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Biomedical subjects

H Kim

Publications and source records attributed to H Kim.

At least 469 records · Page 26Linked to original sources
PubMed1998

Screening and isolation of antibiotic resistance inhibitors from herb materials-resistance inhibition of volatile components of Korean aromatic herbs.

The resistance inhibitory activities of 54 odorant mixtures (essential oil) from 41 Korean aromatic herbs were tested against multi-drug resistant Staphylococcus aureus SA2, which has resistances to 10 usual antibiotics including chloramphenicol. As results, combinations of 28 kinds of samples from 21 herbs and chloramphenicol have resistance inhibitory activities in dose dependent manner.

Chloramphenicol Resistance↗
PubMed1998

Baroreflex-mediated bradycardia but not tachycardia is blunted peripherally by intravenous mu-opioid agonists.

OBJECTIVE: We sought to test the hypothesis that an intravenous dose of H-Tyr-D-Arg-Phe-Lys-NH2, a highly mu-receptor selective opioid peptide, suppresses baroreflex sensitivity through a peripheral mechanism. STUDY DESIGN: A transient change in mean arterial pressure was produced in chronically instrumented pregnant ewes by norepinephrine or sodium nitroprusside in the absence or in the presence of H-Tyr-D-Arg-Phe-Lys-NH2, a highly mu-selective opioid peptide. In some studies naloxone methiodide, a peripheral opioid antagonist, was infused starting 60 minutes before the administration of H-Tyr-D-Arg-Phe-Lys-NH2 and maintained for a total of 90 minutes. Linear plots were obtained when the changes in mean arterial pressure during the pressure rise were plotted against the changes in heart rate and the sensitivity of the baroreflex was derived as the slope of the linear regression line. RESULTS: We observed (1) lower baroreflex sensitivity after H-Tyr-D-Arg-Phe-Lys-NH2 administration with a hypertensive stimulus; (2) unchanged baroreflex sensitivity after H-Tyr-D-Arg-Phe-Lys-NH2 administration with a hypotensive stimulus; and (3) unchanged baroreflex sensitivity after H-Tyr-D-Arg-Phe-Lys-NH2 administration with a hypertensive stimulus in the presence of naloxone methiodide. CONCLUSION: H-Tyr-D-Arg-Phe-Lys-NH2 suppresses the hypertensive but not the hypotensive arm of the baroreflex through peripheral opioid receptors. These results suggest that mu-opioid receptors are present in the vagus nerves and that the activation of these opioid receptors inhibits reflex bradycardia in pregnant sheep.

Animals↗
PubMed1998

Cardiovascular and metabolic responses to two receptor-selective opioid agonists in pregnant sheep.

OBJECTIVE: Our purpose was to assess the effects of an intravenous dose of a highly selective mu-(DALDA) and delta-(DPDPE) opioid peptide to determine which class of peptide has the best clinical potential. STUDY DESIGN: Chronically instrumented pregnant ewes received a 0.3 mg/kg intravenous bolus of each peptide with and without opioid receptor blockade by means of a randomized prospective design. RESULTS: Intravenous DALDA produced only mild hypertension and a loss of heart rate variability, whereas DPDPE produced respiratory depression, maternal hypertension, and a fall in heart rate in both mother and fetus. Uterine blood flow, oxygen uptake, and glucose uptake were unchanged with both drugs. The effects of DALDA but not DPDPE were reversed by opioid receptor blockade. CONCLUSION: The delta-selective agonist had multiple nonopioid adverse effects, whereas the mu-selective agonist was well tolerated by the pregnant ewe, suggesting that mu-selective agonists have better potential for clinical use as an analgesic in pregnancy.

Animals↗
PubMed1998

Accumulated clonal genetic alterations in familial and sporadic colorectal carcinomas with widespread instability in microsatellite sequences.

