Biomedical subjects

Y Ye

Publications and source records attributed to Y Ye.

At least 163 records · Page 9Linked to original sources

PubMed1995

[Detection of human papillomavirus in condyloma acuminata tissues].

UNLABELLED: We used immunohistochemical technique, in situ hybridization and polymerase chain reaction to detect HPV capsid antigen (HPV-Ag) and HPV-DNA sequences in genital condyloma and pseudocondyloma of vulvae tissues. We also observed the relation between HPV distribution in condylomas and their histological changes. RESULTS: 71.4% of condylomas were positive for HPV-Ag with IMHC, 96.5% of condylomas were positive for HPV6/11 DNA with ISH, and 100% of condylomas were positive for HPV6/11/16/18DNA with PCR. Only 21.4% of pseudocondylomas of vulvae were positive for HPV6/11/16/18DNA with PCR. By observing the distribution of labelled HPV-Ag and HPV-DNA, we found a close relation between HPV proliferative infection and the specific changes of condylomas.

Antigens, Viral↗

PubMed1995

[The relationship between H2 receptor of airways and the pathogenesis of bronchial asthma].

In order to explore the relationship between H2 R and the pathogenesis of asthma, we treated 19 stable asthmatic patients with H2-receptor agonist impromidine and observed its effect on bronchial hyperresponsiveness (BHR). The results showed that single dose inhalation of impromidine (2.5mg, in 13 cases) had no effect on the starting respiratory resistance (Rrs) and the minimum amount of cumulative dose (Dmin) to asthmatic airways, while repetitive inhalation of impromidine for 10 days (2. 5mg a day, in 6 cases) decreased the Rrs (P = 0.059) and increased the Dmin significantly (P < 0.05); and that H2R agonist impromidine could reduce the sensitivity of airway to methacholine and improve the BHR of asthmatic patients. The results suggest that H2R agonist may be used as anti-inflammatory drug to treat asthma and H2R may have protective role in the inflammatory reaction of asthmatic airways.

Adolescent↗

PubMed1995

[The relationship between H2 receptor and the pathogenesis of bronchial asthma in guinea-pigs].

UNLABELLED: H2 receptor (H2R) is one of the three histamine receptor subtypes. In order to explore the relationship between H2R and the pathogenesis of bronchial asthma, we investigated the effects of H2R agonist impromidine on guinea-pig isolated tracheal smooth muscle and the effects of dimaprit on the lung function of guinea-pigs provoked by antigen. RESULTS: (1) Impromidine (10(6) mol/L) relaxed partly the guinea-pig isolated tracheal spirals contricted by histamine challenge. After pretreating the spirals with impromidine, the maximum response to histamine was reduced in a dose-dependent manner and the cumulative dose-response curve to histamine was shifted to right. (2) Dimaprit (3mg/kg) given by intravenous injection protected the lung function from damage caused by antigen. These results suggest that H2R agonist produces relaxation of guinea-pig tracheal smooth muscle and inhibits the release of inflammatory mediators in anaphylactic reaction. We concluded that H2R plays some protective roles in the pathogenesis of bronchial asthma.

Animals↗

PubMed1995

[Predictive value of urinary calcium measurement on occurrence of pregnancy-induced hypertension].

OBJECTIVE: To study the predictive value of urinary calcium excretion on occurrence of pregnancy-induced hypertension (PIH). METHODS: Twenty-four-hour urinary calcium excretion, urinary calcium concentration and urinary calcium/creatinine (Ca/Cr) ratio were determined in 184 normal pregnant women and 30 patients with PIH. RESULTS: Twenty-four-hour urinary calcium excretion, urinary calcium concentration, and Ca/Cr ratio in PIH group were significantly lower than that in normal pregnant group (P < 0.01). 3 mmol/L of urinary calcium concentration and 0.04 of Ca/Cr ratio were chosen as predictive thresholds for development of PIH, with sensitivity of 76.2%, 81.0% and specificity of 97.5%, 98.2% respectively. CONCLUSIONS: Low urinary calcium excretion is a valuable marker for prediction of PIH.

Adult↗

PubMed1995

[The comparison of positive rates and clinical significance of 8 bronchodilator testing parameters sarcoidosis].

Twenty asthmatic patients (with mild to severe attacks) were examined with bronchodilator test. Eight parameters, FVC, FEV1, PEF, FEF25-75%, FEF25-75% after inhaling bronchodilator (FEF25-75% Iso), thoracic gas volume (Vtg), airway resistance (Raw) and specific conductance (SGaw), were investigated, compared and analysed. The results showed that the positive rate (PR) of FEV1, the most commonly used parameter at present, was only 70%; the PR of two new parameters FEF 25-75% Iso and SGaw were 95% respectively, the change rate (%) of FEV1 was significantly related to that of many other parameters. The pathophysiology and clinical significance of each parameter were discussed.

