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Biomedical subjects

M Kim

Publications and source records attributed to M Kim.

At least 217 records · Page 12Linked to original sources
PubMed1998

Determination of four anabolic steroid metabolites by gas chromatography/mass spectrometry with negative ion chemical ionization and tandem mass spectrometry.

A gas chromatography/mass spectrometry method is described which uses negative ion chemical ionization and tandem mass spectrometry for the determination of anabolic steroid metabolites. Four anabolic steroid metabolites to be derivatized by Pentafluoropropionic anhydride (PFPA) were determined using gas chromatography/mass spectrometry (GC/MS) with negative chemical ionization (NCI) and NCI/MS/MS. The repeatability and reproducibility of this procedure were in the range of 5.3-9.7% and 6.1-10.2%, respectively. This method of derivatization with PFPA for NCI and NCI/MS/MS was useful to determine four metabolites of nandrolone, dromostanolone, methenolone and boldenone. The derivatized metabolites of boldenone could be detected to 2 ppb and the other three steroids could be detected to 25 ppb in urine at a signal-to-noise ratio of S/N = 3.

Anabolic Agents↗
PubMed1998

Wild-type and mutant huntingtins function in vesicle trafficking in the secretory and endocytic pathways.

Huntingtin is a cytoplasmic protein that is found in neurons and somatic cells. In patients with Huntington's disease (HD), the NH2-terminal region of huntingtin has an expanded polyglutamine tract. An abnormal protein interaction by mutant huntingtin has been proposed as a mechanism for HD pathogenesis. Huntingtin associates with vesicle membranes and interacts with proteins involved in vesicle trafficking. It is unclear where along vesicle transport pathways wild-type and mutant huntingtins are found and whether polyglutamine expansion affects this localization. To distinguish wild-type and mutant huntingtin, fibroblasts from normals and HD patients with two mutant alleles (homozygotes) were examined. Immunofluorescence confocal microscopy showed that mutant huntingtin localized with clathrin in membranes of the trans Golgi network and in clathrin-coated and noncoated endosomal vesicles in the cytoplasm and along plasma membranes. Separation of organelles in Nycodenz gradients showed that in normal and HD homozygote patient cells, huntingtin was present in membrane fractions enriched in clathrin. Similar results were obtained in fibroblasts from heterozyote juvenile HD patients who had a highly expanded polyglutamine tract in the HD allele. Western blot analysis of membrane fractions from rat brain showed that wild-type huntingtin was present in fractions that contained purified clathrin-coated membranes or a mixture of clathrin-coated and noncoated membranes. Electron microscopy of huntingtin immunoreactivity in rat brain revealed labeling along dendritic plasma membranes in association with clathrin-coated pits and clusters of noncoated endosomal vesicles 40-60 nm in diameter. These data suggest that wild-type and mutant huntingtin can influence vesicle transport in the secretory and endocytic pathways through associations with clathrin-coated vesicles.

Alleles↗
PubMed1998

Lateral asymmetries of pupillary responses.

We wanted to learn if pupillary changes induced by looking and attending to stimuli on the right and left are asymmetrical. In humans, there are hemispheric asymmetries in the control of attention-arousal systems. Because attention and arousal may influence pupil size, asymmetric pupillary responses may be seen when looking and attending in different directions. Twelve right-handed, healthy volunteers served as subjects. Using infrared pupillography, we recorded changes of pupillary diameter while subjects were looking and attending to the stimuli on the right and left sides of space. For the one second following a saccade, there are three phasic pupillary responses, an initial constriction (C1) then a dilation (D1), followed by constriction (C2). Evaluation of these three responses revealed right-left asymmetries with more pupil dilation (D1) when looking to the stimulus on the right. Our results suggest that subjects are more aroused when looking to the right than when looking to the left.

Adult↗
PubMed1998

Early-stage HIV infection and hepatitis C virus infection are associated with elevated serum porphyrin levels.

