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Biomedical subjects

R Kim

Publications and source records attributed to R Kim.

At least 199 records · Page 11Linked to original sources
PubMed1979

Flushing syndrome due to mahimahi (scombroid fish) poisoning.

Scombroid fish poisoning, one of the most common adverse reactions to fish, is also probably one of the most common causes of a flushing syndrome. The reaction usually involves fishes of the Scombridae family but, in Hawaii, the reaction is most often due to mahimahi (Coryphaena hippurus). Onset of the reaction is usually abrupt and commonly associated with a prominent flush resembling a sunburn. Headache, tachye to a toxin with histamine-like properties, which is formed because improper refrigeration enables endogenous bacteria to decarboxylate histidine normally present in dark-meat fishes. Symptoms are usually promptly relieved by parenteral antihistamine therapy.

Adult↗
PubMed1979

Treatment of Kaposi's sarcoma with bleomycin.

Two cases of Kaposi's sarcome that responded to bleomycin therapy are reported herein. The first case, resistant to various treatments, responded remarkably well after 240 mg of bleomycin was administered over a thirteen month period. The second case had rapidly progressive untreated Kaposi's sarcoma of six months's duration; a prompt response was obtained to an initial course of 105 mg of bleomycin.

Aged↗
PubMed1976

Projections of the globus pallidus and adjacent structures: an autoradiographic study in the monkey.

Because the globus pallidus gives rise to the principal efferent system of the corpus striatum and is traversed by several fibers systems, attempts were made to study the projections of its cells by autoradiographic technics. Tritiated amino acids (L-leucine, L-proline and L-lysine) were injected into: (1) the medial pallidal segment (MPS), (2) the MPS and the substantia innominata (SI), (3) portions of the MPS and the lateral pallidal segment (LPS) and (4) parts of the putamen. Cells labeled by injections of the MPS transported isotope to thalamic nuclei (ventral anterior, VApc, ventral lateral, VLo and VLm, and the centromedian, CM), the pedunculopontine nucleus (PPN), and the lateral habenular nucleus (Hbl). Labeled cells of the MPS and SI transported isotope to: (1) thalamic nuclei (VLo, VLm and CM), (2) PPN, (3) Hbl, (4) lateral and posterior regions of the hypothalamus, and (5) extensive dorsal regions of the substantia migra (SN). Comparisons of label transported from uptake of isotope by cells of the MPS, and cells of both pallidal segments, suggest that the LPS projects fibers only to the subthalamic nucleus (STN). Not all regions of the STN appear to receive fibers from the LPS. Selectively labeled neurons of the putamen transport isotope to broad regions of both pallidal segments and to the pars reticulata of the SN. This study suggests that cells of the MPS project profusely and topographically to: (1) the rostral ventral tier thalamic nuclei (VApc, VLo and VLm), (2) lateral portions of CM, and (3) the PPN. Fibers of the lenticular fasciculus appear to terminate preferentially in VLo. Cells in sublenticular portions of SI, and those extending into the medullary laminae of the pallidum, appear to project to: (1) HB1 via the stria medullaris, (2) the pars compacta of SN, (3) lateral and posterior regions of the hypothalamus, and (4) the so-called nucleus of the ansa lenticularis. Some fibers from cells of SI appear to join the dorsal stria terminalis, but none enter the inferior thalamic peduncle and none project to any part of the dorsomedial nucleus of the thalamus.

Amygdala↗
PubMed1976

Nigrothalamic projections in the monkey demonstrated by autoradiographic technics.

In spite of repeated demonstrations by degeneration technics, nigrothalamic fibers have been regarded with some skepticism. Attempts were made to trace nigral efferent projections in the monkey by autoradiographic technics. Tritiated amino acids (L-leucine, L-lysine and L-proline), injected into portions of the substantia nigra (SN), labeled cells in four regions, designated as, (1) rostrolateral, (2) caudolateral, (3) rostromedial and (4) central. Rostrolateral nigral neurons transported radioactive label preferentially and abundantly to thalamic nuclei; localized isotope was found in parts of three thalamic nuclei, the medial part of the ventral lateral nucleus (VLm), the magnocellular part of the ventral anterior nucleus (VAmc), and the paralaminar part of the dorsomedial nucleus (DMpl)9 Lateral neurons in the caudal half of the SN transmitted radioactive label to the same thalamic nuclei as rostrolateral nigral neuron. Isotope transported to portions of the striatum was modest and localized. Radioactive label taken up by large cells in the caudal third of the SN was transported to portions of the striatum, but not to thalamic nuclei. Labeled nigral neurons in the medial two-thirds of the rostral half of the SN, and in the middle third of the central part of the SN, transported the label mainly to parts of the caudate nucleus and putamen. In these animals modest radioactive label was seen in VLm and VAmc, but not in other thalamic nuclei. There was no evidence that nigral neurons project to the subthalamic nucleus. No radioactive transport from nigral neurons was detected in the superior colliculus, the midbrain tegmentum, or the red nucleus, and none was transported to more caudal brain stem nuclei. Nigrothalamic fibers arise particularly from cells in rostral and lateral parts of the substantia nigra. While some cells in other parts of the nigra project to thalamic nuclei, these appear scattered and less numerous. Large cells in caudal parts of the SN do not project to thalamic nuclei. These observations confirm nigrothalamic projections to VLm and VAmc, and identify a new nigral projection to part of the dorsomedial nucleus of the thalamus (DMpl). No nigral efferent fibers project to any of the intralaminar thalamic nuclei.

