Biomedical subjects

B Sun

Publications and source records attributed to B Sun.

At least 253 records · Page 14Linked to original sources

PubMed1995

[The experimental observation on the procedure of atherosclerotic restenosis following PTCA].

Angioplasty of stenotic iliac artery was performed in 23 Japanese white rabbits. Angiography and histopathology examinations were performed one day (6 rabbits), 3 days (5 rabbits), one week (5 rabbits) and one month (7 rabbits) after dilation. TXB/PGF in blood was analyzed with radio-immunologic method. TXB/6-K-PGF increased at 1st day, began to reduce at 3rd day, became almost normal after one week and returned to normal level week after one month. Restenosis occurred in all animals. Platelet aggregation and mural thrombi were observed at 1st and 3rd day. New endothelial cells covered the surface of denuded endothelium at 3rd day. At 7th day, repairing of endothelium was completed and proliferation of smooth muscle cells were prominent in new intimia. Stenosis of lumen occurred again after 1 month. The results suggested that intimia injury during the procedure initiates the process of restenosis and aggregation of platelets, imbalance of between TXA and PGI is and proliferation of smooth muscle cells play important roles in the formation of restenosis.

6-Ketoprostaglandin F1 alpha↗

PubMed1995

Prospective studies on the relationship between the 50 g glucose challenge test and pregnant outcome.

The 50 g oral glucose challenge test (50gGCT) was performed on 622 pregnant women, and 75 g oral glucose tolerance test (75gGTT) was further done on subjects with screening tests value of > or = 7.78 mmol/L. The results showed that there were 16.56% (103/622) women with screening value of > or = 7.78 mmol/L, among whom, 32 were identified as having gestational impaired glucose tolerance (GIGT) and 12, gestational diabetes mellitus (GDM) by confirmatory test of 75gGTT. The sensitivity of 50gGCT was 42.72%(44/103). The incidences of edema-proteinuria-hypertension syndrome (EPH-syndrome), premature rupture of membranes, fetal macrosomia, operative deliveries and perinatal morbidity were higher in women with GIGT/GDM than in women without GIGT/GDM. It suggests that 50gGCT is an ideal method of screening for GDM and should be performed on all pregnant women.

Adult↗

PubMed1995

[Changes in serum eosinophil cation protein level and blood eosinophil density in patients with asthma].

To study the functional state as well as the relation-ship between eosinophil and T lymphocyte in the asthmatics, the authors measured the eosinophil density of blood with percoll, the level of serum eosinophil cation protein (ECP) with radioimmunoassay and soluble IL-2 receptor (sIL-2R) concentration with ELISA. The results revealed that the proportion of hypodense eosinophil and the levels of serum ECP and sIL-2R were 36.3% +/- 14.80%, 10.74 +/- 7.22 mg/L and 0.33% +/- 10 U/L respectively in asthmatics, being significantly higher than those in normal subjects (14.71% +/- 8.20%, 6.93 +/- 4.91 mg/L, 0.13 +/- 0.03 U/L, respectively, P < 0.05 in all). There is remarkable correlation between any two of the three parameters (r = 0.40, 0.37, 0.39, respectively, P < 0.05). It is suggested that eosinophil activation is associated with T lymphocyte activation, both may be involved in the pathogenesis of asthma.

Adult↗

PubMed1995

[Effect of tetrandrine on pulmonary hypertension induced by monocrotaline in rats].

The effects of Tetrandrine (Tet) on intraacinous pulmonary arteries (IAPA) and bemodynamics were studied by means of a rat pulmonary hypertension model induced by monocrotaline. The results showed that Tet could reduce the contractive pressure of pulmonary artery, right ventricle and right atrium of heart by 28.0%, 28.3%, and 31.5% respectively. It could also decrease the vascular degeneration of endoepithelial cells of IAPA, the endoepithelial subcavity, the collagens of medial membrane and the numbers of smooth muscles of IAPA.

Alkaloids↗

PubMed1995

[Effect of inhaled corticosteroids on serum eosinophil cationic protein and sIL-2R levels in asthmatics pulmonary hypertension].

