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Biomedical subjects

Y Kim

Publications and source records attributed to Y Kim.

At least 829 records · Page 46Linked to original sources
PubMed1988

Arginine vasopressin receptors in pig cerebral microvessels, cerebral cortex and hippocampus.

We tested for the presence of arginine vasopressin (AVP) receptors in pig cerebral microvessels, cerebral cortex and hippocampus by specific binding methods with [3H]AVP as the ligand. The specific binding of [3H]AVP to all preparations was saturable and Scatchard analysis indicated a single class of high affinity binding sites (dissociation constant of 1-2 nM). Maximal binding capacity in cerebral microvessels was about 60% that of the cerebral cortex; and there were no apparent differences in the maximal binding capacity between cerebral cortex and hippocampus. These findings suggest the existence of AVP receptor sites in cerebral microvessels and support the hypothesis that AVP has a role in the control of the brain microcirculation.

Animals↗
PubMed1988

Multimodality treatment of non-small cell lung cancer: response to cisplatin, VP-16, and 5-FU chemotherapy and to surgery and radiation therapy.

Twenty-one patients with unresectable non-small cell lung cancer (NSCLC), 11 with stage III M0, five with malignant pleural effusion, and five with a single resectable metastasis were treated with multimodality therapy. All received two to three cycles of preoperative chemotherapy with a new sequential combination of cisplatin (50 mg/m2 IV X 1) followed by 5-FU infusion (40 mg/m2/hr X 72) and etoposide (80 mg/m2/day X 3). Thirteen of 21 (62%) had a partial response, and three (14%) had a minor response to chemotherapy. Of the 19 who underwent surgical exploration, 17 were confirmed to have NSCLC. Ten patients with NSCLC and one with choriocarcinoma were rendered disease free by resection of the primary tumor and lymph nodes. Six received intra- and/or perioperative interstitial therapy with 125I and/or 192Ir. Another patient was treated with 32P. Postoperative external radiotherapy was administered in 15 patients, and adjuvant chemotherapy was administered in ten. This multimodality therapy was well tolerated, safe, and highly effective, resulting in excellent palliation even in patients with pleural effusion and metastasis. The most promising results were in unresectable stage III M0 with a partial response rate of 82% following neoadjuvant chemotherapy and a complete response rate of 73% after surgery. In this group, median survival has not yet been reached and will exceed 12 months.

Adult↗
PubMed1988

Rhodoquinone requirement of the Hymenolepis diminuta mitochondrial electron transport system.

The occurrence of rhodoquinone as a mitochondrial membrane component was demonstrated in adult Hymenolepis diminuta. Chromatographic separation of pentane extracts, from lyophilized mitochondrial membranes, coupled with spectral analyses of separated material demonstrated the presence of rhodoquinone. The presence of ubiquinone was not apparent. Rhodoquinone content of membranes was about 1.2 micrograms (mg protein)-1. The rhodoquinone requirement of the H. diminuta electron transport system was demonstrated both in terms of the less active NADH oxidase and the physiologically required, NADH-dependent fumarate reductase employing lyophilized mitochondrial membranes as the source of activities. Pentane extraction of membranes virtually abolished the oxidase and fumarate reductase systems. Supplementation of pentane-treated membranes with H. diminuta rhodoquinone restored oxidase and fumarate reductase activities to levels simulating those of lyophilized membranes. Ubiquinone did not substitute for rhodoquinone. The rhodoquinone-reconstituted membranes displayed rotenone sensitivity. These findings represent the first direct demonstration of the rhodoquinone requirement of helminth electron transport-coupled oxidase and fumarate reductase.

Animals↗
PubMed1988

The glomerular mesangium.

The mesangium is more than simply a support structure for glomerular capillary circulation. Mesangial cells respond to various vasoactive mediators and probably contribute to the regulation of mesangial cell contractility and, consequently, glomerular perfusion. The surrounding extracellular matrix contains several glycoproteins and collagens that may affect the immune interactions of antigens and antibodies and may possibly influence the disposition of immune complexes. These properties may modulate the consequences of deposition of IgA-containing immune complexes in the mesangium in patients with IgA nephropathy and the consequent expression of clinical disease.

Animals↗
PubMed1988

Effects of supervised play in a hospital waiting room.