BACKGROUND: Porphyria cutanea tarda is known to be associated with HIV infection and hepatitis C virus (HCV). OBJECTIVE: Our purpose was to evaluate whether early infection with HIV, with or without HCV infection, is associated with elevated serum porphyrin levels. METHODS: Serum porphyrin levels were measured in samples obtained from 103 patients with early HIV infection. The results were compared with those of 89 late-stage HIV-positive patients and 78 HIV-negative patients. RESULTS: The highest median porphyrin level was in early-stage HIV-positive/HCV-positive samples, followed in decreasing order by those in early-stage HIV-positive/HCV-negative, late-stage HIV-positive/HCV-positive, late-stage HIV-positive/HCV-negative, HIV-negative/HCV-positive, and HIV-negative/HCV-negative groups. Elevated porphyrin levels were independently associated with early-stage HIV infection (P < .0001) and HCV infection (P = .03). CONCLUSION: This finding suggests abnormal porphyrin metabolism is most noticeable in early-stage HIV infection; it becomes less severe with the progression of HIV disease.

Adult↗
PubMed1998

Morphological studies of mesothelial cells in CAPD effluent and their clinical significance.

We studied the mesothelial cells in the effluent of patients undergoing continuous ambulatory peritoneal dialysis (CAPD) and their relationship with CAPD duration, peritoneal function, peritoneal sclerosis (PS), and sclerosing encapsulating peritonitis (SEP) in 49 patients (26 men, 23 women) treated for 3 to 161 months with CAPD. Three patients had SEP and five patients had PS. The overnight effluent was drained and centrifuged. The cell differentiation and surface area of mesothelial cells were studied by a computed light microscope system after cytospin preparation staining. The surface area of 50 cells was measured. The mesothelial cells were classified into three types according to their morphological appearance: normal cell type, with a mean surface area of 335.6+/-31.0 microm2 and mean nucleocytoplasmic ratio (N/C ratio) of 0.66+/-0.01; dyskaryotic cell type, with a mean surface area of 570.5+/-35.9 microm2 and N/C ratio 0.58+/-0.06; and giant cell type, with a mean surface area of 1,821.0+/-68.8 microm2 and N/C ratio of 0.06+/-0.01. There was a low but significant correlation between the fast peritoneal equilibration test and surface area (r=0.495; P=0.0120) and a highly significant correlation between CAPD duration and mean surface area (r=0.719; P < 0.0001). This increased cell surface area was because of both an increased surface area of normal and dyskaryotic cells and an increase in the number of dyskaryotic and giant cells. The mean surface area in patients with SEP was 709.3+/-125.4 microm2 and that in patients with PS was 586.6+/-55.2 microm2. Giant cells were found in the effluent of all three patients with SEP and three of the patients with PS. In conclusion, a marked correlation was found between the surface area of effluent mesothelial cells and the duration of CAPD. Giant cells were almost always found in the effluent of patients with SEP and PS. The surface area of mesothelial cells in the effluent might reflect morphological changes in the peritoneum during CAPD. These morphological changes and the measurement of the size of mesothelial cells may predict critical derangement of peritoneal membrane.

Adult↗
PubMed1998

Cosmic ray hit frequencies in critical sites in the central nervous system.

One outstanding question to be addressed in assessing the risk of exposure to space travelers from galactic cosmic rays (GCR) outside the geomagnetosphere is to ascertain the effects of single heavy-ion hits on cells in critical regions of the central nervous system (CNS). As a first step toward this end, it is important to determine how many "hits" might be received by a neural cell in several critical CNS areas during an extended mission outside the confines of the earth's magnetic field. Critical sites in the CNS: the macula, and an interior brain point (typical of the genu, thalamus, hippocampus and nucleus basalis of Meynert) were chosen for the calculation of hit frequencies from galactic cosmic rays for a mission to Mars during solar minimum (i.e., at maximum cosmic-ray intensity). The shielding at a given position inside the body was obtained using the Computerized Anatomical Man (CAM) model, and a radiation transport code which includes nuclear fragmentation was used to calculate yearly fluences at the point of interest. Since the final Mars spacecraft shielding configuration has not yet been determined, we considered the minimum amount of aluminum required for pressure vessel-wall requirements in the living quarters of a spacecraft, and a typical duty area as a pressure vessel plus necessary equipment. The conclusions are: (1) variation of the position of the "target site" within the head plays only a small role in varying hit frequencies; (2) the average number of hits depends linearly on the cross section of the critical portion of the cell assumed in the calculation; (3) for a three-year mission to Mars at solar minimum (i.e., assuming the 1977 spectrum of galactic cosmic rays), 2% or 13% of the "critical sites" of cells in the CNS would be directly hit at least once by iron ions, depending on whether 60 micrometers2 or 471 micrometers2 is assumed as the critical cross sectional area; and (4) roughly 6 million out of some 43 million hippocampal cells and 55 thousand out of 1.8 million thalamus cell nuclei would be directly hit by iron ions at least once on such a mission for space travelers inside a simple pressure vessel. Also, roughly 20 million out of 43 million hippocampal cells and 230 thousand out of 1.8 million thalamus cell nuclei would be directly hit by one or more particles with z > or = 15 on such a mission.

