Biomedical subjects

C K Kim

Publications and source records attributed to C K Kim.

At least 55 records · Page 3Linked to original sources

PubMed2001

Effects of vehicles and enhancers on transdermal delivery of melatonin.

For a more effective transdermal delivery of melatonin (MT), the effects of vehicles and enhancers on its skin permeation and lag time were evaluated. Skin permeation study was conducted in Franz diffusion cells using excised hairless mouse skins. MT was analyzed by HPLC. As vehicles, ethanol (EtOH), polyethylene glycol 400 (PEG), or propylene glycol (PG) was used alone or mixed with a phosphate buffer. Binary vehicles (EtOH/buffer, PEG/buffer, PG/buffer) showed different effects on the skin permeation of MT and its lag time. Compared with the buffer alone, the PEG/buffer shortened the lag time of MT but reduced its skin permeation. EtOH/buffer significantly increased the flux of MT but prolonged the lag time with the content of EtOH. PG/buffer did not affect the lag time but slightly increased the skin permeation of MT at the higher content of PG (> or =80%). These results indicate that the composition of vehicles exerts significant influence but it per se might have limitation in modulating the transdermal delivery of MT. Next, one tested whether fatty acids could more effectively enhance the skin permeation of MT and shorten its lag time. Given the influence of vehicles on both permeation and lag time, PG was used as a vehicle for fatty acids. The permeation-enhancing effects of saturated fatty acids increased in the following order: C10>C12>C14>C16>C18. The saturated fatty acid, however, did not significantly shorten the lag time regardless of the carbon chain length. Meanwhile, similar to saturated lauric acid (C12), unsaturated oleic acid (C18) dramatically enhanced the skin permeability coefficient of MT more than 950-fold over the effect of PG alone. Moreover, oleic acid showed the shortest lag time (2.1 h). The results suggest that oleic acid in a suitable vehicle could more effectively enhance the skin permeation of MT and shorten its lag time than did the vehicles of various compositions.

Animals↗

PubMed2001

Gene medicine : a new field of molecular medicine.

Gene therapy has emerged as a new concept of therapeutic strategies to treat diseases which do not respond to the conventional therapies. The principle of gene therapy is to introduce genetic materials into patient cells to produce therapeutic proteins in these cells. Gene therapy is now at the stage where a number of dinical trials have been carried out to patients with gene-deficiency disease or cancer. Genetic materials for gene therapy are generally composed of gene expression system and gene delivery system. For the dinical application of gene therapy in a way which conventional drugs are used, researches have been focused on the design of gene delivery system which can offer high transfection efficiency with minimal toxicity. Currently, viral delivery systems generally provide higher transfection efficiency compared with non-viral delivery systems while non-viral delivery systems are less toxic, less immunogenic and manufacturable in large scale compared with viral systems. Recently, novel strategies towards the design of new non-viral delivery system, combination of viral and non-viral delivery systems and targeted delivery system have been extensively studied. The continued effort in this area will lead us to develop gene medicine as 'gene as a drug' in the near future.

Clinical Trials as Topic↗

PubMed2001

Enhanced degradation of naphthalene by immobilization of Pseudomonas sp. strain NGK1 in polyurethane foam.

A Pseudomonas sp. strain NGKI (NCIM 5120) capable of degrading naphthalene was immobilized in polyurethane foam. The naphthalene-degrading activity of the freely suspended cells was compared with that of immobilized cells in batches in shaken culture and in a continuous culture system in a packed-bed reactor. Increasing concentrations of naphthalene were better tolerated and more quickly degraded by immobilized cell cultures than by free cells. An initial naphthalene concentration of 25 mM was completely degraded by freely suspended cells (4 x 10(10) cfu ml(-1)) and polyurethane-foam-immobilized cells (0.8-1 x 10(12) cfu g(-1) foam cubes) after 4 days and 2 days of incubation, respectively. Free cells degraded a maximum of 30 mM naphthalene after 4 days of incubation with 50 mM naphthalene, and no further degradation was observed even after 15 days of incubation, whereas foam-immobilized cells brought about the complete degradation of 50 mM initial naphthalene after 6 days of incubation. Furthermore, with 25 mM naphthalene, the polyurethane-foam-immobilized cells were re-used 45 times over a period of 90 days without losing naphthalene-degrading activity. By contrast, with the same amount of naphthalene, alginate-, agar-, and polyacrylamide-entrapped cells could be reused for 18, 12, and 23 times over a period of 44, 28, and 50 days, respectively. During continuous degradation in a packed-bed reactor, foam-immobilized cells degraded 80 mM naphthalene at a rate of 150 ml(-1) h(-1). With the same flow rate and 40 mM naphthalene, this system operated efficiently and continuously for about 120 days, whereas the packed-bed reactor with alginate-, agar-, and polyacrylamide-entrapped cells could be operated only for 45, 40, and 60 days respectively. Thus, more efficient degradation of naphthalene could be achieved by immobilizing cells of Pseudomonas sp. strain NGK1 in polyurethane foam, rather than in the other matrices tested.

