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Biomedical subjects

H Kim

Publications and source records attributed to H Kim.

At least 577 records · Page 32Linked to original sources
PubMed1997

Prevention of pulmonary morbidity for patients with Duchenne muscular dystrophy.

STUDY OBJECTIVE: To evaluate the effects of a new respiratory management protocol on respiratory morbidity and hospitalization rates for patients with Duchenne muscular dystrophy (DMD). DESIGN: A retrospective cohort study. METHODS: Using a protocol in which oxyhemoglobin desaturation was prevented or reversed by the use of noninvasive intermittent positive pressure ventilation (IPPV) and assisted coughing as needed, the hospitalization rates and days for 24 protocol DMD ventilator users were compared with those of 22 nonprotocol DMD tracheostomy IPPV users. RESULTS: The 22 conventionally managed patients were hospitalized a mean of 72.2+/-112 days when undergoing tracheostomy. This included a 16.1+/-5.4-day period of translaryngeal intubation. The 24 protocol patients were hospitalized a mean of 6.0+/-2.4 days (p<0.005) when beginning ventilator use. Over their next 126.2 patient-years of ventilator use, the 24 protocol patients had significantly lower rates of hospitalization (p<0.008) and hospitalization days (p<0.005) than had the tracheostomy IPPV users over a 167.2 patient-year period. This is true although 14 of the 24 protocol patients went on to require 24-h noninvasive IPPV for 4.5+/-3.6 years. Five of the 14 have yet to be hospitalized. CONCLUSION: The use of inspiratory and expiratory aids can prolong survival while significantly decreasing the pulmonary morbidity and hospitalization rates associated with conventional resort to tracheostomy IPPV.

Adolescent↗
PubMed1997

Is incarceration during pregnancy associated with infant birthweight?

OBJECTIVES: This study examined whether incarceration during pregnancy is associated with infant birthweight. METHODS: Multivariable analyses compared infant birthweight outcomes among three groups of women: 168 women incarcerated during pregnancy, 630 women incarcerated at a time other than during pregnancy, and 3910 women never incarcerated. RESULTS: After confounders were controlled for, infant birthweights among women incarcerated during pregnancy were not significantly different from women never incarcerated; however, infant birthweights were significantly worse among women incarcerated at a time other than during pregnancy than among never-incarcerated women and women incarcerated during pregnancy. CONCLUSIONS: Certain aspects of the prison environment (shelter, food, etc.) may be health-promoting for high-risk pregnant women.

Adult↗
PubMed1997

Tuberculosis of the trachea and main bronchi: CT findings in 17 patients.

OBJECTIVE: The purpose of our study was to describe the CT findings of tuberculosis of the trachea and main bronchi. MATERIALS AND METHODS: Initial (n = 17) and follow-up (n = 7) CT scans were available from 17 patients (five men and 12 women; aged 25-82 years old) with tracheobronchial tuberculosis. The diagnosis of tuberculosis was based on bronchoscopic, microbiologic, or pathologic findings. RESULTS: The trachea (n = 6), the right main bronchus (n = 6), and the left main bronchus (n = 4) were involved in 10 patients with actively caseating tuberculosis. These airways showed irregular (n = 11) or smooth (n = 4) circumferential narrowing and occlusion (n = 1). Also, the trachea (n = 2), the right main bronchus (n = 1), and the left main bronchus (n = 6) were involved in seven patients with fibrotic tuberculosis. These airways showed smooth (n = 4) or irregular (n = 3) circumferential narrowing and occlusion (n = 2). Mediastinitis (increased densities in mediastinal fat) was seen in four of 10 patients with active tuberculosis but not in any of the seven patients with fibrotic disease. Tracheal tuberculosis, which has always been associated with bronchial disease, involved the distal trachea and exceeded 3 cm in length. After the seven patients underwent initial scans and antituberculous chemotherapy, serial CT scans showed improvement in seven of 11 lesion sites: normalized airways (n = 4) or smoothing from irregular narrowing (n = 3). The remaining four sites showed no change. CONCLUSION: On CT scans, actively caseating tracheobronchial tuberculosis showed circumferential and predominantly irregular luminal narrowing and mediastinitis. When fibrotic disease was found, a CT scan revealed equal distribution of smooth and irregular narrowing and less wall thickening than was seen in patients with active disease. On CT scans, tracheal tuberculosis involved the long segment of the distal trachea, a condition associated with bronchial tuberculosis.

