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Biomedical subjects

Kui Hong

Publications and source records attributed to Kui Hong.

22 records · Page 2Linked to original sources

Brugada syndrome: 12 years of progression.

Brugada syndrome is increasingly being recognized in clinical medicine. What started as an electrocardiographic curiosity has become an important focus of attention for individuals working in the different disciplines related to sudden cardiac death, from basic scientists to clinical cardiac electrophysiologists. In just 12 years, since the description of the disease, clinically relevant information is continuously being provided to physicians to help protect the individuals with Brugada syndrome to the best of our ability. And this information has been gathered thanks to the effort of hundreds of basic scientists, physicians and patients who continue to give their time, effort and data to help understand how the electrocardiographic pattern may cause sudden cardiac death. There are still many unanswered questions, both at the clinical and basic field. However, with the further collection of data, the longer follow-up and the continued interest from the basic science world we will have the necessary tools to the successful unraveling of the disease.

Arrhythmias, Cardiac↗

Sudden death associated with short-QT syndrome linked to mutations in HERG.

BACKGROUND: Sudden cardiac death takes the lives of more than 300 000 Americans annually. Malignant ventricular arrhythmias occurring in individuals with structurally normal hearts account for a subgroup of these sudden deaths. The present study describes the genetic basis for a new clinical entity characterized by sudden death and short-QT intervals in the ECG. METHODS AND RESULTS: Three families with hereditary short-QT syndrome and a high incidence of ventricular arrhythmias and sudden cardiac death were studied. In 2 of them, we identified 2 different missense mutations resulting in the same amino acid change (N588K) in the S5-P loop region of the cardiac IKr channel HERG (KCNH2). The mutations dramatically increase IKr, leading to heterogeneous abbreviation of action potential duration and refractoriness, and reduce the affinity of the channels to IKr blockers. CONCLUSIONS: We demonstrate a novel genetic and biophysical mechanism responsible for sudden death in infants, children, and young adults caused by mutations in KCNH2. The occurrence of sudden cardiac death in the first 12 months of life in 2 patients suggests the possibility of a link between KCNH2 gain of function mutations and sudden infant death syndrome. KCNH2 is the binding target for a wide spectrum of cardiac and noncardiac pharmacological compounds. Our findings may provide better understanding of drug interaction with KCNH2 and have implications for diagnosis and therapy of this and other arrhythmogenic diseases.

Adult↗

[Expression of a DNA fragment encoding the active domain of human TNF related apoptosis inducing ligand in pichia pastoris].

Human tumor necrosis factor-related apoptosis-inducing ligand(TRAIL) is a member of the tumor necrosis factor (TNF) family of ligands which has been reported in 1995. The TRAIL protein induces apoptosis of certain types of target cells, such as transformed cells that include but are not limited to cancer cells and virus-infected cells but the normal cells. It is a type II transmembrane protein and the extracellular domain of TRAIL is the functional domain in induction of cell apoptosis. A gene fragment encoding for the active domain of TRAIL was modified with oligo-nucleotide directed mutagenesis according to the characters of Pichia pastoris expressing vector. Arginine at the position of 149 corresponding to the amino acid residue 531 which might be a potential Kex2 protease processing sites was substituted with Lysine to prevent the expressed protein from the digestion by the protease. After proved with DNA sequencing. the modified gene fragment coding soluble TRAIL domain was inserted into the Pichia pastoris expression vector pPIC9K in the same reading frame with alpha-factor secreting signal peptide. The recombinant plasmid pPIC9K - TRAIL was transferred into P. pastoris cell by spheroplast transformation. The recombinant yeasts were identified by antibiotic G418 and Southern dot blot. The transformants (His+ Mut(s)) containing multi-copy gene fragment of TRAIL were selected with increasing concentration of G418 and induced with 0.5% methanol in shaking flask to expression the active domain of TRAIL. After inducing for 3 - 4 days, the proteins in the culture supernatant was assayed with SDS-PAGE and Western blot. Two expressed protein bands whose appearant molecular weight were 19kD and 38kD, respectively, could be specifically recognized by polyclonal antibodies against human TRAIL. The 38kD protein might be a dimers of TRAIL in the culture supernatant. The amount of expressed foreign protein made up to 36% of the total proteins in the culture suprenatant. Biological activity assay, in vitro, indicated that the expressed protein could induce tumor cells apoptosis.

Apoptosis↗

Polyhydroxyalkanoate biosynthesis in Pseudomonas pseudoalcaligenes YS1.

Pseudomonas pseudoalcaligenes strain YS1 isolated from oil contaminated soil was able to produce polyhydroxybutyrate blended with medium-chain-length polyhydroxyalkanoates (mcl PHA). PHA synthesis genes were cloned from this strain. A fadB (gene for fatty acid degradation) deleted mutant Escherichia coli KM32B (FADB::Tet) was constructed to express the cloned PHA synthesis gene phaC1(Pp) or phaC2(Pp). The fadB deleted mutant KM32B harboring phaC1(Pp) or phaC2(Pp) showed mcl PHA accumulation while the intact E. coli KM32 did not. The results demonstrated that P. pseudoalcaligenes YS1 possessed at least two PHA synthesis pathways; one of them was responsible for production of mcl PHA.

Acyltransferases↗