Cell Count↗

PubMed2001

Adaptive and cross-protective responses of Pseudomonas sp. DJ-12 to several aromatics and other stress shocks.

Pseudomonas sp. DJ-12 cells were subjected to mild treatments of stress such as exposure to biphenyl, 4-chlorobiphenyl (4CB), 4-hydroxybenzoate (4HBA), ethanol, and heat, and then were examined for production of stress-shock proteins and morphological changes. The adapted cells were then subjected to lethal stress conditions such as 200 mm 4CB, 100 mm biphenyl, 10 mm 4HBA, 20% ethanol, and 46 degrees C to examine crossly protective responses to the stresses. Several stress-shock proteins including DnaK and GroEL were newly synthesized in the adapted cells. Some of them were commonly produced by those stresses separately treated. The cells treated with these aromatic hydrocarbons showed destructive openings on the cell envelopes. On the other hand, those cells treated with ethanol or heat displayed irregular rod shapes with wrinkled surfaces. The adapted cells to each stress under sublethal conditions exhibited increased resistance to the same stress of lethal conditions. The cells adapted with 5 mm 4HBA showed greater protection for survival than those adapted by other stresses. In addition, those adapted cells showed increased resistance to other stresses as a cross-protection phenomenon. The cells adapted to 42 degrees C exhibited markedly increased resistance to the lethal stresses of 46 degrees C as well as to 20% ethanol.

Adaptation, Physiological↗

PubMed2001

Simultaneous determination of 226Ra and 210Pb in groundwater and soil samples by using the liquid scintillation counter-suspension gel method.

A method for the simultaneous determination of 226Ra and 210Pb in groundwater and soil samples by liquid scintillation counting was developed. Radium and lead were separated together from the samples as Ba(Ra) x PbSO4 co-precipitate, which was centrifuged and dissolved with 0.1 M EDTA solution (pH 9.0). Radium was separated as Ba(Ra)SO4 co-precipitate by adding ammonium sulfate and adjusting the pH of the solution to 4.2. Lead remaining in the solution was separated as PbSO4 precipitate by adding 9 M sulfuric acid. These Ba(Ra)SO4 and PbSO4 precipitates were purified with EDTA solution and used for measurement. To save time and to make counting samples simpler, direct counting of Ba(Ra)SO4 and PbSO4 precipitates instead of the phosphoric acid fusion method was attempted. Ba(Ra)SO4 and PbSO4 precipitates were suspended in the scintillation gel, and measured. Two liquid scintillation cocktails, Instagel XF and UltimaGold AB were used to prepare the counting samples. A mixture of water (40%), Instagel XF (40%) and UltimaGold AB (20%) formed a stable gel. Activities of 226Ra and 210Pb were calculated from the alpha spectrum of Ba(Ra)SO4 and beta spectrum of PbSO4, respectively. The long-term stability of the suspension gel was good. The analytical results of 226Ra and 210Pb in spiked groundwater samples were in good agreement with the known concentrations of 226Ra and 210Pb. The analytical values of 226Ra and 210Pb in the soil reference samples were within 11.5 and 1.6% of the relative error from the reference values, respectively.

Journal Article↗

PubMed2001

Once-a-day oral dosing regimen of cyclosporin A: combined therapy of cyclosporin A premicroemulsion concentrates and enteric coated solid-state premicroemulsion concentrates.