Adult↗
PubMed1997

Epstein Barr virus associated hemophagocytic syndrome--a case report.

Virus associated hemophagocytic syndrome (VAHS) are a heterogeneous group of disorders in which viral infection is associated with a proliferation of hemophagocytic histiocytes through the reticuloendothelial system. We report the case of a 21-year-old Korean man who presented to us with high fever, marked hepatosplenomegaly, severe hepatic dysfunction, coagulopathy, pancytopenia and marked panhypogammaglobulinemia. Bone marrow aspiration and biopsy showed histiocytes proliferation with active phagocytosis of red cells and neutrophils. Primary Epstein-Barr (EB) viral infection at presentation was confirmed by the presence of IgM antibody to viral capsid antigen (VCA) with absence of antibody to EB viral nuclear antigen (EBNA). A liver biopsy performed one month after the presentation showed erythrophagocytic histiocytes within the sinusoids. EB virus was demonstrated in the liver biopsy tissue by DNA PCR method, and EBER mRNA in situ hybridization.

Adult↗
PubMed1997

The effect of early versus late onset of temporal lobe epilepsy on hemispheric memory laterality: an intracarotid amobarbital procedure study.

Thirty-three temporal lobe epilepsy (TLE) patients, 19 left TLE and 14 right TLE, underwent an intracarotid amobarbital procedure. For each patient, hemispheric memory laterality was determined by measuring the relative magnitude of recognition memory following left versus right hemisphere injection of sodium amobarbital. The patients were divided into early and late seizure onset groups, based on the median age (13 yrs) of seizure onset of the total sample. Early-onset left TLE was associated with a greater tendency toward right hemispheric representation of both verbal and visual memory compared with late-onset left TLE. Early-onset right TLE was associated with a greater tendency toward left hemispheric representation of visual, but not verbal, memory compared with late-onset right TLE. These findings indicate that interhemispheric plasticity for memory is greater in early than in late life, bidirectional, and at least partially material-specific.

Adolescent↗
PubMed1997

Triton X-100 induces apoptosis in human hepatoma cell lines.

The detergent Triton X-100 was used to establish a model for apoptosis in hepatoma cell lines. The electrophoresis of DNA extracted from 0.01% Triton X-100 treated hepatoma cell lines showed DNA ladder formation, a hallmark of apoptosis. The DNA fragmentation appeared within less than 60 min of the Triton X-100 treatment. Chromatin condensation and apoptotic bodies were observed by hematoxylin and eosin (H & E) stain, and fragmented nucleosome was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling (TUNEL) test. Apoptosis was semi-quantitated by measuring the lactate dehydrogenase (LDH) level for cytotoxity. It was found that apoptosis had been induced in more than 90% of the cells treated with Triton X-100 for 150 min. These data show that Triton X-100 efficiently induces the apoptotic cell death in hepatoma cell lines.

Apoptosis↗
PubMed1997

Activation of endothelium-derived relaxing factor system in acute unilateral ureteral obstruction.

PURPOSE: To investigate the effects of 1-arginine, a substrate for nitric oxide (NO) synthase, on renal hemodynamics in acute ureteral obstruction (UUO). MATERIALS AND METHODS: Renal blood flow (RBF) and ureteral pressure (UP) were measured in anesthetized dogs with or without UUO. RESULTS: In 9 dogs (Group 1), RBF was 212 +/- 13 ml./min. before UUO, and significantly increased to 302 +/- 18 and 268 +/- 9 ml./min. at 90 and 140 min. post-UUO, respectively, associated with a marked increase in UP from 3 +/_ 1 mm. Hg to 73 +/- 5 and 83 +/-2 mm. Hg at 90 and 140 min. post-UUO, respectively. In 6 dogs (Group 2) prostaglandin synthesis was inhibited with meclofenamate (5 mg./kg., i.v.). After UUO, RBF did not change significantly and the increase in UP was markedly attenuated when compared with Group 1, as UP rose only to 27 +/-3 and 34 +/- 4 mm. Hg at 90 and 140 min. post-UUO, respectively. In 6 dogs pre-treated with meclofenamate, L-arginine was infused into the renal artery at 5 mg./kg./min. at 90 min. after UUO (Group 3). Prostaglandin synthesis inhibition prevented renal vasodilation after UUO and significantly attenuated the increase in UP. Upon infusion of L-arginine, RBF and UP rose sharply from 202 +/- 16 ml./min. and 24 +/- 6 mm. Hg to 264 +/- 22 ml./min. and 70 +/- 4 mm. Hg, respectively, at 140 min. post-UUO (p <0.001), values approaching those in Group 1. In sham-operated dogs, L-arginine infusion did not alter RBF in dogs with or without pretreatment with meclofenamate. CONCLUSION: In UUO the L-arginine-NO pathway is activated, contributing to renal vasodilation and a marked increase in UP.