Thirty 5- to 10-year-old children and the adults accompanying them were observed in the waiting room of an outpatient neurology clinic. Half had appointments on days when supervised play was available to them in the waiting room. Results showed that children displayed less anxious behavior and the adults accompanying them were less irritable and spoke to the staff more when supervised play was available than when it was not.

Adult↗
PubMed1988

Long-term follow-up of patients with steroid-dependent, minimal change nephrotic syndrome.

A subgroup of patients with steroid-responsive minimal change nephrotic syndrome (MCNS) is classified as steroid-dependent because of repeated relapses of proteinuria during prednisone taper, or within four weeks of withdrawal of prednisone. The long-term outcome of this subgroup of patients has not been documented. Thirteen patients with onset of steroid-dependent MCNS (biopsy-proven) in childhood have been followed for 10-22 years (mean 15.6 years); 8 patients have been in stable remission for 2-13 years (mean 5.5 years); 3 remain steroid-dependent 12, 18 and 22 years after onset; and 2 had steroid-responsive relapses after 5 and 8 years of remission. In 3 patients steroid-dependent MCNS remitted without cytotoxic therapy 7-11 years after onset. Cyclophosphamide was administered to the remaining 10 patients: 8 had prolonged remissions (1.1-13 years, mean 4.3 years) and 2 relapsed shortly after cyclophosphamide therapy. Of the 8 patients who had prolonged remissions after cyclophosphamide, 3 have had no relapses 5-13 years after therapy. In 5 of these 8 patients steroid-dependency recurred 1.1-3 years after cyclophosphamide and a second course was given, resulting in remissions of 1.4-8 years in 3 patients, change to a frequently relapsing pattern in 1 patient and remission of 3 months in one patient who then became steroid-dependent again. We conclude that the long-term outcome of steroid-dependent MCNS is favorable. Cyclophosphamide is useful in the management of these patients and a prolonged course of alternate-day prednisone therapy after cyclophosphamide may be helpful in maintaining remission.

Adolescent↗
PubMed1988

Quantitative muscle testing in childhood dermatomyositis.

Sixteen children with dermatomyositis were followed longitudinally by quantitative muscle testing between 1972 and 1982. The time to achievement of normal muscle strength measured quantitatively was significantly delayed (p less than .001) compared to the time muscle strength was clinically assessed as normal by manual muscle testing. A significant difference was also found between the time normal muscle strength was measured and normal muscle enzymes were achieved (p less than .05). Quantitative muscle testing is a useful adjunct to clinical assessment of muscle strength and determination of muscle enzymes in the therapeutic management of patients with dermatomyositis.

Adolescent↗
PubMed1987

Structural characterization of natural human urinary and recombinant DNA-derived erythropoietin. Identification of des-arginine 166 erythropoietin.

Recombinant human erythropoietin (rhEPO) has been purified to apparent homogeneity from a Chinese hamster ovary cell line expressing a cDNA clone of the human gene. NH2-terminal sequencing of the recombinant hormone indicates that the 27-residue leader peptide is correctly and consistently cleaved during secretion of the recombinant protein into conditioned medium, yielding the mature NH2 terminus (Ala-Pro-Pro-Arg...). Analysis of the COOH terminus of rhEPO by peptide mapping and fast atom bombardment mass spectrometry (FABMS) demonstrates that the arginyl residue predicted to be at the COOH terminus (based on confirmation of both genomic and cDNA sequences) is completely missing from the purified protein. The truncated form of the recombinant hormone, designated des-Arg166 rhEPO, displays an in vivo specific activity of greater than 200,000 units/mg protein. Structural characterization of natural human urinary EPO (uEPO) by peptide mapping and FABMS reveals that the urinary hormone is also missing the COOH-terminal Arg166 amino acid residue, a modification that remained undetected until now. There is no evidence of further proteolytic processing at the COOH terminus beyond specific removal of the Arg166 amino acid residue in either rhEPO or uEPO. On the basis of the FABMS data, we propose that the physiologically active form of the hormone circulating in plasma and interacting with target cells in vivo is des-Arg166 EPO.

Amino Acid Sequence↗
PubMed1987

Virulence for guinea pigs of tubercle bacilli isolated from the sputum of participants in the BCG trial, Chingleput District, South India.