PURPOSE: To develop once-a-day oral dosing regimen that provides the blood levels of cyclosporin A (CsA) in the therapeutic ranges over 24 hours. METHODS: CsA premicroemulsion concentrates (preME) were formulated from phase diagrams. Enteric-coated solid-state premicroemulsion concentrates (sME) were prepared by coating preME with enteric-coating matrials and solidifying them. CsA was measured using high-performance liquid chromatography or radioimmunoassay. RESULTS: PreME consisted of CsA, oil, and mixture of surfactants and a cosurfactant. PreME spontaneously formed microemulsions in aqueous medium and showed oral absorption profiles similar to Sandimmune Neoral in dogs. Dispersion of sME in aqueous medium also formed microemulsions. Release rates of CsA from sME depended on pH and the type of enteric-coating materials and highly correlated with the extent of oral absorption. The co-administration of preME and sME (200 mg CsA) showed the maximum blood level of CsA not significantly different from that of preME (100 mg CsA) and the concentration of CsA close to the minimum therapeutic level at 24 hours. CONCLUSIONS: The combined treatment of preME and sME provided controlled oral absorption of CsA over a 24-hour period. Such once-a-day dosing regimens will lead to increased patient compliance and reduced episodes of organ rejection after transplantation.

Administration, Oral↗

PubMed2001

Prolonged organ retention and safety of plasmid DNA administered in polyethylenimine complexes.

Polyethylenimine (PEI) has been studied as an efficient nonviral gene transfer vector. Here, we report the biodistribution fates and safety of plasmid DNA intravenously administered in PEI complexes. Using pCMVbeta as a model gene, the biodistribution of plasmid DNA was measured by quantitative polymerase chain reaction. A deletion mutant of pCMVbeta was used as an internal standard. After intravenous administration of PEI/DNA complexes, the serum levels of DNA rapidly declined for up to 15 min. However, after this point, the serum levels of DNA diminished slowly. At 15 min after dose, PEI/DNA complexes showed 33-fold higher distribution of DNA in the lung than did naked DNA. At 24 h, all the organs tested showed much higher levels of plasmid DNA in PEI/DNA complexes, with distribution in the liver and lung being three orders of magnitude higher than naked DNA. The mRNA expression of DNA was observed in various organs of PEI/DNA-treated mice at 12 days after dose. Once a week dosing of PEI/DNA complexes over 3 consecutive weeks did not alter the histology of the organs. However, twice a week dosing over 3 weeks induced a sign of inflammation in the liver. These results indicate that PEI enhances the delivery and retention of plasmid DNA in the organs, especially the liver, but that safe delivery requires proper dosing intervals.

Animals↗

PubMed2001

Patient evaluation of treatment with fixed implant-supported partial dentures.

The aim of this study was to analyse the patient evaluation of functional treatment outcome in 40 periodontally compromised patients who received implant-supported prostheses (ISPs) as part of the total treatment. The treatment protocol comprised periodontal treatment, extraction of teeth with poor prognosis, placement of dental titanium implants, and after healing, insertion of fixed ISPs. Five of the patients became edentulous in one jaw after extraction of all teeth and received a complete ISP, whereas 35 patients became partially edentulous after extraction of some teeth, 12 receiving a partial ISP on > or = 3 implants, and 23 one on two implants. The follow-up period was on average 1.8 years after the connection of the prostheses, which provided the patients a dentition with a mean of 12 occluding dental units. The first author (S.-W. Yi) performed all implant treatment. Patients' opinions on oral functions--mastication, phonetics, oral hygiene, chewing comfort and aesthetics--were evaluated by means of a questionnaire both before implant installation and at the last follow-up. A control group of 30 subjects with a healthy dentition of 14 occluding natural pairs of teeth answered the same questionnaire on one occasion. A great majority of the patients were extremely satisfied with the oral function after treatment and experienced the ISPs as 'natural teeth'. There was no significant difference between the three treatment groups and the control group for mastication, phonetics, chewing comfort and aesthetics. Patients with ISPs reported a small but significantly greater difficulty with oral hygiene procedures than the controls with natural teeth. Most patients said that they would undergo the treatment again, if necessary, and recommend it to others. It was concluded that the rehabilitation of the periodontally compromised patients, including ISPs on osseointegrated dental titanium implants, resulted in subjectively improved and satisfactory oral function.

Adult↗

PubMed2001

Brain succinic semialdehyde dehydrogenase: identification of reactive lysyl residues labeled with pyridoxal-5'-phosphate.

