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W Park

Publications and source records attributed to W Park.

At least 19 recordsLinked to original sources
PubMed1992

Evaluation of finger blood flow with Tc-99m MDP (methylene diphosphonate).

BACKGROUND: A variety of methods were used to establish objective diagnostic criteria of Raynaud's phenomenon. We intended to introduce another method, using radionuclide (Tc-99m methylene diphosphonate) scintigraphy, which is more objective, simple and economical than the past methods. METHODS: The finger blood flow with radionuclide scintigraphy was evaluated in 10 patients of Raynaud's syndrome, 12 patients of connective disease without Raynaud's symptoms, and 20 normal persons. After immersing one hand in ice water (4 degrees C) for 30 seconds, the hand was exposed to 22 degrees C room air for 15 minutes, and then the patients received the intravenous (IV) bolus of 20 microCi of Tc-99m methylene diphosphonate (MDP). At the same time, scintigraphic image of both hands started with the region of interest, including the second, third, fourth and fifth fingers distal to the metacarpophalangeal (MCP) joints. Computer recording of the counts in the region of interest every 2 seconds for 310 seconds was started on IV bolus injection. RESULTS: The 310 seconds cumulative digital blood flow ratio of cold exposed hand to room air exposed hand was significantly lower in Raynaud's group (p < 0.001), and the ratio of initial slope of activity curve was also lower in the Raynaud's group (p < 0.001). Of the 8 patients showing Raynaud's syndrome, 4 patients of scleroderma and 1 patient of multiple myeloma showed no improvement of finger blood flow in the cold exposed hand after 2 weeks of pharmacological therapy, but 1 patient of mixed connective tissue disease, 1 patient of Behcet's syndrome and 1 patient of SLE showed much improved finger blood flow after combined administration of vasodilator, calcium channel blockers and antiplatelet drugs. CONCLUSIONS: The evaluation of finger blood flow with 99mTc-MDP could be considered to be one of the simple, economical and new methods that can be used in the follow-up, objective assessment of therapeutic effect, and giving an aid in the study of the pathophysiology of the Raynaud's phenomenon.

Adult↗
PubMed1991

So long.

Explore the source record for details and available documents.

Age Factors↗
PubMed1991

Casein kinase II. cDNA sequences, developmental expression, and tissue distribution of mRNAs for alpha, alpha', and beta subunits of the chicken enzyme.

We report the complete primary structures, as deduced from cloned cDNAs, of two catalytic (alpha and alpha') and one beta subunit of chicken casein kinase II. The alpha and alpha' subunits are closely related to each other but differ in their carboxyl termini; moreover, minor differences are distributed throughout the entire lengths of the two proteins, indicating that they are derived from separate genes. Comparison of the chicken protein sequences with those of their mammalian homologs reveals a high degree of evolutionary conservation of all three subunits. Northern analyses were carried out to study the expression of casein kinase II subunits during chicken embryonic development as well as in adult tissues. A single transcript migrating at 1 kilobase was detected when using a beta-specific probe, but multiple transcripts ranging in size from 1.45 to 2.8 kilobase were revealed by alpha- and alpha'-specific probes. Expression of mRNA for all three subunits was high in early embryos but decreased substantially during embryonic development. A comparative analysis of casein kinase II expression in different adult tissues revealed two major findings. First, relative levels of expression of the two catalytic subunits displayed a pronounced tissue specificity, consistent with the possibility that alpha and alpha' subunits may carry out specialized functions. Second, no correlation was observed between levels of transcripts for the catalytic subunits and those of mRNA for the beta subunit.

Amino Acid Sequence↗
PubMed1989

Sucrose-regulated expression of a chimeric potato tuber gene in leaves of transgenic tobacco plants.

Patatin is a family of lipid acyl hydrolases that accounts for 30 to 40% of the total soluble protein in potato tubers. Class-I patatin genes encode 98 to 99% of the patatin mRNA in tubers, but are not normally expressed in other tissues. They are not totally 'tuber-specific'; however, since they can be induced to express at high levels in other tissues under conditions of sink limitation or in explants cultured on medium containing elevated levels of sucrose. To examine the evolution of the mechanisms that regulate patatin gene expression, we introduced a chimeric patatin-beta-glucuronidase (GUS) gene containing 2.5 kb of 5' flanking sequence from the Class-I potato patatin gene PS20 into tobacco plants. The construct was not expressed at significant levels in leaves of juvenile plants or plantlets cultured in vitro, but was expressed at high levels in explants cultured on medium containing 0.3 to 0.4 M sucrose. While there were differences in the expression of the chimeric gene between transgenic tobacco and potato plants, the pattern of sucrose induction was very similar. These results suggest that the mechanism that controls patatin gene expression in potato tubers evolved from a widely distributed mechanism in which gene expression is regulated by the level of available photosynthate.

Carbohydrates↗
PubMed1988

[Determination of the oxidation rate of medium-chain triglycerides in newborn infants with the 13C trioctanoin breath test].

Up to the present time medium chain triglycerides (MCT) have been applied solely for the enteral nutrition of newborn infants. Results of the oxidative utilization of parenterally applicated MCT have not yet been published. We therefore investigated the MCT oxidation with the 13C trioctanoin breath test in neonates. The patients received parenterally 10 mg/kg MCT (1-13C3 trioctanoin) enriched with the stable isotope 13C and emulsified with MCT/LCT 10%. The expired 13CO2 resulting from fat oxidation was determined by a ratio-mass-spectrometer. The 13C content of exhaled air represents the rate of fatty acid oxidation. Within the test period the fatty acid oxidation showed a clear dependency on the simultaneous carbohydrate supply. The oxidation rates of MCT were about twice als high as those of long chain triglycerides (LCT). On account of their high energetic level, MCT-containing emulsions are, in principle, also suitable for the parenteral nutrition of newborn infants.

