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Biomedical subjects

H Sun

Publications and source records attributed to H Sun.

At least 289 records · Page 16Linked to original sources

[Effects of composite blood-activating decoction on bone marrow microenvironment in mice of immune-induced aplastic anemia].

OBJECTIVE: To explore the mechanism of elevating efficacy for aplastic anemia (AA) by using blood-activating and stasis-eliminating drugs. METHODS: Immune-induced aplastic anemia model was established. Each mouse was gastrogavaged by 0.2 ml 100% composite blood-activating decoction (CBAD) twice a day. On the 10th day, the bone marrow histology, CFU-F, adhesive function of the cultured stromal cell layer, bone marrow PO2 were observed. RESULTS: In CBAD group, the WBC count, bone marrow karyocytes, bone marrow hematopoietic tissue volume, CFU-F count were significantly higher than those in AA group (P < 0.01). Moreover, the adhesive function of stromal cells and bone marrow PO2 recovered to normal level. CONCLUSION: The commonly used composite blood-activating decoction could promote the recovery and oxygen-supply of bone marrow microenvironment in AA mice, and improved the bone marrow hematopoiesis.

Anemia, Aplastic↗

[Setting up animal model of traumatic pseudoaneurysm: experimentsal and clinical study].

OBJECTIVE: To patlern the clinical ruptures of injured arteries. METHODS: Traumatic methods and microsurgery were employed. RESULTS: Experimental model of pseudoaneurysm was made in 72 femoral arteries of 54 Japanese white rabbits, with a successful rate of 95.8%. Using these models, the process and the mechanism for the formation of pseudoaneurysm were studied. The effects of color Doppler's ultrasonic image, CT, MRI and arterial angiography in the diagnosis of pseudoaneurysm were evaluated. CONCLUSION: The indicators for clinical signs of the rupture hemorrhage of pseudoaneurysm were put forward. The methods for balloon dilation to block the blood supply of the carrier artery and control the hemorrhage of operation were set up.

Aneurysm, False↗

[Ostium of maxillary sinus in endoscopic sinus surgery].

OBJECTIVE: To determine the clinical significance and operative method of maxillary sinus ostium in the treatment of chronic sinusitis and nasal polyps. METHODS: Fifty-six patients (112 sides) undergone endoscopic sinus surgery were studied. RESULTS: The patency rates of the maxillary ostia in patients with enlarged and unchanged maxillary ostia were 92.9% and 80.4% respectively. Fifty-one patients (64 sides) undergone Caldwell-Luc operations were retrospectively studied. The patency rate of inferior antrostomy was 40.6%. CT scans of the sinuses of 38 cases with unilateral sinisitis or nasal polyps were reviewed. The scaled values of the maxillary hiatus on CT images showed no difference between the normal group and the diseased group. Pneumatization and proliferation of middle turbinate and bent uncinate process were the most common anatomic variation in the diseased group. CONCLUSION: The results suggest that management of anatomic variations surrounding the ostia is very important in the treatment of maxillary ostium.

Adolescent↗

[Correction of cardiac defects through a right minithoracotomy in children].

OBJECTIVE: To review the experience of correction of congenital cardiac defects through a right minithoracotomy. METHOD: 319 patients underwent correction of congenital heart malformations through right lateral thoracotomy under cardiopulmonary bypass. The average age was 3.44 +/- 1.59 years (range, 5 months-8 years). The average body weight was 13.66 - 3.98 kg (range, 6 - 26 kg). Cardiac defects repaired included atrial septal defect in 87 patients (1 patient associated with left superior vena cava (LSVC), 6 pulmonary stenosis, 5 partial anomalous pulmonary venous connection), ventricular septal defect in 200 (7 patients with coexisting patent ductus arteriosus, 7 mitral insufficiency, 3 LSVC, 11 right ventricular outflow tract obstruction), Fallot's Tetralogy in 19 (3 patients associated with LSVC, 1 single coronary malformation), partial endocardial cushion defect in 2 and other defects in 11. The mean cardiopulmonary bypass time was 56.07 +/- 24.90 min (range, 20 - 176 min) and the mean aortic crossclamping time was 32.97 +/- 20.38 min (range, 6 - 140 min). The average mechanical ventilation time after operation was 18.75 +/- 24.57 hr (range, 2 - 140.72 hr), and the mean postoperative hospital stay was 7.08 +/- 0.69 days (range, 7 - 17 days). RESULT: No operative mortality and severe postoperative complications were noted. CONCLUSION: The right lateral thoracotomy is a safe and effective alternative to a median sternotomy for correction of cardiac defects. Advantages of this approach include less injury, maintaining the continuity and the integrity of the bony thorax, and preventing postoperative pigeon breast. The cosmetic result is superior to that of median sternotomy or bilateral submammary incision.