To study the influence of corticosteroid and beta 2-agonist on eosinophil and T lymphocyte functioning state in the asthmatics, we measured the serum ECP sIL-2R levels and airway reactivity before and after 6-week treatment with beclometasone and terbutalin. The result revealed that after inhalation of steroid, the serum ECP sIL-2R levels decreased, whereas the lung function improved and MCH-PC20 values increased. It suggested that steroid could inhibit activation of eosinophil and T lymphocyte as well as show the effect of anti-inflammation and reducing AHR.

Administration, Inhalation↗

PubMed1994

Effect of endotoxin on lipid order and motion in erythrocyte membranes.

Electron paramagnetic resonance employing a lipid-specific spin label has been used to investigate the molecular effects of endotoxin on the physical state of bilayer lipids in rat erythrocyte membranes. When added at a concentration as low as 40 micrograms/ml to whole blood (plasma plus leukocytes present), decreased membrane lipid motion was found in subsequently washed and spin-labeled intact erythrocytes (P < 0.02). However, if endotoxin were added to washed, plasma plus leukocyte-free intact erythrocytes, no change in the motion of the spin label was found, suggesting that plasma-soluble substances and/or leukocytes are required to produce the change in the physical state of lipids. The decreased lipid motion found in these studies is discussed with reference to the known decreased deformability of endotoxin-treated red cells and to the pathogenesis of sepsis.

Animals↗

PubMed1994

In vitro expression of calcitonin gene-related peptide in human endothelial cells transfected with plasmid and retroviral vectors.

Introduction of cDNA encoding human alpha-calcitonin gene-related peptide (CGRP), a potent vasodilator, into cultured human umbilical vein endothelial cells (HUVEC) was undertaken by using plasmids and retroviral vectors. In order to improve expression, modification of context coding sequence for the initiation of CGRP translation and deletion of nontranslated regions of CGRP cDNA in the transfection vectors were tested. Stable transfer of neo in the HUVEC was achieved with both plasmid and retroviral vectors. Integration rates obtained by using retrovirus (approximately 1%), where higher than those achieved with plasmid-mediated transfection (< 1/1000). CGRP expressed in the transfected HUVEC was secreted into culture medium when a leading sequence was included in the expression vectors. CGRP was detected by enzyme-linked immunosorbent assay (ELISA) in the supernatants of both transiently transfected and stably transfected/infected HUVEC. Higher levels of expression were achieved by using plasmid (giving a maximum CGRP concentration of 6.5 +/- 0.5 pM in the supernatant) than retroviruses. Lipofectin-mediated transfer of CGRP cDNA also resulted in transient expression of CGRP in the HUVEC.

Calcitonin Gene-Related Peptide↗

PubMed1994

Biochemical analysis of proteins recognized by anti-HRP antibodies in Drosophila melanogaster: identification and characterization of neuron specific and male specific glycoproteins.

Antibodies recognizing horse radish peroxidase (HRP) stain neurons in Drosophila and other insects. We have used Western blots to analyze and characterize some of the anti-HRP reactive components from Drosophila melanogaster. Anti-HRP reactive components can be reproducibly detected during all developmental stages, although the pattern changes at different developmental times. In adults, there are at least 10 reproducibly stained components. Two of the bands, with molecular sizes of 42 and 80 kDa are likely to be the major contributors to neuronal anti-HRP staining in Drosophila. These components are enriched in adult fly heads. In contrast, many of the other anti-HRP reactive components in adults are enriched in abdomen and are present exclusively or at much higher levels in male flies. We have purified and characterized two of the male specific components with molecular sizes of 62 and 48 kDa. Partial N-terminal amino acid sequencing revealed that the 62 kDa protein is identical to a part of D. melanogaster carboxylesterase to EC 3.1.1.1) while he 48 kDa protein does not match any known sequences. Esterase-6 has previously been shown to be enriched in male accessory gland and consistent with this we show staining of this structure with anti-HRP antibodies.

Animals↗

PubMed1994

Comparison of surface properties and physiological effects of a synthetic and a natural surfactant in preterm rabbits.