Basal Ganglia↗
PubMed1998

Protein adsorption characteristics of a sulfonic-acid-group-containing nonwoven fabric

A sulfonic acid (SO3H)-group-containing nonwoven fabric was prepared by radiation-induced graft polymerizaton of an epoxy-group-containing monomer, glycidyl methacrylate, onto a nonwoven fabric and subsequent sulfonation. The nonwoven fabric containing SO3H groups at different densities was equilibrated with lysozyme in a buffer (pH 6.0). The equilibrium binding capacity (EBC) of lysozyme increased linearly with increasing SO3H group density. The SO3H-group-containing polymer chains extended from the pore surface due to mutual electrostatic repulsion and held lysozyme in multilayers. The maximum EBC was 0.7 kg/kg at a SO3H group density of 1.7 mol/kg.

Journal Article↗
PubMed1998

Nervous system involvement by metastatic hepatocellular carcinoma.

Nineteen patients with nervous system metastasis of hepatocellular carcinoma (HCC) were evaluated retrospectively. Nervous system metastasis was frequently initial presentation of HCC (seven out of 19 patients). Seven patients had metastases of the brain, of whom four had a stroke-like presentation. CT or MRI in these patients showed intracerebral hematomas in watershed areas. Enhancing lesion or edema adjacent to the hematoma helped differentiate these lesions from classical hypertensive hematomas. One patient with metastasis to the clivus presented with isolated six nerve palsy. The remaining 11 patients had spinal epidural metastases producing myelopathy in seven and radiculopathy in four. Radiation therapy failed to control the clinical course.

Adult↗
PubMed1998

Molecular cloning of a novel fimbrin-like cDNA from Arabidopsis thaliana.

Fimbrin is a 68-70 kDa actin-bundling protein in animal cells and lower eukaryotes that participates in diverse morphogenetic processes by cross-linking actin filaments into bundles. Here we report the cloning by degenerate polymerase chain reaction (PCR) of ATFIM1, a 2.3 kb cDNA from Arabidopsis thaliana that codes for a novel 76 kDa fimbrin-like polypeptide (AtFim1). The predicted sequence of AtFim1 shares ca. 40% identity with nonplant fimbrins and contains two tandem repeats, each possessing a 27 amino acid region identified as a putative actin-binding domain in fimbrins and in a larger family of actin cross-linking proteins. Preceding the tandem repeats at the amino terminus of AtFim1 is a single-EF-hand-like domain with moderate homology to calmodulin-like calcium-binding proteins. AtFim1 differs from non-plant fimbrins, however, in that it contains an extended carboxy-terminal tail of ca. 65 amino acids. ATFIM1 is encoded by a single gene, although sequencing of two partial fimbrin-like expressed sequence tag (EST) clones indicates that Arabidopsis contains at least two fimbrin-like proteins. Northern blot analysis and reverse-transcription PCR (RT-PCR) demonstrated that ATFIM1 is expressed in all major organs examined (roots, leaves, stems, flowers and siliques). This is the first report of the cloning of a full length plant gene that encodes a putative actin filament-bundling protein.

Actins↗
PubMed1998

Efficacy of multiple administrations of a recombinant adenovirus expressing wild-type p53 in an immune-competent mouse tumor model.