Cardiopulmonary Bypass↗

[Bile salt induces apoptosis of hepatocytes: the mechanism of hepatic function injury during obstructive jaundice].

OBJECTIVE: To determine if the bile salt induces hepatocyte apoptosis in vitro. METHOD: Hepatocytes were isolated by in situ collagenase perfusion and plated in 6 well flat bottom with DMEM/F12, 0.5 micro/ml insulin. Two hours later, glycochenodeoxcholate (GCDC) 25, 50, 100, 200, 300 micromol was added and cells evaluated by DNA-PI staining FACS and terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) 3, 6, 9, 12, 18, 20, 24 hours later. Agarose gel electrophoresis of DNA extracted from hepatocytes after incubation with GCDC using various experimental conditions. RESULT: The hepatocytes treated with GCDC have a high apoptotic rate as compared with the controls. 100 micromol GCDC treated 24 hours, nearly 61.81% of hepatocytes were apoptotic by FACS evaluation. The TUNEL showed that apoptotic hepatocytes had less cell volume and stained with brown by Biotin-11-dUTP. DNA ladder of bile-salt treated hepatocytes were shown in agarose gel electrophoresis. CONCLUSION: The mechanism of hepatic injury during obstructive jaundice is related to bile salt caused hepatocyte apoptosis.

Animals↗

[Expression of LIF gene during early development of mouse embryo].

Leukemia inhibitory factor (LIF) has the ability to maintain the development potential of pluripotent embryonic stem cells, suggesting that this factor might play an important role during mouse embryogenesis. By whole mount in situ hybridization on early mouse embryos, we have examined the expression pattern of the LIF gene from the two cell stage to the preimplantation blastocyst with the following results. (1) LIF transcripts were detected at all stages before implantation, but the highest level of LIF mRNA expression occurred in the blastocyst stage. (2) For the cleavage stages of mouse embryo, there was no significant distinction of the LIF gene expression level between blastomeres, but a strong signal was detectable in the cells which surrounded the blastocoel cavity of the blastocyst and most of them belonged to future extraembryonic tissues. These results suggest that a principal function of LIF in vivo may be to regulate stem cell population and to play an important role in the implantation of the blastocyst.

Animals↗

[The further studies on the pharmacological actions of Bupleurum smithii var. parvifolium].

Bupleurum smithii var. parvifolium grown widely in Ningxia, had a long history as a common medicinal herb. Its crude saponin had significant protective effect in hepatic damage caused by CCl4 in mice, its ether extract had significant analgesic effect. The ether extract also had significant immunological facilitation effect in mice, it could increase the thymus gland weight and the serum IgG content. These results were similar to or better than that of B. chinense and indicated that B. smithii var. parvifolium could be used as B. chinense.

Analgesics↗

[The expression of human leukocyte antigen from peripheral blood of patients with herpetic keratitis].

PURPOSE: To understand the correlation between the expression of human leukocyte antigen from peripheral blood and herpetic keratitis so as to find the pathogenesis of HSK. METHODS: The expression of HLA-ABC, HLA-DR, HLA-DP, HLA-DQ from peripheral blood of 32 cases with herpes simplex keratitis (the stromatic and ulcer herpetic keratitis are 16 cases respectively), comparing with the normal people, were investigated by flow cytometry. RESULTS: The expression rate of HLA-ABC from peripheral blood of patients with herpetic keratitis (both the stromatic and ulcer groups) was lower, and the expression of HLA-DR and HLA-DP was higher than normal people. No difference was found between the stromatic and the ulcer herpetic keratitis in the expression of HLA-ABC, HLA-DR, HLA-DP, HLA-DQ. CONCLUSION: The immune model in patients with herpetic keratitis is different from normal people. The individual with this kind of immune model can not destroy the infected virus effectively, also show autoimmunization to cornea.

Adult↗

[The thin film and absorption spectra of CsCu2I3].

This paper introduces a method of manufacturing CsCu2I3 thin films through hot evaporation. According to the absorption spectra at low temperature, the excitonic coefficient of CsCu2I3 was calculated. The spectral analysis shows that the localization of electron and exciton excitations in the twofold Chain created by CuI4(3-) causes the complicated character of the optical spectra of CsCu2I3.

English Abstract↗

[Determination of trace lead in copper by enhancing effect FAAS-using derivative technique].

A new method for the determination of trace lead in copper is proposed by enhancing effect-flame atomic absorption spectrometry using derivative technique. Enhancing effect of matrix Cu on lead was investigated. The sensitivity for lead was enhanced 17 times than that of conventional flame atomic absorption spectrometry by combining derivative technique with matrix Cu enhancing effect. Determination result is satisfactory by this method with 0.007 microg/mL detection limit and 0.7% RSD.

English Abstract↗

Preclinical antitumor activity of an antibody against the leukocyte antigen CD48.

