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Biomedical subjects

C S Kim

Publications and source records attributed to C S Kim.

At least 19 recordsLinked to original sources
PubMed1995

Alzheimer and beta-amyloid-treated fibroblasts demonstrate a decrease in a memory-associated GTP-binding protein, Cp20.

The two proteins most consistently identified in the brains of patients with Alzheimer disease (AD) have been beta-amyloid and tau, whose roles in the physiology or pathophysiology of brain cells are not fully understood. To identify other protein(s) involved in AD that have been implicated in physiological contexts, we undertook to analyze a specific memory-associated protein, Cp20, in fibroblasts from AD and control donors. Cp20, a GTP-binding protein that is a member of the ADP-ribosylation factor family, was significantly decreased in fibroblasts from AD patients. Normal control fibroblasts exposed to 10 nM beta-amyloid, the same concentration that induced AD-like K+ changes in control fibroblasts, showed a similar decrease in Cp20. Since it has been previously demonstrated that Cp20 is a potent regulator of K+ channels, these findings suggest that changes in this memory-associated protein may explain previously observed differences in AD K+ channels and suggest a pathophysiologic involvement linked to soluble beta-amyloid metabolism that could contribute to the characteristic memory loss of AD.

Alzheimer Disease↗
PubMed1995

Self-expandable metallic stents in high-risk patients with benign prostatic hyperplasia: long-term follow-up.

PURPOSE: To evaluate the long-term clinical utility of self-expandable metallic Z stents in benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: Under fluoroscopic guidance, 14 multiple-connected Z stents (10 mm in diameter fully expanded, 30-60 mm in length) were placed in 13 patients with bladder obstruction from BPH and high operative risks. The stents were placed in the prostatic urethra with 2-20-mm protrusion into the urinary bladder in six patients (group A) and entirely within the prostatic urethra in seven patients (group B). RESULTS: Eleven of 13 patients could void immediately, and the other two patients with atonic bladder voided within 8 weeks. Maximum urine flow rates just after stent placement were 8-27 mL/sec. Two patients died of unrelated causes within 2 months. During the follow-up period (mean, 37 months) in the other 11 patients, all patients in group A but none in group B underwent surgery owing to stone formation where the stent protruded into the bladder. CONCLUSION: Expandable Z stents are effective in patients with BPH but should not protrude into the urinary bladder because of stone formation.

Aged↗
PubMed1995

Auditory brain stem response changes after application of endotoxin to the round window membrane in experimental otitis media.

The effects of endotoxin (purified Escherichia coli lipopolysaccharide 0111:B4) on cochlear function in normal and otitis media animals were evaluated. Two types of experimental otitis media models were developed in guinea pigs: eustachian tube obstruction and intratympanic injection of endotoxin. In normal animals, three different concentrations (0.01, 0.1, or 1.0 mg/ml) of endotoxin were applied onto the round window membrane, and auditory brain stem responses were recorded at 1, 3, 6, and 12 hours and 1, 2, 3, and 14 days after the application of endotoxin. Concentrations of 0.01 and 0.1 mg/ml of endotoxin did not affect the auditory brain stem response thresholds, whereas a concentration of 1.0 mg/ml resulted in elevation of the auditory brain stem response thresholds. Alteration of the auditory brain stem response threshold began at 3 hours, reached a peak at 24 or 48 hours, and returned to a normal level 2 weeks after the application of endotoxin. However, when the same concentration (1.0 mg/ml) of endotoxin was applied to the round window membranes of animals that underwent eustachian tube obstruction or intratympanic injection of endotoxin, the endotoxin did not cause any alteration of the auditory brain stem response threshold compared with normal animals.

Animals↗
PubMed1995

Prevalence study of nasal septal deformities in Korea: results of a nation-wide survey.

A nation-wide survey investigating the prevalence and risks of nasal septal deformity (NSD) was conducted by a group of otolaryngologists from July through October 1991. The total number of subjects surveyed was 9,284, and these were drawn from 2,899 households residing in 60 different areas throughout the country. The overall prevalence of NSD was 22.38%, and NSD tended to predominate in males and to increase with age. According to Mladina's classification, the most common type was type 1, followed by types 2, 3, 5, 7, 4, and 6. A positive correlation between nasal trauma history (NTH) and NSD was statistically confirmed (p < 0.01).

Adolescent↗
PubMed1994

Residues essential for catalytic activity of soybean beta-amylase.