This study, conducted in Madras, India and in Madison, Wisconsin, USA, was concerned with the virulence of isolates of Mycobacterium tuberculosis obtained from the sputum of individuals living in the Chingleput district of south India. The following results were obtained. 1. The findings of Mitchison with respect to the predominance of low virulence for guinea pigs among isolates from persons living Madras, were confirmed on isolates from the sputum of residents of the Chingleput district. 2. A high correlation was found between the log10 number of tubercle bacilli recovered from the spleen of guinea pigs infected intramuscularly with 1.0 mg of tubercle bacilli and the root index of virulence. 3. A high correlation was found between the log10 number of tubercle bacilli recovered from the spleen of guinea pigs infected intramuscularly with 1.0 mg of tubercle bacilli and the number recovered from the spleen of guinea pigs infected by the respiratory route with 5-10 tubercle bacilli. 4. Relatively low correlations were found between RIV and the susceptibility of isolates to thiophene-2 carboxylic acid hydrazide or to hydrogen peroxide.

Animals↗
PubMed1987

Ultrastructural localization of the membrane attack complex of complement in human renal tissues.

Utilizing a monoclonal antibody (Poly C9-MA) to a neoantigen of the C9 portion of the membrane attack complex of complement (MAC), immunoelectron (IEM) and immunofluorescent (IF) microscopy were performed on kidney tissue from normal humans and patients with insulin-dependent diabetes mellitus (IDDM) and type II membrano-proliferative glomerulonephritis (MPGN II). Comparative studies were conducted using polyclonal antibodies to human C3, C5, IgG, IgA, and IgM. In normal human tissue, there was a close correlation between increasing chronologic age and the quantity of MAC deposited in the mesangial stalk, along the interstitial aspect of and within tubular basement membranes (TBMs) and in arteriolar walls. IF of kidney tissues from 12 patients with IDDM with varying degrees of mesangial expansion and glomerulosclerosis demonstrated a direct relationship between the degree of tissue damage and the amount of MAC deposited in the mesangium. IEM of three normal and four diabetic specimens revealed reaction product of Poly C9-MA on linear and circular membranous structures within the mesangium, TBMs, and vessel walls, and within the glomerular basement membranes (GBMs) in diabetic subjects. Evidence is presented that these structures, which have been previously described by routine electron microscopy, represent cellular debris in these loci on which Poly C9-MA has been deposited. In MPGN II, Poly C9-MA and C3 were distributed within subepithelial deposits, along either side of the dense deposits (DDs) within the GBMs and TBMs, and around circular masses of DDs within the mesangium.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1987

A prototype system and reconstruction algorithms for electrical impedance technique in medical body imaging.

We have developed an impedance imaging system to reconstruct cross-sectional images of the body's electrical characteristics based on static tissue impedance. The hardware system consists of a data collection subsystem and the Intel 380 host microcomputer system with an Intel 80286 microprocessor, an Intel 80287 numeric data processor, and an Intel 80186 microprocessor-based display board. The system is capable of initiating a data collection from an array of current-sensing electrodes and reconstructing impedance images based on these data measurements. We have tested the data collection subsystem with physical phantom models, and we have found that the prototype system is capable of discriminating high resistivity regions in contrast with the low resistivity background. Our system is flexible in that each electrode's function (sensing currents, applying voltages, grounding body surfaces, and disconnected from the body) can be programmed individually so that a variety of electrode configurations for different projection techniques can be tested for optimal system performance. Various reconstruction algorithms have been developed and tested particularly for this imaging modality. Since a computer body model is needed for some impedance reconstruction algorithms, we have created two- and three-dimensional computer body models based on the finite element method approach, and verified our finite element modelling technique by building physical phantoms and comparing measured experimental results with simulation results predicted by the computer model. We have found that the sensitivity is a function of position, pixel size (image resolution) and background resistivity. We have also tried to compensate the low sensitivity of impedance changes in the central region.(ABSTRACT TRUNCATED AT 250 WORDS)

Algorithms↗
PubMed1987

Increased production of arachidonate metabolites in an occlusion-reperfusion model of canine myocardial infarction.