Adult↗

PubMed1994

Evidence that intravenously administered alpha-galactosyl carbohydrates reduce baboon serum cytotoxicity to pig kidney cells (PK15) and transplanted pig hearts.

Methods of inhibiting the hyperacute antibody-mediated rejection that occurs when pig organs are transplanted into primates have been investigated using the baboon as a potential recipient. Baboons were treated with different regimens that included combinations of (1) splenectomy, (2) pharmacologic immunosuppression (CsA, cyclophosphamide, corticosteroids +/- methotrexate), and (3) intravenous infusion of oligosaccharides. The cytotoxicity of the serum was then assessed on cultures of pig kidney cells (PK15). Unmodified serum caused approximate 65-100% pig cell destruction. Splenectomy and/or pharmacologic immunosuppression, and infusions of dextran, dextrose or mannitol, did not result in any reduction of cytotoxicity. Infusions of melibiose and/or arabinogalactan, both of which have terminal non-reducing alpha-galactose, however, decreased relative PK15 cell damage significantly in a dose-dependent manner. At high concentrations (< or = 50 g/hr), complete inhibition of cytotoxicity was achieved in 4 of 15 baboons. The extracorporeal immunoadsorption of baboon serum utilizing immunoaffinity columns of melibiose also resulted in a significant reduction (of approximately 80%) in cytotoxic effect. In 1 baboon, melibiose and arabinogalactan infusion delayed vascular rejection of a pig cardiac xenograft from 10 min to about 12 hr, at which time the baboon died from the toxic effects of the carbohydrate infusion. These observations (1) add further support to the role that anti-alpha-galactosyl antibodies play in the hyperacute rejection of pig tissues transplanted into primates, and (2) demonstrate that serum cytotoxicity can be reduced by the intravenous infusion of alpha-galactosyl oligosaccharides or by extracorporeal immunoadsorption using these carbohydrates.

Animals↗

PubMed1994

Protection of pig kidney (PK15) cells from the cytotoxic effect of anti-pig antibodies by alpha-galactosyl oligosaccharides.

Anti-pig antibodies in human and baboon serum are believed to be directed against alpha-galactosyl (alpha Gal) epitopes expressed on various pig cells, including vascular endothelia. We have investigated the effect of human sera on the PK15 pig kidney cell line, which abundantly expresses alpha Gal epitopes. To quantitate cell viability, we have used a staining method that differentiates live cells from dead ones. Various carbohydrates (n = 28) were added individually to serum at concentrations of 0.125-50 mg/ml. Unmodified serum caused approximate 100% PK15 cell death within 60 min. Carbohydrates that were not alpha Gal based did not significantly protect PK15 cells. Of the alpha Gal-based carbohydrates, only B disaccharide protected PK15 cells from both human and baboon serum (76% and 93% protection, respectively, at 1 mg/ml). Three alpha Gal oligosaccharides provided approximately 80-90% protection against both human and baboon sera at a concentration of 10 mg/ml. Three other closely related structures protected only against baboon serum (> 80%) at high concentration (50 mg/ml), suggesting a difference in anti-pig antibody affinity between baboon and man. Specific anti-alpha Gal antibody-depleted serum caused < 10% pig cell death, whereas the antibodies eluted from the alpha Gal columns caused > 70% pig cell death. In conclusion, this study provides further evidence that (1) alpha Gal structures are the targets for human and baboon anti-pig antibodies, and (2) there may be a therapeutic role for the infusion of specific alpha Gal carbohydrates, or for antibody removal using alpha Gal immunoaffinity columns, in order to prevent hyperacute rejection of pig organs in man.

Animals↗

PubMed1994

The pig as a potential organ donor for man. A study of potentially transferable disease from donor pig to recipient man.

Ten pigs, reared in an unmodified laboratory animal house environment, have been investigated to ascertain the incidence of diseases or disorders, including infection, neoplasia, or metabolic abnormalities, that might preclude the transplantation of major organs from the pig to man. Noninvasive studies were performed in the second month of life (study 1) and repeated after an interval that varied between 3 and 5 1/2 months (study 2). Necropsy was then performed as a means of assessing the accuracy of the 2 screening examinations. A total of 150 tests were performed on each pig. At both studies the feces contained cysts and/or trophozoites of several parasites, all of which were considered commensals. No other organisms potentially infective for man were identified either at study or at necropsy. Neither congenital anomalies nor malignant neoplasia was found at necropsy. However, in 2 pigs a vasculitis of uncertain etiology was present in the kidneys on microscopic examination, and in one of these the same condition affected the heart. This pathology was suspected neither from the screening examinations nor from the macroscopic appearance of these organs. Biopsy and microscopic examination would therefore appear to be essential before any organ is transplanted into a human.