To determine which amino acid residues are essential for the catalytic activity of soybean beta-amylase, deoxyoligonucleotide site-directed mutagenesis was employed against aspartyl, glutamyl, and cysteinyl residues located in highly conserved regions found in beta-amylase family to date. Both substitution of aspartic acid at position 101 and that of glutamic acid at position 186 of the enzyme by neutral and acidic amino acids, respectively, led to the complete elimination of activity, but did not induce any significant changes in circular dichroic spectra or the binding affinity for cyclomaltohexaose, a substrate analogue. Taking account of the results obtained here, the above two amino acid residues are involved in the catalytic site of soybean beta-amylase. The replacement of glutamic acid at position 345 decreased activity to below 6% of the non-mutant level, implying that this residue may also play a crucial role in beta-amylase activity, although it may not be involved at the catalytic site itself. In contrast, substitution of cysteinyl residue at position 95 by a serinyl residue led to a drastic reducing of the optimal temperature (from 50 degrees C to 30 degrees C), suggesting that this cysteinyl residue is responsible for the thermal stability of the enzyme.

Amino Acid Sequence↗
PubMed1994

Soluble beta-amyloid induction of Alzheimer's phenotype for human fibroblast K+ channels.

Although beta-amyloid is the main constituent of neurite plaques and may play a role in the pathophysiology of Alzheimer's disease, mechanisms by which soluble beta-amyloid might produce early symptoms such as memory loss before diffuse plaque deposition have not been implicated. Treatment of fibroblasts with beta-amyloid (10 nM) induced the same potassium channel dysfunction previously shown to occur specifically in fibroblasts from patients with Alzheimer's disease--namely, the absence of a 113-picosiemen potassium channel. A tetraethylammonium-induced increase of intracellular concentrations of calcium, [Ca2+]i, a response that depends on functional 113-picosiemen potassium channels, was also eliminated or markedly reduced by 10 nM beta-amyloid. Increased [Ca2+]i induced by high concentrations of extracellular potassium and 166-picosiemen potassium channels were unaffected by 10 nM beta-amyloid. In Alzheimer's disease, then, beta-amyloid might alter potassium channels and thus impair neuronal function to produce symptoms such as memory loss by a means other than plaque formation.

Alzheimer Disease↗
PubMed1994

Surgical management of congenital aural atresia.

Congenital aural atresia is a relatively common anomaly in otology. It requires an early assessment of hearing status and an early evaluation of the degree of atresia. Its surgical management is aimed at obtaining hearing gain and at establishing appropriate auditory canal status for the application of hearing aids. The authors analyzed the preoperative otologic findings, surgical findings, postoperative complications, and postoperative hearing results of 25 ears in 21 patients with congenital aural atresia. From January 1987 to February 1992, 24 of these ears were surgically corrected by anterior approach; the remaining 1 was corrected by transmastoid approach. Postoperative audiologic follow-up ranged from 8 months to 4 years (N = 21). A new modification of anterior approach is introduced. The final average air-bone gap was 30 dB, in contrast to preoperative 53 dB (N = 21). The final air-bone gap was improved to a level within 30 dB in 52% of the patients. Meatal stenosis was the most frequent postoperative complication and was seen in 12 patients in primary operation (N = 25). There was no postoperative facial nerve palsy and no sensorineural hearing loss. There was little difference in postoperative hearing among the various types of congenital aural atresia and the type of tympanoplasty that had been performed.

Abnormalities, Multiple↗
PubMed1994

Pharmacokinetic modeling of 2,4-dichlorophenoxyacetic acid (2,4-D) in rat and in rabbit brain following single dose administration.

A physiologically based pharmacokinetic (PBPK) model has been developed to describe the kinetics of organic anions in the central nervous system using 2,4-dichlorophenoxyacetic acid (2,4-D) as a model compound. The model consists of brain, body, venous, and arterial compartments. The brain compartment is subdivided into brain plasma, brain tissue and cerebrospinal fluid (CSF). Brain uptake is membrane-limited via a blood-brain barrier with saturable clearance from the CSF into the venous blood by the choroid plexus. The body has both a central and a deep compartment with saturable renal clearance from the central compartment. The model was used to examine venous plasma time course curves with experimental data from rats given 2,4-D by i.v. (5 or 90 mg/kg) or by oral ingestion (10, 50, or 150 mg/kg). The model was then extended to examine studies in which rabbit plasma, brain, and CSF concentrations were measured at 2 h after i.p. injection (40 mg/kg). In the rat, elimination was saturable (Vmax2 = 3.45 mg/h; Km2 = 86 mg/l) and the deep-compartment transfer coefficients were K12 (0.013 l/h) and K21 (0.048 l/h) between body and deep tissue compartment. Both oral and i.v. data were well described with these values. Limited single time point brain data from rabbits were analyzed with a lumped brain model assuming the generic model for 2,4-D in rat applies to the rabbit. The model simulations were in good agreement with rabbit plasma, brain, and CSF concentrations at 2 h after i.p. injection.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1994

Immunocytochemical detection of serotonin content in raphe neurons of newborn and young adult rabbits before and after acute hypoxia.

