receptor mediated signals induce expressions of interleukin 6 and granulocyte colony stimulating factor via NF-kappa B activation in synovial fibroblasts.

OBJECTIVE: To clarify the mechanism of thrombin receptor mediated signal transduction and the induction of cytokines by thrombin stimulation in rheumatoid synovial fibroblasts. METHODS: Cytokines were measured by enzyme linked immunosorbent assay (ELISA) in the supernatants of cultured rheumatoid synovial fibroblasts stimulated by thrombin. To assess the mechanism of thrombin receptor mediated signal transduction in the rheumatoid synovial fibroblasts, electrophoretic mobility gel shift assay (EMSA), immunoglobulin kappa-chloramphenicol acetyltransferase (CAT) assay, and immunostaining for NF-kappa B subunit molecule was performed. RESULTS: Thrombin stimulation activated the inducible transcription factor NF-kappa B, and then induced subsequent expressions of interleukin 6 (IL6) and granulocyte colony stimulating factor (G-CSF) in the cells. CONCLUSION: Thrombin receptor mediated signal transduction could induce the expressions of IL6 and G-CSF, and increase inflammatory events in the cavum articulare via NF-kappa B activation.

Arthritis, Rheumatoid↗
PubMed1999

Minimally invasive port-access coronary artery bypass grafting.

The Port-Access endovascular cardiopulmonary bypass system (Heartport, Inc., Redwood City, CA, USA), a recent technological innovation in minimally invasive cardiac surgery, was conducted successfully in coronary artery bypass grafting on a 69-year-old woman. The left internal thoracic artery was harvested through a limited left anterior thoracotomy and anastomosed to the left anterior descending coronary artery on a protected and arrested heart. Intraoperative coronary angiography confirmed good graft patency. The patient was discharged from the hospital in good condition 7 days after the operation. This was the first successful minimally invasive Port-Access coronary artery bypass grafting in Japan.

Aged↗
PubMed1999

Right ventricular infarction complicating coronary artery bypass grafting.

Intraoperative right ventricular infarction immediately after coronary artery bypass grafting is a rare and potentially serious complication. We report a case in which an additional coronary artery bypass graft to a right ventricular branch with 99% stenosis brought about recovery from profound acute right ventricular failure. This case shows that complete revascularization to all graftable vessels, including even the right ventricular branch, is mandatory for successful coronary artery bypass grafting.

Angina Pectoris↗
PubMed1999

Angioplasty/bypass combination therapy in an 89-year-old man with left main trunk disease.

We report a case of an 89-year-old man presenting with unstable angina and left main trunk disease. Minimally invasive direct coronary artery bypass grafting supplemented by catheter intervention was successfully performed. In view of the increasing elderly population, angioplasty/bypass combination therapy may be an important alternative for elderly coronary artery disease patients.

Aged↗
PubMed1998

Pro-caspase-3 is a major physiologic target of caspase-8.

The apoptotic signal triggered by ligation of members of the death receptor family is promoted by sequential activation of caspase zymogens. We show here that in a purified system, the initiator caspases-8 and -10 directly process the executioner pro-caspase-3 with activation rates (kcat/Km) of 8.7 x 10(5) and 2.8 x 10(5) M-1 s-1, respectively. These rates are of sufficient magnitude to indicate direct processing in vivo. Differentially processed forms of caspase-3 that accumulate during its activation have similar rates of activation, activities, and specificities. The pattern and rate of caspase-8 induced activation of pro-caspase-3 in cytosolic extracts was the same as in a purified system. Moreover, immunodepletion of a putative intermediary in the pathway to activation, pro-caspase-9, was without consequence. Taken together these data demonstrate that the initiator caspase-8 can directly activate pro-caspase-3 without the requirement for an accelerator. The in vitro data thus help to deconvolute previous in vivo transfection studies which have debated the role of a direct versus indirect transmission of the apoptotic signal generated by ligation of death receptors.

Apoptosis↗
PubMed1998

Inhibition of immediate type allergic reactions by the aqueous extract of Kum-Hwang-San.

