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J L Whang

Publications and source records attributed to J L Whang.

6 recordsLinked to original sources
PubMed1996

Physiologic definitions of obliterative bronchiolitis in heart-lung and double lung transplantation: a comparison of the forced expiratory flow between 25% and 75% of the forced vital capacity and forced expiratory volume in one second.

BACKGROUND AND METHODS: A comparison of the forced expiratory flow between 25% and 75% of the forced vital capacity (FEF25-75) and forced expiratory volume in 1 second (FEV1) was conducted for the detection of obstructive airway disease as an early manifestation of obliterative bronchiolitis. Pulmonary function tests performed on heart-lung and double lung transplant recipients between March 1981 and March 1983 were reviewed. Thirty patients were identified who showed progressive deterioration in pulmonary function after transplantation. Ratios determining proportionate decreases were calculated from measurements of absolute values for the FEF25-75 and FEV1 at the point when the FEF25-75 reached < 70% and < or = 30% of predicted, divided by baseline values obtained before the decline in function. Similar ratios were obtained for FEV1 and FEF25-75 at the point the FEV1 declined > or = 20% from its baseline value. RESULTS: Comparison of the ratios for the FEF25-75 and FEV1 at FEF25-75 values < 70% and < or = 30% of predicted and a similar comparison when the FEV1 declined > or = 20% from baseline showed a greater proportional decrease in FEF25-75 than FEV1 (p < 0.01). With the use of the FEF25-75, declines in airway function were detected earlier. After transplantation a decline in FEF25-75 to < 70% of predicted occurred approximately 112 days before a 20% decline a FEV1. CONCLUSION: The FEF25-75 is more sensitive than the FEV1 for the early detection of obliterative bronchiolitis. A presumptive diagnosis of obliterative bronchiolitis can be made with physiologic criteria, providing infection or acute rejection has been ruled out. When conducting epidemiologic studies or for vital statistics we propose that a decline in FEF25-75 to < 70% be used to define the onset of obliterative bronchiolitis.

Adult↗
PubMed1986

Nucleotide sequence of a bovine clone encoding the angiogenic protein, basic fibroblast growth factor.

Basic and acidic fibroblast growth factors (FGF's) are potent mitogens for capillary endothelial cells in vitro, stimulate angiogenesis in vivo, and may participate in tissue repair. An oligonucleotide probe for bovine basic FGF was designed from the nucleotide sequence of the amino-terminal exon of bovine acidic FGF, taking into account the 55 percent amino acid sequence homology between the two factors. With this oligonucleotide probe, a full length complementary DNA for basic FGF was isolated from bovine pituitary. Basic FGF in bovine hypothalamus was shown to be encoded by a single 5.0-kilobase messenger RNA; in a human hepatoma cell line, both 4.6- and 2.2-kilobase basic FGF messenger RNA's were present. Both growth factors seem to be synthesized with short amino-terminal extensions that are not found on the isolated forms for which the amino acid sequences have been determined. Neither basic nor acidic FGF has a classic signal peptide.

Angiogenesis Inducing Agents↗
PubMed1986

Expression and secretion of biologically active human atrial natriuretic peptide in Saccharomyces cerevisiae.

A hybrid gene was constructed containing a fusion between the DNA sequences encoding the secretory precursor of the yeast mating pheromone alpha-factor and a synthetic sequence encoding a biologically active 24-amino acid carboxyl-terminal portion of the human atrial natriuretic peptide (hANP) precursor. Transformation of Saccharomyces cerevisiae with the hybrid gene resulted in the yeast cells secreting biologically active hANP into the extracellular medium. The secreted hANP was purified and found to be accurately processed at the junction in the chimeric alpha-factor/hANP protein, producing the desired mature hANP amino terminus. The secreted product was also folded correctly with respect to the single disulfide bond. However, the carboxyl terminus of the secreted hANP material was heterogeneous such that the major form lacked the last two amino acids of the peptide while the minor form was the full length material. The observed processing at the carboxyl terminus of the secreted hANP may reflect a normal processing event involved in alpha-factor peptide maturation.

Amino Acid Sequence↗
PubMed1986

Human basic fibroblast growth factor: nucleotide sequence and genomic organization.

Clones encoding the angiogenic endothelial cell mitogen, basic fibroblast growth factor (FGF), have been isolated from human cDNA libraries made from kidney, fetal heart, fetal liver, term placenta, and a breast carcinoma. Basic FGF cDNA clones are present in these libraries at very low levels when compared to the quantity of the growth factor in the tissues. This observation, combined with the fact that several of the clones represent unspliced transcripts, suggests that cytoplasmic basic FGF mRNA is unstable and that the protein is stored in tissues. The amino acid sequence of human basic FGF, deduced from the sequence of these cDNAs and from genomic clones, is 99% homologous to that of bovine basic FGF, implying a strong selection pressure for maintenance of function and structure. As with the bovine factor, human basic FGF does not appear to have a signal peptide sequence. Southern blot analysis of human genomic DNA and mapping of the cloned gene shows that there is only one basic FGF gene. All of the basic, heparin-binding endothelial cell mitogens of similar amino acid composition that have been described must therefore be products of this single gene.

Amino Acid Sequence↗
PubMedDate not supplied

The diagnosis of obliterative bronchiolitis after heart-lung and lung transplantation: low yield of transbronchial lung biopsy.

Obliterative bronchiolitis is the most significant long-term complication of lung and heart-lung transplantation characterized by the rapid development of obstructive airway disease. It is thought to be a manifestation of chronic rejection and has been treated, with limited success, with augmentation of immunosuppression. Early detection of obliterative bronchiolitis and prompt initiation of therapy may result in an improved outcome. The role of transbronchial biopsy has been reported in the diagnosis of acute rejection and infection but not for obliterative bronchiolitis. To study this problem we retrospectively reviewed the transbronchial biopsy results of patients with advanced clinical obliterative bronchiolitis, as defined physiologically. Between January 1, 1988, and December 31, 1991, 46 "sets" of adequate transbronchial biopsy specimens were obtained from 16 patients (15 heart-lung recipients and one double lung recipient). Seven sets of transbronchial biopsy specimens (15.2%) showed obliterative bronchiolitis by pathologic study. In four patients with severe clinical obliterative bronchiolitis, only one transbronchial biopsy specimen of seven (14.3%) showed obliterative bronchiolitis. The pathologic diagnosis of obliterative bronchiolitis was confirmed in three of these patients at the time of autopsy or retransplantation. Twelve patients were still alive at the end of the study period, and all experienced further deterioration of lung function typical for obliterative bronchiolitis. We conclude that the sensitivity of transbronchial biopsy for obliterative bronchiolitis is poor. Possible explanations for these results are explored.

Adolescent↗