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Biomedical subjects

Y L Song

Publications and source records attributed to Y L Song.

31 records · Page 2Linked to original sources
PubMed1996

Eosinophil infiltration in nonallergic chronic hyperplastic sinusitis with nasal polyposis (CHS/NP) is associated with endothelial VCAM-1 upregulation and expression of TNF-alpha.

We studied potential mechanisms of eosinophil accumulation in nonallergic chronic hyperplastic sinusitis with nasal polyposis (CHS/NP). We measured expression of endothelial vascular cell adhesion molecule-1 (VCAM-1), which mediates selective eosinophil transendothelial migration, the cytokines interleukin (IL)-1 beta, TNF-alpha and IL-13 which upregulate VCAM-1 expression, and the chemokine RANTES which mediates lymphocyte, monocyte, and eosinophil chemotaxis in chronic hyperplastic sinusitis with nasal polyposis (CHS/NP) nasal polyps (nonallergic versus allergic) and middle turbinate biopsies from normal controls. By immunohistochemical staining, the density of EG2+ eosinophils was increased in both the nonallergic and allergic CHS/NP subgroups compared to normal controls. VCAM-1 expression was significantly increased in CHS/NP subjects compared to normal controls (P = 0.0005), with the highest intensity seen in nonallergic CHS/NP. By in situ hybridization, the densities of IL-1 beta, TNF-alpha, IL-13, and RANTES mRNA+ cells were all increased in nonallergic CHS/NP compared to normal controls (P = 0.009, 0.0005, 0.0005, and 0.001, respectively). In comparison to allergic CHS/NP, nonallergic CHS/NP had a significantly higher tissue density of TNF-alpha (P = 0.04) and a lower density of IL-13 (P = 0.005) mRNA+ cells. In general, VCAM-1 expression correlated strongly in CHS/NP with the density of TNF-alpha (R = .91, P = 0.0005) but not the density of IL-1 beta, IL-13, or RANTES mRNA+ cells. We conclude that upregulation of VCAM-1 and elaboration of RANTES may contribute to the marked accumulation of eosinophils in nonallergic CHS/NP. TNF-alpha may play a critical role in VCAM-1 upregulation in this nonallergic eosinophilic disorder.

Adult↗
PubMed1996

Evidence for major basic protein immunoreactivity and interleukin 5 gene activation during the late phase response in explanted airways.

Current evidence suggests that the events subsequent to antigen challenge in allergic asthmatics involve eosinophil activation and the synthesis of proinflammatory cytokines, in particular interleukin 5 (IL-5). However, little is known about how local inflammatory cell infiltration and activation are related to the changes in lung function following allergen exposure. We have developed a novel technique to investigate the local inflammatory events during late-onset allergic bronchoconstriction in lung explants from sensitized Brown-Norway (BN) rats. In this study we tested the hypothesis that the in vitro late airway response involves IL-5 gene activation and recruitment and activation of eosinophils. Explants were prepared from excised lungs of BN rats (n = 9) sensitized 2 wk previously to ovalbumin (OVA). Lungs were inflated with liquid agarose solution (2% wt/vol, 48 ml/kg) following perfusion with cold Ca2+/Mg(2+)-free Hanks' solution, and refrigerated briefly to gel the agarose, and 0.5- to 1.0-mm slices were prepared and cultured overnight at 37 degrees C. Airways were identified and challenged by direct application of OVA (20 micrograms). Cryostat sections of explants were immunostained for major basic protein (MBP) and IL-5 mRNA was detected by a 35S-uridine triphosphate-labeled probe and in situ hybridization. Explants harvested immediately prior to challenge showed little evidence of MBP and IL-5 mRNA expression. Explants harvested at 6 h which exhibited evidence of bronchoconstriction showed strong cell-associated immunostaining for MBP and high expression of IL-5 mRNA in the bronchial mucosa. colocalization studies performed in lung explants demonstrating late-onset airway responses suggested that the majority of IL-5 mRNA expression was not found in MBP-positive cells. When compared with explants from sham-sensitized rats (n = 4), there was a significant increase in MBP-positive and IL-5 mRNA-positive cells per millimeter of basement membrane of the airway. The presence of MBP immunoreactivity and IL-5 gene expression was not observed in explants taken from sensitized BN rats which did not undergo late-onset airway responses, indicating an association between inflammatory cell activation and airway constriction. The increase in MBP-positive cells several hours after OVA suggests activation, local recruitment, and/or differentiation of eosinophils. This study provides direct evidence for a temporal association between IL-5 expression, eosinophil infiltration, and the late response in individual cultured airways.

Allergens↗
PubMed1991

Interaction of human immunodeficiency virus type I Rev protein with nuclear scaffold nucleoside triphosphatase activity.