A subset of hereditary and sporadic colorectal carcinomas is defined by microsatellite instability (MSI), but the spectra of gene mutations have not been characterized extensively. Thirty-nine hereditary nonpolyposis colorectal cancer syndrome carcinomas (HNPCCa) and 57 sporadic right-sided colonic carcinomas (SRSCCa) were evaluated. Of HNPCCa, 95% (37/39) were MSI-positive as contrasted with 31% (18/57) of SRSCCa (P < 0.000001), but instability tended to be more widespread in SRSCCa (P = 0.08). Absence of nuclear hMSH2 mismatch repair gene product by immunohistochemistry was associated with germline hMSH2 mutation (P = 0.0007). The prevalence of K-ras proto-oncogene mutations was similar in HNPCCa and SRSCCa (30% (11/37) and 30% (16/54)), but no HNPCCa from patients with germline hMSH2 mutation had codon 13 mutation (P = 0.02), and two other HNPCCa had multiple K-ras mutations attributable to subclones. 18q allelic deletion and p53 gene product overexpression were inversely related to MSI (P = 0.0004 and P = 0.0001, respectively). Frameshift mutation of the transforming growth factor beta type II receptor gene was frequent in all MSI-positive cancers (85%, 46/54), but mutation of the E2F-4 transcription factor gene was more common in HNPCCa of patients with germline hMSH2 mutation than in those with germline bMLH1 mutation (100% (8/8) versus 40% (2/5), P = 0.04), and mutation of the Bax proapoptotic gene was more frequent in HNPCCa than in MSI-positive SRSCCa (55% (17/31) versus 13% (2/15), P = 0.01). The most common combination of mutations occurred in only 23% (8/35) of evaluable MSI-positive cancers. Our findings suggest that the accumulation of specific genetic alterations in MSI-positive colorectal cancers is markedly heterogeneous, because the occurrence of some mutations (eg, ras, E2F-4, and Bax genes), but not others (eg, transforming growth factor beta type II receptor gene), depends on the underlying basis of the mismatch repair deficiency. This genetic heterogeneity may contribute to the heterogeneous clinical and pathological features of MSI-positive cancers.

Adaptor Proteins, Signal Transducing↗
PubMed1998

Surgical resection of lung cancer originating in a tracheal bronchus.

We experienced a case of lung cancer that developed from a tracheal bronchus in an 80-year-old man. The tumor was completely resected by right upper lobectomy and resection of the tracheal bronchus as well as dissection of the mediastinal lymph nodes. Postsurgical pathologic staging was stage IB (T2 N0 M0) adenocarcinoma.

Adenocarcinoma↗
PubMed1998

Effects of withdrawal of bracing in matched pairs of children with osteogenesis imperfecta.

OBJECTIVES: To evaluate the effects of withdrawal of long-leg braces (hip-knee-ankle-foot orthoses [HKAFO]) on activity and ambulation in children with osteogenesis imperfecta. DESIGN: A prospective, randomized cross-over trial, that describes the effects of withdrawing HKAFO. PATIENTS: Ten children who were ambulatory with the assistance of braces. All had type III or IV osteogenesis imperfecta. Children were paired for age and clinical severity. Strength testing, fractures, and independence in daily activity were monitored at 4-month intervals for 32 months (16 months each of braced and unbraced periods). Gait was analyzed during braced and unbraced conditions. RESULTS: Muscle strength declined .35 grade during unbraced and .1 grade during braced intervals. Children spent more time in upright activity during braced intervals than during unbraced intervals (p = .17). Children were more independent in daily activities during braced than during unbraced periods (p = .14). Seventeen fractures of lower extremities occurred during all the unbraced periods, and 8 occurred during the braced intervals (p = .08); the fracture rate was higher during unbraced intervals. (p = .06) Bracing was associated with increased hip flexion and stride length and decreased transverse plane pelvic rotation. CONCLUSION: Withdrawal of HKAFO in children with osteogenesis imperfecta who had achieved upright activity was not associated with significant decrease in muscle strength or independence, but there was an associated increase in fracture rate that nearly reached significance.

Activities of Daily Living↗
PubMed1998

Central alveolar hypoventilation in neurosarcoidosis.

Although the lung is almost always involved in sarcoidosis and respiratory failure is not uncommonly caused by intrinsic lung disease, chronic alveolar hypoventilation on the basis of neurosarcoidosis has not been previously described. This report describes the case of a 42-year-old woman with sarcoidosis and documented involvement of the lungs, muscle, peripheral nerves, and skin. She presented with ventilatory failure and a vital capacity of 700mL and required hospitalization for intubation and mechanical ventilation. After failing ventilator weaning attempts and requiring continuous ventilatory assistance, she was extubated to continuous use of noninvasive intermittent positive pressure ventilation (IPPV). She eventually weaned to nocturnal-only use of noninvasive IPPV. However, her PaCO2 remained elevated during daytime hours despite the fact that her vital capacity had returned to 3,600mL. She was not obese, and her oxyhemoglobin saturation (SaO2) was normal on room air. Subsequent attempts to discontinue nocturnal nasal IPPV resulted in marked nocturnal decreases in SaO2 and return of symptoms. This case illustrates successful noninvasive management of an apparently unique occurrence of central alveolar hypoventilation caused by neurosarcoidosis.