An NAD+ dependent succinic semialdehyde dehydrogenase from bovine brain was inactivated by pyridoxal-5'- phosphate. Spectral evidence is presented to indicate that the inactivation proceeds through formation of a Schiff's base with amino groups of the enzyme. After NaBH(4) reduction of the pyridoxal-5'-phosphate inactivated enzyme, it was observed that 3.8 mol phosphopyridoxyl residues were incorporated/enzyme tetramer. The coenzyme, NAD+, protected the enzyme against inactivation by pyridoxal-5'-phosphate. The absorption spectrum of the reduced and dialyzed pyridoxal-5'-phosphate-inactivated enzyme showed a characteristic peak at 325 nm, which was absent in the spectrum of the native enzyme. The fluorescence spectrum of the pyridoxyl enzyme differs completely from that of the native enzyme. After tryptic digestion of the enzyme modified with pyridoxal-5'-phosphate followed by [3H]NaBH4 reduction, a radioactive peptide absorbing at 210 nm was isolated by reverse-phase HPLC. The sequences of the peptide containing the phosphopyridoxyllysine were clearly identical to sequences of other mammalian succinic semialdehyde dehydrogenase brain species including human. It is suggested that the catalytic function of succinic semialdehyde dehydrogenase is modulated by binding of pyridoxal-5'-phosphate to specific Lys(347) residue at or near the coenzyme-binding site of the protein.

Aldehyde Oxidoreductases↗

PubMed2001

Physicochemical characterization and evaluation of buccal adhesive tablets containing omeprazole.

The objective of this study was to develop an effective omeprazole buccal adhesive tablet with excellent bioadhesive force and good drug stability in human saliva. The omeprazole buccal adhesive tablets were prepared with various bioadhesive polymers, alkali materials, and croscarmellose sodium. Their physicochemical properties, such as bioadhesive force and drug stability in human saliva, were investigated. The release and bioavailability of omeprazole delivered by the buccal adhesive tablets were studied. As bioadhesive additives for the omeprazole tablet, a mixture of sodium alginate and hydroxypropylmethylcellulose (HPMC) was selected. The omeprazole tablets prepared with bioadhesive polymers alone had bioadhesive forces suitable for a buccal adhesive tablet, but the stability of omeprazole in human saliva was not satisfactory. Among alkali materials, only magnesium oxide could be an alkali stabilizerfor omeprazole buccal adhesive tablets due to its strong waterproofing effect. Croscarmellose sodium enhanced the release of omeprazole from the tablets; however, it decreased the bioadhesive forces and stability of omeprazole tablets in human saliva. The tablet composed of omeprazole/sodium alginate/HPMC/magnesium oxide/croscarmellose sodium (20/24/6/50/10 mg) could be attached on the human cheek without disintegration, and it enhanced the stability of omeprazole in human saliva for at least 4 h and gave fast release of omeprazole. The plasma concentration of omeprazole in hamsters increased to a maximum of 370 ng/ml at 45 min after buccal administration and continuously maintained a high level of 146-366 ng/ml until 6 h. The buccal bioavailability of omeprazole in hamsters was 13.7% +/- 3.2%. These results demonstrate that the omeprazole buccal adhesive tablet would be useful for delivery of an omeprazole that degrades very rapidly in acidic aqueous medium and undergoes hepatic first-pass metabolism after oral administration.

Adhesives↗

PubMed2001

Terfenadine-beta-Cyclodextrin inclusion complex with antihistaminic activity enhancement.

Terfenadine, an antihistaminic drug, has relatively low bioavailability after oral administration due to its limited solubility in water. To enhance the antihistaminic activity of terfenadine, the terfenadine-beta-cyclodextrin (1:2) inclusion complex was prepared by the neutralization method. The solubility and dissolution of the inclusion complex were carried out, and its antihistaminic activity was then evaluated and compared with terfenadine powder by the passive subcutaneous anaphylaxis method in rats. The formation constant of the inclusion complex was higher at lower pH, while its formation ratio was 1:2 irrespective of pH. For terfenadine, it improved the solubility 200 times and the dissolution rate 5 times. It gave a low histamine level at 30 min, followed by a sustained low level until 60 min, while terfenadine powder gave a low histamine level at 60 min, suggesting that it had faster and more effective antihistaminic activity than terfenadine powder in rats due to fast dissolution and absorption of terfenadine. It is concluded that this inclusion complex enhanced the antihistaminic activity of terfenadine following the enhanced solubility and dissolution of terfenadine.

Algorithms↗

PubMed2001

Natural radionuclides contents and radon exhalation rates in building materials used in South Korea.

