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W Kang

Publications and source records attributed to W Kang.

88 records · Page 5Linked to original sources
PubMed1992

[Validation of Doppler-derived interventricular pressure gradients in patients with ventricular septal defect comparing with catheterization study].

To evaluate the accuracy of Doppler echocardiography for measuring the interventricular pressure gradient in patients with ventricular septal defect (VSD), Doppler echocardiography and dual catheters were performed simultaneously in 31 cases with VSD ranging from 9 to 40 years old. The systolic jet velocities through VSD were recorded by the continuous-wave Doppler technique and converted to the peak instantaneous pressure gradient (delta Pp) and the mean pressure gradient (delta Pm) using a modified Bernoulli's equation with the aid of computer system. Both left and right heart catheters were performed to record the left (LVSP) and the right (RVSP) ventricular systolic pressure simultaneously. Guided by the color flow image Doppler technique, the tip of the right heart catheter was carefully placed within the jet area of the right ventricle. The following parameters were measured from the ventricular pressure curves, the peak instantaneous pressure gradient (IPG), the peak to peak pressure gradient (PPG) and the mean pressure gradient (MPG). The comparison between delta Pp and PPG yielded an excellent correlation (r = 0.99, SEE = 0.69 kPa). There was a close agreement between delta Pp and IPG (r = 0.99, SEE = 0.64 kPa). However, the correlation between delta Pm and MPG was also high (r = 0.98, SEE = 0.67 kPa). We conclude that Doppler echocardiography offers a reliable technique for measuring the interventricular pressure gradient in patients with VSD.

Adolescent↗
PubMed1991

Cloning and analysis of YMR26, the nuclear gene for a mitochondrial ribosomal protein in Saccharomyces cerevisiae.

The nuclear gene for a mitochondrial ribosomal protein, termed YMR26, of Saccharomyces cerevisiae strain DC-5 was cloned by hybridization with synthetic oligonucleotide mixtures corresponding to the N-terminal amino acid sequence of this protein. The gene was found to occur in a single copy on either chromosome VII or chromosome XV. The nucleotide sequence of the cloned segment containing this gene showed the presence of an open reading frame capable of encoding a basic protein of 18.5 kDa with 158 amino acid residues. The deduced amino acid sequence showed no significant similarity to any known ribosomal proteins of prokaryotic or eukaryotic origin or to any other proteins in the NBRF protein data bank. When the gene was disrupted by insertion of a 2.9 kb restriction fragment containing LEU2, cells became PET- indicating that the gene is essential for yeast mitochondria. Northern blot analysis indicated that the size of the transcript from the YMR26 gene was approximately 530 nucleotides long. The expression level of the YMR26 gene was monitored upon catabolite repression, in strains with various mitochondrial genetic backgrounds and in strains harboring an increased dosage of the YMR26 gene. In rho+ cells, the transcription of the YMR26 gene was more repressed in a medium with glucose than in the presence of either galactose or nonfermentable carbon sources. However, in rho o cells, its transcription appeared not to be repressed even by high concentrations of glucose. The amount of the YMR26 mRNA was increased 10-fold when cells carried the YMR26 gene on a high-copy number plasmid.

Amino Acid Sequence↗
PubMed1991

Cloning and analysis of the nuclear gene for YmL33, a protein of the large subunit of the mitochondrial ribosome in Saccharomyces cerevisiae.

The N-terminal amino acid sequence of a large subunit protein, termed YmL33, of the mitochondrial ribosome of the yeast Saccharomyces cerevisiae was determined. The data were obtained to synthesize two kinds of oligonucleotide primers, which were used in the polymerase chain reaction to amplify and clone the nuclear gene for this protein. By nucleotide sequencing, the cloned gene, MRP-L33, was found to encode a basic protein of 11 kDa with 98 amino acid residues. The protein encoded by this gene appears to have no leader sequence at its N terminus. The N-terminal two-thirds of the deduced amino acid sequence showed a significant degree of sequence similarity to ribosomal protein L30 of Escherichia coli and Bacillus stearothermophilus. In addition, the C-terminal one-third showed sequence similarity, though to a lesser extent, to a yeast cytoplasmic ribosomal protein termed L16. By hybridization with the yeast chromosomes and their restriction enzyme fragments, the MRP-L33 gene was concluded to exist on chromosome XIII as a single-copy gene. Disruption of the gene by insertion of a HIS3-containing fragment showed that MRP-L33 was essential for mitochondrial function. The transcriptional level of MRP-L33 in strains with different mitochondrial genetic backgrounds was analyzed in the presence of glucose, galactose, or glycerol.

Amino Acid Sequence↗
PubMedDate not supplied

Effects of tyrosine kinase signaling inhibition on survival after cecal ligation and puncture in diet-restricted mice.

BACKGROUND: Malnutrition impairs host immunity, resulting in high mortality and morbidity due to infections. Phosphorylation of protein tyrosine kinase (PTK) is a key step in the signaling of many cellular functions, including immune cell functions. Malnutrition may affect this signaling in response to surgical insults. The aim of this study was to examine the effects of PTK inhibition on mortality in ad libitum and in diet-restricted mice after cecal ligation and puncture (CLP). Moreover, tyrosine phosphorylation of peritoneal cells from these animals was evaluated. METHODS: Survival study: Mice (n = 45) received chow, 146 g/kg per day (ad libitum) or 36.5 g/kg per day (diet-restricted), for 7 days. Two hours before CLP, one-half the mice in each group were given a tyrosine kinase inhibitor, AG 556 (3.0 mg/kg i.p.), and the others received vehicle. Survival was observed up to 7 days after CLP. Effects of AG 556 on survival with a lesser degree of malnutrition (chow 73 g/kg per day) were also examined (n = 41). Measurement of tyrosine phosphorylation: mice (n = 20) were assigned to the ad libitum and diet-restricted (chow 36.5 g/kg per day) groups. Peritoneal cells were harvested either before or 2 hours after glycogen injection. Glycogen treatment elicits polymorphonuclear neutrophil influx into the peritoneal cavity. The cells were incubated with or without N-formyl-methionyl-leucyl-phenylalanine (fMLP). Tyrosine phosphorylation in the cells was examined using flow cytometry, laser scanning cytometry, and Western blotting. RESULTS: Diet restriction significantly reduced survival compared with the ad libitum group. AG 556 treatment decreased the survival of ad libitum, but not in diet-restricted mice in both survival experiments. Stimulation of peritoneal cells with fMLP increased tyrosine phosphorylation in the ad libitum group (23% increase before glycogen and 18% after glycogen), but not in the diet-restricted group (-9% before glycogen and 3% after glycogen). CONCLUSIONS: Inhibition of tyrosine kinase signaling impairs the ability of a well-nourished host to survive CLP-induced sepsis, while having no effects on survival in diet-restricted mice. Peritoneal cells from diet-restricted animals are unable to increase PTK phosphorylation in response to stimulation, which may be the mechanism underlying impaired host defense during malnutrition.

Animals↗
PubMedDate not supplied

Analysis of interaction between molecules of Bombyx mori nucleopolyhedrovirus IE-2 using a yeast two-hybrid system.

Baculovirus IE-2 protein is one of well-known transactivators. In this report, we demonstrate that Bombyx mori nucleopolyhedrovirus (BmNPV) IE-2 interacts with itself. Several clones were obtained from a yeast two-hybrid screening system using IE-2 as bait and were found to encode IE-2 protein. Nucleotide sequencing of these clones showed that they contained C-terminal regions in common. Further analyses suggest that BmNPV IE-2 protein interacts with itself through 80 amino acid residues of coiled-coil domain in C-terminus.

Animals↗