Human immunodeficiency virus type I encodes a regulatory protein, termed Rev, which is associated with the appearance of unspliced and partially spliced viral RNAs in the cytoplasm. Rev is believed to function via interaction with a sequence element in the env region of the viral RNA, termed the Rev-responsive element (RRE). In this study, we use a stably transfected, Rev-producing mouse cell line to show that low, functional levels of Rev are associated with the nuclear scaffold (NS). Immunohistochemical studies localize Rev to the NS. Furthermore, immunoblot analyses demonstrate the presence of Rev in NS preparations isolated from Rev-producing cells and document binding of purified Rev protein to isolated NS or to cloned lamin C in vitro. Results with an in vitro RNA transport assay suggest that Rev is associated with a significant defect in transport of RNAs which lack RRE, whereas transport of RRE-containing transcripts proceeds efficiently. This Rev-induced transport defect appears to be mediated via direct inhibition of NS nucleoside triphosphatase, an enzyme thought to be involved in the nucleocytoplasmic transport process. NS preparations isolated from Rev-producing cells show a significantly lower nucleoside triphosphatase activity than those from control preparations. Addition of Rev protein to isolated NS produces a significant inhibition of NS nucleoside triphosphatase activity, which is specifically reversed by addition of RRE transcripts. These data suggest that a major aspect of Rev function may involve selective modulation of host cell nucleocytoplasmic transport mechanisms via interaction with the NS.

Animals↗
PubMed1989

[Micronuclei in lymphocytes of smokers].

Micronuclei of peripheral blood lymphocytes of 66 smokers and 88 non-smokers in healthy person were determined. The result is that the average presence rate of micronuclei is markedly higher in the former group than in the latter (P less than 0.01). The lymphocytes of micronuclei of peripheral blood in smokers also increased. This shows that there are more chromosome aberrations in the smokers. The practical value of this investigation and the mutagenic mechanism of the smoke and also discussed.

Adult↗
PubMed1984

The free thigh flap: a new free flap concept based on the septocutaneous artery.

Based on the septocutaneous artery flap concept, the thigh, which is the commonest conventional donor site for split-skin grafts, can also become a donor area for skin flaps. The thigh flap, with its large and long neuro-vascular pedicle, can be used either as a free flap or as an island flap as an alternative to the lower abdominal flap, groin flap, tensor fasciae latae myocutaneous flap, sartorius myocutaneous flap or the gracilis myocutaneous flap. The anatomical basis, operative technique and characteristics of the thigh flap are discussed.

Adult↗
PubMedDate not supplied

Immunostimulation of tiger shrimp (Penaeus monodon) hemocytes for generation of microbicidal substances: analysis of reactive oxygen species.

NBT staining was used to determine the presence of superoxide anions (O2-) produced by tiger shrimp (Penaeus monodon) hemocytes attached to a coverslip. When cells were treated with beta-glucan, blue granules were observed in 41% of studied hemocyte cytoplasm. For zymosan-treated, PMA-treated, and control cells, the percentages of hemocytes showing similar blue granules were 31, 9, and 5%, respectively. A comparison of stimulative effects on 15 hemocyte suspensions, each collected from a single tiger shrimp, showed that beta-glucan had the strongest effect on intracellular O2- generation, followed by zymosan and PMA (2.5, 2, and 1.3 times greater than the O2- generated by the control group, respectively). After oxidizing phenol red to measure the amounts of hydrogen peroxide (H2O2) produced by the hemocytes, we found that beta-glucan had the strongest stimulative effect (12.2 nmol/mg protein), followed by zymosan and PMA (7.2 and 2.6 nmol/mg, respectively). However, a luminol-enhanced chemiluminescence analysis of hypochlorites (OCl-) produced by the experimental hemocytes showed that neither zymosan nor beta-glucan had a stimulative effect on OCl- production. However, following PMA stimulation, hemocyte chemiluminescence was detected although only at 1.7 mV. Using H2O2 as substrate and guaiacol as an electron acceptor, the enzyme activity of crude enzyme extract derived from broken hemocytes was analyzed; enzyme activity similar to that of human myeloperoxidase (MPO) (0.104 U/mg protein) was observed. The data showed that only PMA had any stimulative effect on MPO-like enzyme activity (2.23 times that of the control group); zymosan and beta-glucan did not have any observable effects on this specific enzyme activity. This is the first documented demonstration of a respiratory burst in shrimp hemocytes.

Animals↗
PubMedDate not supplied

Maternal transmission of immunity to white spot syndrome associated virus (WSSV) in shrimp (Penaeus monodon).

Beta-1,3-1,6-glucan, derived from bakers' yeast Saccharomyces cerevisiae, was used in the present study to investigate the extent to which glucan is able to protect spawners from white spot syndrome associated virus (WSSV), and whether this protection (if any) can be passed on to hatchlings via maternal transmission of immunity. Results showed that fewer spawners in the glucan-injected groups showed the clinical symptoms of red body coloration and white spots on the shell during the 15 days between eyestalk ablation and the end of repeated spawning. This suggests that the application of glucan might lead to a slight enhancement of disease resistance in spawners, although the differences were not statistically significant within the confidence limit chosen. Challenge results showed a significant increase in relative percent survival for larvae derived from groups of glucan-injected spawners compared to those derived from groups of untreated spawners. It therefore seems that a maternally transmitted disease resistance induced by glucan, protected the larvae against a WSSV infection. Glucan immersion was not only shown to be effective for nauplii derived from spawners that were not injected with glucan, it also provided additional, cumulative protection for nauplii which already had a maternally transmitted resistance to WSSV. This is the first documented demonstration of a maternal transmission of immunity in invertebrates.

Animals↗