We have evaluated the antitumor activity of a murine antibody (IgG2a) against the leukocyte antigen CD48. CD48 is expressed on T and B lymphocytes, monocytes, and a wide range of lymphoid malignancies. To assess the therapeutic potential of an anti-CD48 antibody, we established a reproducible model of human B-cell (Raji) leukemia/lymphoma in C.B17/scid mice, where untreated mice develop hind leg paralysis due to tumor engraftment. Using this model, the murine anti-CD48 antibody HuLy-m3 was shown to mediate a strong in vivo antitumor effect. Long-term survival (>1 year) of scid mice was obtained after treatment with three 200-microg i.v. doses of anti-CD48 antibody on days 0, 2, and 4 after i.v. injection of tumor cells. In contrast, mice treated with an isotype control antibody developed hind leg paralysis after 34 +/- 3 days. A strong antitumor response was still observed when a dose of 20 microg of HuLy-m3 antibody was used. During preclinical investigations, we also examined a number of properties of the CD48 antigen. CD48 is present at high levels on the surface of T and B cells, but most (>95%) CD34-positive cells do not express CD48. Anti-CD48 antibodies are maintained on the surface of antigen-positive cells for extended periods (>24 h). These properties suggest that anti-CD48 antibodies may be useful in the treatment of a number of diseases including lymphoid leukemias and lymphomas.

Animals↗

Synthesis and biological activity of binuclear platinum complexes containing two monofunctional cis-[Pt(NH3)2Cl]+ units bridged by 4,4'-dipyridyl selenides or sulfides.

The synthesis of four binuclear platinum complexes of general formula ¿cis-[Pt(NH3)2Cl]2(L)¿ (NO3)2 [L is 4,4'-dipyridyl sulfide (compound I), 4,4'-dipyridyl selenide (compound II), bis(3-methyl-4-pyridyl) sulfide (compound III) or bis(3-methyl-4-pyridyl) selenide (compound IV)] has been achieved. These compounds have been characterized by elemental analysis, IR, 1H-NMR, 13C-NMR and 195Pt-NMR spectroscopy. The above dinuclear platinum complexes have been assayed for antitumor activity in vitro against the cisplatin-sensitive L1210 (the mice leukemia) and cisplatin-insensitive HCT8 (the human coloadenocarcinoma) cell lines. The compounds show IC50 values comparable to or higher than cisplatin against L1210 cell line; however, they have lower IC50 values than cisplatin against the cisplatin-insensitive HCT8 cell line. The complexes containing S exhibit a cytotoxicity against the two cancer cell lines superior to the Se analogues. DNA binding studies indicate the compound I possibly interacts with DNA nonintercalatively. The mode of DNA binding of the dinuclear Pt(II) complexes bridged by 4,4'-dipyridyl selenides or sulfides may be different to that of the aliphatic diaminebridged dinuclear Pt(II) complexes reported previously.

Animals↗

Prevention of chronic rejection in mouse aortic allografts by combined treatment with CTLA4-Ig and anti-CD40 ligand monoclonal antibody.

BACKGROUND: In this study, using a murine model of aortic allotransplantation, the role of blockade of signaling through CD28/B7 and CD40/CD40 ligand costimulatory pathways in the evolvement of posttransplant vasculopathy was examined. METHODS: Aortic allografts were transplanted across C57BL/1OJ (H2b)-->C3H (H2k) strain combinations. Transient or more stable blockade of second signaling was achieved by either a single injection or multiple injections of CTLA4-Ig fusion protein (200 microg/dose i.p.) and/or anti-CD40 ligand (CD40L) monoclonal antibody (250 microg i.m.). At day 30 after transplantation, the grafts were harvested for histopathological and immunohistochemical examination. RESULTS: Similar to allografts of untreated animals, aortic allografts obtained from recipients treated with either CTLA4-Ig or anti-CD40L monoclonal antibody alone exhibited marked narrowing of the lumen primarily due to concentric intimal thickening caused by proliferation of alpha-smooth muscle actin-positive cells. Contemporaneous treatment, however, with either a single injection or multiple injections of CTLA4-Ig and anti-CD40L monoclonal antibody resulted in marked diminution of intimal thickening. Interestingly, concurrent prolonged inhibition of CD28/B7 and CD40/CD40L pathways resulted in complete abrogation of the development of posttransplant arteriopathy. CONCLUSION: These data suggest that a more stable disruption of signaling through costimulatory pathways may be required to obviate the development of posttransplant vasculopathy.

Abatacept↗

Transformation of sensory signals into commands for saccadic eye movements: a neural network study.

A biological plausible neural network which simulated the input-output transformation performed by primates during saccadic eye movements is constructed using a selective attention module and multi-layered neural networks with improved back propagation and a competitive learning algorithm. Simulation results show that the trained model can make fine saccades directed by the target. Representations and processing mechanisms in the saccade system are investigated. The features of most hidden units resemble those that have been observed in physiological recordings of neurons in primates visual cortex. The hidden layer even developed structures similar to those of area 7a.