We studied the effect of aqueous extract of Kum-Hwang-San (KHS) on mast cell-mediated immediate type allergic reactions. KHS (1-100 microg/site) inhibited concentration-dependently mast cell-dependent ear swelling response induced by compound 48/80 (200 microg/site) in mice by both topical and intradermal application. KHS (0.1-100 microg/site) inhibited concentration-dependently passive cutaneous anaphylaxis induced by anti-dinitrophenyl (DNP) IgE in rats by both topical and intradermal application. KHS also inhibited concentration-dependently the histamine release from the rat peritoneal mast cells (RPMC) by compound 48/80 and anti-DNP IgE. Moreover, KHS had a significant inhibitory effect on anti-DNP IgE-induced tumor necrosis factor-alpha (TNF-alpha) secretion from RPMC. These results indicate that KHS inhibits immediate type allergic reactions by inhibition of histamine release and TNF-alpha secretion from mast cells in vivo and in vitro.

Animals↗
PubMed1998

[A case of tuberculous pyothorax after an interval of four years of finishing with the first treatment for pulmonary tuberculosis].

We reported a case of tuberculous pyothorax which developed at four years after finishing with the first treatment for pulmonary tuberculosis. A 50-year-old female was admitted to our hospital with right chest pain. Tuberculous pyothorax was diagnosed by means of polymerase chain reaction (PCR method) of pleural effusion and of histological findings of the pleural section. She was cured by operation, pleural drainage and anti-tuberculous drugs. The bone scincigram of 99mTc revealed accumulation in the right 9th rib, tuberculous empyema might have been a secondary development from osteomyelitis.

Empyema, Tuberculous↗
PubMed1998

Plasma (1-->3)-beta-D-glucan measurement and polymerase chain reaction on sputum as practical parameters in Pneumocystis carinii pneumonia.

We report a case of Pneumocystis carinii pneumonia in a patient with acquired immunodeficiency syndrome diagnosed and monitored with polymerase chain reaction (PCR) for Pneumocystis carinii on sputum and measurement of plasma (1-->3)-beta-D-glucan (G-test). Results of both studies paralleled the clinical and radiographic improvement. However, the plasma (1-->3)-beta-D-glucan level remained higher than normal when PCR for Pneumocystis carinii became negative in sputum. Both PCR for Pneumocystis carinii on sputum and measurement of plasma (1-->3)-beta-D-glucan are useful for noninvasive diagnosis and monitoring of Pneumocystis carinii, although further investigation is necessary to quantify their relationship.

AIDS-Related Opportunistic Infections↗
PubMed1998

[Basic approaches in minimally invasive cardiac surgery (MICS) and its selection].

Recently, minimally invasive cardiac surgery (MICS) has been developed and popularized as a less stressful and less invasive technique in the field of cardiac surgery. There are eight currently available MICS approaches for open heart surgery. The optimum approach should be selected for each patient based on the results of preoperative examination including chest X-ray, computed tomography, and angiography. Between December 1996, when we first introduced MICS for mitral repair, and the end of November 1998, we performed MICS in 67 patients [excluding cases of MIDCAB]. These included 11 patients who received the Port-Access (Heartport, Inc.) system. Although no patients died in hospital stay, one died of cerebrovascular bleeding eight months later. All patients were evaluated in the outpatient department as being NYHA class I. In view of future technological progress, we expect that MICS will gradually become more widespread in cardiac surgery.

Cardiac Surgical Procedures↗
PubMed1997

Thrombin activates NF-kappa B through thrombin receptor and results in proliferation of vascular smooth muscle cells: role of thrombin in atherosclerosis and restenosis.

We investigated the role of thrombin in the pathogenesis in atherosclerosis and restenosis. First we examined the effect of thrombin on cultured human vascular smooth muscle cells (VSMC). We showed that thrombin acts as a mitogen on VSMC through thrombin receptor. The expression of thrombin receptor was increased in the cell lines of VSMC established from directional coronary atherectomy (DCA). This is more pronounced in the cells from patients with restenosis after PTCA. Next we investigated the signaling pathway from thrombin/thrombin receptor. Thrombin activates thrombin receptor resulting in the exposing of the agonist peptide domain (thrombin receptor agonist peptide, TRAP). The signal from thrombin/thrombin receptor activated protein C kinase, tyrosine kinase, and MAP kinase and resulted in NF-kappa B activation. Furthermore, treatment of the cells with antisense p65 oligodeoxynucleotides of NF-kappa B inhibited the thrombin-stimulated growth of VSMC in vitro. These results suggest that thrombin may have a role in the pathogenesis of atherosclerosis and restenosis after PTCA through the thrombin receptor.

Arteriosclerosis↗