AIMS: To compare the physical and physiological properties of a synthetic surfactant (Exosurf, Wellcome Foundation) and a natural surfactant (Curosurf, Chiesi Farmaceutici). METHODS: Surface properties of the surfactant suspensions (10 mg phospholipid/ml) were evaluated using the pulsating bubble surfactometer. Lung-thorax compliance was determined in 47 immature newborn rabbits with a gestational age of 27 days, treated with recommended clinical doses of either surfactant (Exosurf 67.5 mg/kg; Curosurf 200 mg/kg). The lungs were examined histologically. RESULTS: The mean (SD) contractile forces of the surface at maximum and minimum bubble size were significantly lower for Curosurf than for Exosurf: 31 (2) and 0 (0) mN/m v 53 (5) and 29 (4) mN/m, respectively. Mean (SD) lung-thorax compliance after one hour of ventilation was significantly higher in rabbits treated with Curosurf compared with animals receiving Exosurf or those serving as controls: 0.60 (0.15) ml/cm H2O.kg v 0.44 (0.03) and 0.34 (0.18) ml/cm H2O.kg, respectively. Both surfactants increased alveolar volume density compared with results for control animals, but only Curosurf significantly reduced the incidence of moderate or severe bronchiolar epithelial disruption. CONCLUSIONS: The natural surfactant, Curosurf, reduced the contractile force at an air-liquid interface to a greater extent than the synthetic surfactant, Exosurf, and led to a greater improvement in compliance and less airway epithelial damage when given in clinical treatment doses to immature rabbits.

Animals↗

PubMed1994

Exogenous surfactant improves lung compliance and oxygenation in adult rats with meconium aspiration.

We studied the effects of exogenous surfactant on lung function and morphology in an adult rat model of severe meconium aspiration syndrome. Animals ventilated with 100% oxygen received 4-6 ml of human meconium (25 mg/ml) intratracheally. After 30 min, lung-thorax compliance had decreased by > 30% and arterial PO2 was < 10 kPa. Animals were then treated with no material (MECO group), 0.9% NaCl (MECO-saline group), natural porcine surfactant (NPS group) at a dose of 100 mg/kg, or modified porcine surfactant at a dose of either 100 (MPS100 group) or 200 mg/kg (MPS200 group) and were ventilated for another 180 min. Immediate and sustained improvement of arterial PO2 and compliance was observed in the MPS200 group, whereas the MPS100 and NPS groups showed less pronounced effects. There was a significant improvement of quasi-static lung volumes at maximum insufflation pressure and during deflation in the MPS200, MPS100, and NPS groups. Recordings with Wilhelmy balance showed that minimum surface tension of bronchoalveolar lavage fluid from animals receiving either type or dose of surfactant was significantly lower than in the MECO and MECO-saline groups. Meconium aspiration induced diffuse and prominent atelectasis, intra-alveolar edema, and hyaline membranes. These morphological abnormalities were reversed by exogenous surfactant, especially by the high-dose regimen.

Animals↗

PubMed1994

Ethamsylate and lung permeability in ventilated immature newborn rabbits.

The leakage of proteins in the immature neonatal lung can reduce the effect of exogenous surfactant. The effect of ethamsylate, a more specific prostaglandin inhibitor than indomethacin and aspirin-like drugs, on alveolar albumin leak was studied in a group of 27 immature newborn rabbits (gestational age 27 days). A pilot study was carried out using 4 animals and low-dose ethamsylate (10 mg/kg). A second group of animals (n = 12) received at birth, by intravenous injection, ethamsylate (50 mg/kg) and 10% human albumin (7 ml/kg). Animals not receiving ethamsylate (n = 11) served as control group. After 30 min of artificial ventilation with standard tidal volume (10 ml/kg) the lungs were lavaged and the amount of human albumin in lung lavage fluid was determined by immunodiffusion. No statistically significant differences were found in lung-thorax compliance and vascular to alveolar albumin leak between ethamsylate-treated animals and controls (p > 0.5). However, there was a statistically significant negative correlation between protein leak and lung compliance (r = -0.41; p < 0.04). These results suggest no direct influence of early ethamsylate administration on neonatal lung permeability in the immature neonate confirming that lung permeability is inversely related to compliance.

Animals↗

PubMed1994

Experimental neonatal group B streptococcal pneumonia: effect of a modified porcine surfactant on bacterial proliferation in ventilated near-term rabbits.