The natural radionuclide (226Ra, 232Th and 40K) contents of building materials commonly used in South Korea have been determined by a gamma ray spectroscopy system using a high purity germanium detector. The radon exhalation rates and emanation coefficients of building materials have also been studied. The average concentrations of 226Ra, 232Th and 40K in building materials were in the range of 6.47-271 Bq.kg-1, N.D.-89.9 Bq.kg-1 and 16.8-1081 Bq.kg-1, respectively. The average radon exhalation rates and emanation coefficients were in the range of 0.0061-0.2404 Bq.kg-1.h-1 and 2.39-11.5%, respectively.

Construction Materials↗

PubMed2001

A normal variant on Tl-201 and Tc-99m MIBI whole-body imaging: the superior right atrial wall (auricle) and superoanterior right ventricular wall are often seen as mediastinal lesions.

PURPOSE: The authors have often observed on Tl-201 and Tc-99m sestamibi (MIBI) scans in patients with thyroid cancer a small focus of increased uptake in the right midparasternal region (focus A) or sometimes in the lower mid chest at the level of the lower sternum (focus B) just inferomedial to focus A. The objective of this study was to assess the frequency of this finding on Tl-201 MIBI studies, to assess the incidence of true pathologic lesions corresponding to these foci, and to identify their nature. MATERIALS AND METHODS: One hundred ten whole body Tl-201 studies using 4 mCi (148 MBq) and 84 MIBI studies using 20 mCi (740 MBq: first-pass, planar, and SPECT images) were reviewed. The appearance of either focus A or focus B on three orthogonal SPECT images was correlated with an atlas of cross-sectional anatomy and computed tomography. If focus A was seen on the immediate static image (obtained at the end of the first-pass acquisition without moving the patient), this image was coregistered with a selected image from the first-pass study showing the superior vena cava and also with another selected image showing the ascending aorta. RESULTS: Focus A was seen in 40% of Tl-201 scans and in 49% of MIBI scans, whereas focus B was seen in 20% of Tl-201 scans and 39% of MIBI scans. On correlation of the SPECT images with a cross-sectional anatomy atlas, focus A and focus B invariably corresponded to the superior portion of the right auricle and basal superoanterior right ventricular wall, respectively. These myocardial regions are prominent and sometimes appear as discrete foci because they are considerably thicker than other parts of the right atrial and right ventricular muscle, respectively, and because they are seen partly end-on in the anterior projection. CONCLUSIONS: The superior portion of the right auricle and basal superoanterior right ventricular myocardium often appear as isolated foci on whole-body Tl-201 and MIBl scans. Neither focus should be interpreted as a metastatic lesion in patients with possible cancer or as an ectopic parathyroid adenoma in patients with hyperparathyroid disease.

Adolescent↗

PubMed2001

Incidental recognition of left subclavian vein obstruction on renal scintigraphy.

In a renal transplant recipient with persistently poor graft function, the flow phase of a renal scan incidentally revealed multiple venous collaterals with focally increased vascular activity near the left lobe of the liver (quadrate lobe). This was initially assumed to represent superior vena cava (SVC) obstruction. A renal biopsy was contemplated to exclude acute rejection because of a nondiagnostic flow phase (loss of a bolus effect). However, because the possibility of venous obstruction at the level of the subclavian and/or brachiocephalic veins (without involving the SVC) also existed, another renal scan was performed, with injection of radiotracer into the contralateral arm. This showed a patent SVC and reasonably preserved renal perfusion consistent with acute tubular necrosis. Subsequently, left subclavian vein obstruction was identified. The graft function improved with conservative management for acute tubular necrosis. These findings illustrate the danger of considering only SVC obstruction when collateral flow patterns and focal hot spots in the liver are present.

Collateral Circulation↗

PubMed2001

Implant-supported fixed prostheses for the rehabilitation of periodontally compromised dentitions: a 3-year prospective clinical study.