Adult↗
PubMed1998

Colon perforation in hyperimmunoglobulin E syndrome.

Colon perforation from hyperimmunoglobulin E syndrome is very rare, and only one case has been reported in the English-language literature. Herein, the authors report another case of colon perforation experienced in hyperimmunoglobulin E syndrome. The patient was an 8-year-old girl with frequent infection, eczematoid dermatitis, and an increased serum level of immunoglobulin E. During admission, panperitonitis developed caused by colon perforation. Treatment was resection of the perforated segment of the colon and a double-barrel colostomy. The patient has been doing well 18 months after treatment.

Child↗
PubMed1998

Renal actions of endothelin-1 under endothelin receptor blockade by BE-18257B.

PURPOSE: Endothelin-1 (ET-1), a peptide produced by the vascular endothelium, causes profound renal vasoconstriction by binding to ET-A receptors. The present study examined the renal actions of ET-1 after ET-A receptors were blocked by BE-18257B to unmask the functions of ET-B receptors. MATERIALS AND METHODS: Renal hemodynamics and clearance measurements were obtained in anesthetized dogs after intrarenal infusion of BE-18257B at 100 ng./kg./min. (Group 1), after intrarenal infusion of ET-1 at 2 ng./kg./min. (Group 2), or after intrarenal infusion of ET-1 superimposed on BE-18257B (Group 3). RESULTS: In Group 1, BE-18257B infusion did not alter arterial pressure, renal blood flow (RBF), GFR or tubular function. In Group 2, ET-1 infusion led to a significant decrease in RBF and GFR (37 and 40%, respectively) without altering arterial pressure. Urinary volume and sodium excretion were not changed but osmolality decreased significantly. In Group 3, BE-18257B infusion significantly attenuated the decrease in RBF caused by ET-1 and increased GFR by 40% without altering arterial pressure, associated with significant diuresis and natriuresis. CONCLUSION: Renal vasoconstriction caused by ET-1 is attenuated by ET-A receptor blockade with BE-18257B, which unmasks the hemodynamic and tubular actions of ET-B receptors. As a result, it limits the ET-1 induced decrease in RBF and raises GFR, and leads to a diuresis and natriuresis.

Anesthesia↗
PubMed1998

Expression and characterization of a novel plasminogen activator from Agkistrodon halys venom.

A venom gland cDNA library of Agkistrodon halys was constructed and screened with a probe based on the consensus sequence of venomic serine proteases. Next, we determined the sequences of the entire open reading frames of two selected positives which were found to encode novel serine proteases of 234 and 233 amino acids in length and named as Haly-PA and Haly 2, respectively. Upon protein data base search, Haly-PA showed the highest similarity of 82% to the previously characterized plasminogen activator, TSV-PA (Zhang et al. 1995, J. Biol. Chem. 270, 10246- 10255). Haly 2 displayed a 78% similarity to beta-fibrinogenase (Hung et al. 1994, B. B. R. C., 205, 1707 1715). Haly-PA was successfully expressed using the baculovirus system and secreted into the culture media as a 32 kDa glycoprotein. In the western analysis of snake venom, anti-Haly-PA antibody detected the same size of band indicating that this enzyme is a component of snake venom. Recombinant Haly-PA was purified to homogeneity using the combination of anion exchange and gel filtration column. In the fibrino(geno)lytic assay, recombinant Haly-PA displayed an indirect fibrino(geno)lytic activity depending on the presence of plasminogen and cleaved the plasminogen to generate the active plasimin. These results indicate that Haly-PA is a plasminogen activator and displays fibrino(geno)lytic activity through conversion of plasminogen to plasmin.

Agkistrodon↗
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

Expression of hMSH2 and hMLH1 in colorectal carcinomas with microsatellite instability.

Microsatellite instability (MIN) due to defective mismatch repair (MMR) genes has been reported in a subset of sporadic colorectal carcinomas and in the majority of tumors from patients with hereditary nonpolyposis colorectal cancer (HNPCC) syndrome. Among the known MMR genes, hMSH2 and hMLH1 genes are known to be predominantly altered in HNPCC patients and MIN-positive tumors. In this study, we examined MIN and the protein expression pattern of the hMSH2 and hMLH1 by Western blot and immunohistochemistry from 32 sporadic colorectal carcinomas. MIN was observed in 6 (18%) colorectal carcinomas. Of the 6 MIN-positive tumors, one case showed no expression of either protein, 3 cases showed an absence of hMSH2 protein expression, one case showed an absence of hMLH1 protein expression and one case showed no altered expression of either protein by immunohistochemistry. The decreased expression of the hMSH2 protein in a tumor compared to the normal mucosa was also observed in 5 of the 6 MIN-positive cases by Western blot analysis. All of the MIN-negative tumors showed expression of both proteins by immunohistochemistry. Thus most of the MIN-positive tumors appear to be directly related to the altered expression of these two genes and can be diagnosed by the examination of protein expression.