We studied bacterial proliferation in relation to surfactant treatment in a model of neonatal group B streptococcal (GBS) pneumonia. Surfactant (Curosurf) was isolated from pig lungs with a method preserving only polar lipids and hydrophobic proteins. Near-term rabbit fetuses were ventilated in a body plethysmograph system. At 15 min, a suspension of GBS strain 090 Ia LD (5 mL/kg, concentration approximately 10(9)/mL) was instilled intratracheally. At 30 min, surfactant (n = 12) or sterile saline (n = 13) was administered via the airways (2.5 mL/kg). A control group (n = 12) received the same volumes of saline. After 5 h the animals were killed, and samples for blood cultures and blood gases were taken from the heart. The left lung was aseptically removed, weighed, homogenized, serially diluted, and cultured on blood agar plates. The results were expressed as mean log10 colony forming units/g lung +/- SD. Compared with animals (n = 12) killed immediately after GBS instillation (8.13 +/- 0.54), there was a significant increase in bacterial numbers in both groups ventilated for 5 h, but values for surfactant-treated animals (8.96 +/- 0.38) were lower than those for animals receiving saline (9.46 +/- 0.50; p < 0.05). After 5 h, 96% of GBS-infected animals had positive blood cultures. Light microscopic examination of the right lung of GBS-infected animals revealed inflammatory changes that tended to be less prominent in surfactant-treated rabbits. We conclude that intratracheal inoculation of near-term rabbits with GBS resulted in a significant bacterial proliferation during 5 h of ventilation and that bacterial growth was mitigated by treatment with surfactant.

Animals↗

PubMed1994

[Heel reconstruction by the composite island flap of the lower leg].

From 1987, 6 to 1992, 6 cases of heel defect were repaired successfully by reverse transfer of the composite island flap from the lateral lower leg. The flap, pedicled with peroneal vessels, consisted of skin, subcutaneous tissue, fibula and adjacent muscles. The contour and function were satisfactory.

Adolescent↗

PubMed1994

[A 5-year retrospective investigation of occupation-related burns in Zhenjiang area].

UNLABELLED: During the 5 years from June 1986 to June 1991, 221 patients were admitted to our department of burn surgery because of occupation-related burns. The average age was 31.2 years, and 83.4 per cent was male. Most of the patients (79.6 per cent) were referred to our hospital within 24 h of their injury. The most common etiology was flame (33.0 per cent). The mean body surface area of all 221 cases was 17.1 per cent, with a mean full-thickness component of 8.1 per cent. COMPLICATIONS: inhalation injury 18 cases (8.1 per cent); sepsis 5 cases (2.3 per cent) confirmed by positive blood cultures at an average time of 10.2 days postburn, and the commonest organism was pseudomonas aeruginosa; pneumonia 5 cases (2.3 per cent). The mortality of these 221 cases was 1.8 per cent. The average time of stay in our hospital was 34.3 days. The total expenditure was about 740,000 Yuan. First aid on the spot and early correct treatment are stressed. It is essential to put prevention first, and the measures to lower the incidence of occupation-related burns were discussed to serve as a reference for labor protection department and occupation-related burns institute.

Accidents, Occupational↗

PubMed1994

[A clinic report of 54 cases of reconstruction for the anterior segment of eye].

54 cases (54 eyes) of severe injury in the anterior segment of eye with little light perception were treated by reconstruction for the anterior segment of eye. The results showed that the eyeballs in 48 cases (88.9%) were survived successfully, and 28 cases (51.9%) of the grafts were clear. The procedures included keratoplasty, iridectomy, lensectomy, anterior vitrectomy, and reconstruction of the anterior chamber to restore the cosmetic shape of the eyeball. The indications, complications of the operation, and the surgical technique are discussed.

Adolescent↗

PubMed1994

[Animal experiments on meridian-reaching actions of traditional Chinese medicinal herbs].

With the level variations of cAMP and cGMP in cat tissues as the criteria, the meridian actions reaching of Fructus Schisandrae, Radix Stephaniae Tetrandrae and Herba Houttuyniae were studied tentatively in animal experiments. The result obtained in this way approximates to the understanding of the meridian reaching actions of Chinese medicinal herbs as approved by traditional Chinese medicine.