Animals↗
PubMed1974

Mutation in Shigella flexneri resulting in loss of ability to penetrate HeLa cells and loss of glycerol kinase activity.

A colonial variant of a virulent Shigella flexneri 2a has lost both virulence and glycerol kinase activity. It also has several other altered characteristics: lowered ability to oxidize tricarboxylic acid cycle intermediates, increased electrophoretic mobility, and decreased sensitivity to sodium lauryl sulfate. Genetic analysis has revealed that the gene governing glycerol kinase activity in Shigella has a different chromosomal locus than that from Escherichia coli. Furthermore, transduction of the Shigella glycerol kinase gene (glp K) into the avirulent Shigella strain can restore the ability to penetrate HeLa cells, whereas the gene from E. coli cannot. About half of the glp K mutants lose this ability, and only about half of the revertants of an avirulent glp K mutant regain it. This indicates that more than one gene affects glycerol kinase activity in Shigella, only one of which is associated with penetration. Glycerol kinase activity is closely correlated with changes in electrophoretic mobility, but does not appear to have any relationship to sodium lauryl sulfate sensitivity nor to the oxidation of tricarboxylic acid cycle intermediates.

Animals↗
PubMed1974

New class of streptomycin-resistant mutants incompatible with supX suppressor mutations in Salmonella typhimurium.

Streptomycin-resistant colonies of Salmonella typhimurium appearing in platings of supX suppressors of strain leu-500 are less variegated in size than are those derived from strain leu-500 counterparts. Several of the streptomycin-resistant leu-500 clones, furthermore, yield suppressors and revertants of the leu-500 auxotrophy at unusually low rates, suggesting that they provide a genetic background inimicable to supX suppression. Two such "suppression-restrictive" leu-500 streptomycin-resistant (str) mutants, designated strains M(1) and M(4), were characterized as to their ability to receive the trp-supX-cysB linkage region by transduction. Coentry of a donor supX deletion mutation with the selected trp(+) marker was not observed even though these sites display more than 10% linkage in control experiments. This was demonstrably the result of nonviability of the combined supX mutant, M(1) or M(4) streptomycin-resistant genotype, rather than the lack of suppression of the leu-500 imparted auxotrophy. Both M(1)- and M(4)-type resistance was accompanied by pleiotropic effects resembling those caused by strB (nonribosomal)- rather than strA (ribosomal)-type resistance, but both restrictive mutants had a high upper limit of resistance corresponding to that of strA-type mutants. Transduction analyses indicated that the str character of neither the M(1) nor the M(4) strain was linked to the strA or the strB gene. These mutations define a previously undescribed locus, which we propose to designate strC, apparently related to streptomycin uptake rather than its intracellular action. Mutation at this locus is evidently incompatible with the inactivation or removal of the supX site, suggesting a functional association between products of the genes.

Chromosome Mapping↗
PubMed1973

Factors affecting virulence of Shigella flexneri: avirulent strain with altered metablism of succinate, fumarate, and malate.

It has been found that a mutation of Shigella flexneri 2a to avirulence can result in altered metabolism of tricarboxylic acid cycle acids, but the effect is strongly dependent on growth conditions. Mutant cells harvested from stationary-phase cultures grown with vigorous shaking in nutrient broth oxidize succinate, fumarate, and malate much more slowly than do wild-type cells. Cell-free extracts from such cells show similar differences in oxidative ability. These differences were less pronounced when cells were harvested from the exponential phase of growth and were nonexistent when the cells were grown without shaking. When tricarboxylic acid cycle acids were used as carbon sources with shaking, mutant cells from exponential phase cultures oxidized tricarboxylic cycle acids almost to the same extent as the wild type. Stationary-phase cells grown on succinate lost succinoxidase activity, but wild-type cells retained more than twice the activity of mutant cells. The effect of growth conditions on oxidative differences between the two strains was similar to the differences in succinate uptake observed under similar conditions.

Azides↗
PubMed1971

Mechanisms and genetics of resistance to sodium lauryl sulfate in strains of Shigella and Escherichia coli.