Adaptor Proteins, Signal Transducing↗
PubMed1998

Open surgery for removal of a failing Gianturco stent with reversed sleeve resection of the right middle and lower lobes.

Although the use of a metallic stent in the treatment of benign tracheobronchial stenosis has been reported as a useful and safe technique, the incorporation of wire stents into the airway may be irreversible and is associated with problems. The authors' experience in a patient with incorrectly positioned metallic stent in the right main bronchus, which was successfully treated with bronchial sleeve resection, is presented.

Adult↗
PubMed1998

In vitro expansion of murine multipotential hematopoietic progenitors from the embryonic aorta-gonad-mesonephros region.

The origin of hematopoietic stem cells (HSCs) and their growth factor requirement are poorly understood. Here we describe a new in vitro culture system of the aorta-gonad-mesonephros (AGM) region, where long-term repopulating HSCs first arise. We demonstrate that oncostatin M (OSM) is expressed in the AGM and is absolutely required for the expansion of multipotential hematopoietic progenitors in vitro. In addition, OSM enhances the formation of endothelial cell clusters. Thus, OSM appears to be a key cytokine for the development of multipotential hematopoietic progenitors in the AGM, possibly acting on common precursor cells between HSCs and endothelial cells. By using the AGM culture derived from macrophage colony-stimulating factor (M-CSF)-deficient op/op mutant embryos, we also show a pivotal role for M-CSF in fetal myelopoiesis.

Animals↗
PubMed1998

Experimental System for X-ray Cone-Beam Microtomography

: A laboratory test of X-ray tomography employing a diverging beam of X-rays rather than the usual parallel X-ray beam is described. We chose to test and demonstrate the advantages of divergent beam tomography by imaging an extracted juvenile human premolar using an ordinary dental X-ray source and a cooled CCD camera. Experiments with a three-piece cover-glass sample and with the human tooth demonstrated that three-dimensional reconstruction can be achieved at 34 µm per pixel resolution employing an X-ray tube spot 800 µm in its smallest direction without requiring close contact with the fluorescent screen. Reconstruction of a 256 x 256 pixel single-plane image from 100 projection images took only 45 sec on a personal computer with a Pentium 166 MHz processor. We have also demonstrated a volume reconstruction of 256 x 256 x 256 voxels from the data. Successful extension of this work to submicrometer projection X-ray microscopy is predicted. Improved resolution of medical tomography is another possible application.

Journal Article↗
PubMed1998

Decreased expression and activity of P-glycoprotein in rat liver during acute inflammation.

PURPOSE: Drug disposition is often altered in inflammatory disease. Although the influence of inflammation on hepatic drug metabolism and protein binding has been well studied, its impact on drug transport has largely been overlooked. The multidrug resistance (MDR) gene product, P-glycoprotein (P-gp) is involved in the active secretion of a large variety of drugs. Our goal was to ascertain the influence of acute inflammation (AI) on the expression and functional activity of P-gp. METHODS: AI was induced in rats through turpentine or lipopolysaccharide (LPS) administration. Expression of P-gp in liver was detected at the level of protein on Western blots using the monoclonal antibody C-219 and at the level of mRNA using an RNase protection assay. P-gp mediated transport activity was assessed by measuring the verapamil-inhibitable efflux of rhodamine 123 (R123) in freshly isolated hepatocytes. RESULTS: Turpentine-induced AI significantly decreased the hepatic protein expression of P-gp isoforms by 50-70% and caused a significant 45-65% reduction in the P-gp mediated efflux of R123. Diminished mRNA levels of all three MDR isoforms were seen. LPS-induced AI similarly resulted in significantly reduced levels and activity of P-gp in liver. Although differences in the constitutive levels of P-gp were seen between male and female rats, the influence of AI on P-gp expression and activity was not gender specific. CONCLUSIONS: Experimentally-induced inflammation decreases the in vivo expression and activity of P-gp in liver. This is the first evidence that expression of P-gp is modulated in response to experimentally-induced inflammation.

ATP Binding Cassette Transporter, Subfamily B, Mem↗