Acute Disease↗
PubMed1997

Contribution of endothelin-1 to renal vasoconstriction in unilateral ureteral obstruction: reversal by verapamil.

PURPOSE: In unilateral ureteral obstruction (UUO) vasoconstriction occurs both during and after release of UUO. ET-1, an endogenous peptide, causes marked vasoconstriction mediated by an increase in cytosolic calcium. We measured renal output of endothelin-1 (ET-1) in dogs with UUO and examined if the renal vasoconstriction that persisted after release of UUO could be reversed by a calcium antagonist, verapamil. MATERIALS AND METHODS: Hemodynamic and clearance experiments were performed in anesthetized mongrel dogs in three groups. Group I consisted of 9 dogs with sham-operation. Group 2 consisted of 7 dogs in whom ureteral obstruction was released 1.9 hours after UUO. Group 3 consisted of 5 dogs in whom verapamil was infused into the renal artery at two doses (5 and 10 microg./min., respectively) after release of UUO of 19-hour duration. ET-1 concentrations (measured by radioimmunoassay) were determined for renal venous and arterial plasma. RESULTS: In Group 1 renal venous plasma ET-1 level was 16.7 +/- 2.2, significantly lowered than 22.8 +/- 3.2 pg./ml. in arterial plasma, indicating a net clearance of ET-1. In Group 2 and 3, renal venous plasma ET-1 levels (28.2 +/- 5.2 and 27.2 +/- 2.4 pg./ml., respectively) were significantly greater than those in arterial plasma (24.2 +/- 5.7 and 17.4 +/- 0.8 pg./ml., respectively), indicating a net output of ET-1 in the kidney, In addition, renal vasoconstriction occurred in Groups 2 and 3 as indicated by significantly lower renal blood flow and GFR than those in Group 1. In Group 3, intrarenal infusion of verapamil at two doses did not change arterial pressure but caused an ipsilateral, significant increase in RBF (from 132 +/- 4 17 to 1.84 +/- 19 and 180 +/- 16 ml./min., respectively) and dose-dependent increases in GFR (from 12 +/- 2 to 25 +/- 3 and 38 +/- 7 ml./min., respectively), associated with a profound dose-dependent ipsilateral diuresis and natriuresis. CONCLUSION: Profound renal vasoconstriction in UUO was associated with an increase in renal production of ET-1, possibly contributing to renal vasoconstriction, and was reversed by intrarenal infusion of verapamil.

Animals↗
PubMed1997

Aminoacyl-tRNA synthesis in Archaea.

The mechanism of aminoacyl-tRNA synthesis differs substantially between Archaea, Bacteria and Eukarya. Sequencing of archaeal genomes has suggested that the asparaginyl-, cysteinyl-, glutaminyl- and lysyl-tRNA synthetases are absent from a number of organisms in this kingdom. The absence of the asparaginyl- and glutaminyl-tRNA synthetases is in agreement with the observation that Asn-tRNA and Gln-tRNA are synthesized by tRNA-dependent transamidation of Asp-tRNA and Glu-tRNA respectively in the archaeon Haloferax volcanii. Biochemical and genetic studies have now shown that while the cysteinyl- and lysyl-tRNA synthetases are present, the enzymes responsible for these activities are unique to Archaea.

Amino Acyl-tRNA Synthetases↗
PubMed1996

Conformational change of cytochrome P450 1A2 induced by sodium chloride.