BACKGROUND: The application of a strict hygiene maintenance care protocol following rehabilitation of periodontally compromised dentitions by means of tooth-supported fixed partial dentures has demonstrated excellent long-term treatment outcome. PURPOSE: A clinical and radiographic study was performed to document and evaluate the short- and medium-term result of occlusal rehabilitation by means of implant-supported fixed prostheses (ISFPs) in patients treated for advanced periodontal disease. MATERIALS AND METHODS: Forty-three consecutive patients were included. All patients were referred because of advanced periodontal disease. Before the implant therapy was initiated, periodontal treatment was performed and the outcome evaluated during at least a 6-month period. An individual maintenance care program was designed for each patient. All 125 implants were placed using a two-stage surgical approach. Following installation of the ISFPs, all patients underwent a baseline examination including evaluation of oral hygiene, periodontal or peri-implant conditions, and radiographs. These examinations were repeated annually during the 3-year observation period. RESULTS: No single implant was lost during the 3-year follow-up period. The percentages of plaque-harboring surfaces and bleeding units on probing were found to be low (< 10%), and no soft-tissue complications were recorded. The mean marginal bone resorption during the observation period amounted to 0.21 mm. In a few patients, apposition of marginal bone was observed. Bone loss amounting to 0.5 mm or less was found around 81% of the implants (101/125 implants). The amount of bone loss around the remaining 24 implants (19%) varied between 0.5 and 2.0 mm. CONCLUSIONS: The present clinical trial demonstrates that, at least during a 3-year period, the ISFP is an acceptable and predictable treatment option for rehabilitation in patients who have lost their teeth because of periodontal disease. This observation seems to be valid in edentulous and partially dentate jaws. A prerequisite to reach such a favorable treatment outcome is possibly the combination of the strict maintenance care program and the careful design of the ISFPs.

Adult↗

PubMed2001

Pretreatment of whole blood for use in immunochromatographic assays for hepatitis B virus surface antigen.

Immunochromatographic assays (ICAs) are also referred to as rapid tests, since they are simple and the results can be obtained within minutes after manually loading a few drops of a sample into each sample well of the test device. However, whole blood cannot be tested with ICA kits due to the visual hindrance caused by the color of red blood cells (RBCs), unless a cell-removing device such as a filter is mounted on the kits. Thus, when testing with blood, the advantage of the ICA kit is lost because of the additional time and machines required to coagulate and separate whole blood before preparing the serum. To overcome this limitation, whole-blood samples were added to a pretreatment solution to decolor the RBCs; the resulting mixtures were then loaded into the sample wells of the test device. The pretreating solution was composed of hydrogen peroxide (H(2)O(2)) to decolor the RBCs, Sag 471 (Osi Specialties) to restrain the mixture from vigorous foaming, sodium azide (NaN(3)) to inhibit the enzyme, which generates excessive foam at the beginning of decolorization, and EDTA as a chelating agent. As a result of this pretreatment, whole blood could be used with the ICA kit without reducing its simplicity and rapidity.

Anticoagulants↗

PubMed2001

Force patterns of heel strike and toe off on different heel heights in normal walking.

This study investigated the changes of force patterns of the heel strike and toe off phases at different heel heights during normal walking. Ten healthy female college students wore running shoes, flat leather shoes and high heeled shoes while walking on a Kistler force platform at their self-comfortable paces. It was found that the high heeled shoes and the leather shoes generated significantly greater vertical impact forces and anterior-posterior forces in the toe off phase than those in the heel strike phase. Accumulated impulses did not show significant increase while the heel heights increased and total support time while wearing the high heeled shoes was significantly longer than while wearing the running shoes.

Adult↗

PubMed2001

Bronchiolitis obliterans in the 1990s in Korea and the United States.

STUDY OBJECTIVES: Our current knowledge of pediatric bronchiolitis obliterans (BO) is based largely on a few small series of patients that were reported in the older literature. In these older cases, the mortality rate was high. This study was conducted to investigate the characteristics of pediatric BO cases in two different countries. DESIGN: We extracted specific information regarding predisposing factors, symptoms and signs, diagnostic studies, treatment, and outcome from the medical records of 31 children who received diagnoses of BO at four university medical centers in Korea and the United States in the 1990s. RESULTS: The large number of Asian children reflects a clustering of cases in Korea due to adenovirus and Mycoplasma pneumoniae epidemics. The characteristic diagnostic features of BO were present in 29 of 30 high-resolution CT (HRCT) studies. Seven of nine children who underwent biopsies had histologic confirmations of BO. In two patients whose biopsy results were nondiagnostic, the diagnosis was established by HRCT together with pulmonary function testing results that were consistent with nonreversible small airways obstruction. Fifteen children (48.4%) had evidence of hypoxemia. At present, all but one are alive. Patients with elevated severity-of-illness scores were observed to have increased likelihoods of lung transplantation or death. CONCLUSIONS: We conclude that BO has a good overall prognosis and that the mortality rate has declined over the past decade. This could be related primarily to the use of HRCT for accurate diagnosis and the availability of pediatric lung transplantation. BO cases in Korea were associated with infectious epidemics, whereas those in United States had variable predisposing factors.

Adenovirus Infections, Human↗