Animals↗

PubMed1994

[Comparative studies of 111In-labeled monoclonal antibody using spacer-containing and non-spacer bifunctional chelates: (I). Conjugation, labeling, immunoreactivity and in vitro stability].

Bifunctional chelates containing chemical spacer, succinimido-EGS-DTPA (EGS-DTPA, diester spacer) and 1-[4-(10-maleimidopropyl)amidobenzyl]ethylenediamine-N,N,N', N'- tetraacetic acid (C10-Bz-EDTA, hydrocarbon spacer) were synthesized and compared in vitro with non-spacer chelates, cyclic DTPA dianhydride (cDTPAA) and isothiocyanatobenzyl-EDTA (SCN-Bz-EDTA). The optimum condition for conjugation with chelates, labeling efficiency, immunoreactivity and stability in the serum were investigated with respect to four chelates. The labeling efficiency for EGS-DTPA-A7 and DTPA-A7 was 90% and over 95%, respectively, when reacted by the chelate to antibody ratios of 10:1 for EGS-DTPA and 2:1 for cDTPAA. The labeling efficiency for SCN-Bz-EDTA and C10-Bz-EDTA was 70% and 80%, respectively, when both of the chelates were conjugated with the antibody in a 1:1 ratio. EGS-DTPA-A7 and DTPA-A7 were unstable when incubated in the human serum at 37 degrees C and showed the transchelation to the transferrin fraction of the 111In activity. Furthermore, the radioactivity from 111In-EGS-DTPA-A7 was also found to be associated with the In-DTPA fraction, indicating that the diester spacer was cleaved in the serum. SCN-Bz-EDTA-A7 and C10-Bz-EDTA-A7 were very stable: there was no evidence of transchelation or any activity was dissociated from the conjugated antibody when incubated in the human serum for 168 hrs. Using C10-Bz-EDTA, immunoconjugate with sufficient specific activity was obtained and high immunoreactivity was maintained. It was considerable that the C10-Bz-EDTA immunoconjugate would produce preferable biodistribution than EGS-DTPA immunoconjugate do.

Antibodies, Monoclonal↗

PubMed1994

[Comparative studies of 111In-labeled monoclonal antibody using spacer-containing and non-spacer bifunctional chelates: (II). Biodistribution, metabolism and excretion in vivo].

Indium-111-labeled A7 monoclonal antibodies using two spacer-containing chelates, succinimido-EGS-DTPA (EGS-DTPA: diester spacer) and maleimido-C10-Bz-EDTA (C10-Bz-EDTA: hydrocarbon spacer) were investigated in human LS180 colon tumor bearing nude mice and were compared with two non-spacer chelates, cyclic DTPA dianhydride (cDTPAA) and isothiocyanatobenzyl-EDTA (SCN-Bz-EDTA). Compared with immunoconjugates using non-spacer chelates, immunoconjugates using spacer-containing chelates, especially C10-Bz-EDTA-A7 showed lower 111In activity in normal organs. The radioactivity in the liver for C10-Bz-EDTA-A7 decreased continuously till 96 hrs postinjection, however, this liver radioactivity for EGS-DTPA-A7 showed little change after 24 hrs. Moreover, in liver subcellular distribution study, EGS-DTPA-A7 showed a higher activity retention in mitochondrial fraction which contained lysosome, a place for metabolizing and storing of 111In labeled antibody, than that of C10-Bz-EDTA-A7. The C10-Bz-EDTA-A7 conjugate demonstrated more preferable tumor-to-non tumor contrast on the scintigrams than that found with other three immunoconjugates. Up to 96 hrs postinjection, tumor bearing nude mice injecting with immunoconjugates using spacer-containing chelates excreted twice radioactivity from whole body than that excreted by using non-spacer chelates. Interestingly, different from other three chelates, C10-Bz-EDTA-A7 were mainly excreted via feces. We conclude that the decrease of radioactivity in normal tissues in the case of EGS-DTPA-A7 was duo to the rapid decrease of activity in the blood, while in the case of C10-Bz-EDTA-A7 it was due to the quickly excreted small metabolite through faces. 111In labeled C10-Bz-EDTA conjugate is superior, at least when conjugated with A7, to other three chelate conjugates used in this study.

Animals↗