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Biomedical subjects

K Kuo

Publications and source records attributed to K Kuo.

16 recordsLinked to original sources
PubMed1996

cDNA sequence and genomic structure of the murine p55 (Mpp1) gene.

MPP1 is an X-linked human gene encoding a heavily palmitoylated membrane protein (p55) with homology to the Drosophila tumor suppressor gene lethal(1) discs-large. As a first step toward studying the effects of mutations in this gene in a mammalian system, the nucleotide sequence of the mouse Mpp1 cDNA has been determined along with the intron-exon boundaries. Mpp1 is ubiquitously expressed and encodes a p55 protein of 466 amino acids with 93 and 65% identity to the human and puffer fish (Fugu rubripes) p55 sequences, respectively. The genomic structure of the Mpp1 gene is likewise conserved with 12 exons. The location of the Mpp1 gene, on the X chromosome, is also conserved between the human and the mouse. Conservation of the Mpp1 gene between mouse and human gives support to the notion that construction and study of a mouse knockout model may help establish the function of the human MPP1 gene, a potential tumor suppressor gene.

Amino Acid Sequence↗
PubMed1996

Germination of Phyllosticta ampelicidaPycnidiospores: Prerequisite of Adhesion to the Substratum and the Relationship of Substratum Wettability

Pycnidiospores of Phyllosticta ampelicida, the causal agent of black rot of grape, were found to germinate only on substrata on which they were firmly attached. Such surfaces were poorly wettable and had advancing contact angles (straight thetaa) formed by a water drop of >80&deg;, e.g., grape leaf, polystyrene, Teflon, polycarbonate, collodion, and glass treated with the silanes n-octadecyltrichlorosilane, dimethyldichlorosilane, or diphenyldichlorosilane. When pycnidiospores were deposited on more wettable surfaces they did not attach firmly and did not germinate. Such highly wettable surfaces had straight thetaa </= 40&deg; and were represented by heat-treated glass, cellophane, nutrient- and water-agars, polystyrene treated with UV-irradiation or sulfuric acid, and glass silanized with n-2-aminoethyl-3-aminopropyltrimethoxysilane, n-(trimethoxysilylpropyl)ethylenediamine triacetic acid trisodium, or 3-aminopropyltriethoxysilane. Adhesion of pycnidiospores was assessed with and without a hydraulic shearing force. Pycnidiospore adhesion occurred over several minutes in distilled deionized water, unless it was first acidified, which decreased attachment time to <0.03 s. Attachment of pycnidiospores treated with sodium azide, formaldehyde, or boiled in water for 10 min was similar to nontreated conidia. Possible mechanisms of adhesion of the conidia to surfaces include hydrophobic and ionic interactions.

Journal Article↗
PubMed1996

Changes of bile duct mucosa after choledochoduodenostomy in rats.

This study investigated the changes of bile duct mucosa in rats after choledochoduodenostomy. Wistar rats were divided into three groups: group I (n = 6) was treated with sham operation as control; group II (n = 10) was treated with common bile duct ligation without choledochoduodenostomy, and group III (n = 12) had both common bile duct ligation and choledochoduodenostomy creation 4 days after common bile duct ligation. From our observations, retrograde induced cholangitis due to enteric reflux into the common bile duct is the possible cause of chronic inflammation after choledochuduodenostomy. At the end of the study, Choledocholithiasis developed in 5 of 12 rats. Severe dysplasia was present in the bile duct mucosa in 6 of 12 rats in group III, but not in group I or II. A technique for silver staining of nucleolar organizing regions (AgNOR) was applied. This technique demonstrated differences in AgNOR counts between normal mucosa and dysplasia. Under AgNOR stain, the number of AgNOR was significantly greater than in the normal or benign counterparts and gradually increased from the normal bile duct mucosa group to the severe dysplasia group (group I 2.1 +/- 0.8, group II 3.2 +/- 1.0, group III 5.3 +/- 1.1). All of these observations suggest that 'sump syndrome' and bile stasis could occur after choledochoduodenostomy in rats and can result in chronic inflammation of the bile duct. It has been well established that calcium bilirubinate is the major type of choledocholithiasis in Orientals. beta-Glucuronidase from bacteria, such as Escherichia coli present in the biliary tree, hydrolyzes bilirubin diglucuronide to bilirubin. Bilirubin combines with calcium in the bile flow to form calcium bilirubinate. Bacterial infection plays a key role in calcium bilirubinate stone formation. Since choledochoduodenostomy did increase reflux cholangitis, and bacterial infection would increase mucin overproduction, bile deconjugation and eventually new calcium bilirubinate stones would be formed. The dysplastic changes in the bile duct mucosa could possibly be related to the prolonged exposure to the biochemically altered infected bile. Thus choledochoduodenostomy might not be the perfect choice in treating calcium bilirubinate choledocholithiasis in Orientals.