Animal Feed↗

PubMed1994

Monomorphic and polymorphic carbohydrate antigens on pig tissues: implications for organ xenotransplantation in the pig-to-human model.

The existence of the alpha Gal epitope in 137 pigs belonging to 23 different breeds suggests that this antigen is either monomorphic or occurs at a high incidence in the porcine species. Its histological location at the surface of pig vascular endothelial cells makes it a target for human natural anti-alpha Gal antibodies and complement, which may be responsible for the hyperacute vascular rejection of transplanted pig organs. The precursor carbohydrate chain (N-acetyllactosamine) and NeuAc-substituted epitopes are also exposed at the surface of pig vascular endothelium and were found in all pigs in this study. However, humans also have these two epitopes on vascular endothelium and, consequently, have not made natural antibodies against these carbohydrate antigens. Therefore, these two pig epitopes cannot be the main target of the hyperacute vascular rejection process. Three pig phenotypes-A+ (51%), A:H+ (38%), and A-H- I+ (11%) were identified among 37 Large-white pigs by the presence of polymorphic A, H, and I carbohydrate antigens on the brush border of the surface epithelium of small intestine. These antigens were also present in other exocrine secretions but were not detected on vascular endothelium of the same pigs, suggesting that they are not involved in the hyperacute vascular rejection, although the pig A tissue antigen can induce an immune response in 0 or B blood group recipients. Once the problem of the initial hyperacute vascular rejection directed against the alpha Gal epitope is overcome, typing donor pigs for A, H, and I, as well as for the protein swine leukocyte antigens (SLA) and other pig antigens, may help in elucidating antigens involved in acute or chronic xenograft rejection.

ABO Blood-Group System↗

PubMed1994

Concurrent generation of nitric oxide and superoxide damages surfactant protein A.

The conditions under which nitric oxide (.NO) may modulate or promote lung injury have not been identified. We hypothesized that .NO-induced injury results from peroxynitrite, formed by the reaction of .NO with superoxide. The simultaneous generation of .NO and superoxide by 3-morpholinosydnonimine (SIN-1, 0.1-2 mM) resulted in oxidation of dihydrorhodamine, a marker of peroxynitrite production, and a dose-dependent decrease in the ability of SP-A to enhance lipid aggregation. Western blot analysis of SIN-1 exposed SP-A samples, overlaid with a polyclonal antibody against nitrotyrosine, were consistent with nitration of SP-A tyrosine residues. Superoxide dismutase (100 U/ml), L-cysteine (5 mM), xanthine oxidase (10 mU/ml) and xanthine (500 microM), or urate (100 microM) prevented the SIN-1-induced dihydrorhodamine oxidation and injury to SP-A. .NO alone, generated by S-nitroso-N-acetylpenicillamine plus 100 microM L-cysteine, or superoxide and hydrogen peroxide, generated by pterin and xanthine oxidase in the absence of iron, did not damage SP-A or oxidize dihydrorhodamine. We concluded that peroxynitrite, but not .NO or superoxide and hydrogen peroxide, in concentrations likely to be encountered in vivo, caused nitrotyrosine formation and decreased the ability of SP-A to aggregate lipids.

Humans↗

PubMed1994

Cardiac allotransplantation across the ABO-blood group barrier by the neutralization of preformed antibodies: the baboon as a model for the human.

The baboon, like the human, expresses A and/or B blood group antigens on its tissues. Anti-A and anti-B antibodies are directed against these antigens, the epitopes of which are carbohydrate structures. Portions of these carbohydrates have been synthesized (trisaccharides A and B, respectively). When infused intravenously, the synthetic trisaccharides form a complex with the specific antibodies and neutralize their activity preventing them from binding to the antigen targets on a transplanted organ. In nonimmunosuppressed, hyperimmunized baboons, the continuous intravenous infusion of the specific trisaccharide alone (for 6 days) inhibited rejection of ABO-incompatible cardiac allografts, extending survival from a mean of 19 min (n = 3) to 8 days (n = 2), at which time the grafts failed from cellular (not vascular) rejection. The combination of long-term pharmacologic immunosuppression plus trisaccharide infusion (for periods of 8 to 19 days) extended survival to a mean of > 28 days (n = 4) with one heart functioning > 52 days. Accommodation clearly occurred in three of the four cases. This form of therapy may permit cadaveric organ allotransplantation across the ABO blood-group barrier in the human.

ABO Blood-Group System↗

PubMed1994