Infection of Renca cells in vitro with a recombinant adenovirus expressing a marker gene beta-galactosidase resulted in high level of the transgene expression. Renca tumors grown in Balb/C mice were also infectable with this recombinant adenovirus. The transgene expression in the tumors lasted for about 7 days, however, administration of another dose of Ad-beta gal, on day 7 produced beta-galactosidase expression. To investigate the effect of antibodies to adenovirus, animals were injected with multiple doses of adenovirus to produce neutralizing antibodies. To these animals Renca cells were injected and tumors formed. Interestingly, when Ad beta-gal was administered into these tumors, a high level of transgene expression was still observed. We next explored the utility of a recombinant adenovirus expressing p53 (AdWTp53) in the Renca tumor model. Renca cells when exposed to an adenovirus expressing p53 (AdWTp53) produced a high level of p53 protein, a p53-inducible gene p21/WAF1/Cip1 and underwent apoptosis. A single injection of AdWTp53 (10(9) plaque forming units) resulted in significant inhibition of tumor growth. However, multiple administrations (four doses of 2.5 x 10(8) plaque forming units) of AdWTp53 were needed for tumor cures. Mixing uninfected and AdWTp53-infected cells showed a bystander effect of AdWTp53-infected Renca cells. Based on these results we believe that an appropriate dose scheduling of AdWTp53 can be efficacious for cancer gene therapy in immune-competent tumor-bearing animals.

Adenoviridae↗
PubMed1998

Pharyngoesophageal reconstruction with a tubed free radial forearm flap.

Various attempts at reconstruction of pharyngoesophageal defects after ablative surgery have been made to restore the function of the pharyngoesophagus. A tubed free radial forearm flap was used to reconstruct the pharyngoesophagus in 23 patients after resection of neoplasms from May 1989 to October 1995. Nineteen were males and four were females, the average patient age was 62.2 years. The follow-up ranged from 10 to 64 months (mean: 18 months). Oral intake within 3 weeks was possible in 18 patients (78 percent) The immediate postoperative complications were hematoma (n = 1), bleeding (n = 2), infection (n = 3), fistula (n = 4), and venous thrombosis (n = 1). A late complication was stricture of the lower anastomosing site (n = 3). The tubed free radial forearm flap has advantages over free jejunal transfer, including the larger caliber of the vascular pedicle, longer possible ischemic time, no laparotomy with less morbidity of the donor site, and better toleration of radiotherapy. Troublesome disadvantages include stricture and fistula formation at the suture sites. The authors modified the conventional free radial forearm flap to reduce complications. A small monitoring flap supplied by the septocutaneous branch of the radial artery was elevated to check the survival of the flap. During tubing, the vertical suture line was overlapped with a deepithelialized skin flap, and double layer sutures were done to prevent fistula. Two small triangular flaps were designed and inserted at the distal anastomotic site to prevent circular contracture. The outer-layer sutures were anchored to the surrounding rigid structure to withstand shrinkage and circular contraction. With this modification, the incidence of stricture and fistula formation was reduced to 13.0 percent and 17.4 percent, respectively, and these complications could be treated conservatively.

Aged↗
PubMed1998

The water-soluble extract of chicory influences serum and liver lipid concentrations, cecal short-chain fatty acid concentrations and fecal lipid excretion in rats.

Sprague-Dawley rats (n = 32) were fed diets without fiber (control) or containing 1 or 5% chicory extract or 5% inulin for 4 wk; 0.2% cholesterol was added to all diets. Rats fed chicory extract and inulin diets had significantly higher serum high density lipoprotein (HDL) cholesterol and generally lower low density lipoprotein (LDL) cholesterol concentrations, thus significantly greater ratios of HDL/LDL cholesterol compared with the controls (P < 0.05). The serum apolipoprotein B/apolipoprotein A-1 ratio was significantly lower in rats fed diets containing chicory extract or inulin than that in rats fed fiber-free diets, due to significant reductions in apolipoprotein B concentration (P < 0.05). Greater liver lipid and triglyceride concentrations were observed in rats fed chicory extract or inulin diets compared with the controls (P < 0.05). However, liver phospholipid and cholesterol concentrations were not significantly different among groups (P > 0.05). Addition of 5% inulin to the diet resulted in greater cecal weight, whereas both 5% chicory extract and 5% inulin resulted in greater cecal propionic acid concentration compared with the controls (P < 0.05). Rats fed chicory extract and inulin had significantly greater fecal lipid, cholesterol and bile acid excretions than those fed fiber-free diets (P < 0.05). The results of this study suggest that the improved lipid metabolism observed in rats fed chicory extract (mainly inulin component) may be caused by an alteration in the absorption and/or synthesis of cholesterol, which might result from the changes in cecal fermentation, and by an increase in the fecal excretion of lipid, cholesterol and bile acid.