Animals↗
PubMed1992

Modified nucleosides in human serum.

Methylated purines and pyrimidines derived from the degradation of transfer ribonucleic acid have been shown to be excreted in abnormal amounts in the urine of patients with cancer. Recent technology developed by Gehrke and Kuo has allowed the separation and quantification of modified nucleosides in serum using reversed-phase high-performance liquid chromatography with diode-array measurement. Serum levels of ten modified nucleosides were measured in 37 normal healthy adults to establish normal values and to correlate activity with age and sex. In addition, serum levels of patients with several malignancies were measured to determine activity in these diseases. Levels of modified nucleosides in normal individuals were consistently reproducible and showed no significant variation among males versus females or with age. Patients with malignant diseases showed consistent elevations and these were highest in patients with more advanced disease. The evidence of no significant differences in the mean levels of modified nucleosides in serum with age or sex in normal adults and elevations in patients with malignancies demonstrate the potential value of modified nucleosides as cancer biomarkers.

Adult↗
PubMed1990

5-[[(carboxymethyl)amino]methyl]uridine is found in the anticodon of yeast mitochondrial tRNAs recognizing two-codon families ending in a purine.

The modified nucleoside (U*) present in the wobble position of Saccharomyces cerevisiae mitochondrial tRNA(Leu) and tRNA(Trp) was isolated by thin-layer chromatography and HPLC. Its chromatographic, UV spectral, and mass spectrometric properties were shown to be identical with those of 5- [[(carboxymethyl)amino]methyl]uridine (cmnm5U). This nucleoside found in yeast mitochondrial tRNAs reading two-codon families ending in a purine permits the selective recognition of A and G in the third codon position.

Anticodon↗
PubMed1978

Biochemical markers of cultured human prostatic epithelium.

Medium from primary cultures of human prostatic cells was examined for polyamines and carcinoembryonic antigen. Spermine was elevated in medium from 5 of 17 epithelial cell cultures but was not found to be a specific marker for cultured human prostatic epithelial cells. Carcinoembryonic antigen was elevated in all 27 prostate epithelial-cell culture fluids tested, 24 of which had more than 20 ng. carcinoembryonic antigen per milliliter. Medium from other cultured human cells (prostate fibroblasts, genitourinary tumor and non-tumor cells), as well as control medium, contained less than 1 ng. carcinoembryonic antigen per milliliter. Carcinoembryonic antigen, as measured in this study, is a way to demonstrate the presence of human prostatic epithelial cells in culture.

Autoanalysis↗
PubMed1975

Search for amino acids in Apollo returned lunar soil.

The lunar samples from Apollo flights 11 through 17 provided the students of chemical evolution with an opportunity of examining extraterrestrial materials for evidence of early prebiological chemistry in the solar system. Our search was directed to water-extractable compounds with emphasis on amino acids. Gas chromatography, ion-exchange chromatography and gas chromatography combined with mass spectrometry were used for the analysis. It is our conclusion that amino acids are not present in the lunar regolith above the background levels of our investigations.

Amino Acids↗
PubMedDate not supplied

Black bronchoscopy.

Explore the source record for details and available documents.

Aged↗
PubMedDate not supplied

Immunocytoma effect upon circadian variation in murine urinary excretion of beta-aminoisobutyric acid, beta-alanine, phenylalanine and tyrosine.

Under the conditions of disynchronization by the manipulation of both the alternation of light and darkness and the availability and unavailability of food, circadian rhythms characterize the excretion of several amino acids by inbred LOU rats bearing an immunocytoma. Large amplitude rhythms can be demonstrated for urinary beta-aminoisobutyric acid, beta-alanine, phenylalanine and tyrosine. Under the same conditions of disynchronization, control animals excrete the same compounds also with a marked circadian variation but at an invariably lower average rate. These excretory rhythms, along with those demonstrated earlier for polyamines and light-chains, are of interest as potential markers for the chronotherapy of cancer.

Amino Acids↗
PubMedDate not supplied

Circadian rhythms in polyamine excretion by rats bearing an immunocytoma.

Large-amplitude circadian rhythms were observed in the urinary excretion of polyamines by rats bearing an immunocytoma. Control animals excreted polyamines at a lower rate but also with marked circadian variation. In confirmation of earlier observations, light-chain excretion by the tumor-bearing rats also exhibited a circadian rhythm, superimposed on an increasing trend. The potential of these rhythms as markers for the chronotherapy of cancer is noted.

Animals↗