To define the role of arachidonate metabolites in evolving ischaemic myocardial damage 10 anaesthetised open chest dogs underwent 90 min occlusion of the left anterior descending coronary artery followed by 5 h reperfusion. Tissue extracts from ischaemic myocardium incubated in vitro were subjected to high pressure liquid chromatography for analysis of lipoxygenase products such as mono hydroxyeicosatetraenoic (HETE) acids and to radioimmunoassay for determining a cyclooxygenase product, thromboxane B2. In ischaemic myocardium the production of 12-HETE (120(35) ng.g-1, mean (SEM)) and thromboxane B2 (18.3(2.4) ng.g-1) was significantly higher than that in normal myocardium (13(2) ng.g-1, p less than 0.01, and 4.2(0.5) ng.g-1, p less than 0.001, respectively). 12-HETE production was linearly correlated with thromboxane B2 production in ischaemic myocardium (r = 0.718, p less than 0.02). The increased production of 12-HETE and thromboxane B2 was in proportion to infarct size as measured by a percentage risk area infarcted (r = 0.732, p less than 0.02, and r = 0.942, p less than 0.001, respectively). Similarly, the increase in production of these eicosanoids was related to the degree of leucocyte infiltration in ischaemic myocardium. These results indicate that altered arachidonate metabolism is strongly associated with the progression of ischaemic myocardial damage, suggesting important roles for these eicosanoids, which may be produced by blood corpuscles during the evolution of acute myocardial infarction.

Animals↗
PubMed1987

A computer-assisted image-analysis system for analyzing polymorphonuclear leukocyte chemotaxis in patients with diabetes mellitus.

A computer-assisted image-analysis system that precisely tracks the cell movements of up to 50 polymorphonuclear leukocytes (PMNLs) was developed and used to quantitatively measure cellular chemokinesis and chemotaxis in normal individuals and in diabetic patients with hyperglycemia. The PMNLs were tested in Zigmond chambers with or without a gradient of 10(-7) M n-formylmethionylleucylphenylalanine (f-Met-Leu-Phe). Cellular movement was recorded on videotape by using a videocamera mounted on the microscope. The videotapes were analyzed by computer programs to calculate the speed and direction of each PMNL at 10-sec intervals. Average rates of chemokinesis were 19.6 microns/min without and 25.3 microns/min with f-Met-Leu-Phe. McCutcheon indices, which measure chemotaxis, were 0.01 without and 0.48 with f-Met-Leu-Phe. Similar values were observed in diabetic patients after fasting (average glucose, 217 mg/100 ml) and 2 hr after glucose challenge (average glucose, 309 mg/100 ml). These values demonstrate that PMNLs from diabetic patients with hyperglycemia move at normal rates and respond appropriately to f-Met-Leu-Phe.

Adolescent↗
PubMed1987

Response of inbred mice to aerosol challenge with Mycobacterium tuberculosis.

An autosomal dominant gene (Bcg), which maps to mouse chromosome 1, has been shown to confer on mice resistance to attenuated Mycobacterium bovis BCG Montreal, Salmonella typhimurium, and Leishmania donovani. Most animal models used for the study of the Bcg gene have involved intravenous injection of a large number of microorganisms (greater than 10(4) CFU). The present study examines the effect of the Bcg gene on the resistance of inbred mice to challenge via the respiratory route with 5 to 10 CFU of virulent Mycobacterium tuberculosis. The number of tubercle bacilli recovered from the lung lobes indicates that the growth kinetics of the microorganism did not differ between BCG-resistant and BCG-susceptible strains of mice. The number of tubercle bacilli recovered from the spleen was also similar among strains. Although there were reproducible differences in the time of first recovery of bacilli from the spleen, these differences appeared to be unrelated to the expression of the Bcg gene. When mice were challenged with purified protein derivative, all strains responded similarly as observed by measurements of footpad swelling.

Aerosols↗
PubMed1987

Childhood dermatomyositis. Clinical course and long-term follow-up.

The presentation, clinical course, and long-term follow-up (3-22 years) of 39 children with dermatomyositis followed from 1962-1982 is presented. The medical course of these patients was complicated by respiratory diseases (20%), gastrointestinal diseases (24%), and calcinosis (30%). Patients presenting prior to 1972 received a wide variety of treatments. Since 1972, treatment has consisted of long-term prednisone, supplemented in some patients with azathioprine. Ten patients died (eight of whom were first seen before 1972) of complications after intestinal perforation (5) or aspiration pneumonia (5). Of 29 survivors, three have persistent calcinosis and/or contractures. Improved outcome since 1972 probably relates to better clinical assessment, management of complications, and regulation of drug therapy.

Adolescent↗