The sensitivity to sodium lauryl sulfate (SLS) of Shigella flexneri and Escherichia coli is determined by at least three genes. One site is located near the lactose operon, and two loci are cotransducible with the arabinose operon. Calcium ions protect against SLS lysis. One gene is concerned with the relative ability of the bacterium to retain calcium against such chelating agents as ethylenediaminetetraacetic acid or phosphate buffer. This was first observed in a mutation from virulence to avirulence in S. flexneri with a concomitant loss of ability to penetrate the intestinal epithelium. The avirulent strain is far less sensitive to lysis by SLS in the presence of phosphate buffer than its virulent parent. The avirulent strain is also less sensitive to lysozyme and ethylenediaminetetraacetic acid. E. coli K-12 is much more sensitive to SLS than both of these Shigella strains. An E. coli-S. flexneri hybrid, which is unable to survive well in the gut and thus only produces an abortive infection, has inherited this extreme sensitivity to SLS.

Arabinose↗
PubMedDate not supplied

A 189-bp fragment of Crithidia fasciculata maxicircle DNA confers autonomous replication in Saccharomyces cerevisiae.

A 189-bp fragment capable of promoting high-frequency transformation in Saccharomyces cerevisiae has been isolated from the maxicircle of the insect trypanosomatid Crithidia fasciculata. Chimeric plasmids containing this autonomously replicating sequence (ars) are maintained as extrachromosomal elements in S. cerevisiae. The nucleotide sequence of the maxicircle fragment, termed ars189, has been determined, and its position has been mapped in the maxicircle. The ars189 fragment has an A + T content of 79.4% and shows a large asymmetry in the distribution of adenine and thymine residues between the two strands. In one strand (the T strand) thymine accounts for 118 out of 189 nucleotides while adenine accounts for only 32 nucleotides. The ars189 DNA does not hybridize with minicircles, and its sequence appears to be unique in the C. fasciculata maxicircle genome. This sequence also shows extensive homology to a sequence within a 2.6-kb ars fragment of the Leishmania tarentolae maxicircle. In addition, ars189 contains two copies of a yeast consensus ars sequence (A/T)TTTATPuTTT(T/A).

Animals↗
PubMedDate not supplied

Longitudinal relationship between dentin lead levels in childhood and bone lead levels in young adulthood.

A retrospective cohort study was conducted to examine the relationship between tooth lead in children and bone lead levels in young adults. Members of a cohort of young adults were reassessed 13 y after initial examination at an ambulatory clinical research center. Dentin lead levels were measured by anodic stripping voltammetry during the years 1975-1978, and bone lead levels of the tibia and patella were measured by K-x-ray fluorescence technique during 1989 and 1990. A total of 63 subjects who had no history of chelation or had no missing information on potential confounders were studied. The median follow-up interval was 13.2 y. Dentin lead levels averaged 13.4 micrograms/g (standard deviation [SD] = 10.7 micrograms/g, range = 2.9-51.8 micrograms/g), and bone lead levels averaged 1.3 micrograms/g (SD = 4.4 micrograms/g, range = -9-13 micrograms/g) for tibia and 5.4 micrograms/g (SD = 8.4 micrograms/g, range = -10-25 micrograms/g) for patella. The authors controlled for age, sex, race, and mother's socioeconomic status, and dentin lead levels were predictive of higher tibia, patella, and mean bone lead levels in 32 subjects (follow-up interval of 11.8-13.2 y). A correction for measurement errors in dentin lead measurements was made, and it was determined that a 10-micrograms/g increase in dentin lead levels in childhood was predictive of a 1-microgram/g increase in tibia lead levels, a 5-micrograms/g increase in patella lead levels, and a 3-micrograms/g increase in mean bone lead levels among the young adults. It was concluded, therefore, that lead exposure in early life may be used to predict elevated body burden up to 13 y later.

Adolescent↗
PubMedDate not supplied

Two-dimensional pulsatile hemodynamic analysis in the magnetic resonance angiography interpretation of a stenosed carotid arterial bifurcation.

A two-dimensional pulsatile hemodynamic analysis based on the finite-element technique was performed on a minimally stenosed carotid artery to identify the possible explanation for the differences in the x-ray and magnetic resonance carotid angiograms of a patient. The magnetic resonance angiogram was obtained by applying the maximum intensity projection algorithm to axial slices, acquired using the time-of-flight principle. The differences in the x-ray and magnetic resonance depictions were interpreted based on velocity profile, wall shear stress, and streamline data provided by the hemodynamic analysis. The specific contribution of the stenosis was further isolated from that of the bifurcation by comparing the flow patterns within the stenotic artery with those of its normal counterpart. The Doppler spectral velocity wave form of the patient constituted the basis for the pulsatile flow velocity specification. The analysis took into consideration the non-Newtonian viscosity of blood. The numerical procedure was validated through different convergence criteria and through shear stress comparisons. The importance of hemodynamic analyses in relation to magnetic resonance angiography was further discussed along with possible shortcomings of the technique.

Angiography↗