The present immunocytochemical study demonstrates serotonin (5-HT) depletion in the dorsal raphe nucleus (DRN) of 3- and 21-day-old rabbits following exposure to mild (10% ambient partial pressure of oxygen) and severe hypoxia (5% ambient oxygen). Under the mild hypoxic condition, 5-HT immunoreactivity in cells and fibers of the DRN was decreased in 3-day-old as well as 21-day-old rabbits, as indicated by decreased intensity of the staining compared to age-matched controls. Although this decrease was more pronounced in the younger animals, recovery from mild hypoxia was seen in both age groups. Hypoxic effects were more striking in 3-day-old animals under the severe hypoxic condition, indicating a greater depletion of 5-HT than in the mildly hypoxic condition. However, little additional effect on the older age group was seen. Further, a decreased ability of the 3-day-old rabbits to recover following severe hypoxia suggests that protracted effects on the developing serotonergic system occur following severe hypoxia during the neonatal period. This was demonstrated by the long-lasting decrease in the number of stained cells and fibers of the DRN 4-hr after return to normal conditions (21% O2). We conclude that newborns have a decreased rate of 5-HT synthesis and/or metabolic turnover that results in rapid depletion of intracellular stores and protracted time to recover from a hypoxic challenge. Similar effects could occur in human fetuses, newborns or infants following birth trauma, apnea or other events associated with severe hypoxia.

Acute Disease↗
PubMed1994

Identification of DNA segments capable of rescuing a non-mendelian mutant in paramecium.

The non-Mendelian mutant d48 of Paramecium tetraurelia contains micronuclear wild type A genes, but at autogamy and conjugation proper processing fails and new macronuclei lack A genes. When cloned A genes are injected into the macronucleus of d48, proper processing is restored at the next autogamy; d48 is rescued, becoming permanently wild type. In the present study we have injected portions of the A gene into d48. We find that the ability to rescue extends over a large portion of the gene, with highest activity near a series of 221-bp repeat units in the middle of the gene. Regions outside the A gene are inactive.

Animals↗
PubMed1994

Balloon dacryocystoplasty: results in the treatment of complete and partial obstructions of the nasolacrimal system.

PURPOSE: To evaluate the effectiveness of balloon dacryocystoplasty (DCP) in the treatment of complete and partial obstruction of the nasolacrimal system (NLS). MATERIALS AND METHODS: Fluoroscopically guided balloon DCP was attempted in 57 eyes of 50 consecutive patients with complete obstruction of the NLS and 24 eyes of 22 patients with partial obstruction of the NLS. With nasal endoscopic guidance, a 0.018-inch guide wire was introduced through the superior punctum into the inferior meatus of the nasal cavity and pulled out through the nare with a hemostat. A deflated angioplasty balloon catheter was introduced in a retrograde direction over the guide wire, and the balloon was dilated. RESULTS: Initial technical and clinical success was achieved in 29 of 57 eyes (51%) with complete obstruction and 17 of 24 eyes (71%) with partial obstruction. The 2-year cumulative clinical patency rates were 25% and 20% for partial and complete obstructions, respectively. The overall cumulative patency rate for all 81 eyes was 23%. CONCLUSION: Balloon DCP is simple and safe but has high failure and recurrence rates.

Adolescent↗
PubMed1994

Determining otitis media severity from middle ear fluid analysis.

Otitis media has a complex multifactorial pathogenesis, and the middle ear inflammatory response is typified by the accumulation of cellular and chemical mediators in middle ear effusion. However, specific biochemical and immunochemical factors that may be responsible for the severity or chronicity of otitis media have not been identified. Identification of factors involved in chronicity appears to be an essential step in the treatment and ultimate prevention of chronic otitis media. We analyzed 70 effusion samples from patients 1 to 10 years of age who had chronic otitis media with effusion for two cytokines (interleukin-1 beta and tumor necrosis factor alpha) and total collagenase. The highest concentrations of all three inflammatory mediators were found in purulent otitis media, and concentrations were higher in younger than in older patients. Mediator concentrations were similar in samples obtained from patients having their first myringotomy for otitis media with effusion and in those who had had multiple previous myringotomies. The multiresponse star, which incorporates several biochemical parameters in one graphic illustration, may best characterize the complex nature of middle ear inflammation.

Child↗
PubMed1994

Ultrastructural changes in the cochlea of the guinea pig after fast neutron irradiation.