Breath Tests↗
PubMed1987

Osteomalacia of the mother--rickets of the newborn.

During the last 4 years we observed four cases of neonatal rickets. The mothers of the infants suffered from osteomalacia for 1-3 years prior to its diagnosis shortly after the birth of their children. All four infants were born with craniotabes, and one infant had, in addition, a radial fracture. The diagnoses were confirmed by radiological and laboratory tests which revealed a rarefied bone structure, decreased serum 25-hydroxy-vitamin D and increased alkaline phosphatase levels in all patients. The disorder regressed under low-dose vitamin D3 therapy. As osteomalacia seems to be predominant in oriental women living in Berlin, it is necessary to consider vitamin D deficiency when clinical symptoms of this disease arise and to treat these women at least during pregnancy.

Cholecalciferol↗
PubMed1987

Mutant isolation and molecular cloning of mre genes, which determine cell shape, sensitivity to mecillinam, and amount of penicillin-binding proteins in Escherichia coli.

A chromosomal region of Escherichia coli contiguous to the fabE gene at 71 min on the chromosomal map contains multiple genes that are responsible for determination of the rod shape and sensitivity to the amidinopenicillin mecillinam. The so-called mre region was cloned and analyzed by complementation of two closely related but distinct E. coli mutants characterized, respectively, by the mutations mre-129 and mre-678, that showed a rounded to irregular cell shape and altered sensitivities to mecillinam; the mre-129 mutant was supersensitive to mecillinam at 30 degrees C, but the mre-678 mutant was resistant. The mre-678 mutation also caused simultaneous overproduction of penicillin-binding proteins 1Bs and 3. A chromosomal region of the wild-type DNA containing the total mre region and the fabE gene was first cloned on a lambda phage; a 7-kilobase (kb) fragment containing the whole mre region, but not the fabE gene, was then recloned on a mini F plasmid, pLG339; and finally, a 2.8-kb fragment complementing only mre-129 was also cloned on this low-copy-number plasmid. The whole 7-kb fragment was required for complementing the mre-678 mutant phenotypes. Fragments containing fabE but not the mre-129 region could be cloned on a high-copy-number plasmid. Southern blot hybridization indicated that the mre-678 mutant had a large deletion of 5.25 kb in its DNA, covering at least part of the mre-129 gene.

Amdinocillin↗
PubMed1987

[Effect of carbohydrate administration on leucine oxidation in newborn infants. Studies using the 13C leucine breath test].

The branched-chain amino acid leucine plays an important role in the protein metabolism of human beings. It not only inhibits protein degradation but also stimulates protein synthesis. The oxidation rate of leucine and the influence which nutritional conditions have on this amino acid can be measured with the intravenous 13C-leucine breath test. In order the apply the breath test on newborn infants, the required dosage of L-(1-13C)-leucine and the reproducibility of the test had, firstly, to be determined. Following this, the extent to which the leucine oxidation rate was influenced by a simultaneous carbohydrate intake was investigated. An evident discrimination between the 13CO2-exhalation and the 13CO2-baseline exhalation is demonstrated after a bolus injection of 1 mg L-(1-13C)-leucine/kg B.W. We were able to measure reproducible values of the leucine oxidation rate in newborn infants with a tracer dosage of 4 mg L-(1-13C)-leucine/kg B.W. We found that a higher intake of carbohydrate given at the same time produced a lower rate of leucine oxidation, which indicates increased utilization of leucine for the benefit of protein synthesis.

Breath Tests↗
PubMed1986

Peptidoglycan synthetic activities in membranes of Escherichia coli caused by overproduction of penicillin-binding protein 2 and rodA protein.

Penicillin-binding protein (PBP)-2 and the RodA protein are known to function in determining the rod shape of Escherichia coli cells. Peptidoglycan biosynthetic reactions that required these two proteins were demonstrated in the membrane fraction prepared from an E. coli strain that overproduced both of these two proteins and which lacked PBP-1B activity (the major peptidoglycan synthetase activity in the normal E. coli membranes). The cross-linked peptidoglycan was synthesized from UDP-N-acetylmuramylpentapeptide and UDP-N-acetylglucosamine in the presence of a high concentration of cefmetazole that inhibited all of PBPs except PBP-2. The peptidoglycan was synthesized via a lipid intermediate and showed up to 30% cross-linking. The cross-linking reaction was strongly inhibited by the amidinopenicillin, mecillinam, and by other beta-lactam antibiotics that have a high affinity for PBP-2, but not by beta-lactams that had very low affinity for PBP-2. The formation of peptidoglycan required the presence of high levels of both PBP-2 and the RodA protein in the membranes, but it is unclear which of the two proteins was primarily responsible for the extension of the glycan chains (transglycosylation). However, the sensitivity of the cross-linking reaction to specific beta-lactam antibiotics strongly suggested that it was catalyzed by PBP-2. The transglycosylase activity of the membranes was sensitive to enramycin and vancomycin and was unusual in being stimulated greatly by a high concentration of a chelating agent.

Bacterial Proteins↗