Animals↗
PubMed1998

The risk of purified protein derivative positivity in homeless men with psychotic symptoms.

BACKGROUND: Homeless people with mental illness have relatively high rates of human immunodeficiency virus, comorbid antisocial personality disorder, and may be homeless more frequently and for greater lengths of time. All of these factors may increase the risk of tuberculosis. METHODS: Our study was done to ascertain if homeless men with psychotic disorders are at an increased risk for tuberculosis infection. One hundred fifty homeless men were interviewed and given purified protein derivatives (PPDs) at a downtown shelter in New Orleans, Louisiana, during a 3-month period. RESULTS: The findings show a strong relationship between psychotic disorders and positive PPDs, with a relative risk of 4.48. CONCLUSIONS: Homelessness and mental illness present barriers to seeking and completing treatment for medical illnesses such as tuberculosis. Use of services may be low even when available; therefore, homeless men with psychotic disorders may be serving as a reservoir for tuberculosis.

Adult↗
PubMed1998

Changes in cardiac troponin I in Kawasaki disease before and after treatment with intravenous gammaglobulin.

Changes in cardiac troponin I (cTnI) in Kawasaki disease before and after treatment with intravenous gamma-globulins (i.v.GG) were investigated in 42 cases in order to confirm the usefulness of cTnI as a serological test for the early onset of acute myocarditis and the effectiveness of i.v.GG as treatment for it. The level of cTnI before i.v.GG treatment was increased in 42.9% (18/42), but 89% (16/18) were in the normal range after treatment as shown by improved clinical symptoms and signs; 9.5% (4/42) were treated twice with i.v.GG because of recurrent high fever, with a positive level of cTnI in the second test. Despite the improved clinical symptoms and signs after retreatment with i.v.GG, 4.7% (2/42) continued to have an increased level of cTnI in follow-up studies. In conclusion, the measurement of cTnI is a useful serologic test for the early diagnosis of myocarditis or myocardial cell injury and for confirming the effectiveness of i.v.GG therapy for the cure and prevention of cardiovascular abnormalities in KD patients.

Biomarkers↗
PubMed1998

The effect of L-ascorbic acid on age-related changes of pyridinoline in cartilage collagen of guinea pigs.

In order to elucidate the effect of L-ascorbic acid (AsA) on the formation of pyridinoline, a mature crosslink of collagen, its content in cartilage collagen of guinea pigs supplemented with and without AsA in the growing process (4-8 weeks of age) and in the period of maturity (10-14 weeks of age) was examined. The AsA-deficient animals, for four weeks during the growing process, had a significantly higher content of pyridinoline in their collagen than the AsA-supplemented group, indicating that the depletion of AsA induced increasing contents of pyridinoline. On the other hand, in the period of maturity, the pyridinoline content in the collagen decreased with age, whereas no difference between AsA-deficient and -supplemented groups was observed. Based on these results, it is assumed that AsA affects the formation of pyridinoline, especially in the growing period.

Adrenal Glands↗
PubMed1998

Expression of Panulirus shaker potassium channel splice variants.

In Drosophila shaker voltage-dependent potassium channels, alternative splicing at the amino and carboxy termini produces currents with different electrophysiological characteristics. We have cloned alternatively spliced forms of shaker from the spiny lobster Panulirus interruptus. Alternative exons were found at three sites of the gene; eight different 5' exons, two alternative exons encoding the pore-forming P region, and an alternative 3' exon. Two of the different amino terminal splice forms were expressed with two alternatively spliced pore forms to produce channels with markedly different characteristics. One of the amino termini produced a channel with transient characteristics while the other produced a delayed rectifier-type channel. The effects of alternative exons at the amino terminus and in the P region appear to be additive. Our results provide new information on the structural requirements for rapid N-type inactivation.

Alternative Splicing↗