Guinea pigs were irradiated with fast neutrons. After a single dose of 2, 6, 10, or 15 Gy was applied, scanning and transmission electron microscopy of the temporal bone was performed to assess the effect of fast neutron irradiation on the cochlea. Outer hair cell damage appeared with neutron irradiation of more than 10 Gy, and inner hair cell damage with neutron irradiation of more than 15 Gy. Outer hair cells were more severely damaged than inner hair cells. No statistically significant differences were found in damage of basal, middle, and apical turns. The second and third rows of outer hair cells were more severely damaged than the first row of outer hair cells. The most significant findings in transmission electron microscopy were clumping of chromatin and extension of the heterochromatin in the nuclei of hair cells. The cytoplasmic changes were sequestration of cytoplasm, various changes of mitochondria, formation of vacuoles, and irregularly arranged stereocilia. The morphologic change in stria vascularis was intercellular and perivascular fluid accumulation. It appeared to be a reversible process.

Animals↗
PubMed1994

Adult presentation of congenital cystic adenomatoid malformation of the lung: a case report.

Adult presentation of congenital cystic adenomatoid malformation(CCAM) of the lung is so rare that only 5 cases have been reported in the literature to date. We report the case of a 19-year-old female with CCAM in the left lower lobe. Computed tomography showed a multilobulated cystic lesion with multiple air-fluid levels and also showed focal enhancement of the solid component in the eccentrical portion of the lesion. Thoracic aortogram and selected bronchial arteriograms show a slightly enlarged and tortuous bronchial artery feeding the multilobulated cystic lesion. We present the clinical and radiological features of our case with a brief review of the literature.

Adult↗
PubMed1994

A case of primary hyperparathyroidism with hypercalcemic nephropathy in children.

Primary hyperparathyroidism is a rare disease in children and is characterized by conspicuous skeletal and renal changes. A 12 year old male patient presented with symptoms of polydipsia, polyuria, general weakness, nausea, and vomiting which had begun 3 months earlier, and showed typical laboratory findings of primary hyperparathyroidism. Confirmatory diagnosis was made by elevated parathyroid hormone concentration in serum, technetium-thallium subtraction scan imaging method and histopathologic finding of chief cell hyperplasia. The laboratory findings revealed elevated levels of BUN, creatinine and decreased GFR. Kidney biopsy showed typical calcium deposits in tubules with marked tubulointerstitial infiltration. After subtotal parathyroidectomy, clinical findings improved remarkably.

Child↗
PubMed1994

Transamniotic fetal feeding: enhancement of growth in a rabbit model of intrauterine growth retardation.

BACKGROUND: Transamniotic fetal feeding has been proposed as prenatal treatment for intrauterine growth retardation as substrates infused into the amniotic cavity are swallowed and absorbed. The rabbit provides an optimal model of intrauterine growth retardation in that a consistent weight ratio of the runt to the favored fetus is found at term. METHODS: Thirty growth-retarded rabbit fetuses underwent transamniotic catheterization in the third trimester with incremental infusion of either dextrose, dextrose plus amino acids, or bovine amniotic fluid. One week later fetal weights were determined. The ipsilateral favored fetus served as an operated, noninfused control. RESULTS: Fetuses receiving amniotic fluid showed significantly increased somatic growth when analyzed by absolute body weight and by weight ratio versus control. Increases in the liver, lung, and small intestinal weights of the fetuses receiving amniotic fluid paralleled the overall increase in somatic weight. No differences were found in the dextrose or dextrose plus amino acid-infused groups. CONCLUSIONS: The increased amount of ingested amniotic fluid, or fetal "force feeding," appears responsible for enhanced growth because bovine and native rabbit amniotic fluid have only negligible differences. This study provides the first report of successful growth augmentation of a fetal rabbit runt with prenatal transamniotic fetal feeding.

Amnion↗
PubMed1992

Carnitine palmitoyltransferase activity in the rabbit choroid plexus: its possible function in fatty acid metabolism and transport.

The purpose of the present study was to measure the activity of carnitine palmitoyltransferase (CPT) in the lateral and fourth ventricular choroid plexus (LVCP, FVCP) as an example of an enzyme committed to mitochondrial long-chain fatty acid oxidation. The CPT activity measured with both assays determines total CPT activity, that is, the activity of both CPT-A (outer form) and CPT-B (inner form). CPT-assay 1 (forward reaction) activity was 893.3 +/- 44.5 mU/g and 803.3 +/- 71.3 mU/g (mean +/- S.E.M.) in LVCP and FVCP, respectively. CPT-assay 2 (backward reaction) activity was 3673.7 +/- 92.4 and 3417.0 +/- 277.1 mU/g in LVCP and FVCP, respectively. These data demonstrate that CPT activity is present in the rabbit choroid plexus, and that the activity is somewhat higher per gram wet weight of tissue than the activity observed in the skeletal muscle (CPT-assay 1 = 514.4 +/- 159, CPT-assay 2 = 2492 +/- 576 mU/g). CPT activity has been exclusively localized to the mitochondria of the liver, heart, kidney and the skeletal muscles. Our present study further demonstrates that the choroid plexus is another organ in which high activity of CPT exists.

Animals↗