Recently, it was reported that the activity of rabbit P450 1A2 is markedly increased at elevated sodium phosphate concentration. Here, the possible structural change of rabbit P450 1A2 accompanying the NaCl-induced increase in its enzyme activity is investigated by fluorescence spectroscopy, circular dichroism, and absorption spectroscopy. It was found that NaCl increased alpha-helix content and lowered beta-sheet content of P450 1A2 in the presence as well as in the absence of a phospholipid. Intrinsic fluorescence emissions also increased with increasing NaCl concentration. The low spin iron configuration of P450 1A2 shifted toward the high spin configuration in response to the increased salt concentration. The effect of increased potassium phosphate and NaCl on the P450 1A2 activity was also studied. It was found that the activity increase of rabbit P450 1A2 occurs concomitantly with the conformational change including raised alpha-helix content.

Animals↗
PubMed1996

Steady-state and time-resolved fluorescence measurements for studying molecular interactions: interaction of a calcium-binding probe with proteins.

The binding of 2-[(2-bis-[carboxymethyl]amino-5-methylphenoxy)-methyl] 6-methoxy-8-bis[carboxymethyl] aminoquinoline, the fluorescent calcium probe Quin2, to serum albumin and several other proteins has been investigated. Changes in fluorescence emission spectra and fluorescence anisotropy revealed interactions between Quin2 and several proteins including human serum albumin, bovine serum albumin, aldolase, phosphoglucose isomerase, glyceraldehyde-3-phosphate dehydrogenase, and alkaline phosphatase. Protein-probe interactions were inhibited by the presence of calcium. Binding was also measured by resonance energy transfer and gel permeation chromatography. Equilibrium binding constants for Quin2 were quantitated by the application of the recently-developed "SPECTRABIND' program to spectroscopic data (D. Toptygin and L. Brand, Anal. Biochem., 224 (1995) 330-338). Binding of Quin2 to human serum albumin is discussed in terms of the published X-ray crystal structure of human serum albumin (X.M. He and D.C. Carter, Nature, 358 (1992) 209-215).

Aminoquinolines↗
PubMed1996

Structure of a methionine-rich segment of Escherichia coli Ffh protein.

The methionine-rich segments of the Ffh protein of Escherichia coli and its eukaryotic counterpart SRP54 are thought to bind signal sequences of secretory proteins. The structure of a chemically synthesized 25-residue-long peptide corresponding to one of the proposed methionine-rich amphiphilic helices of Ffh was determined in water and in aqueous trifluroethanol (TFE) solution using CD and NMR. An appreciable alpha-helix conformation exists even in water and this peptide assumes a stable alpha-helix along most of its length in aqueous TFE solution. It is clear that this segment of Ffh protein has a very strong propensity to form alpha-helical structure.

Amino Acid Sequence↗
PubMed1996

Ethnic variation in the incidence of stomach cancer in Illinois, 1986-1988.

Wide ethnic and geographic variation in stomach cancer incidence has been reported in Eastern and Western countries. Stomach cancer is reported to be the most common malignant neoplasm in Asia, specifically, China, Japan, and Korea. In contrast, stomach cancer incidence in the United States among Caucasians is low and among blacks, moderate to low. Only one other study has directly compared the rates of stomach cancer in the three ethnic groups (i.e., white, African American, and immigrant Korean) living in the same region. The authors extend their investigation by comparing the incidence rate of stomach cancer among the same three ethnic groups in the state of illinois from 1986 to 1988. In this study, the incidence of stomach cancer was observed to be lowest in whites, intermediate in African Americans, and highest in immigrant Koreans. The overall 3-year cumulative incidence rate from 1986 to 1988 was 62.6/100,000 (95% confidence interval (CI) 38.6-86.7), 28.2/100,000 (95% CI 25.7-31), and 22.5/100,000 (95% CI 21.5-23.5) for immigrant Koreans, African Americans, and whites, respectively. The 3-year age-adjusted cumulative incidence rate for immigrant Koreans (172/100,000) was approximately four-and eightfold higher than for African Americans (41/100,000) and whites (21/100,000). The incidence of stomach cancer increased as a function of age in both sexes. Although a higher rate was observed in males than in females, these rates were four-and eightfold higher in African Americans and immigrant Koreans, when compared with their white counterparts in both sexes. Despite a substantial reduction of stomach cancer incidence in the United States and other Western countries, it remains the most frequent malignancy in native and immigrant Koreans. The high rate of stomach cancer in immigrant Koreans compared with African Americans and white populations residing in Illinois indicates either a drastically disproportionate undercount of immigrant Koreans in the 1990 census or a profound genetic-environmental interaction.

Adolescent↗