Algorithms↗

Mu opioid receptor phosphorylation, desensitization, and ligand efficacy.

Mu opioid receptors are subject to phosphorylation and desensitization through actions of at least two distinct biochemical pathways: agonist-dependent mu receptor phosphorylation and desensitization induced by a biochemically distinct second pathway dependent on protein kinase C activation (1). To better understand the nature of the agonist-induced mu receptor phosphorylation events, we have investigated the effects of a variety of opiate ligands of varying potencies and intrinsic activities on mu receptor phosphorylation and desensitization. Exposure to the potent full agonists sufentanil, dihydroetorphine, etorphine, etonitazine, and [D-Ala2, MePhe4, Glyol5]enkephalin (DAMGO) led to strong receptor phosphorylation, while methadone, l-alpha-acetylmethadone (LAAM), morphine, meperidine, DADL, beta-endorphin(1-31), enkephalins, and dynorphin A(1-17) produced intermediate effects. The partial agonist buprenorphine minimally enhanced receptor phosphorylation while antagonists failed to alter phosphorylation. Buprenorphine and full antagonists each antagonized the enhanced mu receptor phosphorylation induced by morphine or DAMGO. The rank order of opiate ligand efficacies in producing mu receptor-mediated functional desensitization generally paralleled their rank order of efficacies in producing receptor phosphorylation. Interestingly, the desensitization and phosphorylation mediated by methadone and LAAM were disproportionate to their efficacies in two distinct test systems. This generally good fit between the efficacies of opiates in mu receptor activation, phosphorylation, and desensitization supports the idea that activated receptor/agonist/G-protein complexes and/or receptor conformational changes induced by agonists are required for agonist-induced mu receptor phosphorylation. Data for methadone and LAAM suggest possible contribution from their enhanced desensitizing abilities to their therapeutic efficacies.

Analgesics, Opioid↗

Identification and characterization of a conserved family of protein serine/threonine phosphatases homologous to Drosophila retinal degeneration C.

The Drosophila retinal degeneration C (rdgC) gene encodes an unusual protein serine/threonine phosphatase in that it contains at least two EF-hand motifs at its carboxy terminus. By a combination of large-scale sequencing of human retina cDNA clones and searches of expressed sequence tag and genomic DNA databases, we have identified two sequences in mammals [Protein Phosphatase with EF-hands-1 and 2 (PPEF-1 and PPEF-2)] and one in Caenorhabditis elegans (PPEF) that closely resemble rdgC. In the adult, PPEF-2 is expressed specifically in retinal rod photoreceptors and the pineal. In the retina, several isoforms of PPEF-2 are predicted to arise from differential splicing. The isoform that most closely resembles rdgC is localized to rod inner segments. Together with the recently described localization of PPEF-1 transcripts to primary somatosensory neurons and inner ear cells in the developing mouse, these data suggest that the PPEF family of protein serine/threonine phosphatases plays a specific and conserved role in diverse sensory neurons.

Alternative Splicing↗

Abrogation of chronic rejection in a murine model of aortic allotransplantation by prior induction of donor-specific tolerance.

Aortic allotransplantation in mice has been well established as a model of choice to study the evolvement of chronic rejection, the etiopathology of which is believed to be that of immune origin. This has prompted the postulation that prior induction of donor-specific tolerance would attenuate or abrogate the underlying events that culminate in posttransplant arteriosclerosis. To study the effects of donor-specific tolerance on chronic rejection, we performed orthotopic liver transplantation without immunosuppression in mice 30 days before aortic allotransplantation across C57Bl/ 10J (H2b)-->C3H (H2k) strain combinations (group III). Aortic allografting in syngeneic (group I; C3H-->C3H) and allogeneic (group II, C57Bl/10J-->C3H) animals served as controls. No morphological changes were evidenced in the transplanted aortas in group I animals. Contrarily, aortic allografts in group II animals underwent a self-limiting acute cellular rejection, which resolved completely and was succeeded by day 30 after transplantation by histopathological changes pathognomonic of chronic rejection. There was evidence for diffuse myointimal thickening, progressive concentric luminal narrowing, and patchy destruction of internal elastic membranes resulting in massive vascular obliteration by day 120 after transplantation. It was of interest that no arteriosclerotic changes were observed for the duration of follow-up (up to 120 days after transplantation) in transplanted aortas (liver donor-type) harvested from animals in group III. However, vasculopathy was prominent in third-party aortic grafts transplanted into tolerant recipients. Taken together, these data suggest that prior induction of tolerance abrogates the development of chronic rejection; this protection seems to be donor specific.

Animals↗